regulator: lp873x: Add support for lp873x PMIC regulators

The regulators set consists of 2 BUCKs and 2 LDOs. The output
voltages are configurable and are meant to supply power to the
main processor and other components. The ramp delay is configurable
for both BUCKs.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -321,6 +321,15 @@ config REGULATOR_LP872X
 	help
 	  This driver supports LP8720/LP8725 PMIC
 
+config REGULATOR_LP873X
+	tristate "TI LP873X Power regulators"
+	depends on MFD_LP873X && OF
+	help
+	  This driver supports LP873X voltage regulator chips. LP873X
+	  provides two step-down converters and two general-purpose LDO
+	  voltage regulators. It supports software based voltage control
+	  for different voltage domains
+
 config REGULATOR_LP8755
 	tristate "TI LP8755 High Performance PMU driver"
 	depends on I2C

drivers/regulator/Makefile

@@ -42,6 +42,7 @@ obj-$(CONFIG_REGULATOR_LM363X) += lm363x-regulator.o
 obj-$(CONFIG_REGULATOR_LP3971) += lp3971.o
 obj-$(CONFIG_REGULATOR_LP3972) += lp3972.o
 obj-$(CONFIG_REGULATOR_LP872X) += lp872x.o
+obj-$(CONFIG_REGULATOR_LP873X) += lp873x-regulator.o
 obj-$(CONFIG_REGULATOR_LP8788) += lp8788-buck.o
 obj-$(CONFIG_REGULATOR_LP8788) += lp8788-ldo.o
 obj-$(CONFIG_REGULATOR_LP8755) += lp8755.o

