mfd: aat2870: Add io mutex into I2C update function.

Adding io mutex into I2C update function to prevent race condition
problem.

Signed-off-by: Jin Park <jinyoungp@nvidia.com>
Change-Id: Ibff85a825a6716bfc88eea55704bbbcc565cf962
Reviewed-on: http://git-master/r/48136
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

4 files changed, 60 insertions, 64 deletions

diff --git a/drivers/mfd/aat2870-core.c b/drivers/mfd/aat2870-core.c
index 6d7e868b8b23..9deb3f34751b 100644
--- a/drivers/mfd/aat2870-core.c
+++ b/drivers/mfd/aat2870-core.c
@@ -103,53 +103,41 @@ static struct mfd_cell aat2870_devs[] = {
 	},
 };
 
-static int aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
+static int __aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
 {
-	struct i2c_client *client = aat2870->client;
-	int ret = 0;
+	int ret;
 
 	if (addr >= AAT2870_REG_NUM) {
 		dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
 		return -EINVAL;
 	}
 
-	mutex_lock(&aat2870->io_lock);
-
 	if (!aat2870->reg_cache[addr].readable) {
 		*val = aat2870->reg_cache[addr].value;
-		goto out_unlock;
+		goto out;
 	}
 
-	ret = i2c_master_send(client, &addr, 1);
+	ret = i2c_master_send(aat2870->client, &addr, 1);
 	if (ret < 0)
-		goto out_unlock;
-	if (ret != 1) {
-		ret = -EIO;
-		goto out_unlock;
-	}
+		return ret;
+	if (ret != 1)
+		return -EIO;
 
-	ret = i2c_master_recv(client, val, 1);
+	ret = i2c_master_recv(aat2870->client, val, 1);
 	if (ret < 0)
-		goto out_unlock;
-	if (ret != 1) {
-		ret = -EIO;
-		goto out_unlock;
-	}
-
-	ret = 0;
-
-out_unlock:
-	mutex_unlock(&aat2870->io_lock);
-	dev_dbg(&client->dev, "read: addr=0x%02x, val=0x%02x\n", addr, *val);
+		return ret;
+	if (ret != 1)
+		return -EIO;
 
-	return ret;
+out:
+	dev_dbg(aat2870->dev, "read: addr=0x%02x, val=0x%02x\n", addr, *val);
+	return 0;
 }
 
-static int aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
+static int __aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
 {
-	struct i2c_client *client = aat2870->client;
 	u8 msg[2];
-	int ret = 0;
+	int ret;
 
 	if (addr >= AAT2870_REG_NUM) {
 		dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
@@ -162,47 +150,62 @@ static int aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
 		return -EINVAL;
 	}
 
-	mutex_lock(&aat2870->io_lock);
-
 	msg[0] = addr;
 	msg[1] = val;
-	ret = i2c_master_send(client, msg, 2);
+	ret = i2c_master_send(aat2870->client, msg, 2);
 	if (ret < 0)
-		goto out_unlock;
-	if (ret != 2) {
-		ret = -EIO;
-		goto out_unlock;
-	}
+		return ret;
+	if (ret != 2)
+		return -EIO;
 
 	aat2870->reg_cache[addr].value = val;
-	ret = 0;
 
-out_unlock:
+	dev_dbg(aat2870->dev, "write: addr=0x%02x, val=0x%02x\n", addr, val);
+	return 0;
+}
+
+static int aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
+{
+	int ret;
+
+	mutex_lock(&aat2870->io_lock);
+	ret = __aat2870_read(aat2870, addr, val);
+	mutex_unlock(&aat2870->io_lock);
+
+	return ret;
+}
+
+static int aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
+{
+	int ret;
+
+	mutex_lock(&aat2870->io_lock);
+	ret = __aat2870_write(aat2870, addr, val);
 	mutex_unlock(&aat2870->io_lock);
-	dev_dbg(&client->dev, "write: addr=0x%02x, val=0x%02x\n", addr, val);
 
 	return ret;
 }
 
-static int aat2870_update_bits(struct aat2870_data *aat2870, u8 addr,
-			       u8 mask, u8 val)
+static int aat2870_update(struct aat2870_data *aat2870, u8 addr, u8 mask,
+			  u8 val)
 {
 	int change;
 	u8 old_val, new_val;
 	int ret;
 
-	ret = aat2870->read(aat2870, addr, &old_val);
+	mutex_lock(&aat2870->io_lock);
+
+	ret = __aat2870_read(aat2870, addr, &old_val);
 	if (ret)
-		return ret;
+		goto out_unlock;
 
 	new_val = (old_val & ~mask) | (val & mask);
 	change = old_val != new_val;
 	if (change)
-		ret = aat2870->write(aat2870, addr, new_val);
+		ret = __aat2870_write(aat2870, addr, new_val);
 
