Re: [PATCH] OMAP: HSMMC: Initialize hsmmc controller registers when resuming

[Adrian Hunter <adrian.hunter@nokia.com>]

>From a2ad80abeb9550782d4962472980e47df4055434 Mon Sep 17 00:00:00 2001
From: Kim Kyuwon <chammoru@gmail.com>
Date: Fri, 20 Feb 2009 13:10:08 +0100
Subject: [PATCH] OMAP: HSMMC: Initialize hsmmc controller registers when resuming

Most registers lose its state when the processor wakes up from sleep state.
Thus registers should be initialized, when the processor wakes up. However the
current hsmmc 'resume' function doesn't consider this issue and finally makes
deadlock. So this patch fixes this problem.

Signed-off-by: Kim Kyuwon <chammoru@gmail.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
---




Here is Kim Kyuwon's patch without the 'host is never null in suspend / resume'
assumption, and leaving the issue of SDBP for later.






 drivers/mmc/host/omap_hsmmc.c |   55 +++++++++++++++++++++++-----------------
 1 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index a631c81..1047cb5 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -56,6 +56,7 @@
 #define SDVS18			(0x5 << 9)
 #define SDVS30			(0x6 << 9)
 #define SDVS33			(0x7 << 9)
+#define SDVS_MASK		0x00000E00
 #define SDVSCLR			0xFFFFF1FF
 #define SDVSDET			0x00000400
 #define AUTOIDLE		0x1
@@ -891,6 +892,34 @@ static int omap_hsmmc_get_ro(struct mmc_host *mmc)
 	return pdata->slots[0].get_ro(host->dev, 0);
 }
 
+static void omap_hsmmc_init(struct mmc_omap_host *host)
+{
+	u32 hctl, capa, value;
+
+	/* Only MMC1 supports 3.0V */
+	if (host->id == OMAP_MMC1_DEVID) {
+		hctl = SDVS30;
+		capa = VS30 | VS18;
+	} else {
+		hctl = SDVS18;
+		capa = VS18;
+	}
+
+	value = OMAP_HSMMC_READ(host->base, HCTL) & ~SDVS_MASK;
+	OMAP_HSMMC_WRITE(host->base, HCTL, value | hctl);
+
+	value = OMAP_HSMMC_READ(host->base, CAPA);
+	OMAP_HSMMC_WRITE(host->base, CAPA, value | capa);
+
+	/* Set the controller to AUTO IDLE mode */
+	value = OMAP_HSMMC_READ(host->base, SYSCONFIG);
+	OMAP_HSMMC_WRITE(host->base, SYSCONFIG, value | AUTOIDLE);
+
+	/* Set SD bus power bit */
+	value = OMAP_HSMMC_READ(host->base, HCTL);
+	OMAP_HSMMC_WRITE(host->base, HCTL, value | SDBP);
+}
+
 static struct mmc_host_ops mmc_omap_ops = {
 	.request = omap_mmc_request,
 	.set_ios = omap_mmc_set_ios,
@@ -906,7 +935,6 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
 	struct mmc_omap_host *host = NULL;
 	struct resource *res;
 	int ret = 0, irq;
-	u32 hctl, capa;
 
 	if (pdata == NULL) {
 		dev_err(&pdev->dev, "Platform Data is missing\n");
@@ -1011,28 +1039,7 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
 	if (pdata->slots[host->slot_id].wires >= 4)
 		mmc->caps |= MMC_CAP_4_BIT_DATA;
 
-	/* Only MMC1 supports 3.0V */
-	if (host->id == OMAP_MMC1_DEVID) {
-		hctl = SDVS30;
-		capa = VS30 | VS18;
-	} else {
-		hctl = SDVS18;
-		capa = VS18;
-	}
-
-	OMAP_HSMMC_WRITE(host->base, HCTL,
-			OMAP_HSMMC_READ(host->base, HCTL) | hctl);
-
-	OMAP_HSMMC_WRITE(host->base, CAPA,
-			OMAP_HSMMC_READ(host->base, CAPA) | capa);
-
-	/* Set the controller to AUTO IDLE mode */
-	OMAP_HSMMC_WRITE(host->base, SYSCONFIG,
-			OMAP_HSMMC_READ(host->base, SYSCONFIG) | AUTOIDLE);
-
-	/* Set SD bus power bit */
-	OMAP_HSMMC_WRITE(host->base, HCTL,
-			OMAP_HSMMC_READ(host->base, HCTL) | SDBP);
+	omap_hsmmc_init(host);
 
 	/* Request IRQ for MMC operations */
 	ret = request_irq(host->irq, mmc_omap_irq, IRQF_DISABLED,
@@ -1222,6 +1229,8 @@ static int omap_mmc_resume(struct platform_device *pdev)
 			dev_dbg(mmc_dev(host->mmc),
 					"Enabling debounce clk failed\n");
 
+		omap_hsmmc_init(host);
+
 		if (host->pdata->resume) {
 			ret = host->pdata->resume(&pdev->dev, host->slot_id);
 			if (ret)
-- 
1.5.6.3