Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-05 Thread Chunyan Zhang
On Tue, 4 Dec 2018 at 18:38, Faiz Abbas  wrote:
>
> Hi,
>
> On 04/12/18 12:54 PM, Chunyan Zhang wrote:
> > Some standard SD host controllers can support both external dma
> > controllers as well as ADMA/SDMA in which the SD host controller
> > acts as DMA master. TI's omap controller is the case as an example.
> >
> > Currently the generic SDHCI code supports ADMA/SDMA integrated in
> > the host controller but does not have any support for external DMA
> > controllers implemented using dmaengine, meaning that custom code is
> > needed for any systems that use an external DMA controller with SDHCI.
> >
> ...
>
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index b001cf4..8e50a97 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -475,6 +475,7 @@ struct sdhci_host {
> >
> >   int irq;/* Device IRQ */
> >   void __iomem *ioaddr;   /* Mapped address */
> > + phys_addr_t mapbase;/* physical address base */
> >   char *bounce_buffer;/* For packing SDMA reads/writes */
> >   dma_addr_t bounce_addr;
> >   unsigned int bounce_buffer_size;
> > @@ -524,6 +525,7 @@ struct sdhci_host {
> >   bool pending_reset; /* Cmd/data reset is pending */
> >   bool irq_wake_enabled;  /* IRQ wakeup is enabled */
> >   bool v4_mode;   /* Host Version 4 Enable */
> > + bool use_external_dma;
> >
> >   struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests done */
> >   struct mmc_command *cmd;/* Current command */
> > @@ -552,6 +554,11 @@ struct sdhci_host {
> >   struct timer_list timer;/* Timer for timeouts */
> >   struct timer_list data_timer;   /* Timer for data timeouts */
> >
> > +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> > + struct dma_chan *rx_chan;
> > + struct dma_chan *tx_chan;
> > +#endif
> > +
> >   u32 caps;   /* CAPABILITY_0 */
> >   u32 caps1;  /* CAPABILITY_1 */
> >   bool read_caps; /* Capability flags have been read */
> > @@ -785,5 +792,6 @@ void sdhci_start_tuning(struct sdhci_host *host);
> >  void sdhci_end_tuning(struct sdhci_host *host);
> >  void sdhci_reset_tuning(struct sdhci_host *host);
> >  void sdhci_send_tuning(struct sdhci_host *host, u32 opcode);
> > +void sdhci_switch_external_dma(struct sdhci_host *host, bool en);
> >
>
> Can you also add a new attribute in sdhci_host->flags for external dma
> in this file? The log still shows
>
> [3.675028] mmc2: SDHCI controller on 4809c000.mmc [4809c000.mmc]
> using ADMA

Ok, will try to add.

Thanks for your test and review.

Chunyan

>
> when using external dma.
>
> Thanks,
> Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-05 Thread Chunyan Zhang
On Tue, 4 Dec 2018 at 18:38, Faiz Abbas  wrote:
>
> Hi,
>
> On 04/12/18 12:54 PM, Chunyan Zhang wrote:
> > Some standard SD host controllers can support both external dma
> > controllers as well as ADMA/SDMA in which the SD host controller
> > acts as DMA master. TI's omap controller is the case as an example.
> >
> > Currently the generic SDHCI code supports ADMA/SDMA integrated in
> > the host controller but does not have any support for external DMA
> > controllers implemented using dmaengine, meaning that custom code is
> > needed for any systems that use an external DMA controller with SDHCI.
> >
> ...
>
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index b001cf4..8e50a97 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -475,6 +475,7 @@ struct sdhci_host {
> >
> >   int irq;/* Device IRQ */
> >   void __iomem *ioaddr;   /* Mapped address */
> > + phys_addr_t mapbase;/* physical address base */
> >   char *bounce_buffer;/* For packing SDMA reads/writes */
> >   dma_addr_t bounce_addr;
> >   unsigned int bounce_buffer_size;
> > @@ -524,6 +525,7 @@ struct sdhci_host {
> >   bool pending_reset; /* Cmd/data reset is pending */
> >   bool irq_wake_enabled;  /* IRQ wakeup is enabled */
> >   bool v4_mode;   /* Host Version 4 Enable */
> > + bool use_external_dma;
> >
> >   struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests done */
> >   struct mmc_command *cmd;/* Current command */
> > @@ -552,6 +554,11 @@ struct sdhci_host {
> >   struct timer_list timer;/* Timer for timeouts */
> >   struct timer_list data_timer;   /* Timer for data timeouts */
> >
> > +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> > + struct dma_chan *rx_chan;
> > + struct dma_chan *tx_chan;
> > +#endif
> > +
> >   u32 caps;   /* CAPABILITY_0 */
> >   u32 caps1;  /* CAPABILITY_1 */
> >   bool read_caps; /* Capability flags have been read */
> > @@ -785,5 +792,6 @@ void sdhci_start_tuning(struct sdhci_host *host);
> >  void sdhci_end_tuning(struct sdhci_host *host);
> >  void sdhci_reset_tuning(struct sdhci_host *host);
> >  void sdhci_send_tuning(struct sdhci_host *host, u32 opcode);
> > +void sdhci_switch_external_dma(struct sdhci_host *host, bool en);
> >
>
> Can you also add a new attribute in sdhci_host->flags for external dma
> in this file? The log still shows
>
> [3.675028] mmc2: SDHCI controller on 4809c000.mmc [4809c000.mmc]
> using ADMA

Ok, will try to add.

Thanks for your test and review.

Chunyan

>
> when using external dma.
>
> Thanks,
> Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-04 Thread Faiz Abbas
Hi,

On 04/12/18 12:54 PM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
> 
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
> 
...

> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index b001cf4..8e50a97 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -475,6 +475,7 @@ struct sdhci_host {
>  
>   int irq;/* Device IRQ */
>   void __iomem *ioaddr;   /* Mapped address */
> + phys_addr_t mapbase;/* physical address base */
>   char *bounce_buffer;/* For packing SDMA reads/writes */
>   dma_addr_t bounce_addr;
>   unsigned int bounce_buffer_size;
> @@ -524,6 +525,7 @@ struct sdhci_host {
>   bool pending_reset; /* Cmd/data reset is pending */
>   bool irq_wake_enabled;  /* IRQ wakeup is enabled */
>   bool v4_mode;   /* Host Version 4 Enable */
> + bool use_external_dma;
>  
>   struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests done */
>   struct mmc_command *cmd;/* Current command */
> @@ -552,6 +554,11 @@ struct sdhci_host {
>   struct timer_list timer;/* Timer for timeouts */
>   struct timer_list data_timer;   /* Timer for data timeouts */
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> + struct dma_chan *rx_chan;
> + struct dma_chan *tx_chan;
> +#endif
> +
>   u32 caps;   /* CAPABILITY_0 */
>   u32 caps1;  /* CAPABILITY_1 */
>   bool read_caps; /* Capability flags have been read */
> @@ -785,5 +792,6 @@ void sdhci_start_tuning(struct sdhci_host *host);
>  void sdhci_end_tuning(struct sdhci_host *host);
>  void sdhci_reset_tuning(struct sdhci_host *host);
>  void sdhci_send_tuning(struct sdhci_host *host, u32 opcode);
> +void sdhci_switch_external_dma(struct sdhci_host *host, bool en);
>  

Can you also add a new attribute in sdhci_host->flags for external dma
in this file? The log still shows

[3.675028] mmc2: SDHCI controller on 4809c000.mmc [4809c000.mmc]
using ADMA

when using external dma.

Thanks,
Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-04 Thread Faiz Abbas
Hi,

On 04/12/18 12:54 PM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
> 
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
> 
...

> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index b001cf4..8e50a97 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -475,6 +475,7 @@ struct sdhci_host {
>  
>   int irq;/* Device IRQ */
>   void __iomem *ioaddr;   /* Mapped address */
> + phys_addr_t mapbase;/* physical address base */
>   char *bounce_buffer;/* For packing SDMA reads/writes */
>   dma_addr_t bounce_addr;
>   unsigned int bounce_buffer_size;
> @@ -524,6 +525,7 @@ struct sdhci_host {
>   bool pending_reset; /* Cmd/data reset is pending */
>   bool irq_wake_enabled;  /* IRQ wakeup is enabled */
>   bool v4_mode;   /* Host Version 4 Enable */
> + bool use_external_dma;
>  
>   struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests done */
>   struct mmc_command *cmd;/* Current command */
> @@ -552,6 +554,11 @@ struct sdhci_host {
>   struct timer_list timer;/* Timer for timeouts */
>   struct timer_list data_timer;   /* Timer for data timeouts */
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> + struct dma_chan *rx_chan;
> + struct dma_chan *tx_chan;
> +#endif
> +
>   u32 caps;   /* CAPABILITY_0 */
>   u32 caps1;  /* CAPABILITY_1 */
>   bool read_caps; /* Capability flags have been read */
> @@ -785,5 +792,6 @@ void sdhci_start_tuning(struct sdhci_host *host);
>  void sdhci_end_tuning(struct sdhci_host *host);
>  void sdhci_reset_tuning(struct sdhci_host *host);
>  void sdhci_send_tuning(struct sdhci_host *host, u32 opcode);
> +void sdhci_switch_external_dma(struct sdhci_host *host, bool en);
>  

Can you also add a new attribute in sdhci_host->flags for external dma
in this file? The log still shows

[3.675028] mmc2: SDHCI controller on 4809c000.mmc [4809c000.mmc]
using ADMA

when using external dma.

Thanks,
Faiz


[PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Chunyan Zhang
Some standard SD host controllers can support both external dma
controllers as well as ADMA/SDMA in which the SD host controller
acts as DMA master. TI's omap controller is the case as an example.

