On Tue, Jun 18, 2013 at 06:16:57PM +0200, Guennadi Liakhovetski wrote:
> This patch adds Device Tree support to the shdma driver. No special DT
> properties are used, only standard DMA DT bindings are implemented. Since
> shdma controllers reside on SoCs, their configuration is SoC-specific and
> shall be passed to the driver from the SoC platform data, using the
> auxdata procedure.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+rene...@gmail.com>
Applied thanks.
Though checkpatch cribbed about space and tabs, fixed up manually...
--
~Vinod
> ---
>
> v3: reimplementation without a common DMAC multiplexer support in
> dmaengine core, the multiplexer is now SHDMA local.
>
> Documentation/devicetree/bindings/dma/shdma.txt | 75 +++++++++++++++++++++
> drivers/dma/sh/Makefile | 2 +-
> drivers/dma/sh/shdma-base.c | 26 ++++++--
> drivers/dma/sh/shdma-of.c | 82
> +++++++++++++++++++++++
> drivers/dma/sh/shdma.c | 31 +++++++--
> include/linux/shdma-base.h | 2 +
> 6 files changed, 205 insertions(+), 13 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/dma/shdma.txt
> create mode 100644 drivers/dma/sh/shdma-of.c
>
> diff --git a/Documentation/devicetree/bindings/dma/shdma.txt
> b/Documentation/devicetree/bindings/dma/shdma.txt
> new file mode 100644
> index 0000000..c15994a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/shdma.txt
> @@ -0,0 +1,75 @@
> +* SHDMA Device Tree bindings
> +
> +Sh-/r-mobile and r-car systems often have multiple identical DMA controller
> +instances, capable of serving any of a common set of DMA slave devices, using
> +the same configuration. To describe this topology we require all compatible
> +SHDMA DT nodes to be placed under a DMA multiplexer node. All such compatible
> +DMAC instances have the same number of channels and use the same DMA
> +descriptors. Therefore respective DMA DT bindings can also all be placed in
> the
> +multiplexer node. Even if there is only one such DMAC instance on a system,
> it
> +still has to be placed under such a multiplexer node.
> +
> +* DMA multiplexer
> +
> +Required properties:
> +- compatible: should be "renesas,shdma-mux"
> +- #dma-cells: should be <1>, see "dmas" property below
> +
> +Optional properties (currently unused):
> +- dma-channels: number of DMA channels
> +- dma-requests: number of DMA request signals
> +
> +* DMA controller
> +
> +Required properties:
> +- compatible: should be "renesas,shdma"
> +
> +Example:
> + dmac: dma-mux0 {
> + compatible = "renesas,shdma-mux";
> + #dma-cells = <1>;
> + dma-channels = <6>;
> + dma-requests = <256>;
> + reg = <0 0>; /* Needed for AUXDATA */
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges;
> +
> + dma0: shdma@fe008020 {
> + compatible = "renesas,shdma";
> + reg = <0xfe008020 0x270>,
> + <0xfe009000 0xc>;
> + interrupt-parent = <&gic>;
> + interrupts = <0 34 4
> + 0 28 4
> + 0 29 4
> + 0 30 4
> + 0 31 4
> + 0 32 4
> + 0 33 4>;
> + interrupt-names = "error",
> + "ch0", "ch1", "ch2", "ch3",
> + "ch4", "ch5";
> + };
> +
> + dma1: shdma@fe018020 {
> + ...
> + };
> +
> + dma2: shdma@fe028020 {
> + ...
