Skip to content

Commit

Permalink
mmc: mmci: implement pre_req() and post_req()
Browse files Browse the repository at this point in the history 
pre_req() runs dma_map_sg() and prepares the dma descriptor for the next
mmc data transfer. post_req() runs dma_unmap_sg.  If not calling pre_req()
before mmci_request(), mmci_request() will prepare the cache and dma just
like it did it before.  It is optional to use pre_req() and post_req()
for mmci.

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
  • Loading branch information
Per Forlin authored and Chris Ball committed Jul 20, 2011
1 parent 9782aff commit 58c7ccb
Show file tree
Hide file tree
Showing 2 changed files with 142 additions and 13 deletions.
147 changes: 134 additions & 13 deletions drivers/mmc/host/mmci.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -226,6 +226,9 @@ static void __devinit mmci_dma_setup(struct mmci_host *host)
return;
}

/* initialize pre request cookie */
host->next_data.cookie = 1;

/* Try to acquire a generic DMA engine slave channel */
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
Expand Down Expand Up @@ -335,7 +338,8 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
dir = DMA_FROM_DEVICE;
}

dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
if (!data->host_cookie)
dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);

/*
* Use of DMA with scatter-gather is impossible.
Expand All @@ -353,7 +357,8 @@ static void mmci_dma_data_error(struct mmci_host *host)
dmaengine_terminate_all(host->dma_current);
}

static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
struct mmci_host_next *next)
{
struct variant_data *variant = host->variant;
struct dma_slave_config conf = {
Expand All @@ -364,13 +369,20 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
.src_maxburst = variant->fifohalfsize >> 2, /* # of words */
.dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
};
struct mmc_data *data = host->data;
struct dma_chan *chan;
struct dma_device *device;
struct dma_async_tx_descriptor *desc;
int nr_sg;

host->dma_current = NULL;
/* Check if next job is already prepared */
if (data->host_cookie && !next &&
host->dma_current && host->dma_desc_current)
return 0;

if (!next) {
host->dma_current = NULL;
host->dma_desc_current = NULL;
}

if (data->flags & MMC_DATA_READ) {
conf.direction = DMA_FROM_DEVICE;
Expand All @@ -385,7 +397,7 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
return -EINVAL;

/* If less than or equal to the fifo size, don't bother with DMA */
if (host->size <= variant->fifosize)
if (data->blksz * data->blocks <= variant->fifosize)
return -EINVAL;

device = chan->device;
Expand All @@ -399,14 +411,38 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
if (!desc)
goto unmap_exit;

/* Okay, go for it. */
host->dma_current = chan;
if (next) {
next->dma_chan = chan;
next->dma_desc = desc;
} else {
host->dma_current = chan;
host->dma_desc_current = desc;
}

return 0;

unmap_exit:
if (!next)
dmaengine_terminate_all(chan);
dma_unmap_sg(device->dev, data->sg, data->sg_len, conf.direction);
return -ENOMEM;
}

static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
{
int ret;
struct mmc_data *data = host->data;

ret = mmci_dma_prep_data(host, host->data, NULL);
if (ret)
return ret;

/* Okay, go for it. */
dev_vdbg(mmc_dev(host->mmc),
"Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
data->sg_len, data->blksz, data->blocks, data->flags);
dmaengine_submit(desc);
dma_async_issue_pending(chan);
dmaengine_submit(host->dma_desc_current);
dma_async_issue_pending(host->dma_current);

datactrl |= MCI_DPSM_DMAENABLE;

Expand All @@ -421,14 +457,90 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
host->base + MMCIMASK0);
return 0;
}

unmap_exit:
dmaengine_terminate_all(chan);
dma_unmap_sg(device->dev, data->sg, data->sg_len, conf.direction);
return -ENOMEM;
static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
{
struct mmci_host_next *next = &host->next_data;

if (data->host_cookie && data->host_cookie != next->cookie) {
printk(KERN_WARNING "[%s] invalid cookie: data->host_cookie %d"
" host->next_data.cookie %d\n",
__func__, data->host_cookie, host->next_data.cookie);
data->host_cookie = 0;
}

if (!data->host_cookie)
return;

host->dma_desc_current = next->dma_desc;
host->dma_current = next->dma_chan;

next->dma_desc = NULL;
next->dma_chan = NULL;
}

static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
bool is_first_req)
{
struct mmci_host *host = mmc_priv(mmc);
struct mmc_data *data = mrq->data;
struct mmci_host_next *nd = &host->next_data;

if (!data)
return;

if (data->host_cookie) {
data->host_cookie = 0;
return;
}

/* if config for dma */
if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
if (mmci_dma_prep_data(host, data, nd))
data->host_cookie = 0;
else
data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
}
}

static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
int err)
{
struct mmci_host *host = mmc_priv(mmc);
struct mmc_data *data = mrq->data;
struct dma_chan *chan;
enum dma_data_direction dir;

if (!data)
return;

if (data->flags & MMC_DATA_READ) {
dir = DMA_FROM_DEVICE;
chan = host->dma_rx_channel;
} else {
dir = DMA_TO_DEVICE;
chan = host->dma_tx_channel;
}


/* if config for dma */
if (chan) {
if (err)
dmaengine_terminate_all(chan);
if (err || data->host_cookie)
dma_unmap_sg(mmc_dev(host->mmc), data->sg,
data->sg_len, dir);
mrq->data->host_cookie = 0;
}
}

#else
/* Blank functions if the DMA engine is not available */
static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
{
}
static inline void mmci_dma_setup(struct mmci_host *host)
{
}
Expand All @@ -449,6 +561,10 @@ static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datac
{
return -ENOSYS;
}

#define mmci_pre_request NULL
#define mmci_post_request NULL

#endif

static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
Expand Down Expand Up @@ -872,6 +988,9 @@ static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)

host->mrq = mrq;

if (mrq->data)
mmci_get_next_data(host, mrq->data);

if (mrq->data && mrq->data->flags & MMC_DATA_READ)
mmci_start_data(host, mrq->data);

Expand Down Expand Up @@ -986,6 +1105,8 @@ static irqreturn_t mmci_cd_irq(int irq, void *dev_id)

static const struct mmc_host_ops mmci_ops = {
.request = mmci_request,
.pre_req = mmci_pre_request,
.post_req = mmci_post_request,
.set_ios = mmci_set_ios,
.get_ro = mmci_get_ro,
.get_cd = mmci_get_cd,
Expand Down
8 changes: 8 additions & 0 deletions drivers/mmc/host/mmci.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -166,6 +166,12 @@ struct clk;
struct variant_data;
struct dma_chan;

struct mmci_host_next {
struct dma_async_tx_descriptor *dma_desc;
struct dma_chan *dma_chan;
s32 cookie;
};

struct mmci_host {
phys_addr_t phybase;
void __iomem *base;
Expand Down Expand Up @@ -203,6 +209,8 @@ struct mmci_host {
struct dma_chan *dma_current;
struct dma_chan *dma_rx_channel;
struct dma_chan *dma_tx_channel;
struct dma_async_tx_descriptor *dma_desc_current;
struct mmci_host_next next_data;

#define dma_inprogress(host) ((host)->dma_current)
#else
Expand Down

0 comments on commit 58c7ccb

Please sign in to comment.