Re: [RFC PATCH 1/4] mmc: core: add cap-enhanced-strobe support

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi Shawn,

On 03/03/2016 11:36 AM, Shawn Lin wrote:
> This patch introduce cap-enhanced-strobe for platforms which
> want to enable enhanced strobe function from DT if the mmc host
> controller claims to support enhanced strobe.

I don't know why need to add the capability and property.

> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> 
> ---
> 
>  Documentation/devicetree/bindings/mmc/mmc.txt | 1 +
>  drivers/mmc/core/host.c                       | 2 ++
>  include/linux/mmc/host.h                      | 6 ++++++
>  3 files changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
> index ed23b9b..51ec979 100644
> --- a/Documentation/devicetree/bindings/mmc/mmc.txt
> +++ b/Documentation/devicetree/bindings/mmc/mmc.txt
> @@ -39,6 +39,7 @@ Optional properties:
>  - cap-power-off-card: powering off the card is safe
>  - cap-mmc-hw-reset: eMMC hardware reset is supported
>  - cap-sdio-irq: enable SDIO IRQ signalling on this interface
> +- cap-enhanced-strobe: enable enhanced strobe function for emmc v5.1+
>  - full-pwr-cycle: full power cycle of the card is supported
>  - mmc-ddr-1_8v: eMMC high-speed DDR mode(1.8V I/O) is supported
>  - mmc-ddr-1_2v: eMMC high-speed DDR mode(1.2V I/O) is supported
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index 1d94607..b49d786 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -270,6 +270,8 @@ int mmc_of_parse(struct mmc_host *host)
>  		host->caps |= MMC_CAP_HW_RESET;
>  	if (of_property_read_bool(np, "cap-sdio-irq"))
>  		host->caps |= MMC_CAP_SDIO_IRQ;
> +	if (of_property_read_bool(np, "cap-enhanced-strobe"))
> +		host->caps |= MMC_CAP_ENHANCED_STROBE;
>  	if (of_property_read_bool(np, "full-pwr-cycle"))
>  		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
>  	if (of_property_read_bool(np, "keep-power-in-suspend"))
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 8dd4d29..2a292b3 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -264,6 +264,7 @@ struct mmc_host {
>  #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
>  #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
>  #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */
> +#define MMC_CAP_ENHANCED_STROBE	(1 << 20)	/* Host supports enhanced strobe */

Need to fix ordering.

>  #define MMC_CAP_CMD23		(1 << 30)	/* CMD23 supported. */
>  #define MMC_CAP_HW_RESET	(1 << 31)	/* Hardware reset */
>  
> @@ -469,6 +470,11 @@ static inline int mmc_host_uhs(struct mmc_host *host)
>  		 MMC_CAP_UHS_DDR50);
>  }
>  
> +static inline int mmc_host_enhanced_strobe(struct mmc_host *host)
> +{
> +	return host->caps & MMC_CAP_ENHANCED_STROBE;
> +}
> +
>  static inline int mmc_host_packed_wr(struct mmc_host *host)
>  {
>  	return host->caps2 & MMC_CAP2_PACKED_WR;
>