c126808243
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. SVN-Revision: 19972
175 lines
4.6 KiB
C
175 lines
4.6 KiB
C
/*
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* RDC321x GPIO driver
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*
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* Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
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* Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/platform_device.h>
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#include <linux/pci.h>
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#include <linux/gpio.h>
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#include <asm/rdc321x_defs.h>
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struct rdc321x_gpio {
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spinlock_t lock;
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u32 data_reg[2];
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} rdc321x_gpio_dev;
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extern int rdc321x_pci_write(int reg, u32 val);
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extern int rdc321x_pci_read(int reg, u32 *val);
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/* read GPIO pin */
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static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
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{
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u32 value = 0;
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int reg;
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reg = gpio < 32 ? RDC321X_GPIO_DATA_REG1 : RDC321X_GPIO_DATA_REG2;
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spin_lock(&rdc321x_gpio_dev.lock);
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rdc321x_pci_write(reg, rdc321x_gpio_dev.data_reg[gpio < 32 ? 0 : 1]);
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rdc321x_pci_read(reg, &value);
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spin_unlock(&rdc321x_gpio_dev.lock);
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return (1 << (gpio & 0x1f)) & value ? 1 : 0;
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}
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static void rdc_gpio_set_value_impl(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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int reg = (gpio < 32) ? 0 : 1;
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if (value)
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rdc321x_gpio_dev.data_reg[reg] |= 1 << (gpio & 0x1f);
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else
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rdc321x_gpio_dev.data_reg[reg] &= ~(1 << (gpio & 0x1f));
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rdc321x_pci_write(reg ? RDC321X_GPIO_DATA_REG2 : RDC321X_GPIO_DATA_REG1,
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rdc321x_gpio_dev.data_reg[reg]);
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}
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/* set GPIO pin to value */
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static void rdc_gpio_set_value(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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spin_lock(&rdc321x_gpio_dev.lock);
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rdc_gpio_set_value_impl(chip, gpio, value);
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spin_unlock(&rdc321x_gpio_dev.lock);
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}
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static int rdc_gpio_config(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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int err;
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u32 reg;
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spin_lock(&rdc321x_gpio_dev.lock);
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err = rdc321x_pci_read(gpio < 32 ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
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®);
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if (err)
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goto unlock;
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reg |= 1 << (gpio & 0x1f);
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err = rdc321x_pci_write(gpio < 32 ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
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reg);
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if (err)
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goto unlock;
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rdc_gpio_set_value_impl(chip, gpio, value);
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unlock:
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spin_unlock(&rdc321x_gpio_dev.lock);
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return err;
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}
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/* configure GPIO pin as input */
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static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
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{
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return rdc_gpio_config(chip, gpio, 1);
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}
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static struct gpio_chip rdc321x_gpio_chip = {
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.label = "rdc321x-gpio",
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.direction_input = rdc_gpio_direction_input,
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.direction_output = rdc_gpio_config,
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.get = rdc_gpio_get_value,
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.set = rdc_gpio_set_value,
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.base = 0,
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.ngpio = RDC321X_MAX_GPIO,
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};
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/* initially setup the 2 copies of the gpio data registers.
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This function is called before the platform setup code. */
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static int __devinit rdc321x_gpio_probe(struct platform_device *pdev)
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{
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int err;
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/* this might not be, what others (BIOS, bootloader, etc.)
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wrote to these registers before, but it's a good guess. Still
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better than just using 0xffffffff. */
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err = rdc321x_pci_read(RDC321X_GPIO_DATA_REG1, &rdc321x_gpio_dev.data_reg[0]);
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if (err)
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return err;
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err = rdc321x_pci_read(RDC321X_GPIO_DATA_REG2, &rdc321x_gpio_dev.data_reg[1]);
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if (err)
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return err;
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spin_lock_init(&rdc321x_gpio_dev.lock);
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printk(KERN_INFO "rdc321x: registering %d GPIOs\n", rdc321x_gpio_chip.ngpio);
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return gpiochip_add(&rdc321x_gpio_chip);
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}
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static int __devexit rdc321x_gpio_remove(struct platform_device *pdev)
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{
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gpiochip_remove(&rdc321x_gpio_chip);
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return 0;
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}
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static struct platform_driver rdc321x_gpio_driver = {
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.driver.name = "rdc321x-gpio",
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.driver.owner = THIS_MODULE,
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.probe = rdc321x_gpio_probe,
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.remove = __devexit_p(rdc321x_gpio_remove),
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};
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static int __init rdc321x_gpio_init(void)
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{
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return platform_driver_register(&rdc321x_gpio_driver);
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}
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static void __exit rdc321x_gpio_exit(void)
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{
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platform_driver_unregister(&rdc321x_gpio_driver);
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}
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module_init(rdc321x_gpio_init);
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module_exit(rdc321x_gpio_exit);
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("RDC321x GPIO driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:rdc321x-gpio");
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