Currently the generic SDHCI code supports ADMA/SDMA integrated in
the host controller but does not have any support for external DMA
controllers implemented using dmaengine, meaning that custom code is
needed for any systems that use an external DMA controller with SDHCI.

Signed-off-by: Chunyan Zhang 
---
 drivers/mmc/host/Kconfig |   3 +
 drivers/mmc/host/sdhci.c | 185 ++-
 drivers/mmc/host/sdhci.h |   8 ++
 3 files changed, 195 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1b58739..3101da6 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -977,3 +977,6 @@ config MMC_SDHCI_OMAP
  If you have a controller with this interface, say Y or M here.
 
  If unsure, say N.
+
+config MMC_SDHCI_EXTERNAL_DMA
+bool
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 99bdae5..04b029c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -14,6 +14,7 @@
  */
 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
struct mmc_request *mrq)
del_timer(>timer);
 }
 
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+static int sdhci_external_dma_init(struct sdhci_host *host)
+{
+   int ret = 0;
+   struct mmc_host *mmc = host->mmc;
+
+   host->tx_chan = dma_request_chan(mmc->parent, "tx");
+   if (IS_ERR(host->tx_chan)) {
+   ret = PTR_ERR(host->tx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request TX DMA channel.\n");
+   host->tx_chan = NULL;
+   return ret;
+   }
+
+   host->rx_chan = dma_request_chan(mmc->parent, "rx");
+   if (IS_ERR(host->rx_chan)) {
+   if (host->tx_chan) {
+   dma_release_channel(host->tx_chan);
+   host->tx_chan = NULL;
+   }
+
+   ret = PTR_ERR(host->rx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request RX DMA channel.\n");
+   host->rx_chan = NULL;
+   }
+
+   return ret;
+}
+
+static inline struct dma_chan *
+sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
+{
+   return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
+}
+
+static int sdhci_external_dma_setup(struct sdhci_host *host,
+   struct mmc_command *cmd)
+{
+   int ret, i;
+   struct dma_async_tx_descriptor *desc;
+   struct mmc_data *data = cmd->data;
+   struct dma_chan *chan;
+   struct dma_slave_config cfg;
+   dma_cookie_t cookie;
+
+   if (!data)
+   return 0;
+
+   if (!host->mapbase)
+   return -EINVAL;
+
+   cfg.src_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.src_maxburst = data->blksz / 4;
+   cfg.dst_maxburst = data->blksz / 4;
+
+   /* Sanity check: all the SG entries must be aligned by block size. */
+   for (i = 0; i < data->sg_len; i++) {
+   if ((data->sg + i)->length % data->blksz)
+   return -EINVAL;
+   }
+
+   chan = sdhci_external_dma_channel(host, data);
+
+   ret = dmaengine_slave_config(chan, );
+   if (ret)
+   return ret;
+
+   desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
+  mmc_get_dma_dir(data),
+  DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+   if (!desc)
+   return -EINVAL;
+
+   desc->callback = NULL;
+   desc->callback_param = NULL;
+
+   cookie = dmaengine_submit(desc);
+   if (cookie < 0)
+   ret = cookie;
+
+   return ret;
+}
+
+static void sdhci_external_dma_release(struct sdhci_host *host)
+{
+   if (host->tx_chan) {
+   dma_release_channel(host->tx_chan);
+   host->tx_chan = NULL;
+   }
+
+   if (host->rx_chan) {
+   dma_release_channel(host->rx_chan);
+   host->rx_chan = NULL;
+   }
+
+   sdhci_switch_external_dma(host, false);
+}
+
+static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
+   struct mmc_command *cmd)
+{
+   if (sdhci_external_dma_setup(host, cmd)) {
+   sdhci_external_dma_release(host);
+   pr_err("%s: Failed to setup external DMA, switch to the DMA/PIO 
which standard SDHCI provides.\n",
+  

[PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Chunyan Zhang
Some standard SD host controllers can support both external dma
controllers as well as ADMA/SDMA in which the SD host controller
acts as DMA master. TI's omap controller is the case as an example.

Currently the generic SDHCI code supports ADMA/SDMA integrated in
the host controller but does not have any support for external DMA
controllers implemented using dmaengine, meaning that custom code is
needed for any systems that use an external DMA controller with SDHCI.

Signed-off-by: Chunyan Zhang 
---
 drivers/mmc/host/Kconfig |   3 +
 drivers/mmc/host/sdhci.c | 185 ++-
 drivers/mmc/host/sdhci.h |   8 ++
 3 files changed, 195 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1b58739..3101da6 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -977,3 +977,6 @@ config MMC_SDHCI_OMAP
  If you have a controller with this interface, say Y or M here.
 
  If unsure, say N.
+
+config MMC_SDHCI_EXTERNAL_DMA
+bool
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 99bdae5..04b029c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -14,6 +14,7 @@
  */
 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
struct mmc_request *mrq)
del_timer(>timer);
 }
 
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+static int sdhci_external_dma_init(struct sdhci_host *host)
+{
+   int ret = 0;
+   struct mmc_host *mmc = host->mmc;
+
+   host->tx_chan = dma_request_chan(mmc->parent, "tx");
+   if (IS_ERR(host->tx_chan)) {
+   ret = PTR_ERR(host->tx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request TX DMA channel.\n");
+   host->tx_chan = NULL;
+   return ret;
+   }
+
+   host->rx_chan = dma_request_chan(mmc->parent, "rx");
+   if (IS_ERR(host->rx_chan)) {
+   if (host->tx_chan) {
+   dma_release_channel(host->tx_chan);
+   host->tx_chan = NULL;
+   }
+
+   ret = PTR_ERR(host->rx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request RX DMA channel.\n");
+   host->rx_chan = NULL;
+   }
+
+   return ret;
+}
+
+static inline struct dma_chan *
+sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
+{
+   return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
+}
+
+static int sdhci_external_dma_setup(struct sdhci_host *host,
+   struct mmc_command *cmd)
+{
+   int ret, i;
+   struct dma_async_tx_descriptor *desc;
+   struct mmc_data *data = cmd->data;
+   struct dma_chan *chan;
+   struct dma_slave_config cfg;
+   dma_cookie_t cookie;
+
+   if (!data)
+   return 0;
+
+   if (!host->mapbase)
+   return -EINVAL;
+
+   cfg.src_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.src_maxburst = data->blksz / 4;
+   cfg.dst_maxburst = data->blksz / 4;
+
+   /* Sanity check: all the SG entries must be aligned by block size. */
+   for (i = 0; i < data->sg_len; i++) {
+   if ((data->sg + i)->length % data->blksz)
+   return -EINVAL;
+   }
+
+   chan = sdhci_external_dma_channel(host, data);
+
+   ret = dmaengine_slave_config(chan, );
+   if (ret)
+   return ret;
+
+   desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
+  mmc_get_dma_dir(data),
+  DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+   if (!desc)
+   return -EINVAL;
+
+   desc->callback = NULL;
+   desc->callback_param = NULL;
+
+   cookie = dmaengine_submit(desc);
+   if (cookie < 0)
+   ret = cookie;
+
+   return ret;
+}
+
+static void sdhci_external_dma_release(struct sdhci_host *host)
+{
+   if (host->tx_chan) {
+   dma_release_channel(host->tx_chan);
+   host->tx_chan = NULL;
+   }
+
+   if (host->rx_chan) {
+   dma_release_channel(host->rx_chan);
+   host->rx_chan = NULL;
+   }
+
+   sdhci_switch_external_dma(host, false);
+}
+
+static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
+   struct mmc_command *cmd)
+{
+   if (sdhci_external_dma_setup(host, cmd)) {
+   sdhci_external_dma_release(host);
+   pr_err("%s: Failed to setup external DMA, switch to the DMA/PIO 
which standard SDHCI provides.\n",
+  

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Chunyan Zhang
Hi Faiz,

On Mon, 3 Dec 2018 at 21:55, Faiz Abbas  wrote:
>
> Hi,
>
> On 03/12/18 5:45 PM, Faiz Abbas wrote:
> > Hi,
> >
> >> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
> >> +struct mmc_command *cmd)
> >> +{
> >
> > Please add a condition for data == NULL here. This was already pointed
> > out by Adrian in v2.

The check for data is added in sdhci_external_dma_setup() .

> >
> > My test with an am335x-evm failed with these patches. Looks like the
> > very first SDIO commands failing.

I guess you didn't add 'dmas' in device tree, like patch 3 shows.

> >
> > https://pastebin.ubuntu.com/p/Y2RDjSKpgd/
> >
> > Currently am335x-evm is using omap_hsmmc driver. I added the following
> > patch to make it work with sdhci_omap.
> >
> > https://pastebin.ubuntu.com/p/VTGrCbJxY3/
> >
> > Will look deeper into this. Please ping if you need any more information.
> >
>
> So I disabled DMA in the driver altogether and still got the same
> messages on am335x-evm in PIO mode. Looks like something more is
> required for it to be supported.
>
> I instead shifted to a dra71-evm which supports both ADMA and external
> DMA. Here is the log:
>
> https://pastebin.ubuntu.com/p/mcJmgcjQsp/
>
> The interface fundamentally works but it complains with the following error:
>

Yes, it switched back to ADMA/PIO since sdhci couldn't find 'dmas'
property in devicetree.

> [3.111693] Failed to request TX DMA channel.

Ok, I will add a check in sdhci-omap.c before switching to external
dma, that should be able to avoid this error logs.

Thanks for the review and test!

Chunyan


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Chunyan Zhang
Hi Faiz,

On Mon, 3 Dec 2018 at 21:55, Faiz Abbas  wrote:
>
> Hi,
>
> On 03/12/18 5:45 PM, Faiz Abbas wrote:
> > Hi,
> >
> >> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
> >> +struct mmc_command *cmd)
> >> +{
> >
> > Please add a condition for data == NULL here. This was already pointed
> > out by Adrian in v2.

