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mmc: sdhci: add support for retuning mode 1 

Host Controller v3.00 can support retuning modes 1,2 or 3 depending on
the bits 46-47 of the Capabilities register. Also, the timer count for
retuning is indicated by bits 40-43 of the same register. We initialize
timer_list for retuning the first time we execute tuning procedure. This
condition is indicated by SDHCI_NEEDS_RETUNING not being set. Since
retuning mode 1 sets a limit of 4MB on the maximum data length, we set
max_blk_count appropriately. Once the tuning timer expires, we set
SDHCI_NEEDS_RETUNING flag, and if the flag is set, we execute tuning
procedure before sending the next command. We need to restore mmc_request
structure after executing retuning procedure since host->mrq is used
inside the procedure to send CMD19. We also disable and re-enable this
flag during suspend and resume respectively, as per the spec v3.00.

Tested by Zhangfei Gao with a Toshiba uhs card and general hs card,
on mmp2 in SDMA mode.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Reviewed-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Acked-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Arindam Nath 2011-05-05 12:19:07 +05:30 committed by Chris Ball
parent c3ed387762
commit cf2b5eea1e
3 changed files with 118 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

109
drivers/mmc/host/sdhci.c
View File

@ -46,6 +46,8 @@ static void sdhci_finish_data(struct sdhci_host *);
static void sdhci_send_command(struct sdhci_host *, struct mmc_command *);
static void sdhci_finish_command(struct sdhci_host *);
static int sdhci_execute_tuning(struct mmc_host *mmc);
static void sdhci_tuning_timer(unsigned long data);
static void sdhci_dumpregs(struct sdhci_host *host)
{
@ -1206,8 +1208,27 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
if (!present || host->flags & SDHCI_DEVICE_DEAD) {
host->mrq->cmd->error = -ENOMEDIUM;
tasklet_schedule(&host->finish_tasklet);
} else
} else {
u32 present_state;
present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);
/*
* Check if the re-tuning timer has already expired and there
* is no on-going data transfer. If so, we need to execute
* tuning procedure before sending command.
*/
if ((host->flags & SDHCI_NEEDS_RETUNING) &&
!(present_state & (SDHCI_DOING_WRITE | SDHCI_DOING_READ))) {
spin_unlock_irqrestore(&host->lock, flags);
sdhci_execute_tuning(mmc);
spin_lock_irqsave(&host->lock, flags);
/* Restore original mmc_request structure */
host->mrq = mrq;
}
sdhci_send_command(host, mrq->cmd);
}
mmiowb();
spin_unlock_irqrestore(&host->lock, flags);
@ -1673,6 +1694,37 @@ static int sdhci_execute_tuning(struct mmc_host *mmc)
}
out:
/*
* If this is the very first time we are here, we start the retuning
* timer. Since only during the first time, SDHCI_NEEDS_RETUNING
* flag won't be set, we check this condition before actually starting
* the timer.
*/
if (!(host->flags & SDHCI_NEEDS_RETUNING) && host->tuning_count &&
(host->tuning_mode == SDHCI_TUNING_MODE_1)) {
mod_timer(&host->tuning_timer, jiffies +
host->tuning_count * HZ);
/* Tuning mode 1 limits the maximum data length to 4MB */
mmc->max_blk_count = (4 * 1024 * 1024) / mmc->max_blk_size;
} else {
host->flags &= ~SDHCI_NEEDS_RETUNING;
/* Reload the new initial value for timer */
if (host->tuning_mode == SDHCI_TUNING_MODE_1)
mod_timer(&host->tuning_timer, jiffies +
host->tuning_count * HZ);
}
/*
* In case tuning fails, host controllers which support re-tuning can
* try tuning again at a later time, when the re-tuning timer expires.
* So for these controllers, we return 0. Since there might be other
* controllers who do not have this capability, we return error for
* them.
*/
if (err && host->tuning_count &&
host->tuning_mode == SDHCI_TUNING_MODE_1)
err = 0;
sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
spin_unlock(&host->lock);
enable_irq(host->irq);
@ -1775,6 +1827,9 @@ static void sdhci_tasklet_finish(unsigned long param)
del_timer(&host->timer);
if (host->version >= SDHCI_SPEC_300)
del_timer(&host->tuning_timer);
mrq = host->mrq;
/*
@ -1848,6 +1903,20 @@ static void sdhci_timeout_timer(unsigned long data)
spin_unlock_irqrestore(&host->lock, flags);
}
static void sdhci_tuning_timer(unsigned long data)
{
struct sdhci_host *host;
unsigned long flags;
host = (struct sdhci_host *)data;
spin_lock_irqsave(&host->lock, flags);
host->flags |= SDHCI_NEEDS_RETUNING;
spin_unlock_irqrestore(&host->lock, flags);
}
/*****************************************************************************\
* *
* Interrupt handling *
@ -2122,6 +2191,14 @@ int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
sdhci_disable_card_detection(host);
/* Disable tuning since we are suspending */
if (host->version >= SDHCI_SPEC_300 && host->tuning_count &&
host->tuning_mode == SDHCI_TUNING_MODE_1) {
host->flags &= ~SDHCI_NEEDS_RETUNING;
mod_timer(&host->tuning_timer, jiffies +
host->tuning_count * HZ);
}
ret = mmc_suspend_host(host->mmc);
if (ret)
return ret;
@ -2163,6 +2240,11 @@ int sdhci_resume_host(struct sdhci_host *host)
ret = mmc_resume_host(host->mmc);
sdhci_enable_card_detection(host);
/* Set the re-tuning expiration flag */
if ((host->version >= SDHCI_SPEC_300) && host->tuning_count &&
(host->tuning_mode == SDHCI_TUNING_MODE_1))
host->flags |= SDHCI_NEEDS_RETUNING;
return ret;
}
@ -2414,6 +2496,21 @@ int sdhci_add_host(struct sdhci_host *host)
if (caps[1] & SDHCI_DRIVER_TYPE_D)
mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
/* Initial value for re-tuning timer count */
host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
SDHCI_RETUNING_TIMER_COUNT_SHIFT;
/*
* In case Re-tuning Timer is not disabled, the actual value of
* re-tuning timer will be 2 ^ (n - 1).
*/
if (host->tuning_count)
host->tuning_count = 1 << (host->tuning_count - 1);
/* Re-tuning mode supported by the Host Controller */
host->tuning_mode = (caps[1] & SDHCI_RETUNING_MODE_MASK) >>
SDHCI_RETUNING_MODE_SHIFT;
ocr_avail = 0;
/*
* According to SD Host Controller spec v3.00, if the Host System
@ -2559,9 +2656,15 @@ int sdhci_add_host(struct sdhci_host *host)
setup_timer(&host->timer, sdhci_timeout_timer, (unsigned long)host);
if (host->version >= SDHCI_SPEC_300)
if (host->version >= SDHCI_SPEC_300) {
init_waitqueue_head(&host->buf_ready_int);
/* Initialize re-tuning timer */
init_timer(&host->tuning_timer);
host->tuning_timer.data = (unsigned long)host;
host->tuning_timer.function = sdhci_tuning_timer;
}
ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
mmc_hostname(mmc), host);
if (ret)
@ -2655,6 +2758,8 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
free_irq(host->irq, host);
del_timer_sync(&host->timer);
if (host->version >= SDHCI_SPEC_300)
del_timer_sync(&host->tuning_timer);
tasklet_kill(&host->card_tasklet);
tasklet_kill(&host->finish_tasklet);

