mfd: Add power control interface for pm8606 chip

The reference group and internal oscillator are shared by sub-devs
like led, backlight and vibrator in PM8606 chip. Now introduce a
voting mechanism to enable/disable it.

Add pm8606_osc_enable() and pm8606_osc_disable() interface and
related defines to support this. This interface will be called by
vibrator led and backlight driver.The refernce group and internal
oscillator are enabled only when at least one of it's clients holds
it on or disabled only all the clients don't use it any more based
on the above mechanism.

Signed-off-by: Jett.Zhou <jtzhou@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/drivers/mfd/88pm860x-core.c b/drivers/mfd/88pm860x-core.c
index 17dfe9bb6d27..78c3a9e1fa1e 100644
--- a/drivers/mfd/88pm860x-core.c
+++ b/drivers/mfd/88pm860x-core.c
@@ -503,6 +503,99 @@ static void device_irq_exit(struct pm860x_chip *chip)
 		free_irq(chip->core_irq, chip);
 }
 
+int pm8606_osc_enable(struct pm860x_chip *chip, unsigned short client)
+{
+	int ret = -EIO;
+	struct i2c_client *i2c = (chip->id == CHIP_PM8606) ?
+		chip->client : chip->companion;
+
+	dev_dbg(chip->dev, "%s(B): client=0x%x\n", __func__, client);
+	dev_dbg(chip->dev, "%s(B): vote=0x%x status=%d\n",
+			__func__, chip->osc_vote,
+			chip->osc_status);
+
+	mutex_lock(&chip->osc_lock);
+	/* Update voting status */
+	chip->osc_vote |= client;
+	/* If reference group is off - turn on*/
+	if (chip->osc_status != PM8606_REF_GP_OSC_ON) {
+		chip->osc_status = PM8606_REF_GP_OSC_UNKNOWN;
+		/* Enable Reference group Vsys */
+		if (pm860x_set_bits(i2c, PM8606_VSYS,
+				PM8606_VSYS_EN, PM8606_VSYS_EN))
+			goto out;
+
+		/*Enable Internal Oscillator */
+		if (pm860x_set_bits(i2c, PM8606_MISC,
+				PM8606_MISC_OSC_EN, PM8606_MISC_OSC_EN))
+			goto out;
+		/* Update status (only if writes succeed) */
+		chip->osc_status = PM8606_REF_GP_OSC_ON;
+	}
+	mutex_unlock(&chip->osc_lock);
+
+	dev_dbg(chip->dev, "%s(A): vote=0x%x status=%d ret=%d\n",
+			__func__, chip->osc_vote,
+			chip->osc_status, ret);
+	return 0;
+out:
+	mutex_unlock(&chip->osc_lock);
+	return ret;
+}
+
+int pm8606_osc_disable(struct pm860x_chip *chip, unsigned short client)
+{
+	int ret = -EIO;
+	struct i2c_client *i2c = (chip->id == CHIP_PM8606) ?
+		chip->client : chip->companion;
+
+	dev_dbg(chip->dev, "%s(B): client=0x%x\n", __func__, client);
+	dev_dbg(chip->dev, "%s(B): vote=0x%x status=%d\n",
+			__func__, chip->osc_vote,
+			chip->osc_status);
+
+	mutex_lock(&chip->osc_lock);
+	/*Update voting status */
+	chip->osc_vote &= ~(client);
+	/* If reference group is off and this is the last client to release
+	 * - turn off */
+	if ((chip->osc_status != PM8606_REF_GP_OSC_OFF) &&
+			(chip->osc_vote == REF_GP_NO_CLIENTS)) {
+		chip->osc_status = PM8606_REF_GP_OSC_UNKNOWN;
+		/* Disable Reference group Vsys */
+		if (pm860x_set_bits(i2c, PM8606_VSYS, PM8606_VSYS_EN, 0))
+			goto out;
+		/* Disable Internal Oscillator */
+		if (pm860x_set_bits(i2c, PM8606_MISC, PM8606_MISC_OSC_EN, 0))
+			goto out;
+		chip->osc_status = PM8606_REF_GP_OSC_OFF;
+	}
+	mutex_unlock(&chip->osc_lock);
+
+	dev_dbg(chip->dev, "%s(A): vote=0x%x status=%d ret=%d\n",
+			__func__, chip->osc_vote,
+			chip->osc_status, ret);
+	return 0;
+out:
+	mutex_unlock(&chip->osc_lock);
+	return ret;
+}
+
+static void __devinit device_osc_init(struct i2c_client *i2c)
+{
+	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
+
+	mutex_init(&chip->osc_lock);
+	/* init portofino reference group voting and status */
+	/* Disable Reference group Vsys */
+	pm860x_set_bits(i2c, PM8606_VSYS, PM8606_VSYS_EN, 0);
+	/* Disable Internal Oscillator */
+	pm860x_set_bits(i2c, PM8606_MISC, PM8606_MISC_OSC_EN, 0);
+
+	chip->osc_vote = REF_GP_NO_CLIENTS;
+	chip->osc_status = PM8606_REF_GP_OSC_OFF;
+}
+
 static void __devinit device_bk_init(struct pm860x_chip *chip,
 				     struct pm860x_platform_data *pdata)
 {
@@ -774,6 +867,7 @@ int __devinit pm860x_device_init(struct pm860x_chip *chip,
 
 	switch (chip->id) {
 	case CHIP_PM8606:
+		device_osc_init(chip->client);
 		device_bk_init(chip, pdata);
 		device_led_init(chip, pdata);
 		break;
@@ -785,6 +879,7 @@ int __devinit pm860x_device_init(struct pm860x_chip *chip,
 	if (chip->companion) {
 		switch (chip->id) {
 		case CHIP_PM8607:
+			device_osc_init(chip->companion);
 			device_bk_init(chip, pdata);
 			device_led_init(chip, pdata);
 			break;