The check for data is added in sdhci_external_dma_setup() .

> >
> > My test with an am335x-evm failed with these patches. Looks like the
> > very first SDIO commands failing.

I guess you didn't add 'dmas' in device tree, like patch 3 shows.

> >
> > https://pastebin.ubuntu.com/p/Y2RDjSKpgd/
> >
> > Currently am335x-evm is using omap_hsmmc driver. I added the following
> > patch to make it work with sdhci_omap.
> >
> > https://pastebin.ubuntu.com/p/VTGrCbJxY3/
> >
> > Will look deeper into this. Please ping if you need any more information.
> >
>
> So I disabled DMA in the driver altogether and still got the same
> messages on am335x-evm in PIO mode. Looks like something more is
> required for it to be supported.
>
> I instead shifted to a dra71-evm which supports both ADMA and external
> DMA. Here is the log:
>
> https://pastebin.ubuntu.com/p/mcJmgcjQsp/
>
> The interface fundamentally works but it complains with the following error:
>

Yes, it switched back to ADMA/PIO since sdhci couldn't find 'dmas'
property in devicetree.

> [3.111693] Failed to request TX DMA channel.

Ok, I will add a check in sdhci-omap.c before switching to external
dma, that should be able to avoid this error logs.

Thanks for the review and test!

Chunyan


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Faiz Abbas
Hi,

On 03/12/18 5:45 PM, Faiz Abbas wrote:
> Hi,
> 
>> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
>> +struct mmc_command *cmd)
>> +{
> 
> Please add a condition for data == NULL here. This was already pointed
> out by Adrian in v2.
> 
> My test with an am335x-evm failed with these patches. Looks like the
> very first SDIO commands failing.
> 
> https://pastebin.ubuntu.com/p/Y2RDjSKpgd/
> 
> Currently am335x-evm is using omap_hsmmc driver. I added the following
> patch to make it work with sdhci_omap.
> 
> https://pastebin.ubuntu.com/p/VTGrCbJxY3/
> 
> Will look deeper into this. Please ping if you need any more information.
> 

So I disabled DMA in the driver altogether and still got the same
messages on am335x-evm in PIO mode. Looks like something more is
required for it to be supported.

I instead shifted to a dra71-evm which supports both ADMA and external
DMA. Here is the log:

https://pastebin.ubuntu.com/p/mcJmgcjQsp/

The interface fundamentally works but it complains with the following error:

[3.111693] Failed to request TX DMA channel.


Thanks,
Faiz



Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Faiz Abbas
Hi,

On 03/12/18 5:45 PM, Faiz Abbas wrote:
> Hi,
> 
>> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
>> +struct mmc_command *cmd)
>> +{
> 
> Please add a condition for data == NULL here. This was already pointed
> out by Adrian in v2.
> 
> My test with an am335x-evm failed with these patches. Looks like the
> very first SDIO commands failing.
> 
> https://pastebin.ubuntu.com/p/Y2RDjSKpgd/
> 
> Currently am335x-evm is using omap_hsmmc driver. I added the following
> patch to make it work with sdhci_omap.
> 
> https://pastebin.ubuntu.com/p/VTGrCbJxY3/
> 
> Will look deeper into this. Please ping if you need any more information.
> 

So I disabled DMA in the driver altogether and still got the same
messages on am335x-evm in PIO mode. Looks like something more is
required for it to be supported.

I instead shifted to a dra71-evm which supports both ADMA and external
DMA. Here is the log:

https://pastebin.ubuntu.com/p/mcJmgcjQsp/

The interface fundamentally works but it complains with the following error:

[3.111693] Failed to request TX DMA channel.


Thanks,
Faiz



Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Faiz Abbas
Hi,

On 29/11/18 11:37 AM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
> 
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
> 
> Signed-off-by: Chunyan Zhang 
> ---
>  drivers/mmc/host/Kconfig |  14 
>  drivers/mmc/host/sdhci.c | 185 
> ++-
>  drivers/mmc/host/sdhci.h |   8 ++
>  3 files changed, 206 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 1b58739..4183f43 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>  config MMC_SDHCI_OMAP
>   tristate "TI SDHCI Controller Support"
>   depends on MMC_SDHCI_PLTFM && OF
> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>   help
> This selects the Secure Digital Host Controller Interface (SDHCI)
> support present in TI's DRA7 SOCs. The controller supports
> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> If you have a controller with this interface, say Y or M here.
>  
> If unsure, say N.
> +
> +config MMC_SDHCI_EXTERNAL_DMA
> +bool "Support external DMA in standard SD host controller"
> + depends on MMC_SDHCI
> + depends on DMA_ENGINE
> + help
> +   This is an option for using external DMA device via dmaengine
> +   framework.
> +
> +   If you have a controller which support using external DMA device
> +   for data transfer, can say Y.
> +
> +   If unsure, say N.
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99bdae5..ad7cc80 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -14,6 +14,7 @@
>   */
>  
>  #include 
> +#include 
>  #include 
>  #include 
>  #include 
> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
> struct mmc_request *mrq)
>   del_timer(>timer);
>  }
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> +static int sdhci_external_dma_init(struct sdhci_host *host)
> +{
> + int ret = 0;
> + struct mmc_host *mmc = host->mmc;
> +
> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> + if (IS_ERR(host->tx_chan)) {
> + ret = PTR_ERR(host->tx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request TX DMA channel.\n");
> + host->tx_chan = NULL;
> + return ret;
> + }
> +
> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> + if (IS_ERR(host->rx_chan)) {
> + if (host->tx_chan) {
> + dma_release_channel(host->tx_chan);
> + host->tx_chan = NULL;
> + }
> +
> + ret = PTR_ERR(host->rx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request RX DMA channel.\n");
> + host->rx_chan = NULL;
> + }
> +
> + return ret;
> +}
> +
> +static inline struct dma_chan *
> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
> +{
> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> +}
> +
> +static int sdhci_external_dma_setup(struct sdhci_host *host,
> + struct mmc_command *cmd)
> +{
> + int ret, i;
> + struct dma_async_tx_descriptor *desc;
> + struct mmc_data *data = cmd->data;
> + struct dma_chan *chan;
> + struct dma_slave_config cfg;
> + dma_cookie_t cookie;
> +
> + if (!host->mapbase)
> + return -EINVAL;
> +
> + if (!data)
> + return 0;
> +
> + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.src_maxburst = data->blksz / 4;
> + cfg.dst_maxburst = data->blksz / 4;
> +
> + /* Sanity check: all the SG entries must be aligned by block size. */
> + for (i = 0; i < data->sg_len; i++) {
> + if ((data->sg + i)->length % data->blksz)
> + return -EINVAL;
> + }
> +
> + chan = sdhci_external_dma_channel(host, data);
> +
> + ret = dmaengine_slave_config(chan, );
> + if (ret)
> + return ret;
> +
> + desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
> +mmc_get_dma_dir(data),
> +DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> + if (!desc)
> + return -EINVAL;
> +
> + desc->callback = NULL;
> + 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Faiz Abbas
Hi,

On 29/11/18 11:37 AM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
> 
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
> 
> Signed-off-by: Chunyan Zhang 
> ---
>  drivers/mmc/host/Kconfig |  14 
>  drivers/mmc/host/sdhci.c | 185 
> ++-
>  drivers/mmc/host/sdhci.h |   8 ++
>  3 files changed, 206 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 1b58739..4183f43 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>  config MMC_SDHCI_OMAP
>   tristate "TI SDHCI Controller Support"
>   depends on MMC_SDHCI_PLTFM && OF
> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>   help
> This selects the Secure Digital Host Controller Interface (SDHCI)
> support present in TI's DRA7 SOCs. The controller supports
> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> If you have a controller with this interface, say Y or M here.
>  
> If unsure, say N.
> +
> +config MMC_SDHCI_EXTERNAL_DMA
> +bool "Support external DMA in standard SD host controller"
> + depends on MMC_SDHCI
> + depends on DMA_ENGINE
> + help
> +   This is an option for using external DMA device via dmaengine
> +   framework.
> +
> +   If you have a controller which support using external DMA device
> +   for data transfer, can say Y.
> +
> +   If unsure, say N.
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99bdae5..ad7cc80 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -14,6 +14,7 @@
>   */
>  
>  #include 
> +#include 
>  #include 
>  #include 
>  #include 
> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
> struct mmc_request *mrq)
>   del_timer(>timer);
>  }
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> +static int sdhci_external_dma_init(struct sdhci_host *host)
> +{
> + int ret = 0;
> + struct mmc_host *mmc = host->mmc;
> +
> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> + if (IS_ERR(host->tx_chan)) {
> + ret = PTR_ERR(host->tx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request TX DMA channel.\n");
> + host->tx_chan = NULL;
> + return ret;
> + }
> +
> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> + if (IS_ERR(host->rx_chan)) {
> + if (host->tx_chan) {
> + dma_release_channel(host->tx_chan);
> + host->tx_chan = NULL;
> + }
> +
> + ret = PTR_ERR(host->rx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request RX DMA channel.\n");
> + host->rx_chan = NULL;
> + }
> +
> + return ret;
> +}
> +
> +static inline struct dma_chan *
> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
> +{
> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> +}
> +
> +static int sdhci_external_dma_setup(struct sdhci_host *host,
> + struct mmc_command *cmd)
> +{
> + int ret, i;
> + struct dma_async_tx_descriptor *desc;
> + struct mmc_data *data = cmd->data;
> + struct dma_chan *chan;
> + struct dma_slave_config cfg;
> + dma_cookie_t cookie;
> +
> + if (!host->mapbase)
> + return -EINVAL;
> +
> + if (!data)
> + return 0;
> +
> + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.src_maxburst = data->blksz / 4;
> + cfg.dst_maxburst = data->blksz / 4;
> +
> + /* Sanity check: all the SG entries must be aligned by block size. */
> + for (i = 0; i < data->sg_len; i++) {
> + if ((data->sg + i)->length % data->blksz)
> + return -EINVAL;
> + }
> +
> + chan = sdhci_external_dma_channel(host, data);
> +
> + ret = dmaengine_slave_config(chan, );
> + if (ret)
> + return ret;
> +
> + desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
> +mmc_get_dma_dir(data),
> +DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> + if (!desc)
> + return -EINVAL;
> +
> + desc->callback = NULL;
> + 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Chunyan Zhang
On Mon, 3 Dec 2018 at 17:01, Faiz Abbas  wrote:
>
> Hi Chunyan,
>
> On 29/11/18 2:53 PM, Adrian Hunter wrote:
> > On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> >> Some standard SD host controllers can support both external dma
> >> controllers as well as ADMA/SDMA in which the SD host controller
> >> acts as DMA master. TI's omap controller is the case as an example.
> >>
> >> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> >> the host controller but does not have any support for external DMA
> >> controllers implemented using dmaengine, meaning that custom code is
> >> needed for any systems that use an external DMA controller with SDHCI.
> >>
> >> Signed-off-by: Chunyan Zhang 
> >> ---
> >>  drivers/mmc/host/Kconfig |  14 
> >>  drivers/mmc/host/sdhci.c | 185 
> >> ++-
> >>  drivers/mmc/host/sdhci.h |   8 ++
> >>  3 files changed, 206 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> >> index 1b58739..4183f43 100644
> >> --- a/drivers/mmc/host/Kconfig
> >> +++ b/drivers/mmc/host/Kconfig
> >> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
> >>  config MMC_SDHCI_OMAP
> >>  tristate "TI SDHCI Controller Support">>depends on 
> >> MMC_SDHCI_PLTFM && OF
> >> +select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>
>
> This should be in patch 2.

