diff options
Diffstat (limited to 'arch/xtensa/variants/s6000/gpio.c')
-rw-r--r-- | arch/xtensa/variants/s6000/gpio.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/xtensa/variants/s6000/gpio.c b/arch/xtensa/variants/s6000/gpio.c new file mode 100644 index 0000000..33a8d95 --- /dev/null +++ b/arch/xtensa/variants/s6000/gpio.c @@ -0,0 +1,71 @@ +/* + * s6000 gpio driver + * + * Copyright (c) 2009 emlix GmbH + * Authors: Oskar Schirmer <os@emlix.com> + * Johannes Weiner <jw@emlix.com> + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/gpio.h> + +#include <variant/hardware.h> + +#define S6_GPIO_DATA 0x000 +#define S6_GPIO_IS 0x404 +#define S6_GPIO_IBE 0x408 +#define S6_GPIO_IEV 0x40C +#define S6_GPIO_IE 0x410 +#define S6_GPIO_RIS 0x414 +#define S6_GPIO_MIS 0x418 +#define S6_GPIO_IC 0x41C +#define S6_GPIO_AFSEL 0x420 +#define S6_GPIO_DIR 0x800 +#define S6_GPIO_BANK(nr) ((nr) * 0x1000) +#define S6_GPIO_MASK(nr) (4 << (nr)) +#define S6_GPIO_OFFSET(nr) \ + (S6_GPIO_BANK((nr) >> 3) + S6_GPIO_MASK((nr) & 7)) + +static int direction_input(struct gpio_chip *chip, unsigned int off) +{ + writeb(0, S6_REG_GPIO + S6_GPIO_DIR + S6_GPIO_OFFSET(off)); + return 0; +} + +static int get(struct gpio_chip *chip, unsigned int off) +{ + return readb(S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off)); +} + +static int direction_output(struct gpio_chip *chip, unsigned int off, int val) +{ + unsigned rel = S6_GPIO_OFFSET(off); + writeb(~0, S6_REG_GPIO + S6_GPIO_DIR + rel); + writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + rel); + return 0; +} + +static void set(struct gpio_chip *chip, unsigned int off, int val) +{ + writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off)); +} + +static struct gpio_chip gpiochip = { + .owner = THIS_MODULE, + .direction_input = direction_input, + .get = get, + .direction_output = direction_output, + .set = set, + .base = 0, + .ngpio = 24, + .can_sleep = 0, /* no blocking io needed */ + .exported = 0, /* no exporting to userspace */ +}; + +static int gpio_init(void) +{ + return gpiochip_add(&gpiochip); +} +device_initcall(gpio_init); |