Re: [PATCH] sdhci: allow for eMMC 74 clock generation by controller

[Chris Ball <cjb@laptop.org>]

Hi Philip,

On Thu, Sep 23, 2010 at 08:24:32AM -0700, Philip Rakity wrote:
> From: Philip Rakity <prakity@marvell.com>
> Date: Thu, 23 Sep 2010 08:15:03 -0700
> Subject: [PATCH] sdhci: allow for initial eMMC 74 clock generation by controller
> 
> resend of patch to fit into 80 char line lengths:
> 
> snippet of code for how adaption layer should handle the call.
> 
> 
> /*
>  * eMMC spec calls for the host to send 74 clocks to the card
>  * during initialization, right after voltage stabilization.
>  * create the clocks manually right here.
>  */
> void generate_init_clocks_A0(struct sdhci_host *host, u8 power_mode)
> {
> 	struct sdhci_mmc_slot *slot = sdhci_priv(host);
> 
> 	DBG ("%s: ENTER %s: slot->power_mode = %d, ios->power_mode = %d\n",
> 	 	__func__, 
> 		mmc_hostname(host->mmc),
> 		slot->power_mode, 
> 		power_mode);
> 
> 	if (slot->power_mode == MMC_POWER_UP 
> 	&& power_mode == MMC_POWER_ON) {
> 	
> 		/* controller specific code here */
> 		/* slot->power_mode holds previous power setting */
> 	}
> 	slot->power_mode = power_mode;
> }
> 
> 
> Signed-off-by: Philip Rakity <prakity@marvell.com>
> ---
>  drivers/mmc/host/sdhci.c |    3 +++
>  drivers/mmc/host/sdhci.h |    2 ++
>  2 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6b8ca32..ba8f9a0 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1169,6 +1169,9 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  	else
>  		sdhci_set_power(host, ios->vdd);
>  
> +	if (host->ops->platform_send_init_74_clocks)
> +		host->ops->platform_send_init_74_clocks(host, ios->power_mode);
> +
>  	ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
>  
>  	if (ios->bus_width == MMC_BUS_WIDTH_8)
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 290b5a8..d73685a 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -325,6 +325,8 @@ struct sdhci_ops {
>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
> +	void (*platform_send_init_74_clocks)(struct sdhci_host *host,
> +		u8 power_mode);
>  };
>  
>  #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
> -- 

Thanks, applied to mmc-next.

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