Ok, will move to.

Thanks,
Chunyan

>
> Thanks,
> Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Chunyan Zhang
On Mon, 3 Dec 2018 at 17:01, Faiz Abbas  wrote:
>
> Hi Chunyan,
>
> On 29/11/18 2:53 PM, Adrian Hunter wrote:
> > On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> >> Some standard SD host controllers can support both external dma
> >> controllers as well as ADMA/SDMA in which the SD host controller
> >> acts as DMA master. TI's omap controller is the case as an example.
> >>
> >> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> >> the host controller but does not have any support for external DMA
> >> controllers implemented using dmaengine, meaning that custom code is
> >> needed for any systems that use an external DMA controller with SDHCI.
> >>
> >> Signed-off-by: Chunyan Zhang 
> >> ---
> >>  drivers/mmc/host/Kconfig |  14 
> >>  drivers/mmc/host/sdhci.c | 185 
> >> ++-
> >>  drivers/mmc/host/sdhci.h |   8 ++
> >>  3 files changed, 206 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> >> index 1b58739..4183f43 100644
> >> --- a/drivers/mmc/host/Kconfig
> >> +++ b/drivers/mmc/host/Kconfig
> >> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
> >>  config MMC_SDHCI_OMAP
> >>  tristate "TI SDHCI Controller Support">>depends on 
> >> MMC_SDHCI_PLTFM && OF
> >> +select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>
>
> This should be in patch 2.

Ok, will move to.

Thanks,
Chunyan

>
> Thanks,
> Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Faiz Abbas
Hi Chunyan,

On 29/11/18 2:53 PM, Adrian Hunter wrote:
> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
>> Some standard SD host controllers can support both external dma
>> controllers as well as ADMA/SDMA in which the SD host controller
>> acts as DMA master. TI's omap controller is the case as an example.
>>
>> Currently the generic SDHCI code supports ADMA/SDMA integrated in
>> the host controller but does not have any support for external DMA
>> controllers implemented using dmaengine, meaning that custom code is
>> needed for any systems that use an external DMA controller with SDHCI.
>>
>> Signed-off-by: Chunyan Zhang 
>> ---
>>  drivers/mmc/host/Kconfig |  14 
>>  drivers/mmc/host/sdhci.c | 185 
>> ++-
>>  drivers/mmc/host/sdhci.h |   8 ++
>>  3 files changed, 206 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 1b58739..4183f43 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>>  config MMC_SDHCI_OMAP
>>  tristate "TI SDHCI Controller Support">>depends on 
>> MMC_SDHCI_PLTFM && OF
>> +select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE


This should be in patch 2.

Thanks,
Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-12-03 Thread Faiz Abbas
Hi Chunyan,

On 29/11/18 2:53 PM, Adrian Hunter wrote:
> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
>> Some standard SD host controllers can support both external dma
>> controllers as well as ADMA/SDMA in which the SD host controller
>> acts as DMA master. TI's omap controller is the case as an example.
>>
>> Currently the generic SDHCI code supports ADMA/SDMA integrated in
>> the host controller but does not have any support for external DMA
>> controllers implemented using dmaengine, meaning that custom code is
>> needed for any systems that use an external DMA controller with SDHCI.
>>
>> Signed-off-by: Chunyan Zhang 
>> ---
>>  drivers/mmc/host/Kconfig |  14 
>>  drivers/mmc/host/sdhci.c | 185 
>> ++-
>>  drivers/mmc/host/sdhci.h |   8 ++
>>  3 files changed, 206 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 1b58739..4183f43 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>>  config MMC_SDHCI_OMAP
>>  tristate "TI SDHCI Controller Support">>depends on 
>> MMC_SDHCI_PLTFM && OF
>> +select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE


This should be in patch 2.

