regulator: add MAX8907 driver

The MAX8907 is an I2C-based power-management IC containing voltage
regulators, a reset controller, a real-time clock, and a touch-screen
controller.

The original driver was written by:
* Gyungoh Yoo <jack.yoo@maxim-ic.com>

Various fixes and enhancements by:
* Jin Park <jinyoungp@nvidia.com>
* Tom Cherry <tcherry@nvidia.com>
* Prashant Gaikwad <pgaikwad@nvidia.com>
* Dan Willemsen <dwillemsen@nvidia.com>
* Laxman Dewangan <ldewangan@nvidia.com>

During upstreaming, I (swarren):
* Converted to regmap.
* Allowed probing from device tree.
* Reworked the regulator driver to be represented as a single device that
  provides multiple regulators, rather than as a device per regulator.
* Replaced many regulator ops with standard functions.
* Added ability to specify supplies for each regulator.
* Removed the WLED regulator. If/when we expose this in the driver, it
  should be a backlight object not a regulator object.
* Renamed from max8907c->max8907, since the driver covers at least the
  C and B revisions.
* General cleanup.

Signed-off-by: Gyungoh Yoo <jack.yoo@maxim-ic.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

3 files changed, 392 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 4e932cc695e9..1c6320c131f4 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -172,6 +172,14 @@ config REGULATOR_MAX8660
           This driver controls a Maxim 8660/8661 voltage output
           regulator via I2C bus.
 