> + };
> + };
> +
> +* DMA client
> +
> +Required properties:
> +- dmas: a list of <[DMA multiplexer phandle] [MID/RID value]>
> pairs,
> + where MID/RID values are fixed handles, specified in the SoC
> + manual
> +- dma-names: a list of DMA channel names, one per "dmas" entry
> +
> +Example:
> + dmas = <&dmac 0xd1
> + &dmac 0xd2>;
> + dma-names = "tx", "rx";
> diff --git a/drivers/dma/sh/Makefile b/drivers/dma/sh/Makefile
> index c07ca46..c962138 100644
> --- a/drivers/dma/sh/Makefile
> +++ b/drivers/dma/sh/Makefile
> @@ -1,3 +1,3 @@
> -obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o
> +obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o shdma-of.o
> obj-$(CONFIG_SH_DMAE) += shdma.o
> obj-$(CONFIG_SUDMAC) += sudmac.o
> diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c
> index 4acb85a..28ca361 100644
> --- a/drivers/dma/sh/shdma-base.c
> +++ b/drivers/dma/sh/shdma-base.c
> @@ -175,7 +175,18 @@ static int shdma_setup_slave(struct shdma_chan *schan,
> int slave_id)
> {
> struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
> const struct shdma_ops *ops = sdev->ops;
> - int ret;
> + int ret, match;
> +
> + if (schan->dev->of_node) {
> + match = schan->hw_req;
> + ret = ops->set_slave(schan, match, true);
> + if (ret < 0)
> + return ret;
> +
> + slave_id = schan->slave_id;
> + } else {
> + match = slave_id;
> + }
>
> if (slave_id < 0 || slave_id >= slave_num)
> return -EINVAL;
> @@ -183,7 +194,7 @@ static int shdma_setup_slave(struct shdma_chan *schan,
> int slave_id)
> if (test_and_set_bit(slave_id, shdma_slave_used))
> return -EBUSY;
>
> - ret = ops->set_slave(schan, slave_id, false);
> + ret = ops->set_slave(schan, match, false);
> if (ret < 0) {
> clear_bit(slave_id, shdma_slave_used);
> return ret;
> @@ -206,23 +217,26 @@ static int shdma_setup_slave(struct shdma_chan *schan,
> int slave_id)
> * services would have to provide their own filters, which first would check
> * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c,
> do
> * this, and only then, in case of a match, call this common filter.
> + * NOTE 2: This filter function is also used in the DT case by
> shdma_of_xlate().
> + * In that case the MID-RID value is used for slave channel filtering and is
> + * passed to this function in the "arg" parameter.
> */
> bool shdma_chan_filter(struct dma_chan *chan, void *arg)
> {
> struct shdma_chan *schan = to_shdma_chan(chan);
> struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
> const struct shdma_ops *ops = sdev->ops;
> - int slave_id = (int)arg;
> + int match = (int)arg;
> int ret;
>
> - if (slave_id < 0)
> + if (match < 0)
> /* No slave requested - arbitrary channel */
> return true;
>
> - if (slave_id >= slave_num)
> + if (!schan->dev->of_node && match >= slave_num)
> return false;
>
> - ret = ops->set_slave(schan, slave_id, true);
> + ret = ops->set_slave(schan, match, true);
> if (ret < 0)
> return false;
>
> diff --git a/drivers/dma/sh/shdma-of.c b/drivers/dma/sh/shdma-of.c
> new file mode 100644
> index 0000000..9ab869d
> --- /dev/null
> +++ b/drivers/dma/sh/shdma-of.c
> @@ -0,0 +1,82 @@
> +/*
> + * SHDMA Device Tree glue
> + *
> + * Copyright (C) 2013 Renesas Electronics Inc.