Thanks,
Faiz


Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Chunyan Zhang
On Thu, 29 Nov 2018 at 18:41, Adrian Hunter  wrote:
>
> On 29/11/18 11:44 AM, Chunyan Zhang wrote:
> > On Thu, 29 Nov 2018 at 17:25, Adrian Hunter  wrote:
> >>
> >> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> >>> Some standard SD host controllers can support both external dma
> >>> controllers as well as ADMA/SDMA in which the SD host controller
> >>> acts as DMA master. TI's omap controller is the case as an example.
> >>>
> >>> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> >>> the host controller but does not have any support for external DMA
> >>> controllers implemented using dmaengine, meaning that custom code is
> >>> needed for any systems that use an external DMA controller with SDHCI.
> >>>
> >>> Signed-off-by: Chunyan Zhang 
> >>> ---
> >>>  drivers/mmc/host/Kconfig |  14 
> >>>  drivers/mmc/host/sdhci.c | 185 
> >>> ++-
> >>>  drivers/mmc/host/sdhci.h |   8 ++
> >>>  3 files changed, 206 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> >>> index 1b58739..4183f43 100644
> >>> --- a/drivers/mmc/host/Kconfig
> >>> +++ b/drivers/mmc/host/Kconfig
> >>> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
> >>>  config MMC_SDHCI_OMAP
> >>>   tristate "TI SDHCI Controller Support"
> >>>   depends on MMC_SDHCI_PLTFM && OF
> >>> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
> >>>   help
> >>> This selects the Secure Digital Host Controller Interface (SDHCI)
> >>> support present in TI's DRA7 SOCs. The controller supports
> >>> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> >>> If you have a controller with this interface, say Y or M here.
> >>>
> >>> If unsure, say N.
> >>> +
> >>> +config MMC_SDHCI_EXTERNAL_DMA
> >>> +bool "Support external DMA in standard SD host controller"
> >>> + depends on MMC_SDHCI
> >>> + depends on DMA_ENGINE
> >>> + help
> >>> +   This is an option for using external DMA device via dmaengine
> >>> +   framework.
> >>> +
> >>> +   If you have a controller which support using external DMA device
> >>> +   for data transfer, can say Y.
> >>> +
> >>> +   If unsure, say N.
> >>
> >> So if you are going to select this, then you don't need the prompt or help
> >> anymore i.e.
> >>
> >> config MMC_SDHCI_EXTERNAL_DMA
> >> bool
> >>
> >>
> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> >>> index 99bdae5..ad7cc80 100644
> >>> --- a/drivers/mmc/host/sdhci.c
> >>> +++ b/drivers/mmc/host/sdhci.c
> >>> @@ -14,6 +14,7 @@
> >>>   */
> >>>
> >>>  #include 
> >>> +#include 
> >>>  #include 
> >>>  #include 
> >>>  #include 
> >>> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host 
> >>> *host, struct mmc_request *mrq)
> >>>   del_timer(>timer);
> >>>  }
> >>>
> >>> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> >>> +static int sdhci_external_dma_init(struct sdhci_host *host)
> >>> +{
> >>> + int ret = 0;
> >>> + struct mmc_host *mmc = host->mmc;
> >>> +
> >>> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> >>> + if (IS_ERR(host->tx_chan)) {
> >>> + ret = PTR_ERR(host->tx_chan);
> >>> + if (ret != -EPROBE_DEFER)
> >>> + pr_warn("Failed to request TX DMA channel.\n");
> >>> + host->tx_chan = NULL;
> >>> + return ret;
> >>> + }
> >>> +
> >>> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> >>> + if (IS_ERR(host->rx_chan)) {
> >>> + if (host->tx_chan) {
> >>> + dma_release_channel(host->tx_chan);
> >>> + host->tx_chan = NULL;
> >>> + }
> >>> +
> >>> + ret = PTR_ERR(host->rx_chan);
> >>> + if (ret != -EPROBE_DEFER)
> >>> + pr_warn("Failed to request RX DMA channel.\n");
> >>> + host->rx_chan = NULL;
> >>> + }
> >>> +
> >>> + return ret;
> >>> +}
> >>> +
> >>> +static inline struct dma_chan *
> >>> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data 
> >>> *data)
> >>> +{
> >>> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> >>> +}
> >>> +
> >>> +static int sdhci_external_dma_setup(struct sdhci_host *host,
> >>> + struct mmc_command *cmd)
> >>> +{
> >>> + int ret, i;
> >>> + struct dma_async_tx_descriptor *desc;
> >>> + struct mmc_data *data = cmd->data;
> >>> + struct dma_chan *chan;
> >>> + struct dma_slave_config cfg;
> >>> + dma_cookie_t cookie;
> >>> +
> >>> + if (!host->mapbase)
> >>> + return -EINVAL;
> >>> +
> >>> + if (!data)
> >>> + return 0;
> >>
> >> It would read better if the above 2 if-statements were the other way 
> >> around i.e.
> >>
> >> if (!data)
> >> return 0;
> >>
> >> if (!host->mapbase)
> >> 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Chunyan Zhang
On Thu, 29 Nov 2018 at 18:41, Adrian Hunter  wrote:
>
> On 29/11/18 11:44 AM, Chunyan Zhang wrote:
> > On Thu, 29 Nov 2018 at 17:25, Adrian Hunter  wrote:
> >>
> >> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> >>> Some standard SD host controllers can support both external dma
> >>> controllers as well as ADMA/SDMA in which the SD host controller
> >>> acts as DMA master. TI's omap controller is the case as an example.
> >>>
> >>> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> >>> the host controller but does not have any support for external DMA
> >>> controllers implemented using dmaengine, meaning that custom code is
> >>> needed for any systems that use an external DMA controller with SDHCI.
> >>>
> >>> Signed-off-by: Chunyan Zhang 
> >>> ---
> >>>  drivers/mmc/host/Kconfig |  14 
> >>>  drivers/mmc/host/sdhci.c | 185 
> >>> ++-
> >>>  drivers/mmc/host/sdhci.h |   8 ++
> >>>  3 files changed, 206 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> >>> index 1b58739..4183f43 100644
> >>> --- a/drivers/mmc/host/Kconfig
> >>> +++ b/drivers/mmc/host/Kconfig
> >>> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
> >>>  config MMC_SDHCI_OMAP
> >>>   tristate "TI SDHCI Controller Support"
> >>>   depends on MMC_SDHCI_PLTFM && OF
> >>> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
> >>>   help
> >>> This selects the Secure Digital Host Controller Interface (SDHCI)
> >>> support present in TI's DRA7 SOCs. The controller supports
> >>> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> >>> If you have a controller with this interface, say Y or M here.
> >>>
> >>> If unsure, say N.
> >>> +
> >>> +config MMC_SDHCI_EXTERNAL_DMA
> >>> +bool "Support external DMA in standard SD host controller"
> >>> + depends on MMC_SDHCI
> >>> + depends on DMA_ENGINE
> >>> + help
> >>> +   This is an option for using external DMA device via dmaengine
> >>> +   framework.
> >>> +
> >>> +   If you have a controller which support using external DMA device
> >>> +   for data transfer, can say Y.
> >>> +
> >>> +   If unsure, say N.
> >>
> >> So if you are going to select this, then you don't need the prompt or help
> >> anymore i.e.
> >>
> >> config MMC_SDHCI_EXTERNAL_DMA
> >> bool
> >>
> >>
> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> >>> index 99bdae5..ad7cc80 100644
> >>> --- a/drivers/mmc/host/sdhci.c
> >>> +++ b/drivers/mmc/host/sdhci.c
> >>> @@ -14,6 +14,7 @@
> >>>   */
> >>>
> >>>  #include 
> >>> +#include 
> >>>  #include 
> >>>  #include 
> >>>  #include 
> >>> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host 
> >>> *host, struct mmc_request *mrq)
> >>>   del_timer(>timer);
> >>>  }
> >>>
> >>> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> >>> +static int sdhci_external_dma_init(struct sdhci_host *host)
> >>> +{
> >>> + int ret = 0;
> >>> + struct mmc_host *mmc = host->mmc;
> >>> +
> >>> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> >>> + if (IS_ERR(host->tx_chan)) {
> >>> + ret = PTR_ERR(host->tx_chan);
> >>> + if (ret != -EPROBE_DEFER)
> >>> + pr_warn("Failed to request TX DMA channel.\n");
> >>> + host->tx_chan = NULL;
> >>> + return ret;
> >>> + }
> >>> +
> >>> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> >>> + if (IS_ERR(host->rx_chan)) {
> >>> + if (host->tx_chan) {
> >>> + dma_release_channel(host->tx_chan);
> >>> + host->tx_chan = NULL;
> >>> + }
> >>> +
> >>> + ret = PTR_ERR(host->rx_chan);
> >>> + if (ret != -EPROBE_DEFER)
> >>> + pr_warn("Failed to request RX DMA channel.\n");
> >>> + host->rx_chan = NULL;
> >>> + }
> >>> +
> >>> + return ret;
> >>> +}
> >>> +
> >>> +static inline struct dma_chan *
> >>> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data 
> >>> *data)
> >>> +{
> >>> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> >>> +}
> >>> +
> >>> +static int sdhci_external_dma_setup(struct sdhci_host *host,
> >>> + struct mmc_command *cmd)
> >>> +{
> >>> + int ret, i;
> >>> + struct dma_async_tx_descriptor *desc;
> >>> + struct mmc_data *data = cmd->data;
> >>> + struct dma_chan *chan;
> >>> + struct dma_slave_config cfg;
> >>> + dma_cookie_t cookie;
> >>> +
> >>> + if (!host->mapbase)
> >>> + return -EINVAL;
> >>> +
> >>> + if (!data)
> >>> + return 0;
> >>
> >> It would read better if the above 2 if-statements were the other way 
> >> around i.e.
> >>
> >> if (!data)
> >> return 0;
> >>
> >> if (!host->mapbase)
> >> 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Adrian Hunter
On 29/11/18 11:44 AM, Chunyan Zhang wrote:
> On Thu, 29 Nov 2018 at 17:25, Adrian Hunter  wrote:
>>
>> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
>>> Some standard SD host controllers can support both external dma
>>> controllers as well as ADMA/SDMA in which the SD host controller
>>> acts as DMA master. TI's omap controller is the case as an example.
>>>
>>> Currently the generic SDHCI code supports ADMA/SDMA integrated in
>>> the host controller but does not have any support for external DMA
>>> controllers implemented using dmaengine, meaning that custom code is
>>> needed for any systems that use an external DMA controller with SDHCI.
>>>
>>> Signed-off-by: Chunyan Zhang 
>>> ---
>>>  drivers/mmc/host/Kconfig |  14 
>>>  drivers/mmc/host/sdhci.c | 185 
>>> ++-
>>>  drivers/mmc/host/sdhci.h |   8 ++
>>>  3 files changed, 206 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>>> index 1b58739..4183f43 100644
>>> --- a/drivers/mmc/host/Kconfig
>>> +++ b/drivers/mmc/host/Kconfig
>>> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>>>  config MMC_SDHCI_OMAP
>>>   tristate "TI SDHCI Controller Support"
>>>   depends on MMC_SDHCI_PLTFM && OF
>>> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>>>   help
>>> This selects the Secure Digital Host Controller Interface (SDHCI)
>>> support present in TI's DRA7 SOCs. The controller supports
>>> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
>>> If you have a controller with this interface, say Y or M here.
>>>
>>> If unsure, say N.
>>> +
>>> +config MMC_SDHCI_EXTERNAL_DMA
>>> +bool "Support external DMA in standard SD host controller"
>>> + depends on MMC_SDHCI
>>> + depends on DMA_ENGINE
>>> + help
>>> +   This is an option for using external DMA device via dmaengine
>>> +   framework.
>>> +
>>> +   If you have a controller which support using external DMA device
>>> +   for data transfer, can say Y.
>>> +
>>> +   If unsure, say N.
>>
