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>

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

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

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");