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/*
* 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 <linux/mfd/rdc321x.h>
#include <linux/slab.h>
struct rdc321x_gpio {
spinlock_t lock;
struct pci_dev *sb_pdev;
u32 data_reg[2];
int reg1_ctrl_base;
int reg1_data_base;
int reg2_ctrl_base;
int reg2_data_base;
struct gpio_chip chip;
};
/* read GPIO pin */
static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
struct rdc321x_gpio *gpch;
u32 value = 0;
int reg;
gpch = container_of(chip, struct rdc321x_gpio, chip);
reg = gpio < 32 ? gpch->reg1_data_base : gpch->reg2_data_base;
spin_lock(&gpch->lock);
pci_write_config_dword(gpch->sb_pdev, reg,
gpch->data_reg[gpio < 32 ? 0 : 1]);
pci_read_config_dword(gpch->sb_pdev, reg, &value);
spin_unlock(&gpch->lock);
return (1 << (gpio & 0x1f)) & value ? 1 : 0;
}
static void rdc_gpio_set_value_impl(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct rdc321x_gpio *gpch;
int reg = (gpio < 32) ? 0 : 1;
gpch = container_of(chip, struct rdc321x_gpio, chip);
if (value)
gpch->data_reg[reg] |= 1 << (gpio & 0x1f);
else
gpch->data_reg[reg] &= ~(1 << (gpio & 0x1f));
pci_write_config_dword(gpch->sb_pdev,
reg ? gpch->reg2_data_base : gpch->reg1_data_base,
gpch->data_reg[reg]);
}
/* set GPIO pin to value */
static void rdc_gpio_set_value(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct rdc321x_gpio *gpch;
gpch = container_of(chip, struct rdc321x_gpio, chip);
spin_lock(&gpch->lock);
rdc_gpio_set_value_impl(chip, gpio, value);
spin_unlock(&gpch->lock);
}
static int rdc_gpio_config(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct rdc321x_gpio *gpch;
int err;
u32 reg;
gpch = container_of(chip, struct rdc321x_gpio, chip);
spin_lock(&gpch->lock);
err = pci_read_config_dword(gpch->sb_pdev, gpio < 32 ?
gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, ®);
if (err)
goto unlock;
reg |= 1 << (gpio & 0x1f);
err = pci_write_config_dword(gpch->sb_pdev, gpio < 32 ?
gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, reg);
if (err)
goto unlock;
rdc_gpio_set_value_impl(chip, gpio, value);
unlock:
spin_unlock(&gpch->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);
}
/*
* Cache the initial value of both GPIO data registers
*/
static int rdc321x_gpio_probe(struct platform_device *pdev)
{
int err;
struct resource *r;
struct rdc321x_gpio *rdc321x_gpio_dev;
struct rdc321x_gpio_pdata *pdata;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_err(&pdev->dev, "no platform data supplied\n");
return -ENODEV;
}
rdc321x_gpio_dev = devm_kzalloc(&pdev->dev, sizeof(struct rdc321x_gpio),
GFP_KERNEL);
if (!rdc321x_gpio_dev)
return -ENOMEM;
r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg1");
if (!r) {
dev_err(&pdev->dev, "failed to get gpio-reg1 resource\n");
return -ENODEV;
}
spin_lock_init(&rdc321x_gpio_dev->lock);
rdc321x_gpio_dev->sb_pdev = pdata->sb_pdev;
rdc321x_gpio_dev->reg1_ctrl_base = r->start;
rdc321x_gpio_dev->reg1_data_base = r->start + 0x4;
r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg2");
if (!r) {
dev_err(&pdev->dev, "failed to get gpio-reg2 resource\n");
return -ENODEV;
}
rdc321x_gpio_dev->reg2_ctrl_base = r->start;
rdc321x_gpio_dev->reg2_data_base = r->start + 0x4;
rdc321x_gpio_dev->chip.label = "rdc321x-gpio";
rdc321x_gpio_dev->chip.owner = THIS_MODULE;
rdc321x_gpio_dev->chip.direction_input = rdc_gpio_direction_input;
rdc321x_gpio_dev->chip.direction_output = rdc_gpio_config;
rdc321x_gpio_dev->chip.get = rdc_gpio_get_value;
rdc321x_gpio_dev->chip.set = rdc_gpio_set_value;
rdc321x_gpio_dev->chip.base = 0;
rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios;
platform_set_drvdata(pdev, rdc321x_gpio_dev);
/* 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 = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,
rdc321x_gpio_dev->reg1_data_base,
&rdc321x_gpio_dev->data_reg[0]);
if (err)
return err;
err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,
rdc321x_gpio_dev->reg2_data_base,
&rdc321x_gpio_dev->data_reg[1]);
if (err)
return err;
dev_info(&pdev->dev, "registering %d GPIOs\n",
rdc321x_gpio_dev->chip.ngpio);
return gpiochip_add(&rdc321x_gpio_dev->chip);
}
static int rdc321x_gpio_remove(struct platform_device *pdev)
{
struct rdc321x_gpio *rdc321x_gpio_dev = platform_get_drvdata(pdev);
gpiochip_remove(&rdc321x_gpio_dev->chip);
return 0;
}
static struct platform_driver rdc321x_gpio_driver = {
.driver.name = "rdc321x-gpio",
.driver.owner = THIS_MODULE,
.probe = rdc321x_gpio_probe,
.remove = rdc321x_gpio_remove,
};
module_platform_driver(rdc321x_gpio_driver);
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("RDC321x GPIO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rdc321x-gpio");
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