SDHI controllers on SuperH, served by the tmio_mmc driver, can use slave DMA
for data transfer. This patch adds support for the dmaengine API to the
tmio_mmc driver.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
---
drivers/mmc/host/tmio_mmc.c | 341 +++++++++++++++++++++++++++++++++++++++----
drivers/mmc/host/tmio_mmc.h | 11 ++
2 files changed, 320 insertions(+), 32 deletions(-)
diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
index b2b577f..7e79ba4 100644
--- a/drivers/mmc/host/tmio_mmc.c
+++ b/drivers/mmc/host/tmio_mmc.c
@@ -29,12 +29,21 @@
#include <linux/irq.h>
#include <linux/device.h>
#include <linux/delay.h>
+#include <linux/dmaengine.h>
#include <linux/mmc/host.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tmio.h>
#include "tmio_mmc.h"
+static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
+{
+#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE)
+ /* Switch DMA mode on or off - SuperH specific? */
+ sd_ctrl_write16(host, 0xd8, enable ? 2 : 0);
+#endif
+}
+
static void tmio_mmc_set_clock(struct tmio_mmc_host *host, int new_clock)
{
u32 clk = 0, clock;
@@ -131,8 +140,8 @@ tmio_mmc_start_command(struct tmio_mmc_host *host, struct mmc_command *cmd)
host->cmd = cmd;
-/* FIXME - this seems to be ok comented out but the spec suggest this bit should
- * be set when issuing app commands.
+/* FIXME - this seems to be ok commented out but the spec suggest this bit
+ * should be set when issuing app commands.
* if(cmd->flags & MMC_FLAG_ACMD)
* c |= APP_CMD;
*/
@@ -155,12 +164,12 @@ tmio_mmc_start_command(struct tmio_mmc_host *host, struct mmc_command *cmd)
return 0;
}
-/* This chip always returns (at least?) as much data as you ask for.
+/*
+ * This chip always returns (at least?) as much data as you ask for.
* I'm unsure what happens if you ask for less than a block. This should be
* looked into to ensure that a funny length read doesnt hose the controller.
- *
*/
-static inline void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
+static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
{
struct mmc_data *data = host->data;
unsigned short *buf;
@@ -180,7 +189,7 @@ static inline void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
count = data->blksz;
pr_debug("count: %08x offset: %08x flags %08x\n",
- count, host->sg_off, data->flags);
+ count, host->sg_off, data->flags);
/* Transfer the data */
if (data->flags & MMC_DATA_READ)
@@ -198,15 +207,13 @@ static inline void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
return;
}
-static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host)
+static void tmio_mmc_data_irq(struct tmio_mmc_host *host)
{
struct mmc_data *data = host->data;
struct mmc_command *stop;
- host->data = NULL;
-
if (!data) {
- pr_debug("Spurious data end IRQ\n");
+ dev_warn(&host->pdev->dev, "Spurious data end IRQ\n");
return;
}
stop = data->stop;
@@ -227,10 +234,17 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host)
* upper layers expect. For now, we do what works.
*/
- if (data->flags & MMC_DATA_READ)
- disable_mmc_irqs(host, TMIO_MASK_READOP);
- else
- disable_mmc_irqs(host, TMIO_MASK_WRITEOP);
+ if (data->flags & MMC_DATA_READ) {
+ if (!host->chan_rx)
+ disable_mmc_irqs(host, TMIO_MASK_READOP);
+ dev_dbg(&host->pdev->dev, "Complete Rx cookie %d, request %p\n",
+ host->cookie, host->mrq);
+ } else {
+ if (!host->chan_tx)
+ disable_mmc_irqs(host, TMIO_MASK_WRITEOP);
+ dev_dbg(&host->pdev->dev, "Complete Tx cookie %d, request %p\n",
+ host->cookie, host->mrq);
+ }
if (stop) {
if (stop->opcode == 12 && !stop->arg)
@@ -242,7 +256,35 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host)
tmio_mmc_finish_request(host);
}
-static inline void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
+static void tmio_mmc_isr_data_irq(struct tmio_mmc_host *host)
+{
+ struct mmc_data *data = host->data;
+
+ if (!data)
+ return;
+
+ if ((data->flags & MMC_DATA_WRITE) && host->chan_tx) {
+ /*
+ * Has all data been written out yet? Testing on SuperH showed,
+ * that in most cases the first interrupt comes already with the
+ * BUSY status bit clear, but on some operations, like mount or
+ * in the beginning of a write / sync / umount, there is one
+ * DATAEND interrupt with the BUSY bit set, in this cases
+ * waiting for one more interrupt fixes the problem.
