[PATCH 3/3] regulator: Add LTC3589 support

From: Philipp Zabel
Date: Tue Apr 29 2014 - 12:37:38 EST

This patch adds support for the Linear Technology LTC3589, LTC3589-1,
and LTC3589-2 8-output I2C voltage regulator ICs.

Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
---
drivers/regulator/Kconfig | 6 +
drivers/regulator/Makefile | 1 +
drivers/regulator/ltc3589.c | 564 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 571 insertions(+)
create mode 100644 drivers/regulator/ltc3589.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 903eb37..5599a61 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -265,6 +265,12 @@ config REGULATOR_LP8788
help
This driver supports LP8788 voltage regulator chip.

+config REGULATOR_LTC3589
+ bool "LTC3589 8-output voltage regulator"
+ help
+ This enables support for the LTC3589, LTC3589-1, and LTC3589-2
+ 8-output regulators controlled via I2C.
+
config REGULATOR_MAX14577
tristate "Maxim 14577 regulator"
depends on MFD_MAX14577
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 12ef277..16d429b 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -37,6 +37,7 @@ 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-$(CONFIG_REGULATOR_LTC3589) += ltc3589.o
obj-$(CONFIG_REGULATOR_MAX14577) += max14577.o
obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
obj-$(CONFIG_REGULATOR_MAX8649) += max8649.o
diff --git a/drivers/regulator/ltc3589.c b/drivers/regulator/ltc3589.c
new file mode 100644
index 0000000..37e18dc
--- /dev/null
+++ b/drivers/regulator/ltc3589.c
@@ -0,0 +1,564 @@
+/*
+ * Linear Technology LTC3589,LTC3589-1 regulator support
+ *
+ * Copyright (c) 2014 Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>, Pengutronix
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define DRIVER_NAME "ltc3589"
+
+#define LTC3589_IRQSTAT 0x02
+#define LTC3589_SCR1 0x07
+#define LTC3589_OVEN 0x10
+#define LTC3589_SCR2 0x12
+#define LTC3589_PGSTAT 0x13
+#define LTC3589_VCCR 0x20
+#define LTC3589_CLIRQ 0x21
+#define LTC3589_B1DTV1 0x23
+#define LTC3589_B1DTV2 0x24
+#define LTC3589_VRRCR 0x25
+#define LTC3589_B2DTV1 0x26
+#define LTC3589_B2DTV2 0x27
+#define LTC3589_B3DTV1 0x29
+#define LTC3589_B3DTV2 0x2a
+#define LTC3589_L2DTV1 0x32
+#define LTC3589_L2DTV2 0x33
+
+#define LTC3589_IRQSTAT_PGOOD_TIMEOUT BIT(3)
+#define LTC3589_IRQSTAT_UNDERVOLT_WARN BIT(4)
+#define LTC3589_IRQSTAT_UNDERVOLT_FAULT BIT(5)
+#define LTC3589_IRQSTAT_THERMAL_WARN BIT(6)
+#define LTC3589_IRQSTAT_THERMAL_FAULT BIT(7)
+
+#define LTC3589_OVEN_SW1 BIT(0)
+#define LTC3589_OVEN_SW2 BIT(1)
+#define LTC3589_OVEN_SW3 BIT(2)
+#define LTC3589_OVEN_BB_OUT BIT(3)
+#define LTC3589_OVEN_LDO2 BIT(4)
+#define LTC3589_OVEN_LDO3 BIT(5)
+#define LTC3589_OVEN_LDO4 BIT(6)
+#define LTC3589_OVEN_SW_CTRL BIT(7)
+
+#define LTC3589_VCCR_SW1_GO BIT(0)
+#define LTC3589_VCCR_SW2_GO BIT(2)
+#define LTC3589_VCCR_SW3_GO BIT(4)
+#define LTC3589_VCCR_LDO2_GO BIT(6)
+
+enum ltc3589_variant {
+ LTC3589,
+ LTC3589_1,
+ LTC3589_2,
+};
+
+enum ltc3589_reg {
+ LTC3589_SW1,
+ LTC3589_SW2,
+ LTC3589_SW3,
+ LTC3589_BB_OUT,
+ LTC3589_LDO1,
+ LTC3589_LDO2,
+ LTC3589_LDO3,
+ LTC3589_LDO4,
+ LTC3589_NUM_REGULATORS,
+};
+
+struct ltc3589_regulator {
+ struct regulator_desc desc;
+
+ /* External feedback voltage divider */
+ unsigned int r1;
+ unsigned int r2;
+};
+
+struct ltc3589 {
+ struct regmap *regmap;
+ struct device *dev;
+ enum ltc3589_variant variant;
+ struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
+ struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
+};
+
+static const int ltc3589_ldo4[] = {
+ 2800000, 2500000, 1800000, 3300000,
+};
+
+static const int ltc3589_12_ldo4[] = {
+ 1200000, 1800000, 2500000, 3200000,
+};
+
+static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
+{
+ struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
+ int sel, shift;
+