>> So if you are going to select this, then you don't need the prompt or help
>> anymore i.e.
>>
>> config MMC_SDHCI_EXTERNAL_DMA
>> bool
>>
>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 99bdae5..ad7cc80 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -14,6 +14,7 @@
>>>   */
>>>
>>>  #include 
>>> +#include 
>>>  #include 
>>>  #include 
>>>  #include 
>>> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host 
>>> *host, struct mmc_request *mrq)
>>>   del_timer(>timer);
>>>  }
>>>
>>> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
>>> +static int sdhci_external_dma_init(struct sdhci_host *host)
>>> +{
>>> + int ret = 0;
>>> + struct mmc_host *mmc = host->mmc;
>>> +
>>> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
>>> + if (IS_ERR(host->tx_chan)) {
>>> + ret = PTR_ERR(host->tx_chan);
>>> + if (ret != -EPROBE_DEFER)
>>> + pr_warn("Failed to request TX DMA channel.\n");
>>> + host->tx_chan = NULL;
>>> + return ret;
>>> + }
>>> +
>>> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
>>> + if (IS_ERR(host->rx_chan)) {
>>> + if (host->tx_chan) {
>>> + dma_release_channel(host->tx_chan);
>>> + host->tx_chan = NULL;
>>> + }
>>> +
>>> + ret = PTR_ERR(host->rx_chan);
>>> + if (ret != -EPROBE_DEFER)
>>> + pr_warn("Failed to request RX DMA channel.\n");
>>> + host->rx_chan = NULL;
>>> + }
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static inline struct dma_chan *
>>> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
>>> +{
>>> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
>>> +}
>>> +
>>> +static int sdhci_external_dma_setup(struct sdhci_host *host,
>>> + struct mmc_command *cmd)
>>> +{
>>> + int ret, i;
>>> + struct dma_async_tx_descriptor *desc;
>>> + struct mmc_data *data = cmd->data;
>>> + struct dma_chan *chan;
>>> + struct dma_slave_config cfg;
>>> + dma_cookie_t cookie;
>>> +
>>> + if (!host->mapbase)
>>> + return -EINVAL;
>>> +
>>> + if (!data)
>>> + return 0;
>>
>> It would read better if the above 2 if-statements were the other way around 
>> i.e.
>>
>> if (!data)
>> return 0;
>>
>> if (!host->mapbase)
>> return -EINVAL;
>>
> 
> Ok.
> 
>>> +
>>> + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
>>> + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
>>> + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>>> + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>>> + cfg.src_maxburst = data->blksz / 4;
>>> + cfg.dst_maxburst 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Adrian Hunter
On 29/11/18 11:44 AM, Chunyan Zhang wrote:
> On Thu, 29 Nov 2018 at 17:25, Adrian Hunter  wrote:
>>
>> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
>>> Some standard SD host controllers can support both external dma
>>> controllers as well as ADMA/SDMA in which the SD host controller
>>> acts as DMA master. TI's omap controller is the case as an example.
>>>
>>> Currently the generic SDHCI code supports ADMA/SDMA integrated in
>>> the host controller but does not have any support for external DMA
>>> controllers implemented using dmaengine, meaning that custom code is
>>> needed for any systems that use an external DMA controller with SDHCI.
>>>
>>> Signed-off-by: Chunyan Zhang 
>>> ---
>>>  drivers/mmc/host/Kconfig |  14 
>>>  drivers/mmc/host/sdhci.c | 185 
>>> ++-
>>>  drivers/mmc/host/sdhci.h |   8 ++
>>>  3 files changed, 206 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>>> index 1b58739..4183f43 100644
>>> --- a/drivers/mmc/host/Kconfig
>>> +++ b/drivers/mmc/host/Kconfig
>>> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>>>  config MMC_SDHCI_OMAP
>>>   tristate "TI SDHCI Controller Support"
>>>   depends on MMC_SDHCI_PLTFM && OF
>>> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>>>   help
>>> This selects the Secure Digital Host Controller Interface (SDHCI)
>>> support present in TI's DRA7 SOCs. The controller supports
>>> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
>>> If you have a controller with this interface, say Y or M here.
>>>
>>> If unsure, say N.
>>> +
>>> +config MMC_SDHCI_EXTERNAL_DMA
>>> +bool "Support external DMA in standard SD host controller"
>>> + depends on MMC_SDHCI
>>> + depends on DMA_ENGINE
>>> + help
>>> +   This is an option for using external DMA device via dmaengine
>>> +   framework.
>>> +
>>> +   If you have a controller which support using external DMA device
>>> +   for data transfer, can say Y.
>>> +
>>> +   If unsure, say N.
>>
>> So if you are going to select this, then you don't need the prompt or help
>> anymore i.e.
>>
>> config MMC_SDHCI_EXTERNAL_DMA
>> bool
>>
>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 99bdae5..ad7cc80 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -14,6 +14,7 @@
>>>   */
>>>
>>>  #include 
>>> +#include 
>>>  #include 
>>>  #include 
>>>  #include 
>>> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host 
>>> *host, struct mmc_request *mrq)
>>>   del_timer(>timer);
>>>  }
>>>
>>> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
>>> +static int sdhci_external_dma_init(struct sdhci_host *host)
>>> +{
>>> + int ret = 0;
>>> + struct mmc_host *mmc = host->mmc;
>>> +
>>> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
>>> + if (IS_ERR(host->tx_chan)) {
>>> + ret = PTR_ERR(host->tx_chan);
>>> + if (ret != -EPROBE_DEFER)
>>> + pr_warn("Failed to request TX DMA channel.\n");
>>> + host->tx_chan = NULL;
>>> + return ret;
>>> + }
>>> +
>>> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
>>> + if (IS_ERR(host->rx_chan)) {
>>> + if (host->tx_chan) {
>>> + dma_release_channel(host->tx_chan);
>>> + host->tx_chan = NULL;
>>> + }
>>> +
>>> + ret = PTR_ERR(host->rx_chan);
>>> + if (ret != -EPROBE_DEFER)
>>> + pr_warn("Failed to request RX DMA channel.\n");
>>> + host->rx_chan = NULL;
>>> + }
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static inline struct dma_chan *
>>> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
>>> +{
>>> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
>>> +}
>>> +
>>> +static int sdhci_external_dma_setup(struct sdhci_host *host,
>>> + struct mmc_command *cmd)
>>> +{
>>> + int ret, i;
>>> + struct dma_async_tx_descriptor *desc;
>>> + struct mmc_data *data = cmd->data;
>>> + struct dma_chan *chan;
>>> + struct dma_slave_config cfg;
>>> + dma_cookie_t cookie;
>>> +
>>> + if (!host->mapbase)
>>> + return -EINVAL;
>>> +
>>> + if (!data)
>>> + return 0;
>>
>> It would read better if the above 2 if-statements were the other way around 
>> i.e.
>>
>> if (!data)
>> return 0;
>>
>> if (!host->mapbase)
>> return -EINVAL;
>>
> 
> Ok.
> 
>>> +
>>> + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
>>> + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
>>> + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>>> + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>>> + cfg.src_maxburst = data->blksz / 4;
>>> + cfg.dst_maxburst 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Chunyan Zhang
On Thu, 29 Nov 2018 at 17:25, Adrian Hunter  wrote:
>
> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> > Some standard SD host controllers can support both external dma
> > controllers as well as ADMA/SDMA in which the SD host controller
> > acts as DMA master. TI's omap controller is the case as an example.
> >
> > Currently the generic SDHCI code supports ADMA/SDMA integrated in
> > the host controller but does not have any support for external DMA
> > controllers implemented using dmaengine, meaning that custom code is
> > needed for any systems that use an external DMA controller with SDHCI.
> >
> > Signed-off-by: Chunyan Zhang 
> > ---
> >  drivers/mmc/host/Kconfig |  14 
> >  drivers/mmc/host/sdhci.c | 185 
> > ++-
> >  drivers/mmc/host/sdhci.h |   8 ++
> >  3 files changed, 206 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> > index 1b58739..4183f43 100644
> > --- a/drivers/mmc/host/Kconfig
> > +++ b/drivers/mmc/host/Kconfig
> > @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
> >  config MMC_SDHCI_OMAP
> >   tristate "TI SDHCI Controller Support"
> >   depends on MMC_SDHCI_PLTFM && OF
> > + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
> >   help
> > This selects the Secure Digital Host Controller Interface (SDHCI)
> > support present in TI's DRA7 SOCs. The controller supports
> > @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> > If you have a controller with this interface, say Y or M here.
> >
> > If unsure, say N.
> > +
> > +config MMC_SDHCI_EXTERNAL_DMA
> > +bool "Support external DMA in standard SD host controller"
> > + depends on MMC_SDHCI
> > + depends on DMA_ENGINE
> > + help
> > +   This is an option for using external DMA device via dmaengine
> > +   framework.
> > +
> > +   If you have a controller which support using external DMA device
> > +   for data transfer, can say Y.
> > +
> > +   If unsure, say N.
>
> So if you are going to select this, then you don't need the prompt or help
> anymore i.e.
>
> config MMC_SDHCI_EXTERNAL_DMA
> bool
>
>
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 99bdae5..ad7cc80 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -14,6 +14,7 @@
> >   */
> >
> >  #include 
> > +#include 
> >  #include 
> >  #include 
> >  #include 
> > @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host 
> > *host, struct mmc_request *mrq)
> >   del_timer(>timer);
> >  }
> >
> > +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> > +static int sdhci_external_dma_init(struct sdhci_host *host)
> > +{
> > + int ret = 0;
> > + struct mmc_host *mmc = host->mmc;
> > +
> > + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> > + if (IS_ERR(host->tx_chan)) {
> > + ret = PTR_ERR(host->tx_chan);
> > + if (ret != -EPROBE_DEFER)
> > + pr_warn("Failed to request TX DMA channel.\n");
> > + host->tx_chan = NULL;
> > + return ret;
> > + }
> > +
> > + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> > + if (IS_ERR(host->rx_chan)) {
> > + if (host->tx_chan) {
> > + dma_release_channel(host->tx_chan);
> > + host->tx_chan = NULL;
> > + }
> > +
> > + ret = PTR_ERR(host->rx_chan);
> > + if (ret != -EPROBE_DEFER)
> > + pr_warn("Failed to request RX DMA channel.\n");
> > + host->rx_chan = NULL;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static inline struct dma_chan *
> > +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
> > +{
> > + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> > +}
> > +
> > +static int sdhci_external_dma_setup(struct sdhci_host *host,
> > + struct mmc_command *cmd)
> > +{
> > + int ret, i;
> > + struct dma_async_tx_descriptor *desc;
> > + struct mmc_data *data = cmd->data;
> > + struct dma_chan *chan;
> > + struct dma_slave_config cfg;
> > + dma_cookie_t cookie;
> > +
> > + if (!host->mapbase)
> > + return -EINVAL;
> > +
> > + if (!data)
> > + return 0;
>
> It would read better if the above 2 if-statements were the other way around 
> i.e.
>
> if (!data)
> return 0;
>
> if (!host->mapbase)
> return -EINVAL;
>

