[PATCH v2] Add ltc3562 voltage regulator driver

From: Mike Looijmans
Date: Thu Oct 30 2014 - 07:27:10 EST

The ltc3562 is an I2C controlled regulator supporting 4 independent
outputs.

v2: Prefix "lltc" to devicetree properties. Use the same property names
as the ltc3589 driver. Remove default-voltage property. Use
devm_register_regulator.

Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
---
.../devicetree/bindings/regulator/ltc3562.txt | 56 ++++
drivers/regulator/Kconfig | 7 +
drivers/regulator/Makefile | 1 +
drivers/regulator/ltc3562.c | 337 ++++++++++++++++++++
4 files changed, 401 insertions(+)
create mode 100644 Documentation/devicetree/bindings/regulator/ltc3562.txt
create mode 100644 drivers/regulator/ltc3562.c

diff --git a/Documentation/devicetree/bindings/regulator/ltc3562.txt b/Documentation/devicetree/bindings/regulator/ltc3562.txt
new file mode 100644
index 0000000..81ed923
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/ltc3562.txt
@@ -0,0 +1,56 @@
+Linear Technology LTC3562 I2C controlled 4-output regulator
+
+Required properties:
+- compatible: "ltc3562"
+- reg: I2C slave address
+
+Required child node:
+- regulators: Contains four regulator child nodes R400B, R600B, R400A, R600A,
+ specifying the initialization data as documented in
+ Documentation/devicetree/bindings/regulator/regulator.txt.
+
+Each regulator is defined using the standard binding for regulators. The
+nodes for R400A and R600A additionally need to specify the resistor values of
+their external feedback voltage dividers:
+
+Required properties (A-type only):
+- lltc,fb-voltage-divider: An array of two integers containing the resistor
+ values R1 and R2 of the feedback voltage divider. Both values must remain in
+ the range 1..1000, only their quotient matters.
+
+Example:
+
+ ltc3562: ltc3562@65 {
+ compatible = "ltc3562";
+ reg = <0x65>;
+ regulators {
+ R400B_reg: R400B {
+ regulator-name = "R400B";
+ regulator-min-microvolt = <600000>;
+ regulator-max-microvolt = <3300000>;
+ regulator-boot-on;
+ regulator-always-on;
+ };
+ R600B_reg: R600B {
+ regulator-name = "R600B";
+ regulator-min-microvolt = <3300000>;
+ regulator-max-microvolt = <3300000>;
+ regulator-boot-on;
+ regulator-always-on;
+ };
+ R400A_reg: R400A {
+ regulator-name = "R400A";
+ regulator-min-microvolt = <425000>;
+ regulator-max-microvolt = <8000000>;
+ lltc,fb-voltage-divider = <1, 1>;
+ };
+ R600A_reg: R600A {
+ regulator-name = "R600A";
+ regulator-min-microvolt = <425000>;
+ regulator-max-microvolt = <1800000>;
+ lltc,fb-voltage-divider = <316, 100>;
+ regulator-boot-on;
+ regulator-always-on;
+ };
+ };
+ };
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 55d7b7b..4012601 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -300,6 +300,13 @@ config REGULATOR_LP8788
help
This driver supports LP8788 voltage regulator chip.

