[PATCH v5 2/5] mmc: core: add mmc-hs400-enhanced-strobe support

[Jaehoon Chung]

On 05/23/2016 01:13 PM, Shawn Lin wrote:
> This patch introduce mmc-hs400-enhanced-strobe for platforms
> which want to enable enhanced strobe function from DT if the
> mmc host controller claims to support enhanced strobe.
> 
> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>

Tested-by: Jaehoon Chung <jh80.chung at samsung.com>

Best Regards,
Jaehoon Chung

> 
> ---
> 
> Changes in v5:
> - avoid to call hs400_enhanced+_strobe in mmc_set_initial_state
>   if no setting MMC_CAP2_HS400_ES.
> - add Adrian's ack for patch[5/5]
> 
> Changes in v4:
> - check avail_type with EXT_CSD_CARD_TYPE_HS400 instead of
>   card_type
> - check if host support 8-bit when selecting hs400es
> - some minor fix suggested by Douglas and add his review tag
> 
> Changes in v3:
> - remove helper function and shorten cap2 to MMC_CAP2_HS400_ES
> - rename callback to hs400_enhanced_strobe and make it return void
> - add enhanced_strobe in mmc_ios and pass it to hs400_enhanced_strobe
> - disable host's enhanced strobe in mmc_set_initial_state
> - remove bus checking after switching hs400es
> - add new function for hs400es timing selection
> - fix wrong judgement of mmc_card_hs400es
> 
> Changes in v2:
> - switch to HS400ES from Highspeed mode directly
> 
>  drivers/mmc/core/host.c  | 2 ++
>  include/linux/mmc/host.h | 1 +
>  2 files changed, 3 insertions(+)
> 
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index e0a3ee1..45773e4 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -289,6 +289,8 @@ int mmc_of_parse(struct mmc_host *host)
>  		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
>  	if (of_property_read_bool(np, "mmc-hs400-1_2v"))
>  		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
> +	if (of_property_read_bool(np, "mmc-hs400-enhanced-strobe"))
> +		host->caps2 |= MMC_CAP2_HS400_ES;
>  
>  	host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
>  	if (host->dsr_req && (host->dsr & ~0xffff)) {
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 85800b4..2a06fb0 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -302,6 +302,7 @@ struct mmc_host {
>  #define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
>  #define MMC_CAP2_NO_WRITE_PROTECT (1 << 18)	/* No physical write protect pin, assume that card is always read-write */
>  #define MMC_CAP2_NO_SDIO	(1 << 19)	/* Do not send SDIO commands during initialization */
> +#define MMC_CAP2_HS400_ES	(1 << 20)	/* Host supports enhanced strobe */
>  
>  	mmc_pm_flag_t		pm_caps;	/* supported pm features */
>  
>