[ARM] 4377/1: KS8695: GPIO driver

Driver to control the GPIO pins on the KS8695 processor.
The driver natively supports the Generic GPIO interface.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -308,6 +308,7 @@ config ARCH_L7200
 
 config ARCH_KS8695
 	bool "Micrel/Kendin KS8695"
+	select GENERIC_GPIO
 	help
 	  Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
 	  System-on-Chip devices.

arch/arm/mach-ks8695/Makefile

@@ -3,7 +3,7 @@
 # Makefile for KS8695 architecture support
 #
 
-obj-y				:= cpu.o irq.o time.o devices.o
+obj-y				:= cpu.o irq.o time.o gpio.o devices.o
 obj-m				:=
 obj-n				:=
 obj-				:=

arch/arm/mach-ks8695/gpio.c

+/*
+ * arch/arm/mach-ks8695/gpio.c
+ *
+ * Copyright (C) 2006 Andrew Victor
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include <asm/io.h>
+#include <asm/hardware.h>
+#include <asm/mach/irq.h>
+
+#include <asm/arch/regs-gpio.h>
+#include <asm/arch/gpio.h>
+
+/*
+ * Configure a GPIO line for either GPIO function, or its internal
+ * function (Interrupt, Timer, etc).
+ */
+static void __init_or_module ks8695_gpio_mode(unsigned int pin, short gpio)
+{
+	unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
+	unsigned long x, flags;
+
+	if (pin > KS8695_GPIO_5)	/* only GPIO 0..5 have internal functions */
+		return;
+
+	local_irq_save(flags);
+
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
+	if (gpio)			/* GPIO: set bit to 0 */
+		x &= ~enable[pin];
+	else				/* Internal function: set bit to 1 */
+		x |= enable[pin];
+	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPC);
+
+	local_irq_restore(flags);
+}
+
+
+static unsigned short gpio_irq[] = { KS8695_IRQ_EXTERN0, KS8695_IRQ_EXTERN1, KS8695_IRQ_EXTERN2, KS8695_IRQ_EXTERN3 };
+
+/*
+ * Configure GPIO pin as external interrupt source.
+ */
+int __init_or_module ks8695_gpio_interrupt(unsigned int pin, unsigned int type)
+{
+	unsigned long x, flags;
+
+	if (pin > KS8695_GPIO_3)	/* only GPIO 0..3 can generate IRQ */
+		return -EINVAL;
+
+	local_irq_save(flags);
+
+	/* set pin as input */
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
+	x &= ~IOPM_(pin);
+	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
+
+	local_irq_restore(flags);
+
+	/* Set IRQ triggering type */
+	set_irq_type(gpio_irq[pin], type);
+
+	/* enable interrupt mode */
+	ks8695_gpio_mode(pin, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL(ks8695_gpio_interrupt);
+
+
+
+/* .... Generic GPIO interface .............................................. */
+
+/*
+ * Configure the GPIO line as an input.
+ */
+int __init_or_module gpio_direction_input(unsigned int pin)
+{
+	unsigned long x, flags;
+
+	if (pin > KS8695_GPIO_15)
+		return -EINVAL;
+
+	/* set pin to GPIO mode */
+	ks8695_gpio_mode(pin, 1);
+
+	local_irq_save(flags);
+
+	/* set pin as input */
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
+	x &= ~IOPM_(pin);
+	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+
+/*
+ * Configure the GPIO line as an output, with default state.
+ */
+int __init_or_module gpio_direction_output(unsigned int pin, unsigned int state)
+{
+	unsigned long x, flags;
+
+	if (pin > KS8695_GPIO_15)
+		return -EINVAL;
+
+	/* set pin to GPIO mode */
+	ks8695_gpio_mode(pin, 1);
+
+	local_irq_save(flags);
+
+	/* set line state */
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
+	if (state)
+		x |= (1 << pin);
+	else
+		x &= ~(1 << pin);
+	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
+
+	/* set pin as output */
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
+	x |= IOPM_(pin);
+	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+
+/*
+ * Set the state of an output GPIO line.
+ */
+void gpio_set_value(unsigned int pin, unsigned int state)
+{
+	unsigned long x, flags;
+
+	if (pin > KS8695_GPIO_15)
+		return;
+
+	local_irq_save(flags);
+
+	/* set output line state */
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
+	if (state)
+		x |= (1 << pin);
+	else
+		x &= ~(1 << pin);
+	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
+
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(gpio_set_value);
+
+
+/*
+ * Read the state of a GPIO line.
+ */
+int gpio_get_value(unsigned int pin)
+{
+	unsigned long x;
+
+	if (pin > KS8695_GPIO_15)
+		return -EINVAL;
+
+	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
+	return (x & (1 << pin)) != 0;
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+
+/*
+ * Map GPIO line to IRQ number.
+ */
+int gpio_to_irq(unsigned int pin)
+{
+	if (pin > KS8695_GPIO_3)	/* only GPIO 0..3 can generate IRQ */
+		return -EINVAL;
+
+	return gpio_irq[pin];
+}
+EXPORT_SYMBOL(gpio_to_irq);
+
+
+/*
+ * Map IRQ number to GPIO line.
+ */
+int irq_to_gpio(unsigned int irq)
+{
+	if ((irq < KS8695_IRQ_EXTERN0) || (irq > KS8695_IRQ_EXTERN3))
+		return -EINVAL;
+
+	return (irq - KS8695_IRQ_EXTERN0);
+}
+EXPORT_SYMBOL(irq_to_gpio);