+config REGULATOR_MAX8907
+        tristate "Maxim 8907 voltage regulator"
+        depends on MFD_MAX8907
+        help
+          This driver controls a Maxim 8907 voltage output regulator
+          via I2C bus. The provided regulator is suitable for Tegra
+          chip to control Step-Down DC-DC and LDOs.
+
 config REGULATOR_MAX8925
         tristate "Maxim MAX8925 Power Management IC"
         depends on MFD_MAX8925
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 3342615cf25e..3a0dbc5de66e 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_REGULATOR_LP8788) += lp8788-ldo.o
 obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
 obj-$(CONFIG_REGULATOR_MAX8649) += max8649.o
 obj-$(CONFIG_REGULATOR_MAX8660) += max8660.o
+obj-$(CONFIG_REGULATOR_MAX8907) += max8907-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8925) += max8925-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8952) += max8952.o
 obj-$(CONFIG_REGULATOR_MAX8997) += max8997.o
diff --git a/drivers/regulator/max8907-regulator.c b/drivers/regulator/max8907-regulator.c
new file mode 100644
index 000000000000..bd3b28b55231
--- /dev/null
+++ b/drivers/regulator/max8907-regulator.c
@@ -0,0 +1,383 @@
+/*
+ * max8907-regulator.c -- support regulators in max8907
+ *
+ * Copyright (C) 2010 Gyungoh Yoo <jack.yoo@maxim-ic.com>
+ * Copyright (C) 2010-2012, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Portions based on drivers/regulator/tps65910-regulator.c,
+ *     Copyright 2010 Texas Instruments Inc.
+ *     Author: Graeme Gregory <gg@slimlogic.co.uk>
+ *     Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
+ *
+ * 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/err.h>
+#include <linux/init.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max8907.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define MAX8907_II2RR_VERSION_MASK      0xF0
+#define MAX8907_II2RR_VERSION_REV_A     0x00
+#define MAX8907_II2RR_VERSION_REV_B     0x10
+#define MAX8907_II2RR_VERSION_REV_C     0x30
+
+struct max8907_regulator {
+        struct regulator_desc desc[MAX8907_NUM_REGULATORS];
+        struct regulator_dev *rdev[MAX8907_NUM_REGULATORS];
+};
+
+#define REG_MBATT() \
+        [MAX8907_MBATT] = { \
+                .name = "MBATT", \
+                .supply_name = "mbatt", \
+                .id = MAX8907_MBATT, \
+                .ops = &max8907_mbatt_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+        }
+
+#define REG_LDO(ids, supply, base, min, max, step) \
+        [MAX8907_##ids] = { \
+                .name = #ids, \
+                .supply_name = supply, \
+                .id = MAX8907_##ids, \
+                .n_voltages = ((max) - (min)) / (step) + 1, \
+                .ops = &max8907_ldo_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+                .min_uV = (min), \
+                .uV_step = (step), \
+                .vsel_reg = (base) + MAX8907_VOUT, \
+                .vsel_mask = 0x3f, \
+                .enable_reg = (base) + MAX8907_CTL, \
+                .enable_mask = MAX8907_MASK_LDO_EN, \
+        }
+
+#define REG_FIXED(ids, supply, voltage) \
+        [MAX8907_##ids] = { \
+                .name = #ids, \
+                .supply_name = supply, \
+                .id = MAX8907_##ids, \
+                .n_voltages = 1, \
+                .ops = &max8907_fixed_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+                .min_uV = (voltage), \
+        }
+
+#define REG_OUT5V(ids, supply, base, voltage) \
+        [MAX8907_##ids] = { \
+                .name = #ids, \
+                .supply_name = supply, \
+                .id = MAX8907_##ids, \
+                .n_voltages = 1, \
+                .ops = &max8907_out5v_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+                .min_uV = (voltage), \
+                .enable_reg = (base), \
+                .enable_mask = MAX8907_MASK_OUT5V_EN, \
+        }
+
+#define REG_BBAT(ids, supply, base, min, max, step) \
+        [MAX8907_##ids] = { \
+                .name = #ids, \
+                .supply_name = supply, \
+                .id = MAX8907_##ids, \
+                .n_voltages = ((max) - (min)) / (step) + 1, \
+                .ops = &max8907_bbat_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+                .min_uV = (min), \
+                .uV_step = (step), \
+                .vsel_reg = (base), \
+                .vsel_mask = MAX8907_MASK_VBBATTCV, \
+        }
+
+#define LDO_750_50(id, supply, base) REG_LDO(id, supply, (base), \
+                        750000, 3900000, 50000)
+#define LDO_650_25(id, supply, base) REG_LDO(id, supply, (base), \
+                        650000, 2225000, 25000)
+
+static struct regulator_ops max8907_mbatt_ops = {
+};
+
+static struct regulator_ops max8907_ldo_ops = {
+        .list_voltage = regulator_list_voltage_linear,
