basic_mmio_gpio: split into a gpio library and platform device
Allow GPIO_BASIC_MMIO_CORE to be used to provide an accessor library
for implementing GPIO drivers whilst abstracting the register access
detail. Based on a patch from Anton Vorontsov[1] and adapted to allow
bgpio_chip to be embedded in another structure.
Changes since v1:
- Register the gpio_chip in the platform device probe
1. https://lkml.org/lkml/2011/4/19/401
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h
index f23ec73..1ae1271 100644
--- a/include/linux/basic_mmio_gpio.h
+++ b/include/linux/basic_mmio_gpio.h
@@ -13,9 +13,64 @@
#ifndef __BASIC_MMIO_GPIO_H
#define __BASIC_MMIO_GPIO_H
+#include <linux/gpio.h>
+#include <linux/types.h>
+#include <linux/compiler.h>
+
struct bgpio_pdata {
int base;
int ngpio;
};
+struct device;
+
+struct bgpio_chip {
+ struct gpio_chip gc;
+
+ unsigned long (*read_reg)(void __iomem *reg);
+ void (*write_reg)(void __iomem *reg, unsigned long data);
+
+ void __iomem *reg_dat;
+ void __iomem *reg_set;
+ void __iomem *reg_clr;
+ void __iomem *reg_dir;
+
+ /* Number of bits (GPIOs): <register width> * 8. */
+ int bits;
+
+ /*
+ * Some GPIO controllers work with the big-endian bits notation,
+ * e.g. in a 8-bits register, GPIO7 is the least significant bit.
+ */
+ unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
+
+ /*
+ * Used to lock bgpio_chip->data. Also, this is needed to keep
+ * shadowed and real data registers writes together.
+ */
+ spinlock_t lock;
+
+ /* Shadowed data register to clear/set bits safely. */
+ unsigned long data;
+
+ /* Shadowed direction registers to clear/set direction safely. */
+ unsigned long dir;
+};
+
+static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
+{
+ return container_of(gc, struct bgpio_chip, gc);
+}
+
+int __devexit bgpio_remove(struct bgpio_chip *bgc);
+int __devinit bgpio_init(struct bgpio_chip *bgc,
+ struct device *dev,
+ unsigned long sz,
+ void __iomem *dat,
+ void __iomem *set,
+ void __iomem *clr,
+ void __iomem *dirout,
+ void __iomem *dirin,
+ bool big_endian);
+
#endif /* __BASIC_MMIO_GPIO_H */