ARM: davinci: gpio: use gpiolib API instead of inline functions

Remove NEED_MACH_GPIO_H config select option for ARCH_DAVINCI
to start using gpiolib interface for davinci platforms. This makes
it easier to use the gpio driver on other platforms as it breaks
dependency on mach-davinci.

Latencies for gpio_get/set APIs will increase. On measurement,
latency was found to have increased by 18 microsecond with
gpiolib API as compared to inline APIs.

Measurement was done on DA850 EVM for gpio_get_value() API by
taking the printk timing across the call with interrupts disabled.

  inline gpio API with interrupt disabled
  [   29.734337] before gpio_get
  [   29.736847] after gpio_get

  Time difference 0.00251

  gpio library with interrupt disabled
  [  272.876763] before gpio_get
  [  272.879291] after gpio_get

  Time difference 0.002528
  Latency increased by (0.002528 -  0.00251) = 18 microsecond.

While at it, remove GPIO_TYPE_DAVINCI enum definition as
gpio-davinci.c is converted to Linux device driver model.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
[nsekhar@ti.com: minor edits to commit message]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

arch/arm/Kconfig

@@ -847,7 +847,6 @@ config ARCH_DAVINCI
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_IRQ_CHIP
 	select HAVE_IDE
-	select NEED_MACH_GPIO_H
 	select TI_PRIV_EDMA
 	select USE_OF
 	select ZONE_DMA

drivers/gpio/gpio-tnetv107x.c

@@ -15,6 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/gpio.h>
+#include <linux/platform_data/gpio-davinci.h>
 
 #include <mach/common.h>
 #include <mach/tnetv107x.h>

include/linux/platform_data/gpio-davinci.h

@@ -16,10 +16,45 @@
 #ifndef __DAVINCI_GPIO_PLATFORM_H
 #define __DAVINCI_GPIO_PLATFORM_H
 
+#include <linux/io.h>
+#include <linux/spinlock.h>
+
+#include <asm-generic/gpio.h>
+
+enum davinci_gpio_type {
+	GPIO_TYPE_TNETV107X = 0,
+};
+
 struct davinci_gpio_platform_data {
 	u32	ngpio;
 	u32	gpio_unbanked;
 	u32	intc_irq_num;
 };
 
+
+struct davinci_gpio_controller {
+	struct gpio_chip	chip;
+	int			irq_base;
+	/* Serialize access to GPIO registers */
+	spinlock_t		lock;
+	void __iomem		*regs;
+	void __iomem		*set_data;
+	void __iomem		*clr_data;
+	void __iomem		*in_data;
+	int			gpio_unbanked;
+	unsigned		gpio_irq;
+};
+
+/*
+ * basic gpio routines
+ */
+#define	GPIO(X)		(X)	/* 0 <= X <= (DAVINCI_N_GPIO - 1) */
+
+/* Convert GPIO signal to GPIO pin number */
+#define GPIO_TO_PIN(bank, gpio)	(16 * (bank) + (gpio))
+
+static inline u32 __gpio_mask(unsigned gpio)
+{
+	return 1 << (gpio % 32);
+}
 #endif