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gpio-ks8695.c
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gpio-ks8695.c
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/*
* arch/arm/mach-ks8695/gpio.c
*
* Copyright (C) 2006 Andrew Victor
* Updated to GPIOLIB, Copyright 2008 Simtec Electronics
* Daniel Silverstone <[email protected]>
*
* 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/gpio.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <asm/mach/irq.h>
#include <mach/regs-gpio.h>
#include <mach/gpio-ks8695.h>
/*
* Configure a GPIO line for either GPIO function, or its internal
* function (Interrupt, Timer, etc).
*/
static void 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 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 */
irq_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.
*/
static int ks8695_gpio_direction_input(struct gpio_chip *gc, 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;
}
/*
* Configure the GPIO line as an output, with default state.
*/
static int ks8695_gpio_direction_output(struct gpio_chip *gc,
unsigned int pin, 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 |= IOPD(pin);
else
x &= ~IOPD(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;
}
/*
* Set the state of an output GPIO line.
*/
static void ks8695_gpio_set_value(struct gpio_chip *gc,
unsigned int pin, 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 |= IOPD(pin);
else
x &= ~IOPD(pin);
__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
local_irq_restore(flags);
}
/*
* Read the state of a GPIO line.
*/
static int ks8695_gpio_get_value(struct gpio_chip *gc, unsigned int pin)
{
unsigned long x;
if (pin > KS8695_GPIO_15)
return -EINVAL;
x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
return (x & IOPD(pin)) != 0;
}
/*
* Map GPIO line to IRQ number.
*/
static int ks8695_gpio_to_irq(struct gpio_chip *gc, unsigned int pin)
{
if (pin > KS8695_GPIO_3) /* only GPIO 0..3 can generate IRQ */
return -EINVAL;
return gpio_irq[pin];
}
/* GPIOLIB interface */
static struct gpio_chip ks8695_gpio_chip = {
.label = "KS8695",
.direction_input = ks8695_gpio_direction_input,
.direction_output = ks8695_gpio_direction_output,
.get = ks8695_gpio_get_value,
.set = ks8695_gpio_set_value,
.to_irq = ks8695_gpio_to_irq,
.base = 0,
.ngpio = 16,
.can_sleep = false,
};
/* Register the GPIOs */
void ks8695_register_gpios(void)
{
if (gpiochip_add_data(&ks8695_gpio_chip, NULL))
printk(KERN_ERR "Unable to register core GPIOs\n");
}
/* .... Debug interface ..................................................... */
#ifdef CONFIG_DEBUG_FS
static int ks8695_gpio_show(struct seq_file *s, void *unused)
{
unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
unsigned int intmask[] = { IOPC_IOEINT0TM, IOPC_IOEINT1TM, IOPC_IOEINT2TM, IOPC_IOEINT3TM };
unsigned long mode, ctrl, data;
int i;
mode = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
ctrl = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
data = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
seq_printf(s, "Pin\tI/O\tFunction\tState\n\n");
for (i = KS8695_GPIO_0; i <= KS8695_GPIO_15 ; i++) {
seq_printf(s, "%i:\t", i);
seq_printf(s, "%s\t", (mode & IOPM(i)) ? "Output" : "Input");
if (i <= KS8695_GPIO_3) {
if (ctrl & enable[i]) {
seq_printf(s, "EXT%i ", i);
switch ((ctrl & intmask[i]) >> (4 * i)) {
case IOPC_TM_LOW:
seq_printf(s, "(Low)"); break;
case IOPC_TM_HIGH:
seq_printf(s, "(High)"); break;
case IOPC_TM_RISING:
seq_printf(s, "(Rising)"); break;
case IOPC_TM_FALLING:
seq_printf(s, "(Falling)"); break;
case IOPC_TM_EDGE:
seq_printf(s, "(Edges)"); break;
}
} else
seq_printf(s, "GPIO\t");
} else if (i <= KS8695_GPIO_5) {
if (ctrl & enable[i])
seq_printf(s, "TOUT%i\t", i - KS8695_GPIO_4);
else
seq_printf(s, "GPIO\t");
} else {
seq_printf(s, "GPIO\t");
}
seq_printf(s, "\t");
seq_printf(s, "%i\n", (data & IOPD(i)) ? 1 : 0);
}
return 0;
}
static int ks8695_gpio_open(struct inode *inode, struct file *file)
{
return single_open(file, ks8695_gpio_show, NULL);
}
static const struct file_operations ks8695_gpio_operations = {
.open = ks8695_gpio_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init ks8695_gpio_debugfs_init(void)
{
/* /sys/kernel/debug/ks8695_gpio */
(void) debugfs_create_file("ks8695_gpio", S_IFREG | S_IRUGO, NULL, NULL, &ks8695_gpio_operations);
return 0;
}
postcore_initcall(ks8695_gpio_debugfs_init);
#endif