Ok.

> > +
> > + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
> > + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
> > + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > + cfg.src_maxburst = data->blksz / 4;
> > + cfg.dst_maxburst = data->blksz / 4;
> > +
> > + /* Sanity check: all the SG entries 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Chunyan Zhang
On Thu, 29 Nov 2018 at 17:25, Adrian Hunter  wrote:
>
> On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> > Some standard SD host controllers can support both external dma
> > controllers as well as ADMA/SDMA in which the SD host controller
> > acts as DMA master. TI's omap controller is the case as an example.
> >
> > Currently the generic SDHCI code supports ADMA/SDMA integrated in
> > the host controller but does not have any support for external DMA
> > controllers implemented using dmaengine, meaning that custom code is
> > needed for any systems that use an external DMA controller with SDHCI.
> >
> > Signed-off-by: Chunyan Zhang 
> > ---
> >  drivers/mmc/host/Kconfig |  14 
> >  drivers/mmc/host/sdhci.c | 185 
> > ++-
> >  drivers/mmc/host/sdhci.h |   8 ++
> >  3 files changed, 206 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> > index 1b58739..4183f43 100644
> > --- a/drivers/mmc/host/Kconfig
> > +++ b/drivers/mmc/host/Kconfig
> > @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
> >  config MMC_SDHCI_OMAP
> >   tristate "TI SDHCI Controller Support"
> >   depends on MMC_SDHCI_PLTFM && OF
> > + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
> >   help
> > This selects the Secure Digital Host Controller Interface (SDHCI)
> > support present in TI's DRA7 SOCs. The controller supports
> > @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> > If you have a controller with this interface, say Y or M here.
> >
> > If unsure, say N.
> > +
> > +config MMC_SDHCI_EXTERNAL_DMA
> > +bool "Support external DMA in standard SD host controller"
> > + depends on MMC_SDHCI
> > + depends on DMA_ENGINE
> > + help
> > +   This is an option for using external DMA device via dmaengine
> > +   framework.
> > +
> > +   If you have a controller which support using external DMA device
> > +   for data transfer, can say Y.
> > +
> > +   If unsure, say N.
>
> So if you are going to select this, then you don't need the prompt or help
> anymore i.e.
>
> config MMC_SDHCI_EXTERNAL_DMA
> bool
>
>
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 99bdae5..ad7cc80 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -14,6 +14,7 @@
> >   */
> >
> >  #include 
> > +#include 
> >  #include 
> >  #include 
> >  #include 
> > @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host 
> > *host, struct mmc_request *mrq)
> >   del_timer(>timer);
> >  }
> >
> > +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> > +static int sdhci_external_dma_init(struct sdhci_host *host)
> > +{
> > + int ret = 0;
> > + struct mmc_host *mmc = host->mmc;
> > +
> > + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> > + if (IS_ERR(host->tx_chan)) {
> > + ret = PTR_ERR(host->tx_chan);
> > + if (ret != -EPROBE_DEFER)
> > + pr_warn("Failed to request TX DMA channel.\n");
> > + host->tx_chan = NULL;
> > + return ret;
> > + }
> > +
> > + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> > + if (IS_ERR(host->rx_chan)) {
> > + if (host->tx_chan) {
> > + dma_release_channel(host->tx_chan);
> > + host->tx_chan = NULL;
> > + }
> > +
> > + ret = PTR_ERR(host->rx_chan);
> > + if (ret != -EPROBE_DEFER)
> > + pr_warn("Failed to request RX DMA channel.\n");
> > + host->rx_chan = NULL;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static inline struct dma_chan *
> > +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
> > +{
> > + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> > +}
> > +
> > +static int sdhci_external_dma_setup(struct sdhci_host *host,
> > + struct mmc_command *cmd)
> > +{
> > + int ret, i;
> > + struct dma_async_tx_descriptor *desc;
> > + struct mmc_data *data = cmd->data;
> > + struct dma_chan *chan;
> > + struct dma_slave_config cfg;
> > + dma_cookie_t cookie;
> > +
> > + if (!host->mapbase)
> > + return -EINVAL;
> > +
> > + if (!data)
> > + return 0;
>
> It would read better if the above 2 if-statements were the other way around 
> i.e.
>
> if (!data)
> return 0;
>
> if (!host->mapbase)
> return -EINVAL;
>

Ok.

> > +
> > + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
> > + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
> > + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > + cfg.src_maxburst = data->blksz / 4;
> > + cfg.dst_maxburst = data->blksz / 4;
> > +
> > + /* Sanity check: all the SG entries 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Adrian Hunter
On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
> 
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
> 
> Signed-off-by: Chunyan Zhang 
> ---
>  drivers/mmc/host/Kconfig |  14 
>  drivers/mmc/host/sdhci.c | 185 
> ++-
>  drivers/mmc/host/sdhci.h |   8 ++
>  3 files changed, 206 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 1b58739..4183f43 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>  config MMC_SDHCI_OMAP
>   tristate "TI SDHCI Controller Support"
>   depends on MMC_SDHCI_PLTFM && OF
> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>   help
> This selects the Secure Digital Host Controller Interface (SDHCI)
> support present in TI's DRA7 SOCs. The controller supports
> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> If you have a controller with this interface, say Y or M here.
>  
> If unsure, say N.
> +
> +config MMC_SDHCI_EXTERNAL_DMA
> +bool "Support external DMA in standard SD host controller"
> + depends on MMC_SDHCI
> + depends on DMA_ENGINE
> + help
> +   This is an option for using external DMA device via dmaengine
> +   framework.
> +
> +   If you have a controller which support using external DMA device
> +   for data transfer, can say Y.
> +
> +   If unsure, say N.

So if you are going to select this, then you don't need the prompt or help
anymore i.e.

config MMC_SDHCI_EXTERNAL_DMA
bool


> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99bdae5..ad7cc80 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -14,6 +14,7 @@
>   */
>  
>  #include 
> +#include 
>  #include 
>  #include 
>  #include 
> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
> struct mmc_request *mrq)
>   del_timer(>timer);
>  }
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> +static int sdhci_external_dma_init(struct sdhci_host *host)
> +{
> + int ret = 0;
> + struct mmc_host *mmc = host->mmc;
> +
> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> + if (IS_ERR(host->tx_chan)) {
> + ret = PTR_ERR(host->tx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request TX DMA channel.\n");
> + host->tx_chan = NULL;
> + return ret;
> + }
> +
> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> + if (IS_ERR(host->rx_chan)) {
> + if (host->tx_chan) {
> + dma_release_channel(host->tx_chan);
> + host->tx_chan = NULL;
> + }
> +
> + ret = PTR_ERR(host->rx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request RX DMA channel.\n");
> + host->rx_chan = NULL;
> + }
> +
> + return ret;
> +}
> +
> +static inline struct dma_chan *
> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
> +{
> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> +}
> +
> +static int sdhci_external_dma_setup(struct sdhci_host *host,
> + struct mmc_command *cmd)
> +{
> + int ret, i;
> + struct dma_async_tx_descriptor *desc;
> + struct mmc_data *data = cmd->data;
> + struct dma_chan *chan;
> + struct dma_slave_config cfg;
> + dma_cookie_t cookie;
> +
> + if (!host->mapbase)
> + return -EINVAL;
> +
> + if (!data)
> + return 0;

It would read better if the above 2 if-statements were the other way around i.e.

if (!data)
return 0;

if (!host->mapbase)
return -EINVAL;

> +
> + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.src_maxburst = data->blksz / 4;
> + cfg.dst_maxburst = data->blksz / 4;
> +
> + /* Sanity check: all the SG entries must be aligned by block size. */
> + for (i = 0; i < data->sg_len; i++) {
> + if ((data->sg + i)->length % data->blksz)
> + return -EINVAL;
> + }
> +
> + chan = sdhci_external_dma_channel(host, data);
> +
> + ret = dmaengine_slave_config(chan, );
> + if (ret)
> + 

Re: [PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-29 Thread Adrian Hunter
On 29/11/18 8:07 AM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
> 
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
> 
> Signed-off-by: Chunyan Zhang 
> ---
>  drivers/mmc/host/Kconfig |  14 
>  drivers/mmc/host/sdhci.c | 185 
> ++-
>  drivers/mmc/host/sdhci.h |   8 ++
>  3 files changed, 206 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 1b58739..4183f43 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
>  config MMC_SDHCI_OMAP
>   tristate "TI SDHCI Controller Support"
>   depends on MMC_SDHCI_PLTFM && OF
> + select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
>   help
> This selects the Secure Digital Host Controller Interface (SDHCI)
> support present in TI's DRA7 SOCs. The controller supports
> @@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
> If you have a controller with this interface, say Y or M here.
>  
> If unsure, say N.
> +
> +config MMC_SDHCI_EXTERNAL_DMA
> +bool "Support external DMA in standard SD host controller"
> + depends on MMC_SDHCI
> + depends on DMA_ENGINE
> + help
> +   This is an option for using external DMA device via dmaengine
> +   framework.
> +
> +   If you have a controller which support using external DMA device
> +   for data transfer, can say Y.
> +
> +   If unsure, say N.

