Re: [PATCH V8] mmc: core: Add Power Off Notify Feature eMMC 4.5

[Chris Ball <cjb@laptop.org>]

Hi Girish, just trivial changes below.

Does anyone have a Tested-by: to add to the patch?

On Thu, Oct 13 2011, Girish K S wrote:
> This patch adds the support for power off notify feature, available in 
> eMMC 4.5 devices. If the the host has support for this feature, then the
> mmc core will notify it to the device by setting the POWER_OFF_NOTIFICATION
> byte in the extended csd register with a value 1(POWER_ON).
>
> For suspend mode short timeout is used, whereas for the normal poweroff long
> timeout is used.
> cc: Chris Ball <cjb@laptop.org>
> Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
> Changes in V8:
> 	Updated with review comments of Chris Ball and rebased to 
> 	chris-mmc/mmc-next branch.
> Changes in V7:
> 	Rebased to chris-mmc/mmc-next branch. merged to patches 
> 	to single patch.
> Changes in V6:
> 	Fixes checkpatch errors. The patches are generated after
> 	rebasing to chris's mmc-next branch.
> Changes in V5:
> 	This patch version fixes the problem with power off
> 	notify function, when called for the first time and
> 	card is not yet initialised.
> Changes in V4:
> 	Updated with review comments of Jeon
> Changes in V2:
> 	Adds poweroff notification handling in suspend/normal.
>
>  drivers/mmc/core/core.c  |   36 ++++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/mmc.c   |   23 +++++++++++++++++++++--
>  drivers/mmc/host/sdhci.c |    9 +++++++++
>  include/linux/mmc/card.h |    6 ++++++
>  include/linux/mmc/host.h |    6 ++++++
>  include/linux/mmc/mmc.h  |    8 ++++++++
>  6 files changed, 86 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 61d7730..db368b2 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1212,11 +1212,45 @@ static void mmc_power_up(struct mmc_host *host)
>  
>  void mmc_power_off(struct mmc_host *host)
>  {
> +	struct mmc_card *card;

struct mmc_card *card = host->card;

> +	unsigned int notify_type;
> +	unsigned int timeout;
> +	int err;
> +
> +	BUG_ON(!host);

Not necessary.

> +
>  	mmc_host_clk_hold(host);
>  
> +	card = host->card;
>  	host->ios.clock = 0;
>  	host->ios.vdd = 0;
>  
> +	if (card != NULL && mmc_card_mmc(card) &&

!= NULL is unnecessary.

> +	    (card->poweroff_notify_state == MMC_POWERED_ON)) {

Extra set of parens unnecessary.

