ISL6271A voltage regulator support.

This device is very simple, it supports one buck and two LDOs. The LDOs are
fixed-voltage. Only the buck is programable over the I2C bus to 16 possible
voltages.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

3 files changed, 243 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 679ea3759449..6bf56c93a336 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -201,6 +201,12 @@ config REGULATOR_88PM8607
         help
           This driver supports 88PM8607 voltage regulator chips.
 
+config REGULATOR_ISL6271A
+        tristate "Intersil ISL6271A Power regulator"
+        depends on I2C
+        help
+          This driver supports ISL6271A voltage regulator chip.
+
 config REGULATOR_AD5398
         tristate "Analog Devices AD5398/AD5821 regulators"
         depends on I2C
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index c256668300a6..451a14a873f6 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -32,5 +32,6 @@ obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
 obj-$(CONFIG_REGULATOR_TPS65023) += tps65023-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6507X) += tps6507x-regulator.o
 obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
+obj-$(CONFIG_REGULATOR_ISL6271A) += isl6271a-regulator.o
 
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/isl6271a-regulator.c b/drivers/regulator/isl6271a-regulator.c
new file mode 100644
index 000000000000..e49d2bd393f2
--- /dev/null
+++ b/drivers/regulator/isl6271a-regulator.c
@@ -0,0 +1,236 @@
+/*
+ * isl6271a-regulator.c
+ *
+ * Support for Intersil ISL6271A voltage regulator
+ *
+ * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+#define ISL6271A_VOLTAGE_MIN    850000
+#define ISL6271A_VOLTAGE_MAX    1600000
+#define ISL6271A_VOLTAGE_STEP   50000
+
+/* PMIC details */
+struct isl_pmic {
+        struct i2c_client       *client;
+        struct regulator_dev    *rdev[3];
+        struct mutex            mtx;
+};
+
+static int isl6271a_get_voltage(struct regulator_dev *dev)
+{
+        struct isl_pmic *pmic = rdev_get_drvdata(dev);
+        int idx, data;
+
+        mutex_lock(&pmic->mtx);
+
+        idx = i2c_smbus_read_byte(pmic->client);
+        if (idx < 0) {
+                dev_err(&pmic->client->dev, "Error getting voltage\n");
+                data = idx;
+                goto out;
+        }
+
+        /* Convert the data from chip to microvolts */
+        data = ISL6271A_VOLTAGE_MIN + (ISL6271A_VOLTAGE_STEP * (idx & 0xf));
+
+out:
+        mutex_unlock(&pmic->mtx);
+        return data;
+}
+
+static int isl6271a_set_voltage(struct regulator_dev *dev, int minuV, int maxuV)
+{
+        struct isl_pmic *pmic = rdev_get_drvdata(dev);
+        int vsel, err, data;
+
+        if (minuV < ISL6271A_VOLTAGE_MIN || minuV > ISL6271A_VOLTAGE_MAX)
+                return -EINVAL;
+        if (maxuV < ISL6271A_VOLTAGE_MIN || maxuV > ISL6271A_VOLTAGE_MAX)
+                return -EINVAL;
+
+        /* Align to 50000 mV */
+        vsel = minuV - (minuV % ISL6271A_VOLTAGE_STEP);
+
+        /* If the result fell out of [minuV,maxuV] range, put it back */
+        if (vsel < minuV)
+                vsel += ISL6271A_VOLTAGE_STEP;
+
+        /* Convert the microvolts to data for the chip */
+        data = (vsel - ISL6271A_VOLTAGE_MIN) / ISL6271A_VOLTAGE_STEP;
+
+        mutex_lock(&pmic->mtx);
+
+        err = i2c_smbus_write_byte(pmic->client, data);
+        if (err < 0)
+                dev_err(&pmic->client->dev, "Error setting voltage\n");
+
+        mutex_unlock(&pmic->mtx);
+        return err;
+}
+
+static int isl6271a_list_voltage(struct regulator_dev *dev, unsigned selector)
+{
+        return ISL6271A_VOLTAGE_MIN + (ISL6271A_VOLTAGE_STEP * selector);
+}
+
+static struct regulator_ops isl_core_ops = {
+        .get_voltage    = isl6271a_get_voltage,
+        .set_voltage    = isl6271a_set_voltage,
