[PATCH v2 2/2] davinci: MMC: updates to suspend/resume implementation

[Chaithrika U S <chaithrika@ti.com>]

Improve the suspend and resume callbacks in DaVinci MMC
host controller driver.

Tested on DA850/OMAP-L138 EVM. This testing requires patches
which add suspen-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 |   51 +++++++++++++++++++++++++++++++++------
 1 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
index 25645bf..d60f648 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
@@ -1297,32 +1298,66 @@ static int __exit davinci_mmcsd_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM
-static int davinci_mmcsd_suspend(struct platform_device *pdev, pm_message_t msg)
+static int davinci_mmcsd_suspend(struct device *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev);
 	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
+	struct pm_message msg = { PM_EVENT_SUSPEND };
+	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)
+static int davinci_mmcsd_resume(struct device *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev);
 	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;
 }
+
+static struct dev_pm_ops davinci_mmcsd_pm = {
+	.suspend        = davinci_mmcsd_suspend,
+	.resume         = davinci_mmcsd_resume,
+};
+
+#define davinci_mmcsd_pm_ops (&davinci_mmcsd_pm)
 #else
-#define davinci_mmcsd_suspend	NULL
-#define davinci_mmcsd_resume	NULL
+#define davinci_mmcsd_pm_ops NULL
 #endif
 
 static struct platform_driver davinci_mmcsd_driver = {
 	.driver		= {
 		.name	= "davinci_mmc",
 		.owner	= THIS_MODULE,
+		.pm	= davinci_mmcsd_pm_ops,
 	},
 	.remove		= __exit_p(davinci_mmcsd_remove),
-	.suspend	= davinci_mmcsd_suspend,
-	.resume		= davinci_mmcsd_resume,
 };
 
 static int __init davinci_mmcsd_init(void)
-- 
1.5.6