drivers/regulator/lp873x-regulator.c

@@ -0,0 +1,241 @@
+/*
+ * Regulator driver for LP873X PMIC
+ *
+ * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether expressed or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License version 2 for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/lp873x.h>
+
+#define LP873X_REGULATOR(_name, _id, _of, _ops, _n, _vr, _vm, _er, _em, \
+			 _delay, _lr, _nlr, _cr)			\
+	[_id] = {							\
+		.desc = {						\
+			.name			= _name,		\
+			.id			= _id,			\
+			.of_match		= of_match_ptr(_of),	\
+			.regulators_node	= of_match_ptr("regulators"),\
+			.ops			= &_ops,		\
+			.n_voltages		= _n,			\
+			.type			= REGULATOR_VOLTAGE,	\
+			.owner			= THIS_MODULE,		\
+			.vsel_reg		= _vr,			\
+			.vsel_mask		= _vm,			\
+			.enable_reg		= _er,			\
+			.enable_mask		= _em,			\
+			.ramp_delay		= _delay,		\
+			.linear_ranges		= _lr,			\
+			.n_linear_ranges	= _nlr,			\
+		},							\
+		.ctrl2_reg = _cr,					\
+	}
+
+struct lp873x_regulator {
+	struct regulator_desc desc;
+	unsigned int ctrl2_reg;
+};
+
+static const struct lp873x_regulator regulators[];
+
+static const struct regulator_linear_range buck0_buck1_ranges[] = {
+	REGULATOR_LINEAR_RANGE(0, 0x0, 0x13, 0),
+	REGULATOR_LINEAR_RANGE(700000, 0x14, 0x17, 10000),
+	REGULATOR_LINEAR_RANGE(735000, 0x18, 0x9d, 5000),
+	REGULATOR_LINEAR_RANGE(1420000, 0x9e, 0xff, 20000),
+};
+
+static const struct regulator_linear_range ldo0_ldo1_ranges[] = {
+	REGULATOR_LINEAR_RANGE(800000, 0x0, 0x19, 100000),
+};
+
+static unsigned int lp873x_buck_ramp_delay[] = {
+	30000, 15000, 10000, 7500, 3800, 1900, 940, 470
+};
+
+/* LP873X BUCK current limit */
+static const unsigned int lp873x_buck_uA[] = {
+	1500000, 2000000, 2500000, 3000000, 3500000, 4000000,
+};
+
+static int lp873x_buck_set_ramp_delay(struct regulator_dev *rdev,
+				      int ramp_delay)
+{
+	int id = rdev_get_id(rdev);
+	struct lp873x *lp873 = rdev_get_drvdata(rdev);
+	unsigned int reg;
+	int ret;
+
+	if (ramp_delay <= 470)
+		reg = 7;
+	else if (ramp_delay <= 940)
+		reg = 6;
+	else if (ramp_delay <= 1900)
+		reg = 5;
+	else if (ramp_delay <= 3800)
+		reg = 4;
+	else if (ramp_delay <= 7500)
+		reg = 3;
+	else if (ramp_delay <= 10000)
+		reg = 2;
+	else if (ramp_delay <= 15000)
+		reg = 1;
+	else
+		reg = 0;
+
+	ret = regmap_update_bits(lp873->regmap, regulators[id].ctrl2_reg,
+				 LP873X_BUCK0_CTRL_2_BUCK0_SLEW_RATE,
+				 reg << __ffs(LP873X_BUCK0_CTRL_2_BUCK0_SLEW_RATE));
+	if (ret) {
+		dev_err(lp873->dev, "SLEW RATE write failed: %d\n", ret);
+		return ret;
+	}
+
+	rdev->constraints->ramp_delay = lp873x_buck_ramp_delay[reg];
+
+	return 0;
+}
+
+static int lp873x_buck_set_current_limit(struct regulator_dev *rdev,
+					 int min_uA, int max_uA)
+{
+	int id = rdev_get_id(rdev);
+	struct lp873x *lp873 = rdev_get_drvdata(rdev);
+	int i;
+
+	for (i = ARRAY_SIZE(lp873x_buck_uA) - 1; i >= 0; i--) {
+		if (lp873x_buck_uA[i] >= min_uA &&
+		    lp873x_buck_uA[i] <= max_uA)
+			return regmap_update_bits(lp873->regmap,
+						  regulators[id].ctrl2_reg,
+						  LP873X_BUCK0_CTRL_2_BUCK0_ILIM,
+						  i << __ffs(LP873X_BUCK0_CTRL_2_BUCK0_ILIM));
+	}
+
+	return -EINVAL;
+}
+
+static int lp873x_buck_get_current_limit(struct regulator_dev *rdev)
+{
+	int id = rdev_get_id(rdev);
+	struct lp873x *lp873 = rdev_get_drvdata(rdev);
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(lp873->regmap, regulators[id].ctrl2_reg, &val);
+	if (ret)
+		return ret;
+
+	val = (val & LP873X_BUCK0_CTRL_2_BUCK0_ILIM) >>
+	       __ffs(LP873X_BUCK0_CTRL_2_BUCK0_ILIM);
+
+	return (val < ARRAY_SIZE(lp873x_buck_uA)) ?
+			lp873x_buck_uA[val] : -EINVAL;
+}
+
+/* Operations permitted on BUCK0, BUCK1 */
+static struct regulator_ops lp873x_buck01_ops = {
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.map_voltage		= regulator_map_voltage_linear_range,
+	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
+	.set_ramp_delay		= lp873x_buck_set_ramp_delay,
+	.set_current_limit	= lp873x_buck_set_current_limit,
+	.get_current_limit	= lp873x_buck_get_current_limit,
+};
+
+/* Operations permitted on LDO0 and LDO1 */
+static struct regulator_ops lp873x_ldo01_ops = {
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.map_voltage		= regulator_map_voltage_linear_range,
+};
+
+static const struct lp873x_regulator regulators[] = {
+	LP873X_REGULATOR("BUCK0", LP873X_BUCK_0, "buck0", lp873x_buck01_ops,
+			 256, LP873X_REG_BUCK0_VOUT,
+			 LP873X_BUCK0_VOUT_BUCK0_VSET, LP873X_REG_BUCK0_CTRL_1,
+			 LP873X_BUCK0_CTRL_1_BUCK0_EN, 10000,
+			 buck0_buck1_ranges, 4, LP873X_REG_BUCK0_CTRL_2),
+	LP873X_REGULATOR("BUCK1", LP873X_BUCK_1, "buck1", lp873x_buck01_ops,
+			 256, LP873X_REG_BUCK1_VOUT,
+			 LP873X_BUCK1_VOUT_BUCK1_VSET, LP873X_REG_BUCK1_CTRL_1,
+			 LP873X_BUCK1_CTRL_1_BUCK1_EN, 10000,
+			 buck0_buck1_ranges, 4, LP873X_REG_BUCK1_CTRL_2),
+	LP873X_REGULATOR("LDO0", LP873X_LDO_0, "ldo0", lp873x_ldo01_ops, 26,
+			 LP873X_REG_LDO0_VOUT, LP873X_LDO0_VOUT_LDO0_VSET,
+			 LP873X_REG_LDO0_CTRL,
+			 LP873X_LDO0_CTRL_LDO0_EN, 0, ldo0_ldo1_ranges, 1,
+			 0xFF),
+	LP873X_REGULATOR("LDO1", LP873X_LDO_1, "ldo1", lp873x_ldo01_ops, 26,
+			 LP873X_REG_LDO1_VOUT, LP873X_LDO1_VOUT_LDO1_VSET,
+			 LP873X_REG_LDO1_CTRL,
+			 LP873X_LDO1_CTRL_LDO1_EN, 0, ldo0_ldo1_ranges, 1,
+			 0xFF),
+};
+
+static int lp873x_regulator_probe(struct platform_device *pdev)
+{
+	struct lp873x *lp873 = dev_get_drvdata(pdev->dev.parent);
+	struct regulator_config config = { };
+	struct regulator_dev *rdev;
+	int i;
+
+	platform_set_drvdata(pdev, lp873);
+
+	config.dev = &pdev->dev;
+	config.dev->of_node = lp873->dev->of_node;
+	config.driver_data = lp873;
+	config.regmap = lp873->regmap;
+
+	for (i = 0; i < ARRAY_SIZE(regulators); i++) {
+		rdev = devm_regulator_register(&pdev->dev, &regulators[i].desc,
+					       &config);
+		if (IS_ERR(rdev)) {
+			dev_err(lp873->dev, "failed to register %s regulator\n",
+				pdev->name);
+			return PTR_ERR(rdev);
+		}
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id lp873x_regulator_id_table[] = {
+	{ "lp873x-regulator", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, lp873x_regulator_id_table);
+
+static struct platform_driver lp873x_regulator_driver = {
+	.driver = {
+		.name = "lp873x-pmic",
+	},
+	.probe = lp873x_regulator_probe,
+	.id_table = lp873x_regulator_id_table,
+};
+module_platform_driver(lp873x_regulator_driver);
+
+MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
+MODULE_DESCRIPTION("LP873X voltage regulator driver");
+MODULE_ALIAS("platform:lp873x-pmic");
+MODULE_LICENSE("GPL v2");