-	dev_dbg(&aat2870->client->dev,
-		"update_bits: change=%d, addr=0x%02x, old=0x%02x, new=0x%02x\n",
-		change, addr, old_val, new_val);
+out_unlock:
+	mutex_unlock(&aat2870->io_lock);
 
 	return ret;
 }
@@ -396,7 +399,7 @@ static int aat2870_i2c_probe(struct i2c_client *client,
 	aat2870->uninit = pdata->uninit;
 	aat2870->read = aat2870_read;
 	aat2870->write = aat2870_write;
-	aat2870->update_bits = aat2870_update_bits;
+	aat2870->update = aat2870_update;
 
 	mutex_init(&aat2870->io_lock);
 
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index ae25549efeef..db02ef4ca442 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -295,7 +295,7 @@ config REGULATOR_GPIO_SWITCH
 	  gpios.
 
 config REGULATOR_AAT2870
-	bool "AnalogicTech AAT2870 Regulators"
+	tristate "AnalogicTech AAT2870 Regulators"
 	depends on MFD_AAT2870_CORE
 	help
 	  If you have a AnalogicTech AAT2870 say Y to enable the
diff --git a/drivers/regulator/aat2870-regulator.c b/drivers/regulator/aat2870-regulator.c
index a119fff6eefc..ae6ddaf3e5a2 100644
--- a/drivers/regulator/aat2870-regulator.c
+++ b/drivers/regulator/aat2870-regulator.c
@@ -82,8 +82,8 @@ static int aat2870_ldo_set_voltage(struct regulator_dev *rdev,
 	if (i >= ri->desc.n_voltages)
 		return -EINVAL;
 
-	return aat2870->update_bits(aat2870, ri->voltage_addr,
-				    ri->voltage_mask, val);
+	return aat2870->update(aat2870, ri->voltage_addr, ri->voltage_mask,
+			       val);
 }
 
 static int aat2870_ldo_get_voltage(struct regulator_dev *rdev)
@@ -109,8 +109,8 @@ static int aat2870_ldo_enable(struct regulator_dev *rdev)
 	struct aat2870_regulator *ri = rdev_get_drvdata(rdev);
 	struct aat2870_data *aat2870 = dev_get_drvdata(ri->pdev->dev.parent);
 
-	return aat2870->update_bits(aat2870, ri->enable_addr,
-				    ri->enable_mask, ri->enable_mask);
+	return aat2870->update(aat2870, ri->enable_addr, ri->enable_mask,
+			       ri->enable_mask);
 }
 
 static int aat2870_ldo_disable(struct regulator_dev *rdev)
@@ -118,8 +118,7 @@ static int aat2870_ldo_disable(struct regulator_dev *rdev)
 	struct aat2870_regulator *ri = rdev_get_drvdata(rdev);
 	struct aat2870_data *aat2870 = dev_get_drvdata(ri->pdev->dev.parent);
 
-	return aat2870->update_bits(aat2870, ri->enable_addr,
-				    ri->enable_mask, 0);
+	return aat2870->update(aat2870, ri->enable_addr, ri->enable_mask, 0);
 }
 
 static int aat2870_ldo_is_enabled(struct regulator_dev *rdev)
@@ -202,15 +201,9 @@ static struct aat2870_regulator *aat2870_get_regulator(int id)
 
 static int aat2870_regulator_probe(struct platform_device *pdev)
 {
-	struct regulator_init_data *init_data = pdev->dev.platform_data;
 	struct aat2870_regulator *ri;
 	struct regulator_dev *rdev;
 
-	if (!init_data) {
-		dev_err(&pdev->dev, "No regulator init data\n");
-		return -ENXIO;
-	}
-
 	ri = aat2870_get_regulator(pdev->id);
 	if (!ri) {
 		dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
@@ -218,7 +211,8 @@ static int aat2870_regulator_probe(struct platform_device *pdev)
 	}
 	ri->pdev = pdev;
 
-	rdev = regulator_register(&ri->desc, &pdev->dev, init_data, ri);
+	rdev = regulator_register(&ri->desc, &pdev->dev,
+				  pdev->dev.platform_data, ri);
 	if (IS_ERR(rdev)) {
 		dev_err(&pdev->dev, "Failed to register regulator %s\n",
 			ri->desc.name);
diff --git a/include/linux/mfd/aat2870.h b/include/linux/mfd/aat2870.h
index d34944e784cf..89212df05622 100644
--- a/include/linux/mfd/aat2870.h
+++ b/include/linux/mfd/aat2870.h
@@ -145,8 +145,7 @@ struct aat2870_data {
 	/* i2c io funcntions */
 	int (*read)(struct aat2870_data *aat2870, u8 addr, u8 *val);
 	int (*write)(struct aat2870_data *aat2870, u8 addr, u8 val);
-	int (*update_bits)(struct aat2870_data *aat2870, u8 addr, u8 mask,
-			   u8 val);
+	int (*update)(struct aat2870_data *aat2870, u8 addr, u8 mask, u8 val);
 
 	/* for debugfs */
 	struct dentry *dentry_root;