drivers: regulator: add Maxim 8998 driver

Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

This patch adds voltage regulator driver for Maxim 8998 chip. This chip
is used on Samsung Aquila and GONI boards and provides following
functionalities:
- 4 BUCK voltage converters, 17 LDO power regulators and 5 other power
  controllers
- battery charger

This patch adds basic driver for voltage regulators and MAX 8998 MFD core.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

3 files changed, 171 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 9da0e504bbe9..ad61a9e8e04e 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -252,6 +252,16 @@ config MFD_MAX8925
           accessing the device, additional drivers must be enabled in order
           to use the functionality of the device.
 
+config MFD_MAX8998
+        bool "Maxim Semiconductor MAX8998 PMIC Support"
+        depends on I2C=y
+        select MFD_CORE
+        help
+          Say yes here to support for Maxim Semiconductor MAX8998. This is
+          a Power Management IC. This driver provies common support for
+          accessing the device, additional drivers must be enabled in order
+          to use the functionality of the device.
+
 config MFD_WM8400
         tristate "Support Wolfson Microelectronics WM8400"
         select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index fb503e77dc60..a362ccfe8997 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_UCB1400_CORE)	+= ucb1400_core.o
 obj-$(CONFIG_PMIC_DA903X)       += da903x.o
 max8925-objs                    := max8925-core.o max8925-i2c.o
 obj-$(CONFIG_MFD_MAX8925)       += max8925.o
+obj-$(CONFIG_MFD_MAX8998)       += max8998.o
 
 pcf50633-objs                   := pcf50633-core.o pcf50633-irq.o
 obj-$(CONFIG_MFD_PCF50633)      += pcf50633.o
diff --git a/drivers/mfd/max8998.c b/drivers/mfd/max8998.c
new file mode 100644
index 000000000000..0d68de21ea9e
--- /dev/null
+++ b/drivers/mfd/max8998.c
@@ -0,0 +1,160 @@
+/*
+ * max8698.c - mfd core driver for the Maxim 8998
+ *
+ *  Copyright (C) 2009-2010 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.com>
+ *  Marek Szyprowski <m.szyprowski@samsung.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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max8998.h>
+#include <linux/mfd/max8998-private.h>
+
+static struct mfd_cell max8998_devs[] = {
+        {
+                .name = "max8998-pmic",
+        }
+};
+
+static int max8998_i2c_device_read(struct max8998_dev *max8998, u8 reg, u8 *dest)
+{
+        struct i2c_client *client = max8998->i2c_client;
+        int ret;
+
+        mutex_lock(&max8998->iolock);
+        ret = i2c_smbus_read_byte_data(client, reg);
+        mutex_unlock(&max8998->iolock);
+        if (ret < 0)
+                return ret;
+
+        ret &= 0xff;
+        *dest = ret;
+        return 0;
+}
+
+static int max8998_i2c_device_write(struct max8998_dev *max8998, u8 reg, u8 value)
+{
+        struct i2c_client *client = max8998->i2c_client;
+        int ret;
+
+        mutex_lock(&max8998->iolock);
+        ret = i2c_smbus_write_byte_data(client, reg, value);
+        mutex_unlock(&max8998->iolock);
+        return ret;
+}
+
+static int max8998_i2c_device_update(struct max8998_dev *max8998, u8 reg,
+                                     u8 val, u8 mask)
+{
+        struct i2c_client *client = max8998->i2c_client;
+        int ret;
+
+        mutex_lock(&max8998->iolock);
+        ret = i2c_smbus_read_byte_data(client, reg);
+        if (ret >= 0) {
+                u8 old_val = ret & 0xff;
+                u8 new_val = (val & mask) | (old_val & (~mask));
+                ret = i2c_smbus_write_byte_data(client, reg, new_val);
+                if (ret >= 0)
+                        ret = 0;
+        }
+        mutex_unlock(&max8998->iolock);
+        return ret;
+}
+
+static int max8998_i2c_probe(struct i2c_client *i2c,
+                            const struct i2c_device_id *id)
+{
+        struct max8998_dev *max8998;
+        int ret = 0;
+
+        max8998 = kzalloc(sizeof(struct max8998_dev), GFP_KERNEL);
+        if (max8998 == NULL) {
+                kfree(i2c);
+                return -ENOMEM;
+        }
+
+        i2c_set_clientdata(i2c, max8998);
+        max8998->dev = &i2c->dev;
+        max8998->i2c_client = i2c;
+        max8998->dev_read = max8998_i2c_device_read;
+        max8998->dev_write = max8998_i2c_device_write;
+        max8998->dev_update = max8998_i2c_device_update;
+        mutex_init(&max8998->iolock);
+
+        ret = mfd_add_devices(max8998->dev, -1,
+                              max8998_devs, ARRAY_SIZE(max8998_devs),
+                              NULL, 0);
+        if (ret < 0)
+                goto err;
+
+        return ret;
+
+err:
+        mfd_remove_devices(max8998->dev);
+        kfree(max8998);
+        return ret;
+}
+
+static int max8998_i2c_remove(struct i2c_client *i2c)
+{
+        struct max8998_dev *max8998 = i2c_get_clientdata(i2c);
+
+        mfd_remove_devices(max8998->dev);
+        kfree(max8998);
+
+        return 0;
+}
+
+static const struct i2c_device_id max8998_i2c_id[] = {
+       { "max8998", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, max8998_i2c_id);
+
+static struct i2c_driver max8998_i2c_driver = {
+        .driver = {
+                   .name = "max8998",
+                   .owner = THIS_MODULE,
+        },
+        .probe = max8998_i2c_probe,
+        .remove = max8998_i2c_remove,
+        .id_table = max8998_i2c_id,
+};
+
+static int __init max8998_i2c_init(void)
+{
+        return i2c_add_driver(&max8998_i2c_driver);
+}
+/* init early so consumer devices can complete system boot */
+subsys_initcall(max8998_i2c_init);
+
+static void __exit max8998_i2c_exit(void)
+{
+        i2c_del_driver(&max8998_i2c_driver);
+}
+module_exit(max8998_i2c_exit);
+
+MODULE_DESCRIPTION("MAXIM 8998 multi-function core driver");
+MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
+MODULE_LICENSE("GPL");