Hi,
On Thu, Jul 28 2011, Ido Yariv wrote:
> Some devices connected to the MMC bus are power controlled by external
> means. For instance, an SDIO device may be powered down/up by an
> external gpio line.
>
> In order to avoid toggling power from within the MMC host driver, add a
> set_power callback function, which will be called by set_ios upon
> powering down/up.
>
> Signed-off-by: Ido Yariv <ido@xxxxxxxxxx>
Acked-by: Chris Ball <cjb@xxxxxxxxxx>
> CC: Chris Ball <cjb@xxxxxxxxxx>
> ---
> arch/arm/mach-davinci/include/mach/mmc.h | 3 +++
> drivers/mmc/host/davinci_mmc.c | 13 +++++++++++++
> 2 files changed, 16 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-davinci/include/mach/mmc.h b/arch/arm/mach-davinci/include/mach/mmc.h
> index d4f1e96..5ba6b22 100644
> --- a/arch/arm/mach-davinci/include/mach/mmc.h
> +++ b/arch/arm/mach-davinci/include/mach/mmc.h
> @@ -12,6 +12,9 @@ struct davinci_mmc_config {
> /* get_cd()/get_wp() may sleep */
> int (*get_cd)(int module);
> int (*get_ro)(int module);
> +
> + void (*set_power)(int module, bool on);
> +
> /* wires == 0 is equivalent to wires == 4 (4-bit parallel) */
> u8 wires;
>
> diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
> index 0076c74..64a8325 100644
> --- a/drivers/mmc/host/davinci_mmc.c
> +++ b/drivers/mmc/host/davinci_mmc.c
> @@ -807,12 +807,25 @@ static void calculate_clk_divider(struct mmc_host *mmc, struct mmc_ios *ios)
> static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> {
> struct mmc_davinci_host *host = mmc_priv(mmc);
> + struct platform_device *pdev = to_platform_device(mmc->parent);
> + struct davinci_mmc_config *config = pdev->dev.platform_data;
>
> dev_dbg(mmc_dev(host->mmc),
> "clock %dHz busmode %d powermode %d Vdd %04x\n",
> ios->clock, ios->bus_mode, ios->power_mode,
> ios->vdd);
>
> + switch (ios->power_mode) {
> + case MMC_POWER_OFF:
> + if (config && config->set_power)
> + config->set_power(pdev->id, false);
> + break;
> + case MMC_POWER_UP:
> + if (config && config->set_power)
> + config->set_power(pdev->id, true);
> + break;
> + }
> +
> switch (ios->bus_width) {
> case MMC_BUS_WIDTH_8:
> dev_dbg(mmc_dev(host->mmc), "Enabling 8 bit mode\n");
--
Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
One Laptop Per Child
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