mfd: axp20x: Split the driver into core and i2c bits

The axp20x driver assumes the device is i2c based. This is not the
case with later chips, which use a proprietary 2 wire serial bus
by Allwinner called "Reduced Serial Bus".

This patch follows the example of mfd/wm831x and splits it into
an interface independent core, and an i2c specific glue layer.
MFD_AXP20X and the new MFD_AXP20X_I2C are changed to tristate
symbols, allowing the driver to be built as modules.

Whitespace and other style errors in the moved i2c specific code
have been fixed. Included but unused header files are removed as
well.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 104 insertions, 0 deletions

diff --git a/drivers/mfd/axp20x-i2c.c b/drivers/mfd/axp20x-i2c.c
new file mode 100644
index 000000000000..b1b865822c07
--- /dev/null
+++ b/drivers/mfd/axp20x-i2c.c
@@ -0,0 +1,104 @@
+/*
+ * I2C driver for the X-Powers' Power Management ICs
+ *
+ * AXP20x typically comprises an adaptive USB-Compatible PWM charger, BUCK DC-DC
+ * converters, LDOs, multiple 12-bit ADCs of voltage, current and temperature
+ * as well as configurable GPIOs.
+ *
+ * This driver supports the I2C variants.
+ *
+ * Copyright (C) 2014 Carlo Caione
+ *
+ * Author: Carlo Caione <carlo@caione.org>
+ *
+ * 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/acpi.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+static int axp20x_i2c_probe(struct i2c_client *i2c,
+			    const struct i2c_device_id *id)
+{
+	struct axp20x_dev *axp20x;
+	int ret;
+
+	axp20x = devm_kzalloc(&i2c->dev, sizeof(*axp20x), GFP_KERNEL);
+	if (!axp20x)
+		return -ENOMEM;
+
+	axp20x->dev = &i2c->dev;
+	axp20x->irq = i2c->irq;
+	dev_set_drvdata(axp20x->dev, axp20x);
+
+	ret = axp20x_match_device(axp20x);
+	if (ret)
+		return ret;
+
+	axp20x->regmap = devm_regmap_init_i2c(i2c, axp20x->regmap_cfg);
+	if (IS_ERR(axp20x->regmap)) {
+		ret = PTR_ERR(axp20x->regmap);
+		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	return axp20x_device_probe(axp20x);
+}
+
+static int axp20x_i2c_remove(struct i2c_client *i2c)
+{
+	struct axp20x_dev *axp20x = i2c_get_clientdata(i2c);
+
+	return axp20x_device_remove(axp20x);
+}
+
+static const struct of_device_id axp20x_i2c_of_match[] = {
+	{ .compatible = "x-powers,axp152", .data = (void *)AXP152_ID },
+	{ .compatible = "x-powers,axp202", .data = (void *)AXP202_ID },
+	{ .compatible = "x-powers,axp209", .data = (void *)AXP209_ID },
+	{ .compatible = "x-powers,axp221", .data = (void *)AXP221_ID },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, axp20x_i2c_of_match);
+
+/*
+ * This is useless for OF-enabled devices, but it is needed by I2C subsystem
+ */
+static const struct i2c_device_id axp20x_i2c_id[] = {
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, axp20x_i2c_id);
+
+static const struct acpi_device_id axp20x_i2c_acpi_match[] = {
+	{
+		.id = "INT33F4",
+		.driver_data = AXP288_ID,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, axp20x_i2c_acpi_match);
+
+static struct i2c_driver axp20x_i2c_driver = {
+	.driver = {
+		.name	= "axp20x-i2c",
+		.of_match_table	= of_match_ptr(axp20x_i2c_of_match),
+		.acpi_match_table = ACPI_PTR(axp20x_i2c_acpi_match),
+	},
+	.probe		= axp20x_i2c_probe,
+	.remove		= axp20x_i2c_remove,
+	.id_table	= axp20x_i2c_id,
+};
+
+module_i2c_driver(axp20x_i2c_driver);
+
+MODULE_DESCRIPTION("PMIC MFD I2C driver for AXP20X");
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_LICENSE("GPL");