Commit cf2b5eea authored by Arindam Nath's avatar Arindam Nath Committed by Chris Ball
Browse files

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: default avatarArindam Nath <arindam.nath@amd.com>
Reviewed-by: default avatarPhilip Rakity <prakity@marvell.com>
Tested-by: default avatarPhilip Rakity <prakity@marvell.com>
Acked-by: default avatarZhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent c3ed3877

drivers/mmc/host/sdhci.c

+107 −2
Original line number Diff line number Diff line
@@ -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);

drivers/mmc/host/sdhci.h

+5 −1
Original line number Diff line number Diff line
@@ -191,7 +191,11 @@ 
#define  SDHCI_DRIVER_TYPE_A	0x00000010

#define  SDHCI_DRIVER_TYPE_C	0x00000020

#define  SDHCI_DRIVER_TYPE_D	0x00000040

#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

include/linux/mmc/sdhci.h

+6 −0
Original line number Diff line number Diff line
@@ -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 */

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