> + * Author: Guennadi Liakhovetski <g.liakhovet...@gmx.de>
> + *
> + * This is free software; you can redistribute it and/or modify
> + * it under the terms of version 2 of the GNU General Public License as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/dmaengine.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_dma.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/shdma-base.h>
> +
> +#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)
> +
> +static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma)
> +{
> + u32 id = dma_spec->args[0];
> + dma_cap_mask_t mask;
> + struct dma_chan *chan;
> +
> + if (dma_spec->args_count != 1)
> + return NULL;
> +
> + dma_cap_zero(mask);
> + /* Only slave DMA channels can be allocated via DT */
> + dma_cap_set(DMA_SLAVE, mask);
> +
> + chan = dma_request_channel(mask, shdma_chan_filter, (void *)id);
> + if (chan)
> + to_shdma_chan(chan)->hw_req = id;
> +
> + return chan;
> +}
> +
> +static int shdma_of_probe(struct platform_device *pdev)
> +{
> + const struct of_dev_auxdata *lookup = pdev->dev.platform_data;
> + int ret;
> +
> + if (!lookup)
> + return -EINVAL;
> +
> + ret = of_dma_controller_register(pdev->dev.of_node,
> + shdma_of_xlate, pdev);
> + if (ret < 0)
> + return ret;
> +
> + ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);
> + if (ret < 0)
> + of_dma_controller_free(pdev->dev.of_node);
> +
> + return ret;
> +}
> +
> +static const struct of_device_id shdma_of_match[] = {
> + { .compatible = "renesas,shdma-mux", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
> +
> +static struct platform_driver shdma_of = {
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = "shdma-of",
> + .of_match_table = shdma_of_match,
> + },
> + .probe = shdma_of_probe,
> +};
> +
> +module_platform_driver(shdma_of);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("SH-DMA driver DT glue");
> +MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovet...@gmx.de>");
> diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
> index a5a1887..b67f45f 100644
> --- a/drivers/dma/sh/shdma.c
> +++ b/drivers/dma/sh/shdma.c
> @@ -301,20 +301,32 @@ static void sh_dmae_setup_xfer(struct shdma_chan *schan,
> }
> }
>
> +/*
> + * Find a slave channel configuration from the contoller list by either a
> slave
> + * ID in the non-DT case, or by a MID/RID value in the DT case
> + */
> static const struct sh_dmae_slave_config *dmae_find_slave(
> - struct sh_dmae_chan *sh_chan, int slave_id)
> + struct sh_dmae_chan *sh_chan, int match)
> {
> struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
> struct sh_dmae_pdata *pdata = shdev->pdata;
> const struct sh_dmae_slave_config *cfg;
> int i;
>
> - if (slave_id >= SH_DMA_SLAVE_NUMBER)
> - return NULL;
> + if (!sh_chan->shdma_chan.dev->of_node) {
> + if (match >= SH_DMA_SLAVE_NUMBER)
> + return NULL;
>
> - for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
> - if (cfg->slave_id == slave_id)
> - return cfg;
> + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++,
> cfg++)
> + if (cfg->slave_id == match)
> + return cfg;
> + } else {
> + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++,
> cfg++)
> + if (cfg->mid_rid == match) {
> + sh_chan->shdma_chan.slave_id = cfg->slave_id;
> + return cfg;
> + }
> + }
>
> return NULL;
> }
> @@ -920,11 +932,18 @@ static int sh_dmae_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct of_device_id sh_dmae_of_match[] = {
> + { .compatible = "renesas,shdma", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
> +
> static struct platform_driver sh_dmae_driver = {
> .driver = {
> .owner = THIS_MODULE,
> .pm = &sh_dmae_pm,
> .name = SH_DMAE_DRV_NAME,
> + .of_match_table = sh_dmae_of_match,
> },
> .remove = sh_dmae_remove,
> .shutdown = sh_dmae_shutdown,
> diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h
> index 9a93897..382cf71 100644
> --- a/include/linux/shdma-base.h
> +++ b/include/linux/shdma-base.h
> @@ -68,6 +68,8 @@ struct shdma_chan {
> int id; /* Raw id of this channel */
> int irq; /* Channel IRQ */
> int slave_id; /* Client ID for slave DMA */
> + int hw_req; /* DMA request line for slave DMA - same
> + * as MID/RID, used with DT */
> enum shdma_pm_state pm_state;
> };
>
> --
> 1.7.2.5
>
--
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