diff options
Diffstat (limited to 'kernel/drivers/gpio/gpio-loongson.c')
-rw-r--r-- | kernel/drivers/gpio/gpio-loongson.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpio-loongson.c b/kernel/drivers/gpio/gpio-loongson.c new file mode 100644 index 000000000..ccc65a1ae --- /dev/null +++ b/kernel/drivers/gpio/gpio-loongson.c @@ -0,0 +1,115 @@ +/* + * Loongson-2F/3A/3B GPIO Support + * + * Copyright (c) 2008 Richard Liu, STMicroelectronics <richard.liu@st.com> + * Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com> + * Copyright (c) 2013 Hongbing Hu <huhb@lemote.com> + * Copyright (c) 2014 Huacai Chen <chenhc@lemote.com> + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/err.h> +#include <asm/types.h> +#include <loongson.h> +#include <linux/gpio.h> + +#define STLS2F_N_GPIO 4 +#define STLS3A_N_GPIO 16 + +#ifdef CONFIG_CPU_LOONGSON3 +#define LOONGSON_N_GPIO STLS3A_N_GPIO +#else +#define LOONGSON_N_GPIO STLS2F_N_GPIO +#endif + +#define LOONGSON_GPIO_IN_OFFSET 16 + +static DEFINE_SPINLOCK(gpio_lock); + +static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) +{ + u32 temp; + u32 mask; + + spin_lock(&gpio_lock); + mask = 1 << gpio; + temp = LOONGSON_GPIOIE; + temp |= mask; + LOONGSON_GPIOIE = temp; + spin_unlock(&gpio_lock); + + return 0; +} + +static int loongson_gpio_direction_output(struct gpio_chip *chip, + unsigned gpio, int level) +{ + u32 temp; + u32 mask; + + gpio_set_value(gpio, level); + spin_lock(&gpio_lock); + mask = 1 << gpio; + temp = LOONGSON_GPIOIE; + temp &= (~mask); + LOONGSON_GPIOIE = temp; + spin_unlock(&gpio_lock); + + return 0; +} + +static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio) +{ + u32 val; + u32 mask; + + mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET); + spin_lock(&gpio_lock); + val = LOONGSON_GPIODATA; + spin_unlock(&gpio_lock); + + return (val & mask) != 0; +} + +static void loongson_gpio_set_value(struct gpio_chip *chip, + unsigned gpio, int value) +{ + u32 val; + u32 mask; + + mask = 1 << gpio; + + spin_lock(&gpio_lock); + val = LOONGSON_GPIODATA; + if (value) + val |= mask; + else + val &= (~mask); + LOONGSON_GPIODATA = val; + spin_unlock(&gpio_lock); +} + +static struct gpio_chip loongson_chip = { + .label = "Loongson-gpio-chip", + .direction_input = loongson_gpio_direction_input, + .get = loongson_gpio_get_value, + .direction_output = loongson_gpio_direction_output, + .set = loongson_gpio_set_value, + .base = 0, + .ngpio = LOONGSON_N_GPIO, + .can_sleep = false, +}; + +static int __init loongson_gpio_setup(void) +{ + return gpiochip_add(&loongson_chip); +} +postcore_initcall(loongson_gpio_setup); |