+        .set_voltage_sel = regulator_set_voltage_sel_regmap,
+        .get_voltage_sel = regulator_get_voltage_sel_regmap,
+        .enable = regulator_enable_regmap,
+        .disable = regulator_disable_regmap,
+        .is_enabled = regulator_is_enabled_regmap,
+};
+
+static struct regulator_ops max8907_ldo_hwctl_ops = {
+        .list_voltage = regulator_list_voltage_linear,
+        .set_voltage_sel = regulator_set_voltage_sel_regmap,
+        .get_voltage_sel = regulator_get_voltage_sel_regmap,
+};
+
+static struct regulator_ops max8907_fixed_ops = {
+        .list_voltage = regulator_list_voltage_linear,
+};
+
+static struct regulator_ops max8907_out5v_ops = {
+        .list_voltage = regulator_list_voltage_linear,
+        .enable = regulator_enable_regmap,
+        .disable = regulator_disable_regmap,
+        .is_enabled = regulator_is_enabled_regmap,
+};
+
+static struct regulator_ops max8907_out5v_hwctl_ops = {
+        .list_voltage = regulator_list_voltage_linear,
+};
+
+static struct regulator_ops max8907_bbat_ops = {
+        .list_voltage = regulator_list_voltage_linear,
+        .set_voltage_sel = regulator_set_voltage_sel_regmap,
+        .get_voltage_sel = regulator_get_voltage_sel_regmap,
+};
+
+static struct regulator_desc max8907_regulators[] = {
+        REG_MBATT(),
+        REG_LDO(SD1, "in-v1", MAX8907_REG_SDCTL1, 650000, 2225000, 25000),
+        REG_LDO(SD2, "in-v2", MAX8907_REG_SDCTL2, 637500, 1425000, 12500),
+        REG_LDO(SD3, "in-v3", MAX8907_REG_SDCTL3, 750000, 3900000, 50000),
+        LDO_750_50(LDO1, "in1", MAX8907_REG_LDOCTL1),
+        LDO_650_25(LDO2, "in2", MAX8907_REG_LDOCTL2),
+        LDO_650_25(LDO3, "in3", MAX8907_REG_LDOCTL3),
+        LDO_750_50(LDO4, "in4", MAX8907_REG_LDOCTL4),
+        LDO_750_50(LDO5, "in5", MAX8907_REG_LDOCTL5),
+        LDO_750_50(LDO6, "in6", MAX8907_REG_LDOCTL6),
+        LDO_750_50(LDO7, "in7", MAX8907_REG_LDOCTL7),
+        LDO_750_50(LDO8, "in8", MAX8907_REG_LDOCTL8),
+        LDO_750_50(LDO9, "in9", MAX8907_REG_LDOCTL9),
+        LDO_750_50(LDO10, "in10", MAX8907_REG_LDOCTL10),
+        LDO_750_50(LDO11, "in11", MAX8907_REG_LDOCTL11),
+        LDO_750_50(LDO12, "in12", MAX8907_REG_LDOCTL12),
+        LDO_750_50(LDO13, "in13", MAX8907_REG_LDOCTL13),
+        LDO_750_50(LDO14, "in14", MAX8907_REG_LDOCTL14),
+        LDO_750_50(LDO15, "in15", MAX8907_REG_LDOCTL15),
+        LDO_750_50(LDO16, "in16", MAX8907_REG_LDOCTL16),
+        LDO_650_25(LDO17, "in17", MAX8907_REG_LDOCTL17),
+        LDO_650_25(LDO18, "in18", MAX8907_REG_LDOCTL18),
+        LDO_750_50(LDO19, "in19", MAX8907_REG_LDOCTL19),
+        LDO_750_50(LDO20, "in20", MAX8907_REG_LDOCTL20),
+        REG_OUT5V(OUT5V, "mbatt", MAX8907_REG_OUT5VEN, 5000000),
+        REG_OUT5V(OUT33V, "mbatt",  MAX8907_REG_OUT33VEN, 3300000),
+        REG_BBAT(BBAT, "MBATT", MAX8907_REG_BBAT_CNFG,
+                                                2400000, 3000000, 200000),
+        REG_FIXED(SDBY, "MBATT", 1200000),
+        REG_FIXED(VRTC, "MBATT", 3300000),
+};
+
+#ifdef CONFIG_OF
+
+#define MATCH(_name, _id) \
+        [MAX8907_##_id] = { \
+                .name = #_name, \
+                .driver_data = (void *)&max8907_regulators[MAX8907_##_id], \
+        }
+
+static struct of_regulator_match max8907_matches[] = {
+        MATCH(mbatt, MBATT),
+        MATCH(sd1, SD1),
+        MATCH(sd2, SD2),
+        MATCH(sd3, SD3),
+        MATCH(ldo1, LDO1),
+        MATCH(ldo2, LDO2),
+        MATCH(ldo3, LDO3),
+        MATCH(ldo4, LDO4),
+        MATCH(ldo5, LDO5),
+        MATCH(ldo6, LDO6),
+        MATCH(ldo7, LDO7),
+        MATCH(ldo8, LDO8),
+        MATCH(ldo9, LDO9),
+        MATCH(ldo10, LDO10),
+        MATCH(ldo11, LDO11),
+        MATCH(ldo12, LDO12),
+        MATCH(ldo13, LDO13),
+        MATCH(ldo14, LDO14),
+        MATCH(ldo15, LDO15),
+        MATCH(ldo16, LDO16),
+        MATCH(ldo17, LDO17),
+        MATCH(ldo18, LDO18),
+        MATCH(ldo19, LDO19),
+        MATCH(ldo20, LDO20),
+        MATCH(out5v, OUT5V),
+        MATCH(out33v, OUT33V),
+        MATCH(bbat, BBAT),
+        MATCH(sdby, SDBY),
+        MATCH(vrtc, VRTC),
+};
+
+static int max8907_regulator_parse_dt(struct platform_device *pdev)
+{
+        struct device_node *np = pdev->dev.parent->of_node;
+        struct device_node *regulators;
+        int ret;
+
+        if (!pdev->dev.parent->of_node)
+                return 0;
+
+        regulators = of_find_node_by_name(np, "regulators");
+        if (!regulators) {
+                dev_err(&pdev->dev, "regulators node not found\n");
+                return -EINVAL;
+        }
+
+        ret = of_regulator_match(pdev->dev.parent, regulators,
+                                 max8907_matches,
+                                 ARRAY_SIZE(max8907_matches));
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Error parsing regulator init data: %d\n",
+                        ret);