+config REGULATOR_LTC3562
+ tristate "LCT3562 quad output voltage regulator"
+ depends on I2C
+ help
+ This enables support for the LCT3562 quad output voltage regulator
+ controlled via I2C.
+
config REGULATOR_LTC3589
tristate "LTC3589 8-output voltage regulator"
depends on I2C
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 1029ed3..9a15146 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_REGULATOR_LP872X) += lp872x.o
obj-$(CONFIG_REGULATOR_LP8788) += lp8788-buck.o
obj-$(CONFIG_REGULATOR_LP8788) += lp8788-ldo.o
obj-$(CONFIG_REGULATOR_LP8755) += lp8755.o
+obj-$(CONFIG_REGULATOR_LTC3562) += ltc3562.o
obj-$(CONFIG_REGULATOR_LTC3589) += ltc3589.o
obj-$(CONFIG_REGULATOR_MAX14577) += max14577.o
obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
diff --git a/drivers/regulator/ltc3562.c b/drivers/regulator/ltc3562.c
new file mode 100644
index 0000000..b73eee7
--- /dev/null
+++ b/drivers/regulator/ltc3562.c
@@ -0,0 +1,337 @@
+/*
+ * Regulator driver for Linear Technology LTC3562
+ *
+ * Copyright (C) 2014 Topic Embedded Products
+ *
+ * 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.
+ */
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/slab.h>
+#include <linux/regulator/of_regulator.h>
+
+#define LTC3562_NUM_REGULATORS 4
+
+#define REGULATOR_TYPE_A_NUM_VOLTAGES 16
+#define REGULATOR_TYPE_A_MIN_UV 425000
+#define REGULATOR_TYPE_A_UV_STEP 25000
+
+#define REGULATOR_TYPE_B_NUM_VOLTAGES 128
+#define REGULATOR_TYPE_B_MIN_UV 600000
+#define REGULATOR_TYPE_B_UV_STEP 25000
+
+struct ltc3562_status {
+ u8 shadow_addr; /* Shadow register of address byte */
+ u8 shadow_data; /* Shadow register of data byte */
+};
+
+struct ltc3562 {
+ struct device *dev;
+ struct i2c_client *i2c;
+ struct mutex mutex;
+ struct regulator_dev *rdev[LTC3562_NUM_REGULATORS];
+ struct ltc3562_status rstatus[LTC3562_NUM_REGULATORS];
+};
+
+static int ltc3562_write(struct i2c_client *i2c, u8 reg_a, u8 reg_b);
+static int ltc3562_dummy_write(struct i2c_client *i2c);
+
+#define LTC3562_R400B_ID 0x00
+#define LTC3562_R600B_ID 0x01
+#define LTC3562_R400A_ID 0x02
+#define LTC3562_R600A_ID 0x03
+
+#define OPERATING_MODE_MASK 0x03
+
+#define PROGRAM_R400B_MASK 0x10
+#define PROGRAM_R600B_MASK 0x20
+#define PROGRAM_R400A_MASK 0x40
+#define PROGRAM_R600A_MASK 0x80
+
+#define OPERATING_MODE_PULSE_SKIP 0x00
+#define OPERATING_MODE_LDO 0x01
+#define OPERATING_MODE_FOCED_BURST 0x02
+#define OPERATING_MODE_BURST 0x03
+
+#define REGULATOR_ENABLE_BIT 0x80
+
+static int ltc3562_regulator_enable(struct regulator_dev *dev)
+{
+ int ret;
+ struct ltc3562 *ltc3562 = rdev_get_drvdata(dev);
+ int id = rdev_get_id(dev);
+ struct ltc3562_status *status = &ltc3562->rstatus[id];
+
+ mutex_lock(&ltc3562->mutex);
+
+ status->shadow_data |= REGULATOR_ENABLE_BIT;
+
+ ret = ltc3562_write(ltc3562->i2c,
+ status->shadow_addr | PROGRAM_R400B_MASK << id,
+ status->shadow_data);
+
+ mutex_unlock(&ltc3562->mutex);
+
+ return ret;
+}
+
+static int ltc3562_regulator_disable(struct regulator_dev *dev)
+{
+ int ret;
+ struct ltc3562 *ltc3562 = rdev_get_drvdata(dev);
+ int id = rdev_get_id(dev);
