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

From: Janakiram Sistla
Date: Fri Dec 18 2009 - 06:11:57 EST


On 12/17/09, Chaithrika U S <chaithrika@xxxxxx> 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@xxxxxx>
> ---
> 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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