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mmc: mxcmmc: use dmaengine API
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This switches the mxcmmc driver to use the dmaengine API. Unlike
the old one this one is always present in the tree, even if no DMA
is implemented, hence we can remove all the #ifdefs in from the driver.
The driver automatically switches to PIO mode if no DMA support or no
suitable channel is available.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Sascha Hauer authored and Chris Ball committed Mar 15, 2011
1 parent c9b2a06 commit f53fbde
Showing 1 changed file with 104 additions and 77 deletions.
181 changes: 104 additions & 77 deletions drivers/mmc/host/mxcmmc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -32,16 +32,14 @@
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/dmaengine.h>

#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/sizes.h>
#include <mach/mmc.h>

#ifdef CONFIG_ARCH_MX2
#include <mach/dma-mx1-mx2.h>
#define HAS_DMA
#endif
#include <mach/dma.h>

#define DRIVER_NAME "mxc-mmc"

Expand Down Expand Up @@ -118,7 +116,8 @@ struct mxcmci_host {
void __iomem *base;
int irq;
int detect_irq;
int dma;
struct dma_chan *dma;
struct dma_async_tx_descriptor *desc;
int do_dma;
int default_irq_mask;
int use_sdio;
Expand All @@ -129,7 +128,6 @@ struct mxcmci_host {
struct mmc_command *cmd;
struct mmc_data *data;

unsigned int dma_nents;
unsigned int datasize;
unsigned int dma_dir;

Expand All @@ -144,6 +142,11 @@ struct mxcmci_host {
spinlock_t lock;

struct regulator *vcc;

int burstlen;
int dmareq;
struct dma_slave_config dma_slave_config;
struct imx_dma_data dma_data;
};

static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
Expand Down Expand Up @@ -206,17 +209,16 @@ static void mxcmci_softreset(struct mxcmci_host *host)

writew(0xff, host->base + MMC_REG_RES_TO);
}
static int mxcmci_setup_dma(struct mmc_host *mmc);

static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
{
unsigned int nob = data->blocks;
unsigned int blksz = data->blksz;
unsigned int datasize = nob * blksz;
#ifdef HAS_DMA
struct scatterlist *sg;
int i;
int ret;
#endif
int i, nents;

if (data->flags & MMC_DATA_STREAM)
nob = 0xffff;

Expand All @@ -227,42 +229,40 @@ static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
writew(blksz, host->base + MMC_REG_BLK_LEN);
host->datasize = datasize;

#ifdef HAS_DMA
if (!mxcmci_use_dma(host))
return 0;

for_each_sg(data->sg, sg, data->sg_len, i) {
if (sg->offset & 3 || sg->length & 3) {
host->do_dma = 0;
return 0;
}
}

if (data->flags & MMC_DATA_READ) {
if (data->flags & MMC_DATA_READ)
host->dma_dir = DMA_FROM_DEVICE;
host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
data->sg_len, host->dma_dir);

ret = imx_dma_setup_sg(host->dma, data->sg, host->dma_nents,
datasize,
host->res->start + MMC_REG_BUFFER_ACCESS,
DMA_MODE_READ);
} else {
else
host->dma_dir = DMA_TO_DEVICE;
host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
data->sg_len, host->dma_dir);

ret = imx_dma_setup_sg(host->dma, data->sg, host->dma_nents,
datasize,
host->res->start + MMC_REG_BUFFER_ACCESS,
DMA_MODE_WRITE);
}
nents = dma_map_sg(host->dma->device->dev, data->sg,
data->sg_len, host->dma_dir);
if (nents != data->sg_len)
return -EINVAL;

host->desc = host->dma->device->device_prep_slave_sg(host->dma,
data->sg, data->sg_len, host->dma_dir,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

if (ret) {
dev_err(mmc_dev(host->mmc), "failed to setup DMA : %d\n", ret);
return ret;
if (!host->desc) {
dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
host->dma_dir);
host->do_dma = 0;
return 0; /* Fall back to PIO */
}
wmb();

imx_dma_enable(host->dma);
#endif /* HAS_DMA */
dmaengine_submit(host->desc);

return 0;
}

Expand Down Expand Up @@ -337,13 +337,11 @@ static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
struct mmc_data *data = host->data;
int data_error;

#ifdef HAS_DMA
if (mxcmci_use_dma(host)) {
imx_dma_disable(host->dma);
dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_nents,
dmaengine_terminate_all(host->dma);
dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
host->dma_dir);
}
#endif

if (stat & STATUS_ERR_MASK) {
dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
Expand Down Expand Up @@ -545,7 +543,6 @@ static void mxcmci_datawork(struct work_struct *work)
}
}

#ifdef HAS_DMA
static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
{
struct mmc_data *data = host->data;
Expand All @@ -568,7 +565,6 @@ static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
mxcmci_finish_request(host, host->req);
}
}
#endif /* HAS_DMA */

static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
{
Expand Down Expand Up @@ -606,12 +602,10 @@ static irqreturn_t mxcmci_irq(int irq, void *devid)
sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
spin_unlock_irqrestore(&host->lock, flags);

#ifdef HAS_DMA
if (mxcmci_use_dma(host) &&
(stat & (STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE)))
writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
host->base + MMC_REG_STATUS);
#endif

if (sdio_irq) {
writel(STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
Expand All @@ -621,14 +615,14 @@ static irqreturn_t mxcmci_irq(int irq, void *devid)
if (stat & STATUS_END_CMD_RESP)
mxcmci_cmd_done(host, stat);

