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 <g.liakhovetski@xxxxxx>
---
...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
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