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, 32 insertions, 1 deletions

diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
index b24c771cebd5..00697c6ad8b0 100644
--- a/include/linux/mfd/axp20x.h
+++ b/include/linux/mfd/axp20x.h
@@ -396,7 +396,7 @@ enum axp288_irqs {
 
 struct axp20x_dev {
 	struct device			*dev;
-	struct i2c_client		*i2c_client;
+	int				irq;
 	struct regmap			*regmap;
 	struct regmap_irq_chip_data	*regmap_irqc;
 	long				variant;
@@ -462,4 +462,35 @@ static inline int axp20x_read_variable_width(struct regmap *regmap,
 	return result;
 }
 
+/**
+ * axp20x_match_device(): Setup axp20x variant related fields
+ *
+ * @axp20x: axp20x device to setup (.dev field must be set)
+ * @dev: device associated with this axp20x device
+ *
+ * This lets the axp20x core configure the mfd cells and register maps
+ * for later use.
+ */
+int axp20x_match_device(struct axp20x_dev *axp20x);
+
+/**
+ * axp20x_device_probe(): Probe a configured axp20x device
+ *
+ * @axp20x: axp20x device to probe (must be configured)
+ *
+ * This function lets the axp20x core register the axp20x mfd devices
+ * and irqchip. The axp20x device passed in must be fully configured
+ * with axp20x_match_device, its irq set, and regmap created.
+ */
+int axp20x_device_probe(struct axp20x_dev *axp20x);
+
+/**
+ * axp20x_device_probe(): Remove a axp20x device
+ *
+ * @axp20x: axp20x device to remove
+ *
+ * This tells the axp20x core to remove the associated mfd devices
+ */
+int axp20x_device_remove(struct axp20x_dev *axp20x);
+
 #endif /* __LINUX_MFD_AXP20X_H */