+ */
+ if (!(sd_ctrl_read32(host, CTL_STATUS) & TMIO_STAT_CMD_BUSY)) {
+ disable_mmc_irqs(host, TMIO_STAT_DATAEND);
+ tasklet_schedule(&host->dma_complete);
+ }
+ } else if ((data->flags & MMC_DATA_READ) && host->chan_rx) {
+ disable_mmc_irqs(host, TMIO_STAT_DATAEND);
+ tasklet_schedule(&host->dma_complete);
+ } else {
+ tmio_mmc_data_irq(host);
+ }
+}
+
+static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
unsigned int stat)
{
struct mmc_command *cmd = host->cmd;
@@ -282,10 +324,16 @@ static inline void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
* If theres no data or we encountered an error, finish now.
*/
if (host->data && !cmd->error) {
- if (host->data->flags & MMC_DATA_READ)
- enable_mmc_irqs(host, TMIO_MASK_READOP);
- else
- enable_mmc_irqs(host, TMIO_MASK_WRITEOP);
+ if (host->data->flags & MMC_DATA_READ) {
+ if (!host->chan_rx)
+ enable_mmc_irqs(host, TMIO_MASK_READOP);
+ } else {
+ struct dma_chan *chan = host->chan_tx;
+ if (!chan)
+ enable_mmc_irqs(host, TMIO_MASK_WRITEOP);
+ else
+ tasklet_schedule(&host->dma_issue);
+ }
} else {
tmio_mmc_finish_request(host);
}
@@ -293,7 +341,6 @@ static inline void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
return;
}
-
static irqreturn_t tmio_mmc_irq(int irq, void *devid)
{
struct tmio_mmc_host *host = devid;
@@ -311,7 +358,7 @@ static irqreturn_t tmio_mmc_irq(int irq, void *devid)
if (!ireg) {
disable_mmc_irqs(host, status & ~irq_mask);
- pr_debug("tmio_mmc: Spurious irq, disabling! "
+ pr_warning("tmio_mmc: Spurious irq, disabling! "
"0x%08x 0x%08x 0x%08x\n", status, irq_mask, ireg);
pr_debug_status(status);
@@ -346,7 +393,7 @@ static irqreturn_t tmio_mmc_irq(int irq, void *devid)
/* Data transfer completion */
if (ireg & TMIO_STAT_DATAEND) {
ack_mmc_irqs(host, TMIO_STAT_DATAEND);
- tmio_mmc_data_irq(host);
+ tmio_mmc_isr_data_irq(host);
}
/* Check status - keep going until we've handled it all */
@@ -363,16 +410,152 @@ out:
return IRQ_HANDLED;
}
+static void tmio_dma_complete(void *arg)
+{
+ struct tmio_mmc_host *host = arg;
+
+ dev_dbg(&host->pdev->dev, "Command completed\n");
+
+ if (!host->data)
+ dev_warn(&host->pdev->dev, "NULL data in DMA completion!\n");
+ else
+ enable_mmc_irqs(host, TMIO_STAT_DATAEND);
+}
+
+static int tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
+{
+ struct scatterlist *sg = host->sg_ptr;
+ struct dma_async_tx_descriptor *desc = NULL;
+ struct dma_chan *chan = host->chan_rx;
+ int ret;
+
+ ret = dma_map_sg(&host->pdev->dev, sg, host->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) {
+ host->desc = desc;
+ desc->callback = tmio_dma_complete;
+ desc->callback_param = host;
+ host->cookie = desc->tx_submit(desc);
+ if (host->cookie < 0) {
+ host->desc = NULL;
+ ret = host->cookie;
+ } else {
+ chan->device->device_issue_pending(chan);
+ }
+ }
+ dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
+ __func__, host->sg_len, ret, host->cookie, host->mrq);
+
+ if (!host->desc) {
+ /* DMA failed, fall back to PIO */
+ if (ret >= 0)
+ ret = -EIO;
+ host->chan_rx = NULL;
+ 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->pdev->dev,
+ "DMA failed: %d, falling back to PIO\n", ret);
+ tmio_mmc_enable_dma(host, false);
+ reset(host);
+ /* Fail this request, let above layers recover */
+ host->mrq->cmd->error = ret;