+                return ret;
+        }
+
+        return 0;
+}
+#else
+static int max8907_regulator_parse_dt(struct platform_device *pdev)
+{
+        return 0;
+}
+#endif
+
+static __devinit int max8907_regulator_probe(struct platform_device *pdev)
+{
+        struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
+        struct max8907_platform_data *pdata = dev_get_platdata(max8907->dev);
+        int ret;
+        struct max8907_regulator *pmic;
+        unsigned int val;
+        int i;
+        struct regulator_config config = {};
+        struct regulator_init_data *idata;
+        const char *mbatt_rail_name = NULL;
+
+        ret = max8907_regulator_parse_dt(pdev);
+        if (ret)
+                return ret;
+
+        pmic = devm_kzalloc(&pdev->dev, sizeof(*pmic), GFP_KERNEL);
+        if (!pmic) {
+                dev_err(&pdev->dev, "Failed to alloc pmic\n");
+                return -ENOMEM;
+        }
+        platform_set_drvdata(pdev, pmic);
+
+        memcpy(pmic->desc, max8907_regulators, sizeof(pmic->desc));
+
+        /* Backwards compatibility with MAX8907B; SD1 uses different voltages */
+        regmap_read(max8907->regmap_gen, MAX8907_REG_II2RR, &val);
+        if ((val & MAX8907_II2RR_VERSION_MASK) ==
+            MAX8907_II2RR_VERSION_REV_B) {
+                pmic->desc[MAX8907_SD1].min_uV = 637500;
+                pmic->desc[MAX8907_SD1].uV_step = 12500;
+                pmic->desc[MAX8907_SD1].n_voltages = (1425000 - 637500) / 12500;
+        }
+
+        for (i = 0; i < MAX8907_NUM_REGULATORS; i++) {
+                config.dev = pdev->dev.parent;
+                if (pdata)
+                        idata = pdata->init_data[i];
+                else
+                        idata = max8907_matches[i].init_data;
+                config.init_data = idata;
+                config.driver_data = pmic;
+                config.regmap = max8907->regmap_gen;
+                config.of_node = max8907_matches[i].of_node;
+
+                switch (pmic->desc[i].id) {
+                case MAX8907_MBATT:
+                        mbatt_rail_name = idata->constraints.name;
+                        break;
+                case MAX8907_BBAT:
+                case MAX8907_SDBY:
+                case MAX8907_VRTC:
+                        idata->supply_regulator = mbatt_rail_name;
+                        break;
+                }
+
+                if (pmic->desc[i].ops == &max8907_ldo_ops) {
+                        regmap_read(config.regmap, pmic->desc[i].enable_reg,
+                                    &val);
+                        if ((val & MAX8907_MASK_LDO_SEQ) !=
+                            MAX8907_MASK_LDO_SEQ)
+                                pmic->desc[i].ops = &max8907_ldo_hwctl_ops;
+                } else if (pmic->desc[i].ops == &max8907_out5v_ops) {
+                        regmap_read(config.regmap, pmic->desc[i].enable_reg,
+                                    &val);
+                        if ((val & (MAX8907_MASK_OUT5V_VINEN |
+                                                MAX8907_MASK_OUT5V_ENSRC)) !=
+                            MAX8907_MASK_OUT5V_ENSRC)
+                                pmic->desc[i].ops = &max8907_out5v_hwctl_ops;
+                }
+
+                pmic->rdev[i] = regulator_register(&pmic->desc[i], &config);
+                if (IS_ERR(pmic->rdev[i])) {
+                        dev_err(&pdev->dev,
+                                "failed to register %s regulator\n",
+                                pmic->desc[i].name);
+                        ret = PTR_ERR(pmic->rdev[i]);
+                        goto err_unregister_regulator;
+                }
+        }
+
+        return 0;
+
+err_unregister_regulator:
+        while (--i >= 0)
+                regulator_unregister(pmic->rdev[i]);
+        return ret;
+}
+
+static __devexit int max8907_regulator_remove(struct platform_device *pdev)
+{
+        struct max8907_regulator *pmic;
+        int i;
+
+        for (i = 0; i < MAX8907_NUM_REGULATORS; i++)
+                regulator_unregister(pmic->rdev[i]);
+
+        return 0;
+}
+
+static struct platform_driver max8907_regulator_driver = {
+        .driver = {
+                   .name = "max8907-regulator",
+                   .owner = THIS_MODULE,
+                   },
+        .probe = max8907_regulator_probe,
+        .remove = __devexit_p(max8907_regulator_remove),
+};
+
+static int __init max8907_regulator_init(void)
+{
+        return platform_driver_register(&max8907_regulator_driver);
+}
+
+subsys_initcall(max8907_regulator_init);
+
+static void __exit max8907_reg_exit(void)
+{
+        platform_driver_unregister(&max8907_regulator_driver);
+}
+
+module_exit(max8907_reg_exit);
+
+MODULE_DESCRIPTION("MAX8907 regulator driver");
+MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@maxim-ic.com>");
+MODULE_LICENSE("GPL v2");