Re: [PATCH 2/2] davinci: MMC: updates to suspend/resume implementation

[Janakiram Sistla <janakiram.sistla@gmail.com>]

On 12/17/09, Chaithrika U S <chaithrika@ti.com> wrote:
> Improve the suspend and resume callbacks in DaVinci MMC
> host controller driver.
[Ram] I came cross in the mailing some days back that "direct"
.suspend and .resume calls will stop being supported.Is This
true??This patch does require a migration then again.

> Tested on DA850/OMAP-L138 EVM. This testing requires patches
> which add suspend-to-RAM support to DA850/OMAP-L138 SoC[1].
>
> [1]http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
> 2009-September/016118.html
>
> Signed-off-by: Chaithrika U S <chaithrika@ti.com>
> ---
> Applies to Linus' kernel tree.
>
>  drivers/mmc/host/davinci_mmc.c |   31 +++++++++++++++++++++++++++++--
>  1 files changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
> index 25645bf..7d05cc1 100644
> --- a/drivers/mmc/host/davinci_mmc.c
> +++ b/drivers/mmc/host/davinci_mmc.c
> @@ -170,6 +170,7 @@ struct mmc_davinci_host {
>  #define DAVINCI_MMC_DATADIR_READ       1
>  #define DAVINCI_MMC_DATADIR_WRITE      2
>        unsigned char data_dir;
> +       unsigned char suspended;
>
>        /* buffer is used during PIO of one scatterlist segment, and
>         * is updated along with buffer_bytes_left.  bytes_left applies
> @@ -1300,15 +1301,41 @@ static int __exit davinci_mmcsd_remove(struct platform_device *pdev)
>  static int davinci_mmcsd_suspend(struct platform_device *pdev, pm_message_t msg)
>  {
>        struct mmc_davinci_host *host = platform_get_drvdata(pdev);
> +       int ret;
>
> -       return mmc_suspend_host(host->mmc, msg);
> +       mmc_host_enable(host->mmc);
> +       ret = mmc_suspend_host(host->mmc, msg);
> +       if (!ret) {
> +               writel(0, host->base + DAVINCI_MMCIM);
> +               mmc_davinci_reset_ctrl(host, 1);
> +               mmc_host_disable(host->mmc);
> +               clk_disable(host->clk);
> +               host->suspended = 1;
> +       } else {
> +               host->suspended = 0;
> +               mmc_host_disable(host->mmc);
> +       }
> +
> +       return ret;
>  }
>
>  static int davinci_mmcsd_resume(struct platform_device *pdev)
>  {
>        struct mmc_davinci_host *host = platform_get_drvdata(pdev);
> +       int ret;
>
> -       return mmc_resume_host(host->mmc);
> +       if (!host->suspended)
> +               return 0;
> +
> +       clk_enable(host->clk);
> +       mmc_host_enable(host->mmc);
> +
> +       mmc_davinci_reset_ctrl(host, 0);
> +       ret = mmc_resume_host(host->mmc);
> +       if (!ret)
> +               host->suspended = 0;
> +
> +       return ret;
>  }
>  #else
>  #define davinci_mmcsd_suspend  NULL
> --
> 1.5.6
>
> --
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