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openwrt-xburst/target/linux/rdc/files-2.6.30/arch/x86/mach-rdc321x/gpio.c
florian a0438292e5 [rdc] add a new southbridge driver which registers the gpio and watchdog platform devices
This also fixes the watchdog logic and abstracts the access to the RDC321x
southbridge PCI configuration register space. Based on a patch by Bernhard Loos.

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19972 3c298f89-4303-0410-b956-a3cf2f4a3e73
2010-03-04 07:54:25 +00:00

175 lines
4.6 KiB
C

/*
* RDC321x GPIO driver
*
* Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
* Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/gpio.h>
#include <asm/rdc321x_defs.h>
struct rdc321x_gpio {
spinlock_t lock;
u32 data_reg[2];
} rdc321x_gpio_dev;
extern int rdc321x_pci_write(int reg, u32 val);
extern int rdc321x_pci_read(int reg, u32 *val);
/* read GPIO pin */
static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
u32 value = 0;
int reg;
reg = gpio < 32 ? RDC321X_GPIO_DATA_REG1 : RDC321X_GPIO_DATA_REG2;
spin_lock(&rdc321x_gpio_dev.lock);
rdc321x_pci_write(reg, rdc321x_gpio_dev.data_reg[gpio < 32 ? 0 : 1]);
rdc321x_pci_read(reg, &value);
spin_unlock(&rdc321x_gpio_dev.lock);
return (1 << (gpio & 0x1f)) & value ? 1 : 0;
}
static void rdc_gpio_set_value_impl(struct gpio_chip *chip,
unsigned gpio, int value)
{
int reg = (gpio < 32) ? 0 : 1;
if (value)
rdc321x_gpio_dev.data_reg[reg] |= 1 << (gpio & 0x1f);
else
rdc321x_gpio_dev.data_reg[reg] &= ~(1 << (gpio & 0x1f));
rdc321x_pci_write(reg ? RDC321X_GPIO_DATA_REG2 : RDC321X_GPIO_DATA_REG1,
rdc321x_gpio_dev.data_reg[reg]);
}
/* set GPIO pin to value */
static void rdc_gpio_set_value(struct gpio_chip *chip,
unsigned gpio, int value)
{
spin_lock(&rdc321x_gpio_dev.lock);
rdc_gpio_set_value_impl(chip, gpio, value);
spin_unlock(&rdc321x_gpio_dev.lock);
}
static int rdc_gpio_config(struct gpio_chip *chip,
unsigned gpio, int value)
{
int err;
u32 reg;
spin_lock(&rdc321x_gpio_dev.lock);
err = rdc321x_pci_read(gpio < 32 ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
&reg);
if (err)
goto unlock;
reg |= 1 << (gpio & 0x1f);
err = rdc321x_pci_write(gpio < 32 ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
reg);
if (err)
goto unlock;
rdc_gpio_set_value_impl(chip, gpio, value);
unlock:
spin_unlock(&rdc321x_gpio_dev.lock);
return err;
}
/* configure GPIO pin as input */
static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
return rdc_gpio_config(chip, gpio, 1);
}
static struct gpio_chip rdc321x_gpio_chip = {
.label = "rdc321x-gpio",
.direction_input = rdc_gpio_direction_input,
.direction_output = rdc_gpio_config,
.get = rdc_gpio_get_value,
.set = rdc_gpio_set_value,
.base = 0,
.ngpio = RDC321X_MAX_GPIO,
};
/* initially setup the 2 copies of the gpio data registers.
This function is called before the platform setup code. */
static int __devinit rdc321x_gpio_probe(struct platform_device *pdev)
{
int err;
/* this might not be, what others (BIOS, bootloader, etc.)
wrote to these registers before, but it's a good guess. Still
better than just using 0xffffffff. */
err = rdc321x_pci_read(RDC321X_GPIO_DATA_REG1, &rdc321x_gpio_dev.data_reg[0]);
if (err)
return err;
err = rdc321x_pci_read(RDC321X_GPIO_DATA_REG2, &rdc321x_gpio_dev.data_reg[1]);
if (err)
return err;
spin_lock_init(&rdc321x_gpio_dev.lock);
printk(KERN_INFO "rdc321x: registering %d GPIOs\n", rdc321x_gpio_chip.ngpio);
return gpiochip_add(&rdc321x_gpio_chip);
}
static int __devexit rdc321x_gpio_remove(struct platform_device *pdev)
{
gpiochip_remove(&rdc321x_gpio_chip);
return 0;
}
static struct platform_driver rdc321x_gpio_driver = {
.driver.name = "rdc321x-gpio",
.driver.owner = THIS_MODULE,
.probe = rdc321x_gpio_probe,
.remove = __devexit_p(rdc321x_gpio_remove),
};
static int __init rdc321x_gpio_init(void)
{
return platform_driver_register(&rdc321x_gpio_driver);
}
static void __exit rdc321x_gpio_exit(void)
{
platform_driver_unregister(&rdc321x_gpio_driver);
}
module_init(rdc321x_gpio_init);
module_exit(rdc321x_gpio_exit);
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("RDC321x GPIO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rdc321x-gpio");