+ struct ltc3562_status *status = &ltc3562->rstatus[id];
+
+ mutex_lock(&ltc3562->mutex);
+
+ status->shadow_data &= ~(REGULATOR_ENABLE_BIT);
+
+ ret = ltc3562_write(ltc3562->i2c,
+ status->shadow_addr, status->shadow_data);
+
+ mutex_unlock(&ltc3562->mutex);
+
+ return ret;
+}
+
+static int ltc3562_regulator_is_enabled(struct regulator_dev *dev)
+{
+ int ret;
+ struct ltc3562 *ltc3562 = rdev_get_drvdata(dev);
+ int id = rdev_get_id(dev);
+ struct ltc3562_status *status = &ltc3562->rstatus[id];
+
+ mutex_lock(&ltc3562->mutex);
+
+ ret = (status->shadow_data & REGULATOR_ENABLE_BIT) ? 1 : 0;
+
+ mutex_unlock(&ltc3562->mutex);
+
+ return ret;
+}
+
+static int ltc3562_set_voltage_sel(struct regulator_dev *dev,
+ unsigned int selector)
+{
+ int ret;
+ struct ltc3562 *ltc3562 = rdev_get_drvdata(dev);
+ int id = rdev_get_id(dev);
+ struct ltc3562_status *status = &ltc3562->rstatus[id];
+
+ mutex_lock(&ltc3562->mutex);
+
+ status->shadow_data =
+ (status->shadow_data & REGULATOR_ENABLE_BIT) | selector;
+
+ ret = ltc3562_write(ltc3562->i2c,
+ status->shadow_addr, status->shadow_data);
+
+ mutex_unlock(&ltc3562->mutex);
+
+ return ret;
+}
+
+static int ltc3562_get_voltage_sel(struct regulator_dev *dev)
+{
+ int ret;
+ struct ltc3562 *ltc3562 = rdev_get_drvdata(dev);
+ int id = rdev_get_id(dev);
+ struct ltc3562_status *status = &ltc3562->rstatus[id];
+
+ mutex_lock(&ltc3562->mutex);
+
+ ret = status->shadow_data & ~(REGULATOR_ENABLE_BIT);
+
+ mutex_unlock(&ltc3562->mutex);
+
+ return ret;
+}
+
+static struct regulator_ops ltc3562_regulator_ops = {
+ .is_enabled = ltc3562_regulator_is_enabled,
+ .enable = ltc3562_regulator_enable,
+ .disable = ltc3562_regulator_disable,
+ .set_voltage_sel = ltc3562_set_voltage_sel,
+ .get_voltage_sel = ltc3562_get_voltage_sel,
+ .list_voltage = regulator_list_voltage_linear,
+ .map_voltage = regulator_map_voltage_linear,
+};
+
+static struct regulator_desc ltc3562_regulators[] = {
+ {
+ .name = "R400B",
+ .id = LTC3562_R400B_ID,
+ .ops = &ltc3562_regulator_ops,
+ .min_uV = REGULATOR_TYPE_B_MIN_UV,
+ .uV_step = REGULATOR_TYPE_B_UV_STEP,
+ .n_voltages = REGULATOR_TYPE_B_NUM_VOLTAGES,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ },
+ {
+ .name = "R600B",
+ .id = LTC3562_R600B_ID,
+ .ops = &ltc3562_regulator_ops,
+ .min_uV = REGULATOR_TYPE_B_MIN_UV,
+ .uV_step = REGULATOR_TYPE_B_UV_STEP,
+ .n_voltages = REGULATOR_TYPE_B_NUM_VOLTAGES,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ },
+ {
+ .name = "R400A",
+ .id = LTC3562_R400A_ID,
+ .ops = &ltc3562_regulator_ops,
+ .min_uV = REGULATOR_TYPE_A_MIN_UV,
+ .uV_step = REGULATOR_TYPE_A_UV_STEP,
+ .n_voltages = REGULATOR_TYPE_A_NUM_VOLTAGES,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ },
+ {
+ .name = "R600A",
+ .id = LTC3562_R600A_ID,
+ .ops = &ltc3562_regulator_ops,
+ .min_uV = REGULATOR_TYPE_A_MIN_UV,
+ .uV_step = REGULATOR_TYPE_A_UV_STEP,
+ .n_voltages = REGULATOR_TYPE_A_NUM_VOLTAGES,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ },
+};
+
+
+static int ltc3562_write(struct i2c_client *i2c, u8 reg_a, u8 reg_b)
+{
+ dev_dbg(&i2c->dev, "%s(%#x, %#x)\n", __func__, reg_a, reg_b);