+ tmio_mmc_finish_request(host);
+ }
+
+ dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
+ desc, host->cookie, host->sg_len);
+
+ return ret > 0 ? 0 : ret;
+}
+
+static int tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
+{
+ struct scatterlist *sg = host->sg_ptr;
+ struct dma_async_tx_descriptor *desc = NULL;
+ struct dma_chan *chan = host->chan_tx;
+ int ret;
+
+ ret = dma_map_sg(&host->pdev->dev, sg, host->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) {
+ host->desc = desc;
+ desc->callback = tmio_dma_complete;
+ desc->callback_param = host;
+ host->cookie = desc->tx_submit(desc);
+ if (host->cookie < 0) {
+ host->desc = NULL;
+ ret = host->cookie;
+ }
+ }
+ dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
+ __func__, host->sg_len, ret, host->cookie, host->mrq);
+
+ if (!host->desc) {
+ /* DMA failed, fall back to PIO */
+ if (ret >= 0)
+ ret = -EIO;
+ host->chan_tx = NULL;
+ 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->pdev->dev,
+ "DMA failed: %d, falling back to PIO\n", ret);
+ tmio_mmc_enable_dma(host, false);
+ reset(host);
+ /* Fail this request, let above layers recover */
+ host->mrq->cmd->error = ret;
+ tmio_mmc_finish_request(host);
+ }
+
+ dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
+ desc, host->cookie);
+
+ return ret > 0 ? 0 : ret;
+}
+
+static int tmio_mmc_start_dma(struct tmio_mmc_host *host,
+ struct mmc_data *data)
+{
+ if (data->flags & MMC_DATA_READ) {
+ if (host->chan_rx)
+ return tmio_mmc_start_dma_rx(host);
+ } else {
+ if (host->chan_tx)
+ return tmio_mmc_start_dma_tx(host);
+ }
+
+ return 0;
+}
+
static int tmio_mmc_start_data(struct tmio_mmc_host *host,
struct mmc_data *data)
{
pr_debug("setup data transfer: blocksize %08x nr_blocks %d\n",
- data->blksz, data->blocks);
+ data->blksz, data->blocks);
/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
- printk(KERN_ERR "%s: %d byte block unsupported in 4 bit mode\n",
- mmc_hostname(host->mmc), data->blksz);
+ pr_err("%s: %d byte block unsupported in 4 bit mode\n",
+ mmc_hostname(host->mmc), data->blksz);
return -EINVAL;
}
@@ -383,7 +566,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
sd_ctrl_write16(host, CTL_SD_XFER_LEN, data->blksz);
sd_ctrl_write16(host, CTL_XFER_BLK_COUNT, data->blocks);
- return 0;
+ return tmio_mmc_start_dma(host, data);
}
/* Process requests from the MMC layer */
@@ -404,7 +587,6 @@ static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
}
ret = tmio_mmc_start_command(host, mrq->cmd);
-
if (!ret)
return;
@@ -459,10 +641,10 @@ static int tmio_mmc_get_ro(struct mmc_host *mmc)
{
struct tmio_mmc_host *host = mmc_priv(mmc);
- return (sd_ctrl_read16(host, CTL_STATUS) & TMIO_STAT_WRPROTECT) ? 0 : 1;
+ return (sd_ctrl_read32(host, CTL_STATUS) & TMIO_STAT_WRPROTECT) ? 0 : 1;
}
-static struct mmc_host_ops tmio_mmc_ops = {
+static const struct mmc_host_ops tmio_mmc_ops = {
.request = tmio_mmc_request,
.set_ios = tmio_mmc_set_ios,
.get_ro = tmio_mmc_get_ro,
@@ -507,6 +689,92 @@ out:
#define tmio_mmc_resume NULL
#endif
+static void tmio_issue_tasklet_fn(unsigned long priv)
+{
+ struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
+ struct dma_chan *chan = host->chan_tx;
+
+ chan->device->device_issue_pending(chan);
+}
+
+static void tmio_tasklet_fn(unsigned long arg)
+{
+ struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
+
+ if (host->data->flags & MMC_DATA_READ)
+ dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->dma_sglen,
+ DMA_FROM_DEVICE);
+ else
+ dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->dma_sglen,
+ DMA_TO_DEVICE);
+
+ tmio_mmc_data_irq(host);
+}
+
+/* It might be necessary to make filter MFD specific */
+static bool 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 tmio_mmc_request_dma(struct tmio_mmc_host *host,
+ struct tmio_mmc_data *pdata)
+{
+ host->cookie = -EINVAL;
+ host->desc = NULL;
+
+ /* 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, filter,
+ pdata->dma->chan_priv_tx);
+ dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
+ host->chan_tx);
+
+ if (!host->chan_tx)
+ return;
+
+ host->chan_rx = dma_request_channel(mask, filter,
+ pdata->dma->chan_priv_rx);
+ dev_dbg(&host->pdev->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;
+ }
+
+ tasklet_init(&host->dma_complete, tmio_tasklet_fn, (unsigned long)host);
+ tasklet_init(&host->dma_issue, tmio_issue_tasklet_fn, (unsigned long)host);
+
+ tmio_mmc_enable_dma(host, true);
+ }
+}
+
+static void tmio_mmc_release_dma(struct tmio_mmc_host *host)
+{
+ 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->cookie = -EINVAL;
+ host->desc = NULL;
+}
+
static int __devinit tmio_mmc_probe(struct platform_device *dev)
{
struct mfd_cell *cell = (struct mfd_cell *)dev->dev.platform_data;
@@ -515,6 +783,7 @@ static int __devinit tmio_mmc_probe(struct platform_device *dev)
struct tmio_mmc_host *host;
struct mmc_host *mmc;
int ret = -EINVAL;
+ u32 irq_mask = TMIO_MASK_CMD;
if (dev->num_resources != 2)
goto out;
@@ -578,13 +847,20 @@ static int __devinit tmio_mmc_probe(struct platform_device *dev)
if (ret)
goto cell_disable;
+ /* See if we also get DMA */
+ tmio_mmc_request_dma(host, pdata);
+
mmc_add_host(mmc);
- printk(KERN_INFO "%s at 0x%08lx irq %d\n", mmc_hostname(host->mmc),
- (unsigned long)host->ctl, host->irq);
+ pr_info("%s at 0x%08lx irq %d\n", mmc_hostname(host->mmc),
+ (unsigned long)host->ctl, host->irq);
/* Unmask the IRQs we want to know about */
- enable_mmc_irqs(host, TMIO_MASK_IRQ);
+ if (!host->chan_rx)
+ irq_mask |= TMIO_MASK_READOP;
+ if (!host->chan_tx)
+ irq_mask |= TMIO_MASK_WRITEOP;
+ enable_mmc_irqs(host, irq_mask);
return 0;
@@ -609,6 +885,7 @@ static int __devexit tmio_mmc_remove(struct platform_device *dev)
if (mmc) {
struct tmio_mmc_host *host = mmc_priv(mmc);
mmc_remove_host(mmc);
+ tmio_mmc_release_dma(host);
free_irq(host->irq, host);
if (cell->disable)
cell->disable(dev);
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index dafecfb..1008d1e 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -10,6 +10,8 @@
*/
#include <linux/highmem.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
#define CTL_SD_CMD 0x00
#define CTL_ARG_REG 0x04
@@ -106,6 +108,15 @@ struct tmio_mmc_host {
unsigned int sg_off;
struct platform_device *pdev;
+
+ /* DMA support */
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_tx;
+ struct dma_async_tx_descriptor *desc;
+ unsigned int dma_sglen;
+ struct tasklet_struct dma_complete;
+ struct tasklet_struct dma_issue;
+ dma_cookie_t cookie;
};
#include <linux/io.h>
--
1.6.2.4
--
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