mtd: OneNAND: OMAP2/3: prevent regulator sleeping while OneNAND is in use

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=9ac4e613a88d7f6a7a9651d863e9c8f63b582718
Commit:     9ac4e613a88d7f6a7a9651d863e9c8f63b582718
Parent:     cf24dc85ff29a41abd8e73730e5feb22b2666bd3
Author:     Adrian Hunter <adrian.hunter at nokia.com>
AuthorDate: Fri Feb 19 15:39:53 2010 +0100
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Thu Jan 6 15:34:34 2011 +0000

    mtd: OneNAND: OMAP2/3: prevent regulator sleeping while OneNAND is in use
    
    Prevent OneNAND's voltage regulator from going to sleep while
    OneNAND is in use, by explicitly enabling and disabling the
    regulator as appropriate.
    
    Signed-off-by: Adrian Hunter <adrian.hunter at nokia.com>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 arch/arm/plat-omap/include/plat/onenand.h |    1 +
 drivers/mtd/onenand/omap2.c               |   41 ++++++++++++++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/onenand.h b/arch/arm/plat-omap/include/plat/onenand.h
index 72f433d..affe87e 100644
--- a/arch/arm/plat-omap/include/plat/onenand.h
+++ b/arch/arm/plat-omap/include/plat/onenand.h
@@ -23,6 +23,7 @@ struct omap_onenand_platform_data {
 	int                     (*onenand_setup)(void __iomem *, int freq);
 	int			dma_channel;
 	u8			flags;
+	u8			regulator_can_sleep;
 };
 
 #define ONENAND_MAX_PARTITIONS 8
diff --git a/drivers/mtd/onenand/omap2.c b/drivers/mtd/onenand/omap2.c
index 324402f..1a07bfc 100644
--- a/drivers/mtd/onenand/omap2.c
+++ b/drivers/mtd/onenand/omap2.c
@@ -35,6 +35,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/regulator/consumer.h>
 
 #include <asm/mach/flash.h>
 #include <plat/gpmc.h>
@@ -63,6 +64,7 @@ struct omap2_onenand {
 	int dma_channel;
 	int freq;
 	int (*setup)(void __iomem *base, int freq);
+	struct regulator *regulator;
 };
 
 #ifdef CONFIG_MTD_PARTITIONS
@@ -601,6 +603,30 @@ static void omap2_onenand_shutdown(struct platform_device *pdev)
 	memset((__force void *)c->onenand.base, 0, ONENAND_BUFRAM_SIZE);
 }
 
+static int omap2_onenand_enable(struct mtd_info *mtd)
+{
+	int ret;
+	struct omap2_onenand *c = container_of(mtd, struct omap2_onenand, mtd);
+
+	ret = regulator_enable(c->regulator);
+	if (ret != 0)
+		dev_err(&c->pdev->dev, "cant enable regulator\n");
+
+	return ret;
+}
+
+static int omap2_onenand_disable(struct mtd_info *mtd)
+{
+	int ret;
+	struct omap2_onenand *c = container_of(mtd, struct omap2_onenand, mtd);
+
+	ret = regulator_disable(c->regulator);
+	if (ret != 0)
+		dev_err(&c->pdev->dev, "cant disable regulator\n");
+
+	return ret;
+}
+
 static int __devinit omap2_onenand_probe(struct platform_device *pdev)
 {
 	struct omap_onenand_platform_data *pdata;
@@ -715,8 +741,18 @@ static int __devinit omap2_onenand_probe(struct platform_device *pdev)
 		}
 	}
 
+	if (pdata->regulator_can_sleep) {
+		c->regulator = regulator_get(&pdev->dev, "vonenand");
+		if (IS_ERR(c->regulator)) {
+			dev_err(&pdev->dev,  "Failed to get regulator\n");
+			goto err_release_dma;
+		}
+		c->onenand.enable = omap2_onenand_enable;
+		c->onenand.disable = omap2_onenand_disable;
+	}
+
 	if ((r = onenand_scan(&c->mtd, 1)) < 0)
-		goto err_release_dma;
+		goto err_release_regulator;
 
 	switch ((c->onenand.version_id >> 4) & 0xf) {
 	case 0:
@@ -751,6 +787,8 @@ static int __devinit omap2_onenand_probe(struct platform_device *pdev)
 
 err_release_onenand:
 	onenand_release(&c->mtd);
+err_release_regulator:
+	regulator_put(c->regulator);
 err_release_dma:
 	if (c->dma_channel != -1)
 		omap_free_dma(c->dma_channel);
@@ -777,6 +815,7 @@ static int __devexit omap2_onenand_remove(struct platform_device *pdev)
 	struct omap2_onenand *c = dev_get_drvdata(&pdev->dev);
 
 	onenand_release(&c->mtd);
+	regulator_put(c->regulator);
 	if (c->dma_channel != -1)
 		omap_free_dma(c->dma_channel);
 	omap2_onenand_shutdown(pdev);