+ if (unlikely(ramp_delay <= 0))
+ return -EINVAL;
+
+ /* VRRCR slew rate offsets are the same as VCCR go bit offsets */
+ shift = ffs(rdev->desc->apply_bit) - 1;
+
+ /* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
+ for (sel = 0; sel < 4; sel++) {
+ if ((880 << sel) >= ramp_delay) {
+ return regmap_update_bits(ltc3589->regmap,
+ LTC3589_VRRCR,
+ 0x3 << shift, sel << shift);
+ }
+ }
+ return -EINVAL;
+}
+
+static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
+{
+ struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
+ int sel;
+
+ sel = regulator_map_voltage_linear(rdev, uV, uV);
+ if (sel < 0)
+ return sel;
+
+ /* DTV2 register follows right after the corresponding DTV1 register */
+ return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
+ rdev->desc->vsel_mask, sel);
+}
+
+static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
+ unsigned int mode)
+{
+ struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
+ int mask, bit = 0;
+
+ /* VCCR reference selects are right next to the VCCR go bits */
+ mask = rdev->desc->apply_bit << 1;
+
+ if (mode == REGULATOR_MODE_STANDBY)
+ bit = mask; /* Select DTV2 */
+
+ mask |= rdev->desc->apply_bit;
+ bit |= rdev->desc->apply_bit;
+ return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
+}
+
+static int ltc3589_list_voltage_fixed(struct regulator_dev *rdev,
+ unsigned int selector)
+{
+ if (selector)
+ return -EINVAL;
+
+ return rdev->desc->fixed_uV;
+}
+
+/* SW1, SW2, SW3, LDO2 */
+static struct regulator_ops ltc3589_linear_regulator_ops = {
+ .enable = regulator_enable_regmap,
+ .disable = regulator_disable_regmap,
+ .is_enabled = regulator_is_enabled_regmap,
+ .list_voltage = regulator_list_voltage_linear,
+ .set_voltage_sel = regulator_set_voltage_sel_regmap,
+ .get_voltage_sel = regulator_get_voltage_sel_regmap,
+ .set_ramp_delay = ltc3589_set_ramp_delay,
+ .set_voltage_time_sel = regulator_set_voltage_time_sel,
+ .set_suspend_voltage = ltc3589_set_suspend_voltage,
+ .set_suspend_mode = ltc3589_set_suspend_mode,
+};
+
+/* BB_OUT, LDO3 */
+static struct regulator_ops ltc3589_fixed_regulator_ops = {
+ .enable = regulator_enable_regmap,
+ .disable = regulator_disable_regmap,
+ .is_enabled = regulator_is_enabled_regmap,
+ .list_voltage = ltc3589_list_voltage_fixed,
+};
+
+/* LDO1 */
+static struct regulator_ops ltc3589_standby_regulator_ops = {
+ .list_voltage = ltc3589_list_voltage_fixed,
+};
+
+/* LDO4 */
+static struct regulator_ops ltc3589_table_regulator_ops = {
+ .enable = regulator_enable_regmap,
+ .disable = regulator_disable_regmap,
+ .is_enabled = regulator_is_enabled_regmap,
+ .list_voltage = regulator_list_voltage_table,
+ .set_voltage_sel = regulator_set_voltage_sel_regmap,
+ .get_voltage_sel = regulator_get_voltage_sel_regmap,
+};
+
+
+#define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit) \
+ [LTC3589_ ## _name] = { \
+ .desc = { \
+ .name = #_name, \
+ .n_voltages = (dtv_mask) + 1, \
+ .min_uV = (go_bit) ? 362500 : 0, \
+ .uV_step = (go_bit) ? 12500 : 0, \
+ .fixed_uV = (dtv_mask) ? 0 : 800000, \
+ .ops = &ltc3589_ ## _ops ## _regulator_ops, \
+ .type = REGULATOR_VOLTAGE, \
+ .id = LTC3589_ ## _name, \
+ .owner = THIS_MODULE, \
+ .vsel_reg = (dtv1_reg), \
+ .vsel_mask = (dtv_mask), \
+ .apply_reg = (go_bit) ? LTC3589_VCCR : 0, \
+ .apply_bit = (go_bit), \
+ .enable_reg = (en_bit) ? LTC3589_OVEN : 0, \
+ .enable_mask = (en_bit), \
+ }, \
+ }
+
+#define LTC3589_LINEAR_REG(_name, _dtv1) \
+ LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name, \
+ LTC3589_ ## _dtv1, 0x1f, \
+ LTC3589_VCCR_ ## _name ## _GO)
+
+#define LTC3589_FIXED_REG(_name) \
+ LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)
+
+static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
+ LTC3589_LINEAR_REG(SW1, B1DTV1),
+ LTC3589_LINEAR_REG(SW2, B2DTV1),
+ LTC3589_LINEAR_REG(SW3, B3DTV1),
+ LTC3589_FIXED_REG(BB_OUT),