+        .list_voltage   = isl6271a_list_voltage,
+};
+
+static int isl6271a_get_fixed_voltage(struct regulator_dev *dev)
+{
+        int id = rdev_get_id(dev);
+        return (id == 1) ? 1100000 : 1300000;
+}
+
+static int isl6271a_list_fixed_voltage(struct regulator_dev *dev, unsigned selector)
+{
+        int id = rdev_get_id(dev);
+        return (id == 1) ? 1100000 : 1300000;
+}
+
+static struct regulator_ops isl_fixed_ops = {
+        .get_voltage    = isl6271a_get_fixed_voltage,
+        .list_voltage   = isl6271a_list_fixed_voltage,
+};
+
+static struct regulator_desc isl_rd[] = {
+        {
+                .name           = "Core Buck",
+                .id             = 0,
+                .n_voltages     = 16,
+                .ops            = &isl_core_ops,
+                .type           = REGULATOR_VOLTAGE,
+                .owner          = THIS_MODULE,
+        }, {
+                .name           = "LDO1",
+                .id             = 1,
+                .n_voltages     = 1,
+                .ops            = &isl_fixed_ops,
+                .type           = REGULATOR_VOLTAGE,
+                .owner          = THIS_MODULE,
+        }, {
+                .name           = "LDO2",
+                .id             = 2,
+                .n_voltages     = 1,
+                .ops            = &isl_fixed_ops,
+                .type           = REGULATOR_VOLTAGE,
+                .owner          = THIS_MODULE,
+        },
+};
+
+static int __devinit isl6271a_probe(struct i2c_client *i2c,
+                                     const struct i2c_device_id *id)
+{
+        struct regulator_init_data *init_data   = i2c->dev.platform_data;
+        struct isl_pmic *pmic;
+        int err, i;
+
+        if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+                return -EIO;
+
+        if (!init_data) {
+                dev_err(&i2c->dev, "no platform data supplied\n");
+                return -EIO;
+        }
+
+        pmic = kzalloc(sizeof(struct isl_pmic), GFP_KERNEL);
+        if (!pmic)
+                return -ENOMEM;
+
+        pmic->client = i2c;
+
+        mutex_init(&pmic->mtx);
+
+        for (i = 0; i < 3; i++) {
+                pmic->rdev[i] = regulator_register(&isl_rd[0], &i2c->dev,
+                                                init_data, pmic);
+                if (IS_ERR(pmic->rdev[i])) {
+                        dev_err(&i2c->dev, "failed to register %s\n", id->name);
+                        err = PTR_ERR(pmic->rdev);
+                        goto error;
+                }
+        }
+
+        i2c_set_clientdata(i2c, pmic);
+
+        return 0;
+
+error:
+        while (--i >= 0)
+                regulator_unregister(pmic->rdev[i]);
+
+        kfree(pmic);
+        return err;
+}
+
+static int __devexit isl6271a_remove(struct i2c_client *i2c)
+{
+        struct isl_pmic *pmic = i2c_get_clientdata(i2c);
+        int i;
+
+        i2c_set_clientdata(i2c, NULL);
+
+        for (i = 0; i < 3; i++)
+                regulator_unregister(pmic->rdev[i]);
+
+        kfree(pmic);
+
+        return 0;
+}
+
+static const struct i2c_device_id isl6271a_id[] = {
+        {.name = "isl6271a", 0 },
+        { },
+};
+
+MODULE_DEVICE_TABLE(i2c, isl6271a_id);
+
+static struct i2c_driver isl6271a_i2c_driver = {
+        .driver = {
+                .name = "isl6271a",
+                .owner = THIS_MODULE,
+        },
+        .probe = isl6271a_probe,
+        .remove = __devexit_p(isl6271a_remove),
+        .id_table = isl6271a_id,
+};
+
+static int __init isl6271a_init(void)
+{
+        return i2c_add_driver(&isl6271a_i2c_driver);
+}
+
+static void __exit isl6271a_cleanup(void)
+{
+        i2c_del_driver(&isl6271a_i2c_driver);
+}
+
+subsys_initcall(isl6271a_init);
+module_exit(isl6271a_cleanup);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
+MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
+MODULE_LICENSE("GPL v2");