linux-kernel - [PATCH 5/5] regulator: 88pm800: Add support for configuration of dual phase on BUCK1

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Message-Id: <1437070618-21330-6-git-send-email-vaibhav.hiremath@linaro.org>
Date:	Thu, 16 Jul 2015 23:46:58 +0530
From:	Vaibhav Hiremath <vaibhav.hiremath@...aro.org>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	broonie@...nel.org, lgirdwood@...il.com, sameo@...ux.intel.com,
	lee.jones@...aro.org, linux-kernel@...r.kernel.org,
	Vaibhav Hiremath <vaibhav.hiremath@...aro.org>
Subject: [PATCH 5/5] regulator: 88pm800: Add support for configuration of dual phase on BUCK1

88PM860 device supports dual phase mode on BUCK1 output.
In normal usecase, BUCK1A and BUCK1B operates independently with 3A
capacity. And they both can work as a dual phase providing 6A capacity.

This patch adds support for regulator_ops.set_current_limit() callback fn,
in turn enabling support for current min and max supply constraint on BUCK1
(and optionally on BUCK1B). Based on that driver enables dual-phase mode.

Note that, if max current supply constraint is > 3A on BUCK1(A) then driver
enables the dual-phase mode, irrespective of BUCK1B constraint.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@...aro.org>
---
 drivers/regulator/88pm800.c | 38 ++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/88pm80x.h |  3 +++
 2 files changed, 41 insertions(+)

diff --git a/drivers/regulator/88pm800.c b/drivers/regulator/88pm800.c
index e846e4c..1da18fa 100644
--- a/drivers/regulator/88pm800.c
+++ b/drivers/regulator/88pm800.c
@@ -185,6 +185,43 @@ static int pm800_get_current_limit(struct regulator_dev *rdev)
 	return info->max_ua;
 }
 
+/*
+ * 88pm860 device supports dual-phase mode on BUCK1, where BUCK1A and BUCK1B can
+ * be used together to supply 6A current.  Note that, independently, they can
+ * source 3A each.
+ *
+ * So, this function checks for max_uA for BUCK1 (only), and if it is more than
+ * 3A, then enable dual-phase mode.
+ */
+static int pm800_set_current_limit(struct regulator_dev *rdev,
+				int min_uA, int max_uA)
+{
+	struct pm800_regulators *pm800_data =
+				dev_get_drvdata(rdev_get_dev(rdev)->parent);
+	struct pm80x_chip *chip = pm800_data->chip;
+	int ret;
+
+	/* Currently only supported on 88pm860 device */
+	if (chip->type != CHIP_PM860)
+		return 0;
+
+	if (rdev->desc->id == PM800_ID_BUCK1) {
+		/* If max_uA is greater that 3A, enable dual-phase on BUCK1 */
+		if (max_uA > 3000000) {
+			ret = regmap_update_bits(chip->subchip->regmap_power,
+					PM860_BUCK1_MISC,
+					BUCK1_DUAL_PHASE_SEL,
+					BUCK1_DUAL_PHASE_SEL);
+			if (ret) {
+				dev_err(chip->dev, "failed to access registers\n");
+				return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+
 static struct regulator_ops pm800_volt_range_ops = {
 	.list_voltage		= regulator_list_voltage_linear_range,
 	.map_voltage		= regulator_map_voltage_linear_range,
@@ -194,6 +231,7 @@ static struct regulator_ops pm800_volt_range_ops = {
 	.disable		= regulator_disable_regmap,
 	.is_enabled		= regulator_is_enabled_regmap,
 	.get_current_limit	= pm800_get_current_limit,
+	.set_current_limit	= pm800_set_current_limit,
 };
 
 static struct regulator_ops pm800_volt_table_ops = {
diff --git a/include/linux/mfd/88pm80x.h b/include/linux/mfd/88pm80x.h
index a92d173..05d9bad 100644
--- a/include/linux/mfd/88pm80x.h
+++ b/include/linux/mfd/88pm80x.h
@@ -295,6 +295,9 @@ enum {
 #define PM860_BUCK4_MISC2		(0x82)
 #define PM860_BUCK4_FULL_DRV		BIT(2)
 
+#define PM860_BUCK1_MISC		(0x8E)
+#define BUCK1_DUAL_PHASE_SEL		BIT(2)
+
 struct pm80x_rtc_pdata {
 	int		vrtc;
 	int		rtc_wakeup;
-- 
1.9.1

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