mfd: Initial max8925 support

Basic Max8925 support, which is a power management IC from Maxim
Semiconductor.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 210 insertions, 0 deletions

diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c
new file mode 100644
index 0000000..942068e
--- /dev/null
+++ b/drivers/mfd/max8925-i2c.c
@@ -0,0 +1,210 @@
+/*
+ * I2C driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ *	Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/mfd/max8925.h>
+
+static inline int max8925_read_device(struct i2c_client *i2c,
+				      int reg, int bytes, void *dest)
+{
+	unsigned char data;
+	unsigned char *buf;
+	int ret;
+
+	buf = kzalloc(bytes + 1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	data = (unsigned char)reg;
+	ret = i2c_master_send(i2c, &data, 1);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_master_recv(i2c, buf, bytes + 1);
+	if (ret < 0)
+		return ret;
+	memcpy(dest, buf, bytes);
+	return 0;
+}
+
+static inline int max8925_write_device(struct i2c_client *i2c,
+				       int reg, int bytes, void *src)
+{
+	unsigned char buf[bytes + 1];
+	int ret;
+
+	buf[0] = (unsigned char)reg;
+	memcpy(&buf[1], src, bytes);
+
+	ret = i2c_master_send(i2c, buf, bytes + 1);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+int max8925_reg_read(struct i2c_client *i2c, int reg)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(i2c);
+	unsigned char data;
+	int ret;
+
+	mutex_lock(&chip->io_lock);
+	ret = max8925_read_device(i2c, reg, 1, &data);
+	mutex_unlock(&chip->io_lock);
+
+	if (ret < 0)
+		return ret;
+	else
+		return (int)data;
+}
+EXPORT_SYMBOL(max8925_reg_read);
+
+int max8925_reg_write(struct i2c_client *i2c, int reg,
+		unsigned char data)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(i2c);
+	int ret;
+
+	mutex_lock(&chip->io_lock);
+	ret = max8925_write_device(i2c, reg, 1, &data);
+	mutex_unlock(&chip->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(max8925_reg_write);
+
+int max8925_bulk_read(struct i2c_client *i2c, int reg,
+		int count, unsigned char *buf)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(i2c);
+	int ret;
+
+	mutex_lock(&chip->io_lock);
+	ret = max8925_read_device(i2c, reg, count, buf);
+	mutex_unlock(&chip->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(max8925_bulk_read);
+
+int max8925_bulk_write(struct i2c_client *i2c, int reg,
+		int count, unsigned char *buf)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(i2c);
+	int ret;
+
+	mutex_lock(&chip->io_lock);
+	ret = max8925_write_device(i2c, reg, count, buf);
+	mutex_unlock(&chip->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(max8925_bulk_write);
+
+int max8925_set_bits(struct i2c_client *i2c, int reg,
+		unsigned char mask, unsigned char data)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(i2c);
+	unsigned char value;
+	int ret;
+
+	mutex_lock(&chip->io_lock);
+	ret = max8925_read_device(i2c, reg, 1, &value);
+	if (ret < 0)
+		goto out;
+	value &= ~mask;
+	value |= data;
+	ret = max8925_write_device(i2c, reg, 1, &value);
+out:
+	mutex_unlock(&chip->io_lock);
+	return ret;
+}
+EXPORT_SYMBOL(max8925_set_bits);
+
+
+static const struct i2c_device_id max8925_id_table[] = {
+	{ "max8925", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, max8925_id_table);
+
+static int __devinit max8925_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
+{
+	struct max8925_platform_data *pdata = client->dev.platform_data;
+	struct max8925_chip *chip;
+
+	if (!pdata) {
+		pr_info("%s: platform data is missing\n", __func__);
+		return -EINVAL;
+	}
+	if ((pdata->chip_id <= MAX8925_INVALID)
+		|| (pdata->chip_id >= MAX8925_MAX)) {
+		pr_info("#%s: wrong chip identification\n", __func__);
+		return -EINVAL;
+	}
+
+	chip = kzalloc(sizeof(struct max8925_chip), GFP_KERNEL);
+	if (chip == NULL)
+		return -ENOMEM;
+	chip->i2c = client;
+	chip->chip_id = pdata->chip_id;
+	i2c_set_clientdata(client, chip);
+	chip->dev = &client->dev;
+	mutex_init(&chip->io_lock);
+	dev_set_drvdata(chip->dev, chip);
+	max8925_device_init(chip, pdata);
+
+	return 0;
+}
+
+static int __devexit max8925_remove(struct i2c_client *client)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(client);
+
+	max8925_device_exit(chip);
+	i2c_set_clientdata(client, NULL);
+	kfree(chip);
+	return 0;
+}
+
+static struct i2c_driver max8925_driver = {
+	.driver	= {
+		.name	= "max8925",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= max8925_probe,
+	.remove		= __devexit_p(max8925_remove),
+	.id_table	= max8925_id_table,
+};
+
+static int __init max8925_i2c_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&max8925_driver);
+	if (ret != 0)
+		pr_err("Failed to register MAX8925 I2C driver: %d\n", ret);
+	return ret;
+}
+subsys_initcall(max8925_i2c_init);
+
+static void __exit max8925_i2c_exit(void)
+{
+	i2c_del_driver(&max8925_driver);
+}
+module_exit(max8925_i2c_exit);
+
+MODULE_DESCRIPTION("I2C Driver for Maxim 8925");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");