+ return i2c_smbus_write_byte_data(i2c, reg_a, reg_b);
+}
+
+/* Write dummy data to detect presence of physical device */
+static int ltc3562_dummy_write(struct i2c_client *i2c)
+{
+ return ltc3562_write(i2c, 0, 0);
+}
+
+static int ltc3562_i2c_probe(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ int i, error;
+ unsigned long uV;
+ struct ltc3562 *ltc3562;
+ struct regulator_config rconfig = { };
+ struct device_node *np_regulators, *np;
+ struct device_node *np_child;
+ u32 value;
+
+ ltc3562 = devm_kzalloc(&i2c->dev,
+ sizeof(struct ltc3562), GFP_KERNEL);
+ if (ltc3562 == NULL)
+ return -ENOMEM;
+
+ ltc3562->i2c = i2c;
+
+ mutex_init(&ltc3562->mutex);
+
+ if (ltc3562_dummy_write(i2c) < 0) {
+ dev_err(&i2c->dev,
+ "Could not find device LTC3562 on i2c bus\n");
+ error = -ENODEV;
+ goto lbl_exit;
+ }
+
+ np = of_node_get(i2c->dev.of_node);
+ np_regulators = of_get_child_by_name(np, "regulators");
+
+ if (np_regulators == NULL) {
+ dev_err(&i2c->dev, "Could not find regulators node\n");
+ error = -EINVAL;
+ goto lbl_exit;
+ }
+
+ for (i = 0; i < LTC3562_NUM_REGULATORS; ++i) {
+ np_child = of_get_child_by_name(np_regulators,
+ ltc3562_regulators[i].name);
+ if (np_child == NULL) {
+ dev_err(&i2c->dev,
+ "Could not find regulator data for %s in devicetree\n",
+ ltc3562_regulators[i].name);
+ return -EINVAL;
+ }
+
+ if ((ltc3562_regulators[i].id == LTC3562_R400A_ID) ||
+ (ltc3562_regulators[i].id == LTC3562_R600A_ID)) {
+ /* If regulator is A type get resistor values */
+ u32 vdiv[2];
+
+ error = of_property_read_u32_array(np_child,
+ "lltc,fb-voltage-divider", vdiv, 2);
+ if (error) {
+ dev_err(&i2c->dev,
+ "Failed to parse voltage divider: %d\n",
+ error);
+ return error;
+ }
+
+ uV = ltc3562_regulators[i].min_uV / 1000;
+ ltc3562_regulators[i].min_uV =
+ (uV + mult_frac(uV, vdiv[0], vdiv[1])) * 1000;
+
+ uV = ltc3562_regulators[i].uV_step / 1000;
+ ltc3562_regulators[i].uV_step =
+ (uV + mult_frac(uV, vdiv[0], vdiv[1])) * 1000;
+ }
+
+ rconfig.dev = &i2c->dev;
+ rconfig.init_data =
+ of_get_regulator_init_data(&i2c->dev, np_child);
+ rconfig.driver_data = ltc3562;
+ rconfig.of_node = np_child;
+
+ ltc3562->rdev[i] = devm_regulator_register(&i2c->dev,
+ &ltc3562_regulators[i], &rconfig);
+
+ if (IS_ERR(ltc3562->rdev[i])) {
+ error = PTR_ERR(ltc3562->rdev[i]);
+ dev_err(&i2c->dev,
+ "could not register regulator, Error %d\n",
+ error);
+ }
+ }
+
+ i2c_set_clientdata(i2c, ltc3562);
+ dev_dbg(&i2c->dev, "LTC3562 Driver loaded\n");
+ return 0;
+
+lbl_exit:
+ return error;
+}
+
+static const struct i2c_device_id ltc3562_i2c_id[] = {
+ { "ltc3562", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltc3562_i2c_id);
+
+static struct i2c_driver ltc3562_i2c_driver = {
+ .driver = {
+ .name = "LTC3562",
+ .owner = THIS_MODULE,
+ },
+ .probe = ltc3562_i2c_probe,
+ .id_table = ltc3562_i2c_id,
+};
+
+module_i2c_driver(ltc3562_i2c_driver);
+
+MODULE_DESCRIPTION("LTC3562 Regulator Driver");
+MODULE_AUTHOR("auryn.verwegen@xxxxxxxx");
+MODULE_AUTHOR("mike.looijmans@xxxxxxxx");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5

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