File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c
new file mode 100644
index 0000000..b0fe810
--- /dev/null
+++ b/drivers/mfd/max8925-i2c.c
@@ -0,0 +1,276 @@
+/*
+ * 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>
+#include <linux/slab.h>
+
+#define RTC_I2C_ADDR		0x68
+#define ADC_I2C_ADDR		0x47
+
+static inline int max8925_read_device(struct i2c_client *i2c,
+				      int reg, int bytes, void *dest)
+{
+	int ret;
+
+	if (bytes > 1)
+		ret = i2c_smbus_read_i2c_block_data(i2c, reg, bytes, dest);
+	else {
+		ret = i2c_smbus_read_byte_data(i2c, reg);
+		if (ret < 0)
+			return ret;
+		*(unsigned char *)dest = (unsigned char)ret;
+	}
+	return ret;
+}
+
+static inline int max8925_write_device(struct i2c_client *i2c,
+				       int reg, int bytes, void *src)
+{
+	unsigned char buf[9];
+	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 = 0;
+	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 max8925_dt_init(struct device_node *np, struct device *dev,
+			   struct max8925_platform_data *pdata)
+{
+	int ret;
+
+	ret = of_property_read_u32(np, "maxim,tsc-irq", &pdata->tsc_irq);
+	if (ret) {
+		dev_err(dev, "Not found maxim,tsc-irq property\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int max8925_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
+{
+	struct max8925_platform_data *pdata = dev_get_platdata(&client->dev);
+	static struct max8925_chip *chip;
+	struct device_node *node = client->dev.of_node;
+
+	if (node && !pdata) {
+		/* parse DT to get platform data */
+		pdata = devm_kzalloc(&client->dev,
+				     sizeof(struct max8925_platform_data),
+				     GFP_KERNEL);
+		if (!pdata)
+			return -ENOMEM;
+
+		if (max8925_dt_init(node, &client->dev, pdata))
+			return -EINVAL;
+	} else if (!pdata) {
+		pr_info("%s: platform data is missing\n", __func__);
+		return -EINVAL;
+	}
+
+	chip = devm_kzalloc(&client->dev,
+			    sizeof(struct max8925_chip), GFP_KERNEL);
+	if (chip == NULL)
+		return -ENOMEM;
+	chip->i2c = client;
+	chip->dev = &client->dev;
+	i2c_set_clientdata(client, chip);
+	dev_set_drvdata(chip->dev, chip);
+	mutex_init(&chip->io_lock);
+
+	chip->rtc = i2c_new_dummy(chip->i2c->adapter, RTC_I2C_ADDR);
+	if (!chip->rtc) {
+		dev_err(chip->dev, "Failed to allocate I2C device for RTC\n");
+		return -ENODEV;
+	}
+	i2c_set_clientdata(chip->rtc, chip);
+
+	chip->adc = i2c_new_dummy(chip->i2c->adapter, ADC_I2C_ADDR);
+	if (!chip->adc) {
+		dev_err(chip->dev, "Failed to allocate I2C device for ADC\n");
+		i2c_unregister_device(chip->rtc);
+		return -ENODEV;
+	}
+	i2c_set_clientdata(chip->adc, chip);
+
+	device_init_wakeup(&client->dev, 1);
+
+	max8925_device_init(chip, pdata);
+
+	return 0;
+}
+
+static int max8925_remove(struct i2c_client *client)
+{
+	struct max8925_chip *chip = i2c_get_clientdata(client);
+
+	max8925_device_exit(chip);
+	i2c_unregister_device(chip->adc);
+	i2c_unregister_device(chip->rtc);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max8925_suspend(struct device *dev)
+{
+	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+	struct max8925_chip *chip = i2c_get_clientdata(client);
+
+	if (device_may_wakeup(dev) && chip->wakeup_flag)
+		enable_irq_wake(chip->core_irq);
+	return 0;
+}
+
+static int max8925_resume(struct device *dev)
+{
+	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+	struct max8925_chip *chip = i2c_get_clientdata(client);
+
+	if (device_may_wakeup(dev) && chip->wakeup_flag)
+		disable_irq_wake(chip->core_irq);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(max8925_pm_ops, max8925_suspend, max8925_resume);
+
+static const struct of_device_id max8925_dt_ids[] = {
+	{ .compatible = "maxim,max8925", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max8925_dt_ids);
+
+static struct i2c_driver max8925_driver = {
+	.driver	= {
+		.name	= "max8925",
+		.pm     = &max8925_pm_ops,
+		.of_match_table = max8925_dt_ids,
+	},
+	.probe		= max8925_probe,
+	.remove		= 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");