diff options
Diffstat (limited to 'drivers/gpio/gpio-digic.c')
| -rw-r--r-- | drivers/gpio/gpio-digic.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-digic.c b/drivers/gpio/gpio-digic.c new file mode 100644 index 0000000000..468aaa79ab --- /dev/null +++ b/drivers/gpio/gpio-digic.c @@ -0,0 +1,180 @@ +/* + * Copyright (C) 2013 Antony Pavlov <antonynpavlov@gmail.com> + * + * This file is part of barebox. + * See file CREDITS for list of people who contributed to this project. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * 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. + * + */ + +#include <common.h> +#include <malloc.h> +#include <errno.h> +#include <io.h> +#include <gpio.h> +#include <init.h> + +/* + * See http://magiclantern.wikia.com/wiki/Register_Map#GPIO_Ports + */ + +#define DIGIC_GPIO_IN_LVL 1 +#define DIGIC_GPIO_OUT_LVL 2 +#define DIGIC_GPIO_DIR 4 +#define DIGIC_GPIO_TRISTATE 8 + +struct digic_gpio_chip { + void __iomem *base; + struct gpio_chip gc; +}; + +#define to_digic_gpio_chip(c) container_of(c, struct digic_gpio_chip, gc) + +static inline uint32_t digic_gpio_readl(struct digic_gpio_chip *chip, + uint32_t offset) +{ + return readl(chip->base + 4 * offset); +} + +static inline void digic_gpio_writel(struct digic_gpio_chip *chip, + uint32_t value, uint32_t offset) +{ + writel(value, chip->base + 4 * offset); +} + +static int digic_gpio_get_value(struct gpio_chip *gc, unsigned offset) +{ + struct digic_gpio_chip *chip = to_digic_gpio_chip(gc); + + if (offset >= gc->ngpio) + return -EINVAL; + + return digic_gpio_readl(chip, offset) & DIGIC_GPIO_IN_LVL; +} + +static void digic_gpio_set_value(struct gpio_chip *gc, unsigned offset, + int value) +{ + struct digic_gpio_chip *chip = to_digic_gpio_chip(gc); + uint32_t t; + + if (offset >= gc->ngpio) + return; + + t = digic_gpio_readl(chip, offset); + /* Port direction (1 = OUT, 0 = IN) */ + if (value) + t |= DIGIC_GPIO_OUT_LVL; + else + t &= ~(DIGIC_GPIO_OUT_LVL); + digic_gpio_writel(chip, t, offset); +} + +static int digic_gpio_direction_input(struct gpio_chip *gc, unsigned offset) +{ + struct digic_gpio_chip *chip = to_digic_gpio_chip(gc); + uint32_t t; + + if (offset >= gc->ngpio) + return -EINVAL; + + t = digic_gpio_readl(chip, offset); + /* Port direction (1 = OUT, 0 = IN) */ + t &= ~(DIGIC_GPIO_DIR); + digic_gpio_writel(chip, t, offset); + + return 0; +} + +static int digic_gpio_direction_output(struct gpio_chip *gc, unsigned offset, + int value) +{ + struct digic_gpio_chip *chip = to_digic_gpio_chip(gc); + uint32_t t; + + if (offset >= gc->ngpio) + return -EINVAL; + + t = digic_gpio_readl(chip, offset); + /* Port direction (1 = OUT, 0 = IN) */ + t |= DIGIC_GPIO_DIR; + digic_gpio_writel(chip, t, offset); + + digic_gpio_set_value(gc, offset, value); + + return 0; +} + +static struct gpio_ops digic_gpio_ops = { + .direction_input = digic_gpio_direction_input, + .direction_output = digic_gpio_direction_output, + .get = digic_gpio_get_value, + .set = digic_gpio_set_value, +}; + +static int digic_gpio_probe(struct device_d *dev) +{ + struct digic_gpio_chip *chip; + struct resource *res; + resource_size_t rsize; + int ret = -EINVAL; + + chip = xzalloc(sizeof(*chip)); + + res = dev_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) + goto err; + + rsize = resource_size(res); + chip->gc.ngpio = rsize / sizeof(int32_t); + + chip->base = dev_request_mem_region(dev, 0); + chip->gc.ops = &digic_gpio_ops; + chip->gc.base = 0; + + chip->gc.dev = dev; + + ret = gpiochip_add(&chip->gc); + if (ret) { + dev_err(dev, "couldn't add gpiochip, ret = %d\n", ret); + goto err; + } + + dev_info(dev, "probed gpiochip%d with base %d\n", + dev->id, chip->gc.base); + + return 0; + +err: + kfree(chip); + + return ret; +} + +static __maybe_unused struct of_device_id digic_gpio_dt_ids[] = { + { + .compatible = "canon,digic-gpio", + }, { + /* sentinel */ + } +}; + +static struct driver_d digic_gpio_driver = { + .name = "digic-gpio", + .probe = digic_gpio_probe, + .of_compatible = DRV_OF_COMPAT(digic_gpio_dt_ids), +}; + +static int digic_gpio_init(void) +{ + return platform_driver_register(&digic_gpio_driver); +} +coredevice_initcall(digic_gpio_init); |