6
drivers/mmc/host/sdhci.h
View File

@ -191,7 +191,11 @@
#define SDHCI_DRIVER_TYPE_A 0x00000010
#define SDHCI_DRIVER_TYPE_C 0x00000020
#define SDHCI_DRIVER_TYPE_D 0x00000040
#define SDHCI_USE_SDR50_TUNING 0x00002000
#define SDHCI_RETUNING_TIMER_COUNT_MASK 0x00000F00
#define SDHCI_RETUNING_TIMER_COUNT_SHIFT 8
#define SDHCI_USE_SDR50_TUNING 0x00002000
#define SDHCI_RETUNING_MODE_MASK 0x0000C000
#define SDHCI_RETUNING_MODE_SHIFT 14
#define SDHCI_CLOCK_MUL_MASK 0x00FF0000
#define SDHCI_CLOCK_MUL_SHIFT 16

6
include/linux/mmc/sdhci.h
View File

@ -112,6 +112,7 @@ struct sdhci_host {
#define SDHCI_REQ_USE_DMA (1<<2) /* Use DMA for this req. */
#define SDHCI_DEVICE_DEAD (1<<3) /* Device unresponsive */
#define SDHCI_SDR50_NEEDS_TUNING (1<<4) /* SDR50 needs tuning */
#define SDHCI_NEEDS_RETUNING (1<<5) /* Host needs retuning */
unsigned int version; /* SDHCI spec. version */
@ -152,6 +153,11 @@ struct sdhci_host {
wait_queue_head_t buf_ready_int; /* Waitqueue for Buffer Read Ready interrupt */
unsigned int tuning_done; /* Condition flag set when CMD19 succeeds */
unsigned int tuning_count; /* Timer count for re-tuning */
unsigned int tuning_mode; /* Re-tuning mode supported by host */
#define SDHCI_TUNING_MODE_1 0
struct timer_list tuning_timer; /* Timer for tuning */
unsigned long private[0] ____cacheline_aligned;
};
#endif /* __SDHCI_H */