include/asm-arm/arch-ks8695/gpio.h

+/*
+ * include/asm-arm/arch-ks8695/gpio.h
+ *
+ * Copyright (C) 2006 Andrew Victor
+ *
+ * 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.
+ */
+
+#ifndef __ASM_ARCH_GPIO_H_
+#define __ASM_ARCH_GPIO_H_
+
+#define KS8695_GPIO_0		0
+#define KS8695_GPIO_1		1
+#define KS8695_GPIO_2		2
+#define KS8695_GPIO_3		3
+#define KS8695_GPIO_4		4
+#define KS8695_GPIO_5		5
+#define KS8695_GPIO_6		6
+#define KS8695_GPIO_7		7
+#define KS8695_GPIO_8		8
+#define KS8695_GPIO_9		9
+#define KS8695_GPIO_10		10
+#define KS8695_GPIO_11		11
+#define KS8695_GPIO_12		12
+#define KS8695_GPIO_13		13
+#define KS8695_GPIO_14		14
+#define KS8695_GPIO_15		15
+
+
+/*
+ * Configure GPIO pin as external interrupt source.
+ */
+int __init_or_module ks8695_gpio_interrupt(unsigned int pin, unsigned int type);
+
+/*
+ * Configure the GPIO line as an input.
+ */
+int __init_or_module gpio_direction_input(unsigned int pin);
+
+/*
+ * Configure the GPIO line as an output, with default state.
+ */
+int __init_or_module gpio_direction_output(unsigned int pin, unsigned int state);
+
+/*
+ * Set the state of an output GPIO line.
+ */
+void gpio_set_value(unsigned int pin, unsigned int state);
+
+/*
+ * Read the state of a GPIO line.
+ */
+int gpio_get_value(unsigned int pin);
+
+/*
+ * Map GPIO line to IRQ number.
+ */
+int gpio_to_irq(unsigned int pin);
+
+/*
+ * Map IRQ number to GPIO line.
+ */
+int irq_to_gpio(unsigned int irq);
+
+
+#include <asm-generic/gpio.h>
+
+static inline int gpio_request(unsigned int pin, const char *label)
+{
+	return 0;
+}
+
+static inline void gpio_free(unsigned int pin)
+{
+}
+
+#endif