[PATCH 3/5] staging: drivers: regulator: Add MAX77541 Regulator Support

[Okan Sahin <okan.sahin@analog.com>]

This patch adds regulator driver for both MAX77541 and MAX77540.
The MAX77541 is a high-efficiency step-down converter
with two 3A switching phases for single-cell Li+ battery and 5VDC systems.

The MAX77540 is a high-efficiency step-down converter
with two 3A switching phases.

Signed-off-by: Okan Sahin <okan.sahin@analog.com>
---
 MAINTAINERS                            |   1 +
 drivers/regulator/Kconfig              |   9 ++
 drivers/regulator/Makefile             |   1 +
 drivers/regulator/max77541-regulator.c | 181 +++++++++++++++++++++++++
 4 files changed, 192 insertions(+)
 create mode 100644 drivers/regulator/max77541-regulator.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 22f5a9c490e3..5704ed5afce3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12503,6 +12503,7 @@ L:	linux-kernel@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/mfd/adi,max77541.yaml
 F:	drivers/mfd/max77541.c
+F:	drivers/regulator/max77541-regulator.c
 F:	include/linux/mfd/max77541.h
 
 MAXIM MAX77650 PMIC MFD DRIVER
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 070e4403c6c2..1e416c195af9 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -556,6 +556,15 @@ config REGULATOR_MAX597X
 	  The MAX5970/5978 is a smart switch with no output regulation, but
 	  fault protection and voltage and current monitoring capabilities.
 