+ LTC3589_REG(LDO1, standby, 0, 0, 0, 0),
+ LTC3589_LINEAR_REG(LDO2, L2DTV1),
+ LTC3589_FIXED_REG(LDO3),
+ LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
+};
+
+#ifdef CONFIG_OF
+static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
+ { .name = "sw1", },
+ { .name = "sw2", },
+ { .name = "sw3", },
+ { .name = "bb-out", },
+ { .name = "ldo1", }, /* standby */
+ { .name = "ldo2", },
+ { .name = "ldo3", },
+ { .name = "ldo4", },
+};
+
+static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
+{
+ struct device *dev = ltc3589->dev;
+ struct device_node *node;
+ int i, ret;
+
+ node = of_find_node_by_name(dev->of_node, "regulators");
+ if (!node) {
+ dev_err(dev, "regulators node not found\n");
+ return -EINVAL;
+ }
+
+ ret = of_regulator_match(dev, node, ltc3589_matches,
+ ARRAY_SIZE(ltc3589_matches));
+ of_node_put(node);
+ if (ret < 0) {
+ dev_err(dev, "Error parsing regulator init data: %d\n", ret);
+ return ret;
+ }
+ if (ret != LTC3589_NUM_REGULATORS) {
+ dev_err(dev, "Only %d regulators described in device tree\n",
+ ret);
+ return -EINVAL;
+ }
+
+ /* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
+ for (i = 0; i < LTC3589_LDO3; i++) {
+ struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
+ struct device_node *np = ltc3589_matches[i].of_node;
+ u32 vdiv[2];
+
+ ret = of_property_read_u32_array(np, "ltc,fb-voltage-divider",
+ vdiv, 2);
+ if (ret) {
+ dev_err(dev, "Failed to parse voltage divider: %d\n",
+ ret);
+ return ret;
+ }
+
+ desc->r1 = vdiv[0];
+ desc->r2 = vdiv[1];
+ }
+
+ return 0;
+}
+
+static inline struct regulator_init_data *match_init_data(int index)
+{
+ return ltc3589_matches[index].init_data;
+}
+
+static inline struct device_node *match_of_node(int index)
+{
+ return ltc3589_matches[index].of_node;
+}
+#else
+static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
+{
+ return 0;
+}
+
+static inline struct regulator_init_data *match_init_data(int index)
+{
+ return NULL;
+}
+
+static inline struct device_node *match_of_node(int index)
+{
+ return NULL;
+}
+#endif
+
+static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case LTC3589_IRQSTAT:
+ case LTC3589_SCR1:
+ case LTC3589_OVEN:
+ case LTC3589_SCR2:
+ case LTC3589_VCCR:
+ case LTC3589_CLIRQ:
+ case LTC3589_B1DTV1:
+ case LTC3589_B1DTV2:
+ case LTC3589_VRRCR:
+ case LTC3589_B2DTV1:
+ case LTC3589_B2DTV2:
+ case LTC3589_B3DTV1:
+ case LTC3589_B3DTV2:
+ case LTC3589_L2DTV1:
+ case LTC3589_L2DTV2:
+ return true;
+ }
+ return false;
+}
+
+static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case LTC3589_IRQSTAT:
+ case LTC3589_SCR1:
+ case LTC3589_OVEN:
+ case LTC3589_SCR2:
+ case LTC3589_PGSTAT:
+ case LTC3589_VCCR:
+ case LTC3589_B1DTV1:
+ case LTC3589_B1DTV2:
+ case LTC3589_VRRCR:
+ case LTC3589_B2DTV1:
+ case LTC3589_B2DTV2:
+ case LTC3589_B3DTV1:
+ case LTC3589_B3DTV2:
+ case LTC3589_L2DTV1:
+ case LTC3589_L2DTV2:
+ return true;
+ }
+ return false;
+}
+
+static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case LTC3589_IRQSTAT:
+ case LTC3589_PGSTAT:
+ return true;
+ }
+ return false;
+}
+
+struct reg_default ltc3589_reg_defaults[] = {
+ { LTC3589_SCR1, 0x00 },
+ { LTC3589_OVEN, 0x00 },
+ { LTC3589_SCR2, 0x00 },
+ { LTC3589_VCCR, 0x00 },
+ { LTC3589_B1DTV1, 0x19 },
+ { LTC3589_B1DTV2, 0x19 },
+ { LTC3589_VRRCR, 0xff },
+ { LTC3589_B2DTV1, 0x19 },
+ { LTC3589_B2DTV2, 0x19 },
+ { LTC3589_B3DTV1, 0x19 },
+ { LTC3589_B3DTV2, 0x19 },
+ { LTC3589_L2DTV1, 0x19 },
+ { LTC3589_L2DTV2, 0x19 },
+};
+
+static const struct regmap_config ltc3589_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .writeable_reg = ltc3589_writeable_reg,
+ .readable_reg = ltc3589_readable_reg,
+ .volatile_reg = ltc3589_volatile_reg,
+ .max_register = LTC3589_L2DTV2,
+ .reg_defaults = ltc3589_reg_defaults,
+ .num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
