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, 15 insertions, 75 deletions

diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
index cec51e689d1d..8e569bcfe3bc 100644
--- a/drivers/mfd/axp20x.c
+++ b/drivers/mfd/axp20x.c
@@ -1,10 +1,12 @@
 /*
- * axp20x.c - MFD core driver for the X-Powers' Power Management ICs
+ * MFD core 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 file contains the interface independent core functions.
+ *
  * Copyright (C) 2014 Carlo Caione
  *
  * Author: Carlo Caione <carlo@caione.org>
@@ -15,18 +17,15 @@
  */
 
 #include <linux/err.h>
-#include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
-#include <linux/slab.h>
 #include <linux/regulator/consumer.h>
 #include <linux/mfd/axp20x.h>
 #include <linux/mfd/core.h>
 #include <linux/of_device.h>
-#include <linux/of_irq.h>
 #include <linux/acpi.h>
 
 #define AXP20X_OFF	0x80
@@ -378,32 +377,6 @@ static const struct regmap_irq axp288_regmap_irqs[] = {
 	INIT_REGMAP_IRQ(AXP288, BC_USB_CHNG,            5, 1),
 };
 
-static const struct of_device_id axp20x_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_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_acpi_match[] = {
-	{
-		.id = "INT33F4",
-		.driver_data = AXP288_ID,
-	},
-	{ },
-};
-MODULE_DEVICE_TABLE(acpi, axp20x_acpi_match);
-
 static const struct regmap_irq_chip axp152_regmap_irq_chip = {
 	.name			= "axp152_irq_chip",
 	.status_base		= AXP152_IRQ1_STATE,
@@ -608,7 +581,7 @@ static void axp20x_power_off(void)
 		     AXP20X_OFF);
 }
 
-static int axp20x_match_device(struct axp20x_dev *axp20x)
+int axp20x_match_device(struct axp20x_dev *axp20x)
 {
 	struct device *dev = axp20x->dev;
 	const struct acpi_device_id *acpi_id;
@@ -665,38 +638,18 @@ static int axp20x_match_device(struct axp20x_dev *axp20x)
 
 	return 0;
 }
+EXPORT_SYMBOL(axp20x_match_device);
 
-static int axp20x_i2c_probe(struct i2c_client *i2c,
-			 const struct i2c_device_id *id)
+int axp20x_device_probe(struct axp20x_dev *axp20x)
 {
-	struct axp20x_dev *axp20x;
 	int ret;
 
-	axp20x = devm_kzalloc(&i2c->dev, sizeof(*axp20x), GFP_KERNEL);
-	if (!axp20x)
-		return -ENOMEM;
-
-	axp20x->i2c_client = i2c;
-	axp20x->dev = &i2c->dev;
-	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;
-	}
-
-	ret = regmap_add_irq_chip(axp20x->regmap, i2c->irq,
+	ret = regmap_add_irq_chip(axp20x->regmap, axp20x->irq,
 				  IRQF_ONESHOT | IRQF_SHARED, -1,
 				  axp20x->regmap_irq_chip,
 				  &axp20x->regmap_irqc);
 	if (ret) {
-		dev_err(&i2c->dev, "failed to add irq chip: %d\n", ret);
+		dev_err(axp20x->dev, "failed to add irq chip: %d\n", ret);
 		return ret;
 	}
 
@@ -704,8 +657,8 @@ static int axp20x_i2c_probe(struct i2c_client *i2c,
 			axp20x->nr_cells, NULL, 0, NULL);
 
 	if (ret) {
-		dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
-		regmap_del_irq_chip(i2c->irq, axp20x->regmap_irqc);
+		dev_err(axp20x->dev, "failed to add MFD devices: %d\n", ret);
+		regmap_del_irq_chip(axp20x->irq, axp20x->regmap_irqc);
 		return ret;
 	}
 
@@ -714,38 +667,25 @@ static int axp20x_i2c_probe(struct i2c_client *i2c,
 		pm_power_off = axp20x_power_off;
 	}
 
-	dev_info(&i2c->dev, "AXP20X driver loaded\n");
+	dev_info(axp20x->dev, "AXP20X driver loaded\n");
 
 	return 0;
 }
+EXPORT_SYMBOL(axp20x_device_probe);
 
-static int axp20x_i2c_remove(struct i2c_client *i2c)
+int axp20x_device_remove(struct axp20x_dev *axp20x)
 {
-	struct axp20x_dev *axp20x = i2c_get_clientdata(i2c);
-
 	if (axp20x == axp20x_pm_power_off) {
 		axp20x_pm_power_off = NULL;
 		pm_power_off = NULL;
 	}
 
 	mfd_remove_devices(axp20x->dev);
-	regmap_del_irq_chip(axp20x->i2c_client->irq, axp20x->regmap_irqc);
+	regmap_del_irq_chip(axp20x->irq, axp20x->regmap_irqc);
 
 	return 0;
 }
-
-static struct i2c_driver axp20x_i2c_driver = {
-	.driver = {
-		.name	= "axp20x",
-		.of_match_table	= of_match_ptr(axp20x_of_match),
-		.acpi_match_table = ACPI_PTR(axp20x_acpi_match),
-	},
-	.probe		= axp20x_i2c_probe,
-	.remove		= axp20x_i2c_remove,
-	.id_table	= axp20x_i2c_id,
-};
-
-module_i2c_driver(axp20x_i2c_driver);
+EXPORT_SYMBOL(axp20x_device_remove);
 
 MODULE_DESCRIPTION("PMIC MFD core driver for AXP20X");
 MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");