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mmc: add DMA support to tmio_mmc driver, when used on SuperH 

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@gmx.de>
Acked-by: Ian Molton <ian@mnementh.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Guennadi Liakhovetski 2010-05-19 18:34:22 +00:00 committed by Paul Mundt
parent 056676dabd
commit 311f3ac768
3 changed files with 348 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/mfd/Kconfig
View File

@ -49,6 +49,7 @@ config MFD_SH_MOBILE_SDHI
bool "Support for SuperH Mobile SDHI"
depends on SUPERH || ARCH_SHMOBILE
select MFD_CORE
select TMIO_MMC_DMA
---help---
This driver supports the SDHI hardware block found in many
SuperH Mobile SoCs.
@ -162,6 +163,11 @@ config MFD_TMIO
bool
default n
config TMIO_MMC_DMA
bool
select DMA_ENGINE
select DMADEVICES
config MFD_T7L66XB
bool "Support Toshiba T7L66XB"
depends on ARM && HAVE_CLK

359
drivers/mmc/host/tmio_mmc.c
View File

@ -29,6 +29,7 @@
#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>
@ -131,8 +132,8 @@ 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 +156,12 @@ 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 +181,7 @@ 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)
@ -198,7 +199,7 @@ 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_do_data_irq(struct tmio_mmc_host *host)
{
struct mmc_data *data = host->data;
struct mmc_command *stop;
@ -206,7 +207,7 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host)
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;
@ -219,7 +220,8 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host)
pr_debug("Completed data request\n");
/*FIXME - other drivers allow an optional stop command of any given type
/*
* FIXME: other drivers allow an optional stop command of any given type
* which we dont do, as the chip can auto generate them.
* Perhaps we can be smarter about when to use auto CMD12 and
* only issue the auto request when we know this is the desired
@ -227,10 +229,17 @@ 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 request %p\n",
host->mrq);
} else {
if (!host->chan_tx)
disable_mmc_irqs(host, TMIO_MASK_WRITEOP);
dev_dbg(&host->pdev->dev, "Complete Tx request %p\n",
host->mrq);
}
if (stop) {
if (stop->opcode == 12 && !stop->arg)
@ -242,7 +251,35 @@ 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_data_irq(struct tmio_mmc_host *host)
{
struct mmc_data *data = host->data;
if (!data)
return;
if (host->chan_tx && (data->flags & MMC_DATA_WRITE)) {
/*
* 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 (host->chan_rx && (data->flags & MMC_DATA_READ)) {
disable_mmc_irqs(host, TMIO_STAT_DATAEND);
tasklet_schedule(&host->dma_complete);
} else {
tmio_mmc_do_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 +319,16 @@ 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 +336,6 @@ 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 +353,7 @@ 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);
@ -363,16 +405,265 @@ out:
return IRQ_HANDLED;
}
#ifdef CONFIG_TMIO_MMC_DMA
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_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 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_do_data_irq(host);
}
/* It might be necessary to make filter MFD specific */
static bool tmio_mmc_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, tmio_mmc_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, tmio_mmc_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;
}
#else
static int tmio_mmc_start_dma(struct tmio_mmc_host *host,
struct mmc_data *data)
{
return 0;
}
static void tmio_mmc_request_dma(struct tmio_mmc_host *host,
struct tmio_mmc_data *pdata)
{
host->chan_tx = NULL;
host->chan_rx = NULL;
}
static void tmio_mmc_release_dma(struct tmio_mmc_host *host)
{
}
#endif
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 +674,7 @@ 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 +695,6 @@ 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 +749,10 @@ 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,
@ -515,6 +805,7 @@ 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 +869,20 @@ 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 +907,7 @@ 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);

13
drivers/mmc/host/tmio_mmc.h
View File

@ -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 +108,17 @@ 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 tasklet_struct dma_complete;
struct tasklet_struct dma_issue;
#ifdef CONFIG_TMIO_MMC_DMA
struct dma_async_tx_descriptor *desc;
unsigned int dma_sglen;
dma_cookie_t cookie;
#endif
};
#include <linux/io.h>