> +
> +		if (host->power_notify_type == MMC_HOST_PW_NOTIFY_SHORT) {
> +			notify_type = EXT_CSD_POWER_OFF_SHORT;
> +			timeout = card->ext_csd.generic_cmd6_time;
> +			card->poweroff_notify_state = MMC_POWEROFF_SHORT;
> +		} else {
> +			notify_type = EXT_CSD_POWER_OFF_LONG;
> +			timeout = card->ext_csd.power_off_longtime;
> +			card->poweroff_notify_state = MMC_POWEROFF_LONG;
> +		}
> +
> +		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> +				 EXT_CSD_POWER_OFF_NOTIFICATION,
> +				 notify_type, timeout);
> +
> +		if (err && err != -EBADMSG)
> +			pr_err("Device failed to respond within %d poweroff "
> +			       "time. Forcefully powering down the device\n",
> +			       timeout);
> +
> +		/* Set the card state to no notification after the poweroff */
> +		card->poweroff_notify_state = MMC_NO_POWER_NOTIFICATION;
> +	}
> +
>  	/*
>  	 * Reset ocr mask to be the highest possible voltage supported for
>  	 * this mmc host. This value will be used at next power up.
> @@ -2208,6 +2242,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>  
>  		spin_lock_irqsave(&host->lock, flags);
>  		host->rescan_disable = 1;
> +		host->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
>  		spin_unlock_irqrestore(&host->lock, flags);
>  		cancel_delayed_work_sync(&host->detect);
>  
> @@ -2231,6 +2266,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
>  
>  		spin_lock_irqsave(&host->lock, flags);
>  		host->rescan_disable = 0;
> +		host->power_notify_type = MMC_HOST_PW_NOTIFY_LONG;
>  		spin_unlock_irqrestore(&host->lock, flags);
>  		mmc_detect_change(host, 0);
>  
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 4e869d3..f8ea938 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -458,10 +458,12 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>  	else
>  		card->erased_byte = 0x0;
>  
> -	if (card->ext_csd.rev >= 6)
> +	if (card->ext_csd.rev >= 6) {
>  		card->ext_csd.generic_cmd6_time = 10 *
>  			ext_csd[EXT_CSD_GENERIC_CMD6_TIME];
> -	else
> +		card->ext_csd.power_off_longtime = 10 *
> +			ext_csd[EXT_CSD_POWER_OFF_LONG_TIME];
> +	} else
>  		card->ext_csd.generic_cmd6_time = 0;
>  
>  out:
> @@ -846,6 +848,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>  	}
>  
>  	/*
> +	 * If the host supports the power_off_notify capability then
> +	 * set the notification byte in the ext_csd register of device
> +	 */
> +	if ((host->caps2 & MMC_CAP2_POWEROFF_NOTIFY) &&
> +	    (card->poweroff_notify_state == MMC_NO_POWER_NOTIFICATION)) {
> +		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> +				 EXT_CSD_POWER_OFF_NOTIFICATION,
> +				 EXT_CSD_POWER_ON,
> +				 card->ext_csd.generic_cmd6_time);
> +		if (err && err != -EBADMSG)
> +			goto free_card;
> +	}
> +
> +	if (!err)
> +		card->poweroff_notify_state = MMC_POWERED_ON;
> +
> +	/*
>  	 * Activate high speed (if supported)
>  	 */
>  	if ((card->ext_csd.hs_max_dtr != 0) &&
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 2cc3ffa..91fdaed 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2739,6 +2739,15 @@ int sdhci_add_host(struct sdhci_host *host)
>  	if (caps[1] & SDHCI_DRIVER_TYPE_D)
>  		mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
>  
> +	/*
> +	 * If Notify capability is enabled by the host, set notify to
> +	 * short power off notify timeout value.
> +	 */
> +	if (mmc->caps2 & MMC_CAP2_POWEROFF_NOTIFY)
> +		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_SHORT;
> +	else
> +		mmc->power_notify_type = MMC_HOST_PW_NOTIFY_NONE;
> +
>  	/* Initial value for re-tuning timer count */
>  	host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
>  			      SDHCI_RETUNING_TIMER_COUNT_SHIFT;
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 30d493c..fce88b3 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -54,6 +54,7 @@ struct mmc_ext_csd {
>  	unsigned int		part_time;		/* Units: ms */
>  	unsigned int		sa_timeout;		/* Units: 100ns */
>  	unsigned int		generic_cmd6_time;	/* Units: 10ms */
> +	unsigned int            power_off_longtime;     /* Units: ms */
>  	unsigned int		hs_max_dtr;
>  	unsigned int		sectors;
>  	unsigned int		card_type;
> @@ -209,6 +210,11 @@ struct mmc_card {
>  #define MMC_QUIRK_BLK_NO_CMD23	(1<<7)		/* Avoid CMD23 for regular multiblock */
>  #define MMC_QUIRK_BROKEN_BYTE_MODE_512 (1<<8)	/* Avoid sending 512 bytes in */
>  						/* byte mode */
> +	unsigned int    poweroff_notify_state;	/* eMMC4.5 notify feature */
> +#define MMC_NO_POWER_NOTIFICATION	0
> +#define MMC_POWERED_ON			1
> +#define MMC_POWEROFF_SHORT		2
> +#define MMC_POWEROFF_LONG		3
>  
>  	unsigned int		erase_size;	/* erase size in sectors */
>   	unsigned int		erase_shift;	/* if erase unit is power 2 */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index aed5bc7..65c47fc 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -239,8 +239,14 @@ struct mmc_host {
>  	unsigned int		caps2;		/* More host capabilities */
>  
>  #define MMC_CAP2_BOOTPART_NOACC	(1 << 0)	/* Boot partition no access */
> +#define MMC_CAP2_CACHE_CTRL	(1 << 1)	/* Allow cache control. */
> +#define MMC_CAP2_POWEROFF_NOTIFY (1 << 2)	/* Notify poweroff supported */
>  
>  	mmc_pm_flag_t		pm_caps;	/* supported pm features */
> +	unsigned int        power_notify_type;

You can align "power_notify_type" alongside "pm_caps" here.

Thanks,

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child