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 000000000000..942068e730f9
--- /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");