diff options
Diffstat (limited to 'drivers/gpio/gpio-octeon.c')
| -rw-r--r-- | drivers/gpio/gpio-octeon.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-octeon.c b/drivers/gpio/gpio-octeon.c new file mode 100644 index 0000000000..afb0e8a791 --- /dev/null +++ b/drivers/gpio/gpio-octeon.c @@ -0,0 +1,137 @@ +/* + * 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"); |