+config REGULATOR_MAX77541
+	tristate "Analog Devices MAX77541/77540 Regulator"
+	depends on MFD_MAX77541
+	help
+	  This driver controls a Analog Devices MAX77541/77540 regulators
+	  via I2C bus. Both MAX77540 and MAX77541 are dual-phase
+	  high-efficiency buck converter. Say Y here to
+	  enable the regulator driver.
+
 config REGULATOR_MAX77620
 	tristate "Maxim 77620/MAX20024 voltage regulator"
 	depends on MFD_MAX77620 || COMPILE_TEST
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 5962307e1130..c19efc7cfbef 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_REGULATOR_LTC3676) += ltc3676.o
 obj-$(CONFIG_REGULATOR_MAX14577) += max14577-regulator.o
 obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
 obj-$(CONFIG_REGULATOR_MAX597X) += max597x-regulator.o
+obj-$(CONFIG_REGULATOR_MAX77541) += max77541-regulator.o
 obj-$(CONFIG_REGULATOR_MAX77620) += max77620-regulator.o
 obj-$(CONFIG_REGULATOR_MAX77650) += max77650-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8649)	+= max8649.o
diff --git a/drivers/regulator/max77541-regulator.c b/drivers/regulator/max77541-regulator.c
new file mode 100644
index 000000000000..9204b15f8eed
--- /dev/null
+++ b/drivers/regulator/max77541-regulator.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 Analog Devices, Inc.
+ * ADI Regulator driver for the MAX77540 and MAX77541
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/mfd/max77541.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+static const struct regulator_ops max77541_buck_ops = {
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.is_enabled		= regulator_is_enabled_regmap,
+	.list_voltage		= regulator_list_voltage_pickable_linear_range,
+	.get_voltage_sel	= regulator_get_voltage_sel_pickable_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_pickable_regmap,
+};
+
+static const struct linear_range max77540_buck_ranges[] = {
+	/* Ranges when VOLT_SEL bits are 0x00 */
+	REGULATOR_LINEAR_RANGE(500000, 0x00, 0x8B, 5000),
+	REGULATOR_LINEAR_RANGE(1200000, 0x8C, 0xFF, 0),
+	/* Ranges when VOLT_SEL bits are 0x40 */
+	REGULATOR_LINEAR_RANGE(1200000, 0x00, 0x8B, 10000),
+	REGULATOR_LINEAR_RANGE(2400000, 0x8C, 0xFF, 0),
+	/* Ranges when VOLT_SEL bits are  0x80 */
+	REGULATOR_LINEAR_RANGE(2000000, 0x00, 0x9F, 20000),
+	REGULATOR_LINEAR_RANGE(5200000, 0xA0, 0xFF, 0),
+};
+
+static const struct linear_range max77541_buck_ranges[] = {
+	/* Ranges when VOLT_SEL bits are 0x00 */
+	REGULATOR_LINEAR_RANGE(300000, 0x00, 0xB3, 5000),
+	REGULATOR_LINEAR_RANGE(1200000, 0xB4, 0xFF, 0),
+	/* Ranges when VOLT_SEL bits are 0x40 */
+	REGULATOR_LINEAR_RANGE(1200000, 0x00, 0x8B, 10000),
+	REGULATOR_LINEAR_RANGE(2400000, 0x8C, 0xFF, 0),
+	/* Ranges when VOLT_SEL bits are  0x80 */
+	REGULATOR_LINEAR_RANGE(2000000, 0x00, 0x9F, 20000),
+	REGULATOR_LINEAR_RANGE(5200000, 0xA0, 0xFF, 0),
+};
+
+static const unsigned int max77541_buck_volt_range_sel[] = {
+	0x00, 0x00, 0x40, 0x40, 0x80, 0x80
+};
+
+#define MAX77540_BUCK(_id, _ops)					\
+	{	.id = MAX77541_BUCK ## _id,				\
+		.name = "BUCK"#_id,					\
+		.of_match = "BUCK"#_id,					\
+		.regulators_node = "regulators",			\
+		.enable_reg = MAX77541_REG_EN_CTRL,			\
+		.enable_mask = MAX77541_BIT_M ## _id ## _EN,		\
+		.ops = &(_ops),						\
+		.type = REGULATOR_VOLTAGE,				\
+		.linear_ranges = max77540_buck_ranges,			\
+		.n_linear_ranges = ARRAY_SIZE(max77540_buck_ranges),	\
+		.vsel_reg = MAX77541_REG_M ## _id ## _VOUT,		\
+		.vsel_mask = MAX77541_BITS_MX_VOUT,			\
+		.vsel_range_reg = MAX77541_REG_M ## _id ## _CFG1,	\
+		.vsel_range_mask = MAX77541_BITS_MX_CFG1_RNG,		\
+		.linear_range_selectors = max77541_buck_volt_range_sel, \
+		.owner = THIS_MODULE,					\
+	}
+
+#define MAX77541_BUCK(_id, _ops)					\
+	{	.id = MAX77541_BUCK ## _id,				\
+		.name = "BUCK"#_id,					\
+		.of_match = "BUCK"#_id,					\
+		.regulators_node = "regulators",			\
+		.enable_reg = MAX77541_REG_EN_CTRL,			\
+		.enable_mask = MAX77541_BIT_M ## _id ## _EN,		\
+		.ops = &(_ops),						\
+		.type = REGULATOR_VOLTAGE,				\
+		.linear_ranges = max77541_buck_ranges,			\
+		.n_linear_ranges = ARRAY_SIZE(max77541_buck_ranges),	\
+		.vsel_reg = MAX77541_REG_M ## _id ## _VOUT,		\
+		.vsel_mask = MAX77541_BITS_MX_VOUT,			\
+		.vsel_range_reg = MAX77541_REG_M ## _id ## _CFG1,	\
+		.vsel_range_mask = MAX77541_BITS_MX_CFG1_RNG,		\
+		.linear_range_selectors = max77541_buck_volt_range_sel, \
+		.owner = THIS_MODULE,					\
+	}
+
+static const struct regulator_desc max77540_regulators_desc[] = {
+	MAX77540_BUCK(1, max77541_buck_ops),
+	MAX77540_BUCK(2, max77541_buck_ops)
+};
+
+static const struct regulator_desc max77541_regulators_desc[] = {
+	MAX77541_BUCK(1, max77541_buck_ops),
+	MAX77541_BUCK(2, max77541_buck_ops)
+};
+
+struct max77541_regulator_dev {
+	struct device *dev;
+	struct max77541_dev *max77541;
+};
+
+static int max77541_regulator_probe(struct platform_device *pdev)
+{
+	struct max77541_dev *max77541 = dev_get_drvdata(pdev->dev.parent);
+	struct max77541_regulator_dev *regulator;
+	struct regulator_config config = {};
+	struct regulator_dev *rdev;
+	int i;
+
+	regulator = devm_kzalloc(&pdev->dev, sizeof(*regulator), GFP_KERNEL);
+	if (!regulator)
+		return -ENOMEM;
+
+	regulator->dev = &pdev->dev;
+	regulator->max77541 = max77541;
+
+	config.dev = pdev->dev.parent;
+	config.driver_data = regulator;
+	config.regmap = regulator->max77541->regmap;
+
+	for (i = 0; i < MAX77541_MAX_REGULATORS; i++) {
+		switch (regulator->max77541->type) {
+		case MAX77540:
+			rdev = devm_regulator_register(&pdev->dev,
+						       &max77540_regulators_desc[i], &config);
+			if (IS_ERR(rdev))
+				return dev_err_probe(&pdev->dev, PTR_ERR(rdev),
+							"Failed to register regulator\n");
+			break;
+		case MAX77541:
+			rdev = devm_regulator_register(&pdev->dev,
+						       &max77541_regulators_desc[i], &config);
+			if (IS_ERR(rdev))
+				return dev_err_probe(&pdev->dev, PTR_ERR(rdev),
+						"Failed to register regulator\n");
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id max77541_regulator_platform_id[] = {
+	{ "max77540-regulator", MAX77540 },
+	{ "max77541-regulator", MAX77541 },
+	{  /* sentinel */  }
+};
+MODULE_DEVICE_TABLE(platform, max77541_regulator_platform_id);
+
+static const struct of_device_id max77541_regulator_of_id[] = {
+	{
+		.compatible = "adi,max77540-regulator",
+		.data = (void *)MAX77540,
+	},
+	{
+		.compatible = "adi,max77541-regulator",
+		.data = (void *)MAX77541,
+	},
+	{ /* sentinel */  }
+};
+MODULE_DEVICE_TABLE(of, max77541_regulator_of_id);
+
+static struct platform_driver max77541_regulator_driver = {
+	.driver = {
+		.name = "max77541-regulator",
+		.of_match_table = max77541_regulator_of_id,
+	},
+	.probe = max77541_regulator_probe,
+	.id_table = max77541_regulator_platform_id,
+};
+
+module_platform_driver(max77541_regulator_driver);
+
+MODULE_AUTHOR("Okan Sahin <Okan.Sahin@analog.com>");
+MODULE_DESCRIPTION("MAX77540/MAX77541 regulator driver");
+MODULE_LICENSE("GPL");
-- 
2.30.2