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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2011, 2012 Cavium Inc.
*/
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-gpio-defs.h>
#define RX_DAT 0x80
#define TX_SET 0x88
#define TX_CLEAR 0x90
/*
* The address offset of the GPIO configuration register for a given
* line.
*/
static unsigned int bit_cfg_reg(unsigned int offset)
{
/*
* The register stride is 8, with a discontinuity after the
* first 16.
*/
if (offset < 16)
return 8 * offset;
else
return 8 * (offset - 16) + 0x100;
}
struct octeon_gpio {
struct gpio_chip chip;
u64 register_base;
};
static int octeon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
{
struct octeon_gpio *gpio = gpiochip_get_data(chip);
cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), 0);
return 0;
}
static void octeon_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct octeon_gpio *gpio = gpiochip_get_data(chip);
u64 mask = 1ull << offset;
u64 reg = gpio->register_base + (value ? TX_SET : TX_CLEAR);
cvmx_write_csr(reg, mask);
}
static int octeon_gpio_dir_out(struct gpio_chip *chip, unsigned offset,
int value)
{
struct octeon_gpio *gpio = gpiochip_get_data(chip);
union cvmx_gpio_bit_cfgx cfgx;
octeon_gpio_set(chip, offset, value);
cfgx.u64 = 0;
cfgx.s.tx_oe = 1;
cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), cfgx.u64);
return 0;
}
static int octeon_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct octeon_gpio *gpio = gpiochip_get_data(chip);
u64 read_bits = cvmx_read_csr(gpio->register_base + RX_DAT);
return ((1ull << offset) & read_bits) != 0;
}
static int octeon_gpio_probe(struct platform_device *pdev)
{
struct octeon_gpio *gpio;
struct gpio_chip *chip;
void __iomem *reg_base;
int err = 0;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
chip = &gpio->chip;
reg_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(reg_base))
return PTR_ERR(reg_base);
gpio->register_base = (u64)reg_base;
pdev->dev.platform_data = chip;
chip->label = "octeon-gpio";
chip->parent = &pdev->dev;
chip->owner = THIS_MODULE;
chip->base = 0;
chip->can_sleep = false;
chip->ngpio = 20;
chip->direction_input = octeon_gpio_dir_in;
chip->get = octeon_gpio_get;
chip->direction_output = octeon_gpio_dir_out;
chip->set = octeon_gpio_set;
err = devm_gpiochip_add_data(&pdev->dev, chip, gpio);
if (err)
return err;
dev_info(&pdev->dev, "OCTEON GPIO driver probed.\n");
return 0;
}
static const struct of_device_id octeon_gpio_match[] = {
{
.compatible = "cavium,octeon-3860-gpio",
},
{},
};
MODULE_DEVICE_TABLE(of, octeon_gpio_match);
static struct platform_driver octeon_gpio_driver = {
.driver = {
.name = "octeon_gpio",
.of_match_table = octeon_gpio_match,
},
.probe = octeon_gpio_probe,
};
module_platform_driver(octeon_gpio_driver);
MODULE_DESCRIPTION("Cavium Inc. OCTEON GPIO Driver");
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");
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