So if you are going to select this, then you don't need the prompt or help
anymore i.e.

config MMC_SDHCI_EXTERNAL_DMA
bool


> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99bdae5..ad7cc80 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -14,6 +14,7 @@
>   */
>  
>  #include 
> +#include 
>  #include 
>  #include 
>  #include 
> @@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
> struct mmc_request *mrq)
>   del_timer(>timer);
>  }
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> +static int sdhci_external_dma_init(struct sdhci_host *host)
> +{
> + int ret = 0;
> + struct mmc_host *mmc = host->mmc;
> +
> + host->tx_chan = dma_request_chan(mmc->parent, "tx");
> + if (IS_ERR(host->tx_chan)) {
> + ret = PTR_ERR(host->tx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request TX DMA channel.\n");
> + host->tx_chan = NULL;
> + return ret;
> + }
> +
> + host->rx_chan = dma_request_chan(mmc->parent, "rx");
> + if (IS_ERR(host->rx_chan)) {
> + if (host->tx_chan) {
> + dma_release_channel(host->tx_chan);
> + host->tx_chan = NULL;
> + }
> +
> + ret = PTR_ERR(host->rx_chan);
> + if (ret != -EPROBE_DEFER)
> + pr_warn("Failed to request RX DMA channel.\n");
> + host->rx_chan = NULL;
> + }
> +
> + return ret;
> +}
> +
> +static inline struct dma_chan *
> +sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
> +{
> + return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
> +}
> +
> +static int sdhci_external_dma_setup(struct sdhci_host *host,
> + struct mmc_command *cmd)
> +{
> + int ret, i;
> + struct dma_async_tx_descriptor *desc;
> + struct mmc_data *data = cmd->data;
> + struct dma_chan *chan;
> + struct dma_slave_config cfg;
> + dma_cookie_t cookie;
> +
> + if (!host->mapbase)
> + return -EINVAL;
> +
> + if (!data)
> + return 0;

It would read better if the above 2 if-statements were the other way around i.e.

if (!data)
return 0;

if (!host->mapbase)
return -EINVAL;

> +
> + cfg.src_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
> + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + cfg.src_maxburst = data->blksz / 4;
> + cfg.dst_maxburst = data->blksz / 4;
> +
> + /* Sanity check: all the SG entries must be aligned by block size. */
> + for (i = 0; i < data->sg_len; i++) {
> + if ((data->sg + i)->length % data->blksz)
> + return -EINVAL;
> + }
> +
> + chan = sdhci_external_dma_channel(host, data);
> +
> + ret = dmaengine_slave_config(chan, );
> + if (ret)
> + 

[PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-28 Thread Chunyan Zhang
Some standard SD host controllers can support both external dma
controllers as well as ADMA/SDMA in which the SD host controller
acts as DMA master. TI's omap controller is the case as an example.

Currently the generic SDHCI code supports ADMA/SDMA integrated in
the host controller but does not have any support for external DMA
controllers implemented using dmaengine, meaning that custom code is
needed for any systems that use an external DMA controller with SDHCI.

Signed-off-by: Chunyan Zhang 
---
 drivers/mmc/host/Kconfig |  14 
 drivers/mmc/host/sdhci.c | 185 ++-
 drivers/mmc/host/sdhci.h |   8 ++
 3 files changed, 206 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1b58739..4183f43 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
 config MMC_SDHCI_OMAP
tristate "TI SDHCI Controller Support"
depends on MMC_SDHCI_PLTFM && OF
+   select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
help
  This selects the Secure Digital Host Controller Interface (SDHCI)
  support present in TI's DRA7 SOCs. The controller supports
@@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
  If you have a controller with this interface, say Y or M here.
 
  If unsure, say N.
+
+config MMC_SDHCI_EXTERNAL_DMA
+bool "Support external DMA in standard SD host controller"
+   depends on MMC_SDHCI
+   depends on DMA_ENGINE
+   help
+ This is an option for using external DMA device via dmaengine
+ framework.
+
+ If you have a controller which support using external DMA device
+ for data transfer, can say Y.
+
+ If unsure, say N.
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 99bdae5..ad7cc80 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -14,6 +14,7 @@
  */
 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
struct mmc_request *mrq)
del_timer(>timer);
 }
 
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+static int sdhci_external_dma_init(struct sdhci_host *host)
+{
+   int ret = 0;
+   struct mmc_host *mmc = host->mmc;
+
+   host->tx_chan = dma_request_chan(mmc->parent, "tx");
+   if (IS_ERR(host->tx_chan)) {
+   ret = PTR_ERR(host->tx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request TX DMA channel.\n");
+   host->tx_chan = NULL;
+   return ret;
+   }
+
+   host->rx_chan = dma_request_chan(mmc->parent, "rx");
+   if (IS_ERR(host->rx_chan)) {
+   if (host->tx_chan) {
+   dma_release_channel(host->tx_chan);
+   host->tx_chan = NULL;
+   }
+
+   ret = PTR_ERR(host->rx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request RX DMA channel.\n");
+   host->rx_chan = NULL;
+   }
+
+   return ret;
+}
+
+static inline struct dma_chan *
+sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
+{
+   return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
+}
+
+static int sdhci_external_dma_setup(struct sdhci_host *host,
+   struct mmc_command *cmd)
+{
+   int ret, i;
+   struct dma_async_tx_descriptor *desc;
+   struct mmc_data *data = cmd->data;
+   struct dma_chan *chan;
+   struct dma_slave_config cfg;
+   dma_cookie_t cookie;
+
+   if (!host->mapbase)
+   return -EINVAL;
+
+   if (!data)
+   return 0;
+
+   cfg.src_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.src_maxburst = data->blksz / 4;
+   cfg.dst_maxburst = data->blksz / 4;
+
+   /* Sanity check: all the SG entries must be aligned by block size. */
+   for (i = 0; i < data->sg_len; i++) {
+   if ((data->sg + i)->length % data->blksz)
+   return -EINVAL;
+   }
+
+   chan = sdhci_external_dma_channel(host, data);
+
+   ret = dmaengine_slave_config(chan, );
+   if (ret)
+   return ret;
+
+   desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
+  mmc_get_dma_dir(data),
+  DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+   if (!desc)
+   return -EINVAL;
+
+   desc->callback = NULL;
+   desc->callback_param = NULL;
+
+   cookie = dmaengine_submit(desc);
+   if (cookie < 0)
+   ret = cookie;
+
+   return ret;
+}
+
+static void 

[PATCH V3 1/3] mmc: sdhci: add support for using external DMA devices

2018-11-28 Thread Chunyan Zhang
Some standard SD host controllers can support both external dma
controllers as well as ADMA/SDMA in which the SD host controller
acts as DMA master. TI's omap controller is the case as an example.

Currently the generic SDHCI code supports ADMA/SDMA integrated in
the host controller but does not have any support for external DMA
controllers implemented using dmaengine, meaning that custom code is
needed for any systems that use an external DMA controller with SDHCI.

Signed-off-by: Chunyan Zhang 
---
 drivers/mmc/host/Kconfig |  14 
 drivers/mmc/host/sdhci.c | 185 ++-
 drivers/mmc/host/sdhci.h |   8 ++
 3 files changed, 206 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1b58739..4183f43 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -969,6 +969,7 @@ config MMC_SDHCI_XENON
 config MMC_SDHCI_OMAP
tristate "TI SDHCI Controller Support"
depends on MMC_SDHCI_PLTFM && OF
+   select MMC_SDHCI_EXTERNAL_DMA if DMA_ENGINE
help
  This selects the Secure Digital Host Controller Interface (SDHCI)
  support present in TI's DRA7 SOCs. The controller supports
@@ -977,3 +978,16 @@ config MMC_SDHCI_OMAP
  If you have a controller with this interface, say Y or M here.
 
  If unsure, say N.
+
+config MMC_SDHCI_EXTERNAL_DMA
+bool "Support external DMA in standard SD host controller"
+   depends on MMC_SDHCI
+   depends on DMA_ENGINE
+   help
+ This is an option for using external DMA device via dmaengine
+ framework.
+
+ If you have a controller which support using external DMA device
+ for data transfer, can say Y.
+
+ If unsure, say N.
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 99bdae5..ad7cc80 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -14,6 +14,7 @@
  */
 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -1309,6 +1310,162 @@ static void sdhci_del_timer(struct sdhci_host *host, 
struct mmc_request *mrq)
del_timer(>timer);
 }
 
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+static int sdhci_external_dma_init(struct sdhci_host *host)
+{
+   int ret = 0;
+   struct mmc_host *mmc = host->mmc;
+
+   host->tx_chan = dma_request_chan(mmc->parent, "tx");
+   if (IS_ERR(host->tx_chan)) {
+   ret = PTR_ERR(host->tx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request TX DMA channel.\n");
+   host->tx_chan = NULL;
+   return ret;
+   }
+
+   host->rx_chan = dma_request_chan(mmc->parent, "rx");
+   if (IS_ERR(host->rx_chan)) {
+   if (host->tx_chan) {
+   dma_release_channel(host->tx_chan);
+   host->tx_chan = NULL;
+   }
+
+   ret = PTR_ERR(host->rx_chan);
+   if (ret != -EPROBE_DEFER)
+   pr_warn("Failed to request RX DMA channel.\n");
+   host->rx_chan = NULL;
+   }
+
+   return ret;
+}
+
+static inline struct dma_chan *
+sdhci_external_dma_channel(struct sdhci_host *host, struct mmc_data *data)
+{
+   return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
+}
+
+static int sdhci_external_dma_setup(struct sdhci_host *host,
+   struct mmc_command *cmd)
+{
+   int ret, i;
+   struct dma_async_tx_descriptor *desc;
+   struct mmc_data *data = cmd->data;
+   struct dma_chan *chan;
+   struct dma_slave_config cfg;
+   dma_cookie_t cookie;
+
+   if (!host->mapbase)
+   return -EINVAL;
+
+   if (!data)
+   return 0;
+
+   cfg.src_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
+   cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+   cfg.src_maxburst = data->blksz / 4;
+   cfg.dst_maxburst = data->blksz / 4;
+
+   /* Sanity check: all the SG entries must be aligned by block size. */
+   for (i = 0; i < data->sg_len; i++) {
+   if ((data->sg + i)->length % data->blksz)
+   return -EINVAL;
+   }
+
+   chan = sdhci_external_dma_channel(host, data);
+
+   ret = dmaengine_slave_config(chan, );
+   if (ret)
+   return ret;
+
+   desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
+  mmc_get_dma_dir(data),
+  DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+   if (!desc)
+   return -EINVAL;
+
+   desc->callback = NULL;
+   desc->callback_param = NULL;
+
+   cookie = dmaengine_submit(desc);
+   if (cookie < 0)
+   ret = cookie;
+
+   return ret;
+}
+
+static void