+ .use_single_rw = true,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+
+static irqreturn_t ltc3589_isr(int irq, void *dev_id)
+{
+ struct ltc3589 *ltc3589 = dev_id;
+ unsigned int i, irqstat, event;
+
+ regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);
+
+ if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
+ event = REGULATOR_EVENT_OVER_TEMP;
+ for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
+ regulator_notifier_call_chain(ltc3589->regulators[i],
+ event, NULL);
+ }
+
+ if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
+ event = REGULATOR_EVENT_UNDER_VOLTAGE;
+ for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
+ regulator_notifier_call_chain(ltc3589->regulators[i],
+ event, NULL);
+ }
+
+ /* Clear warning condition */
+ regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);
+
+ return IRQ_HANDLED;
+}
+
+static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
+{
+ uint64_t tmp;
+ if (uV == 0)
+ return 0;
+ tmp = (uint64_t)uV * r1;
+ do_div(tmp, r2);
+ return uV + (unsigned int)tmp;
+}
+
+static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
+{
+ struct regulator_desc *desc = &rdesc->desc;
+
+ if (!rdesc->r1 || !rdesc->r2)
+ return;
+
+ desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
+ desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
+ desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
+}
+
+static int ltc3589_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct ltc3589_regulator *descs;
+ struct ltc3589 *ltc3589;
+ int i, ret;
+
+ ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
+ if (!ltc3589)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ltc3589);
+ ltc3589->variant = id->driver_data;
+ ltc3589->dev = dev;
+
+ descs = ltc3589->regulator_descs;
+ memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
+ if (ltc3589->variant == LTC3589) {
+ descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
+ descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
+ } else {
+ descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
+ descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
+ }
+
+ ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
+ if (IS_ERR(ltc3589->regmap)) {
+ ret = PTR_ERR(ltc3589->regmap);
+ dev_err(dev, "failed to initialize regmap: %d\n", ret);
+ return ret;
+ }
+
+ ret = ltc3589_parse_regulators_dt(ltc3589);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
+ struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
+ struct regulator_desc *desc = &rdesc->desc;
+ struct regulator_init_data *init_data;
+ struct regulator_config config = { };
+
+ init_data = match_init_data(i);
+
+ if (i < LTC3589_LDO3)
+ ltc3589_apply_fb_voltage_divider(rdesc);
+
+ config.dev = dev;
+ config.init_data = init_data;
+ config.driver_data = ltc3589;
+ config.of_node = match_of_node(i);
+
+ ltc3589->regulators[i] = devm_regulator_register(dev, desc,
+ &config);
+ if (IS_ERR(ltc3589->regulators[i])) {
+ ret = PTR_ERR(ltc3589->regulators[i]);
+ dev_err(dev, "failed to register regulator %s: %d\n",
+ desc->name, ret);
+ return ret;
+ }
+ }
+
+ ret = devm_request_threaded_irq(dev, client->irq, NULL, ltc3589_isr,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ client->name, ltc3589);
+ if (ret) {
+ dev_err(dev, "Failed to request IRQ: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct i2c_device_id ltc3589_i2c_id[] = {
+ { "ltc3589", LTC3589 },
+ { "ltc3589-1", LTC3589_1 },
+ { "ltc3589-2", LTC3589_2 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);
+
+static struct i2c_driver ltc3589_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = ltc3589_probe,
+ .id_table = ltc3589_i2c_id,
+};
+module_i2c_driver(ltc3589_driver);
+
+MODULE_AUTHOR("Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("i2c:ltc3589");
--
1.9.1

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