#ifdef HAS_DMA
if (mxcmci_use_dma(host) &&
(stat & (STATUS_DATA_TRANS_DONE | STATUS_WRITE_OP_DONE)))
mxcmci_data_done(host, stat);
#endif

if (host->default_irq_mask &&
(stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
mmc_detect_change(host->mmc, msecs_to_jiffies(200));

return IRQ_HANDLED;
}

Expand All @@ -642,9 +636,10 @@ static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)

host->req = req;
host->cmdat &= ~CMD_DAT_CONT_INIT;
#ifdef HAS_DMA
host->do_dma = 1;
#endif

if (host->dma)
host->do_dma = 1;

if (req->data) {
error = mxcmci_setup_data(host, req->data);
if (error) {
Expand All @@ -660,6 +655,7 @@ static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
}

error = mxcmci_start_cmd(host, req->cmd, cmdat);

out:
if (error)
mxcmci_finish_request(host, req);
Expand Down Expand Up @@ -698,22 +694,46 @@ static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
prescaler, divider, clk_in, clk_ios);
}

static int mxcmci_setup_dma(struct mmc_host *mmc)
{
struct mxcmci_host *host = mmc_priv(mmc);
struct dma_slave_config *config = &host->dma_slave_config;

config->dst_addr = host->res->start + MMC_REG_BUFFER_ACCESS;
config->src_addr = host->res->start + MMC_REG_BUFFER_ACCESS;
config->dst_addr_width = 4;
config->src_addr_width = 4;
config->dst_maxburst = host->burstlen;
config->src_maxburst = host->burstlen;

return dmaengine_slave_config(host->dma, config);
}

static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct mxcmci_host *host = mmc_priv(mmc);
#ifdef HAS_DMA
unsigned int blen;
int burstlen, ret;

/*
* use burstlen of 64 in 4 bit mode (--> reg value 0)
* use burstlen of 16 in 1 bit mode (--> reg value 16)
*/
if (ios->bus_width == MMC_BUS_WIDTH_4)
blen = 0;
burstlen = 64;
else
blen = 16;
burstlen = 16;

if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
host->burstlen = burstlen;
ret = mxcmci_setup_dma(mmc);
if (ret) {
dev_err(mmc_dev(host->mmc),
"failed to config DMA channel. Falling back to PIO\n");
dma_release_channel(host->dma);
host->do_dma = 0;
}
}

imx_dma_config_burstlen(host->dma, blen);
#endif
if (ios->bus_width == MMC_BUS_WIDTH_4)
host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
else
Expand Down Expand Up @@ -794,6 +814,18 @@ static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
host->caps |= MMC_CAP_4_BIT_DATA;
}

static bool filter(struct dma_chan *chan, void *param)
{
struct mxcmci_host *host = param;

if (!imx_dma_is_general_purpose(chan))
return false;

chan->private = &host->dma_data;

return true;
}

static const struct mmc_host_ops mxcmci_ops = {
.request = mxcmci_request,
.set_ios = mxcmci_set_ios,
Expand All @@ -808,6 +840,7 @@ static int mxcmci_probe(struct platform_device *pdev)
struct mxcmci_host *host = NULL;
struct resource *iores, *r;
int ret = 0, irq;
dma_cap_mask_t mask;

printk(KERN_INFO "i.MX SDHC driver\n");

Expand Down Expand Up @@ -883,29 +916,23 @@ static int mxcmci_probe(struct platform_device *pdev)

writel(host->default_irq_mask, host->base + MMC_REG_INT_CNTR);

#ifdef HAS_DMA
host->dma = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_LOW);
if (host->dma < 0) {
dev_err(mmc_dev(host->mmc), "imx_dma_request_by_prio failed\n");
ret = -EBUSY;
goto out_clk_put;
}

r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
if (!r) {
ret = -EINVAL;
goto out_free_dma;
if (r) {
host->dmareq = r->start;
host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
host->dma_data.priority = DMA_PRIO_LOW;
host->dma_data.dma_request = host->dmareq;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
host->dma = dma_request_channel(mask, filter, host);
if (host->dma)
mmc->max_seg_size = dma_get_max_seg_size(
host->dma->device->dev);
}

ret = imx_dma_config_channel(host->dma,
IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_FIFO,
IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
r->start, 0);
if (ret) {
dev_err(mmc_dev(host->mmc), "failed to config DMA channel\n");
goto out_free_dma;
}
#endif
if (!host->dma)
dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");

INIT_WORK(&host->datawork, mxcmci_datawork);

ret = request_irq(host->irq, mxcmci_irq, 0, DRIVER_NAME, host);
Expand All @@ -928,9 +955,8 @@ static int mxcmci_probe(struct platform_device *pdev)
out_free_irq:
free_irq(host->irq, host);
out_free_dma:
#ifdef HAS_DMA
imx_dma_free(host->dma);
#endif
if (host->dma)
dma_release_channel(host->dma);
out_clk_put:
clk_disable(host->clk);
clk_put(host->clk);
Expand Down Expand Up @@ -960,9 +986,10 @@ static int mxcmci_remove(struct platform_device *pdev)

free_irq(host->irq, host);
iounmap(host->base);
#ifdef HAS_DMA
imx_dma_free(host->dma);
#endif

if (host->dma)
dma_release_channel(host->dma);

clk_disable(host->clk);
clk_put(host->clk);

Expand Down

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