[PATCH 2/6] mfd: 88pm800: Add init time initial configuration support

[vaibhav.hiremath@linaro.org (Vaibhav Hiremath)]

This patch adds init time configuration of 88PM800/805 and
88PM860. It includes,

  - Enable BUCK clock gating in low power mode
  - Full mode support for BUCK2 and 4
  - Enable voltage change (LPF, DVC) in PMIC

Note that both 88PM800 and 88PM860 do share common configurations,
but since I can not validate the configuration on 88PM800,
restricting myself only to 88PM860.
If anyone can validate on 88PM800, we can move common code accordingly.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
---
 drivers/mfd/88pm800.c       | 64 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/88pm80x.h | 13 +++++++++
 2 files changed, 77 insertions(+)

diff --git a/drivers/mfd/88pm800.c b/drivers/mfd/88pm800.c
index 95c8ad4..80a1bc1 100644
--- a/drivers/mfd/88pm800.c
+++ b/drivers/mfd/88pm800.c
@@ -521,6 +521,63 @@ out:
 	return ret;
 }
 
+static int pm800_init_config(struct pm80x_chip *chip, struct device_node *np)
+{
+	int ret;
+	unsigned int val;
+
+	switch (chip->type) {
+	case CHIP_PM800:
+	case CHIP_PM805:
+		break;
+	case CHIP_PM860:
+		/* Enable LDO and BUCK clock gating in low power mode */
+		ret = regmap_update_bits(chip->regmap, PM800_LOW_POWER_CONFIG3,
+					PM800_LDOBK_FREEZE, PM800_LDOBK_FREEZE);
+		if (ret)
+			goto error;
+
+		/* Enable voltage change in pmic, POWER_HOLD = 1 */
+		ret = regmap_update_bits(chip->regmap, PM800_WAKEUP1,
+					PM800_PWR_HOLD_EN, PM800_PWR_HOLD_EN);
+		if (ret)
+			goto error;
+
+		/*
+		 * Set buck2 and buck4 driver selection to be full.
+		 * The default value is 0, for full drive support
+		 * it should be set to 1.
+		 * In A1 version it will be set to 1 by default.
+		 * To be on safer side, set it explicitly
+		 */
+		ret = regmap_update_bits(chip->subchip->regmap_power,
+					PM860_BUCK2_MISC2,
+					PM860_BUCK2_FULL_DRV,
+					PM860_BUCK2_FULL_DRV);
+		if (ret)
+			goto error;
+
+		ret = regmap_update_bits(chip->subchip->regmap_power,
+					PM860_BUCK4_MISC2,
+					PM860_BUCK4_FULL_DRV,
+					PM860_BUCK4_FULL_DRV);
+		if (ret)
+			goto error;
+
+
+		break;
+	default:
+		dev_err(chip->dev, "Unknown device type: %d\n", chip->type);
+		break;
+	}
+
+	return 0;
+
+error:
+	dev_err(chip->dev, "failed to access registers\n");
+	return ret;
+}
+
 static int pm800_probe(struct i2c_client *client,
 				 const struct i2c_device_id *id)
 {
@@ -585,6 +642,13 @@ static int pm800_probe(struct i2c_client *client,
 	if (pdata->plat_config)
 		pdata->plat_config(chip, pdata);
 
+	/* common register configurations , init time only */
+	ret = pm800_init_config(chip, np);
+	if (ret) {
+		dev_err(chip->dev, "Failed to configure 88pm800 devices\n");
+		goto err_device_init;
+	}
+
 	return 0;
 
 err_device_init:
diff --git a/include/linux/mfd/88pm80x.h b/include/linux/mfd/88pm80x.h
index 2e25fb1..2ef62af 100644
--- a/include/linux/mfd/88pm80x.h
+++ b/include/linux/mfd/88pm80x.h
@@ -74,6 +74,7 @@ enum {
 
 /* Wakeup Registers */
 #define PM800_WAKEUP1			(0x0D)
+#define PM800_PWR_HOLD_EN		BIT(7)
 
 #define PM800_WAKEUP2			(0x0E)
 #define PM800_WAKEUP2_INV_INT		BIT(0)
@@ -87,7 +88,10 @@ enum {
 /* Referance and low power registers */
 #define PM800_LOW_POWER1		(0x20)
 #define PM800_LOW_POWER2		(0x21)
+
 #define PM800_LOW_POWER_CONFIG3		(0x22)
+#define PM800_LDOBK_FREEZE		BIT(7)
+
 #define PM800_LOW_POWER_CONFIG4		(0x23)
 
 /* GPIO register */
@@ -279,6 +283,15 @@ enum {
 #define PM805_EARPHONE_SETTING		(0x29)
 #define PM805_AUTO_SEQ_SETTING		(0x2A)
 
+
+/* 88PM860 Registers */
+
+#define PM860_BUCK2_MISC2		(0x7C)
+#define PM860_BUCK2_FULL_DRV		BIT(2)
+
+#define PM860_BUCK4_MISC2		(0x82)
+#define PM860_BUCK4_FULL_DRV		BIT(2)
+
 struct pm80x_rtc_pdata {
 	int		vrtc;
 	int		rtc_wakeup;
-- 
1.9.1