The MMCIF controller on sh-mobile platforms can use the DMA controller for data transfers. Interface to the SH dmaengine driver to enable DMA.
Signed-off-by: Guennadi Liakhovetski <[email protected]> --- ...This has been a nice exception: just one missing piece of the datasheet puzzle had to be guessed and it worked straight away just as expected;) At least so far... Nice! drivers/mmc/host/Kconfig | 6 + drivers/mmc/host/sh_mmcif.c | 239 +++++++++++++++++++++++++++++++++++++++++- include/linux/mmc/sh_mmcif.h | 15 ++- 3 files changed, 254 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index d618e86..859e352 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -466,6 +466,12 @@ config MMC_SH_MMCIF This driver supports MMCIF in sh7724/sh7757/sh7372. +config SH_MMCIF_DMA + bool "Use DMA for MMCIF" + depends on MMC_SH_MMCIF + help + Use SH dma-engine driver for data transfer + config MMC_JZ4740 tristate "JZ4740 SD/Multimedia Card Interface support" depends on MACH_JZ4740 diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c index 51a0160..ff3c8da 100644 --- a/drivers/mmc/host/sh_mmcif.c +++ b/drivers/mmc/host/sh_mmcif.c @@ -20,6 +20,7 @@ #include <linux/completion.h> #include <linux/delay.h> #include <linux/dma-mapping.h> +#include <linux/dmaengine.h> #include <linux/mmc/card.h> #include <linux/mmc/core.h> #include <linux/mmc/host.h> @@ -185,8 +186,13 @@ struct sh_mmcif_host { long timeout; void __iomem *addr; struct completion intr_wait; -}; + /* DMA support */ + struct dma_chan *chan_rx; + struct dma_chan *chan_tx; + struct completion dma_complete; + unsigned int dma_sglen; +}; static inline void sh_mmcif_bitset(struct sh_mmcif_host *host, unsigned int reg, u32 val) @@ -200,6 +206,208 @@ static inline void sh_mmcif_bitclr(struct sh_mmcif_host *host, writel(~val & readl(host->addr + reg), host->addr + reg); } +#ifdef CONFIG_SH_MMCIF_DMA +static void mmcif_dma_complete(void *arg) +{ + struct sh_mmcif_host *host = arg; + dev_dbg(&host->pd->dev, "Command completed\n"); + + if (WARN(!host->data, "%s: NULL data in DMA completion!\n", + dev_name(&host->pd->dev))) + return; + + if (host->data->flags & MMC_DATA_READ) + dma_unmap_sg(&host->pd->dev, host->data->sg, host->dma_sglen, + DMA_FROM_DEVICE); + else + dma_unmap_sg(&host->pd->dev, host->data->sg, host->dma_sglen, + DMA_TO_DEVICE); + + complete(&host->dma_complete); +} + +static void sh_mmcif_start_dma_rx(struct sh_mmcif_host *host) +{ + struct scatterlist *sg = host->data->sg; + struct dma_async_tx_descriptor *desc = NULL; + struct dma_chan *chan = host->chan_rx; + dma_cookie_t cookie = -EINVAL; + int ret; + + ret = dma_map_sg(&host->pd->dev, sg, host->data->sg_len, DMA_FROM_DEVICE); + if (ret > 0) { + host->dma_sglen = ret; + desc = chan->device->device_prep_slave_sg(chan, sg, ret, + DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + } + + if (desc) { + desc->callback = mmcif_dma_complete; + desc->callback_param = host; + cookie = desc->tx_submit(desc); + if (cookie < 0) { + desc = NULL; + ret = cookie; + } else { + sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN); + chan->device->device_issue_pending(chan); + } + } + dev_dbg(&host->pd->dev, "%s(): mapped %d -> %d, cookie %d\n", + __func__, host->data->sg_len, ret, cookie); + + if (!desc) { + /* DMA failed, fall back to PIO */ + if (ret >= 0) + ret = -EIO; + host->chan_rx = NULL; + host->dma_sglen = 0; + dma_release_channel(chan); + /* Free the Tx channel too */ + chan = host->chan_tx; + if (chan) { + host->chan_tx = NULL; + dma_release_channel(chan); + } + dev_warn(&host->pd->dev, + "DMA failed: %d, falling back to PIO\n", ret); + sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN | BUF_ACC_DMAWEN); + } + + dev_dbg(&host->pd->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__, + desc, cookie, host->data->sg_len); +} + +static void sh_mmcif_start_dma_tx(struct sh_mmcif_host *host) +{ + struct scatterlist *sg = host->data->sg; + struct dma_async_tx_descriptor *desc = NULL; + struct dma_chan *chan = host->chan_tx; + dma_cookie_t cookie = -EINVAL; + int ret; + + ret = dma_map_sg(&host->pd->dev, sg, host->data->sg_len, DMA_TO_DEVICE); + if (ret > 0) { + host->dma_sglen = ret; + desc = chan->device->device_prep_slave_sg(chan, sg, ret, + DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + } + + if (desc) { + desc->callback = mmcif_dma_complete; + desc->callback_param = host; + cookie = desc->tx_submit(desc); + if (cookie < 0) { + desc = NULL; + ret = cookie; + } else { + sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAWEN); + chan->device->device_issue_pending(chan); + } + } + dev_dbg(&host->pd->dev, "%s(): mapped %d -> %d, cookie %d\n", + __func__, host->data->sg_len, ret, cookie); + + if (!desc) { + /* DMA failed, fall back to PIO */ + if (ret >= 0) + ret = -EIO; + host->chan_tx = NULL; + host->dma_sglen = 0; + dma_release_channel(chan); + /* Free the Rx channel too */ + chan = host->chan_rx; + if (chan) { + host->chan_rx = NULL; + dma_release_channel(chan); + } + dev_warn(&host->pd->dev, + "DMA failed: %d, falling back to PIO\n", ret); + sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN | BUF_ACC_DMAWEN); + } + + dev_dbg(&host->pd->dev, "%s(): desc %p, cookie %d\n", __func__, + desc, cookie); +} + +static bool sh_mmcif_filter(struct dma_chan *chan, void *arg) +{ + dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg); + chan->private = arg; + return true; +} + +static void sh_mmcif_request_dma(struct sh_mmcif_host *host, + struct sh_mmcif_plat_data *pdata) +{ + host->dma_sglen = 0; + + /* We can only either use DMA for both Tx and Rx or not use it at all */ + if (pdata->dma) { + dma_cap_mask_t mask; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + host->chan_tx = dma_request_channel(mask, sh_mmcif_filter, + &pdata->dma->chan_priv_tx); + dev_dbg(&host->pd->dev, "%s: TX: got channel %p\n", __func__, + host->chan_tx); + + if (!host->chan_tx) + return; + + host->chan_rx = dma_request_channel(mask, sh_mmcif_filter, + &pdata->dma->chan_priv_rx); + dev_dbg(&host->pd->dev, "%s: RX: got channel %p\n", __func__, + host->chan_rx); + + if (!host->chan_rx) { + dma_release_channel(host->chan_tx); + host->chan_tx = NULL; + return; + } + + init_completion(&host->dma_complete); + } +} + +static void sh_mmcif_release_dma(struct sh_mmcif_host *host) +{ + sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN | BUF_ACC_DMAWEN); + /* Descriptors are freed automatically */ + if (host->chan_tx) { + struct dma_chan *chan = host->chan_tx; + host->chan_tx = NULL; + dma_release_channel(chan); + } + if (host->chan_rx) { + struct dma_chan *chan = host->chan_rx; + host->chan_rx = NULL; + dma_release_channel(chan); + } + + host->dma_sglen = 0; +} +#else +static void sh_mmcif_start_dma_tx(struct sh_mmcif_host *host) +{ +} + +static void sh_mmcif_start_dma_rx(struct sh_mmcif_host *host) +{ +} + +static void sh_mmcif_request_dma(struct sh_mmcif_host *host, + struct sh_mmcif_plat_data *pdata) +{ + /* host->chan_tx, host->chan_tx and host->dma_sglen are all zero */ +} + +static void sh_mmcif_release_dma(struct sh_mmcif_host *host) +{ +} +#endif static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk) { @@ -587,7 +795,20 @@ static void sh_mmcif_start_cmd(struct sh_mmcif_host *host, } sh_mmcif_get_response(host, cmd); if (host->data) { - ret = sh_mmcif_data_trans(host, mrq, cmd->opcode); + if (!host->dma_sglen) { + ret = sh_mmcif_data_trans(host, mrq, cmd->opcode); + } else { + long time = + wait_for_completion_interruptible_timeout(&host->dma_complete, + host->timeout); + if (!time) + ret = -ETIMEDOUT; + else if (time < 0) + ret = time; + sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, + BUF_ACC_DMAREN | BUF_ACC_DMAWEN); + host->dma_sglen = 0; + } if (ret < 0) mrq->data->bytes_xfered = 0; else @@ -645,6 +866,15 @@ static void sh_mmcif_request(struct mmc_host *mmc, struct mmc_request *mrq) break; } host->data = mrq->data; + if (mrq->data) { + if (mrq->data->flags & MMC_DATA_READ) { + if (host->chan_rx) + sh_mmcif_start_dma_rx(host); + } else { + if (host->chan_tx) + sh_mmcif_start_dma_tx(host); + } + } sh_mmcif_start_cmd(host, mrq, mrq->cmd); host->data = NULL; @@ -837,6 +1067,10 @@ static int __devinit sh_mmcif_probe(struct platform_device *pdev) sh_mmcif_sync_reset(host); platform_set_drvdata(pdev, host); + + /* See if we also get DMA */ + sh_mmcif_request_dma(host, pd); + mmc_add_host(mmc); ret = request_irq(irq[0], sh_mmcif_intr, 0, "sh_mmc:error", host); @@ -875,6 +1109,7 @@ static int __devexit sh_mmcif_remove(struct platform_device *pdev) int irq[2]; mmc_remove_host(host->mmc); + sh_mmcif_release_dma(host); if (host->addr) iounmap(host->addr); diff --git a/include/linux/mmc/sh_mmcif.h b/include/linux/mmc/sh_mmcif.h index d19e211..fcf3d11 100644 --- a/include/linux/mmc/sh_mmcif.h +++ b/include/linux/mmc/sh_mmcif.h @@ -14,8 +14,9 @@ #ifndef __SH_MMCIF_H__ #define __SH_MMCIF_H__ -#include <linux/platform_device.h> #include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/sh_dma.h> /* * MMCIF : CE_CLK_CTRL [19:16] @@ -31,13 +32,19 @@ * 1111 : Peripheral clock (sup_pclk set '1') */ +struct sh_mmcif_dma { + struct sh_dmae_slave chan_priv_tx; + struct sh_dmae_slave chan_priv_rx; +}; + struct sh_mmcif_plat_data { void (*set_pwr)(struct platform_device *pdev, int state); void (*down_pwr)(struct platform_device *pdev); int (*get_cd)(struct platform_device *pdef); - u8 sup_pclk; /* 1 :SH7757, 0: SH7724/SH7372 */ - unsigned long caps; - u32 ocr; + struct sh_mmcif_dma *dma; + u8 sup_pclk; /* 1 :SH7757, 0: SH7724/SH7372 */ + unsigned long caps; + u32 ocr; }; #define MMCIF_CE_CMD_SET 0x00000000 -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
