diff options
Diffstat (limited to 'drivers/gpio/omap_gpio.c')
| -rw-r--r-- | drivers/gpio/omap_gpio.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/drivers/gpio/omap_gpio.c b/drivers/gpio/omap_gpio.c new file mode 100644 index 0000000000..fc89f2a42b --- /dev/null +++ b/drivers/gpio/omap_gpio.c @@ -0,0 +1,243 @@ +/* + * Copyright (c) 2009 Wind River Systems, Inc. + * Tom Rix <Tom.Rix@windriver.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. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * This work is derived from the linux 2.6.27 kernel source + * To fetch, use the kernel repository + * git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + * Use the v2.6.27 tag. + * + * Below is the original's header including its copyright + * + * linux/arch/arm/plat-omap/gpio.c + * + * Support functions for OMAP GPIO + * + * Copyright (C) 2003-2005 Nokia Corporation + * Written by Juha Yrjölä <juha.yrjola@nokia.com> + * + * 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. + */ +#include <common.h> +#include <asm/gpio.h> +#include <asm/io.h> +#include <asm/errno.h> + +#define OMAP_GPIO_DIR_OUT 0 +#define OMAP_GPIO_DIR_IN 1 + +static inline const struct gpio_bank *get_gpio_bank(int gpio) +{ + return &omap_gpio_bank[gpio >> 5]; +} + +static inline int get_gpio_index(int gpio) +{ + return gpio & 0x1f; +} + +static inline int gpio_valid(int gpio) +{ + if (gpio < 0) + return -1; + if (gpio < 192) + return 0; + return -1; +} + +static int check_gpio(int gpio) +{ + if (gpio_valid(gpio) < 0) { + printf("ERROR : check_gpio: invalid GPIO %d\n", gpio); + return -1; + } + return 0; +} + +static void _set_gpio_direction(const struct gpio_bank *bank, int gpio, + int is_input) +{ + void *reg = bank->base; + u32 l; + + switch (bank->method) { + case METHOD_GPIO_24XX: + reg += OMAP_GPIO_OE; + break; + default: + return; + } + l = __raw_readl(reg); + if (is_input) + l |= 1 << gpio; + else + l &= ~(1 << gpio); + __raw_writel(l, reg); +} + +/** + * Get the direction of the GPIO by reading the GPIO_OE register + * corresponding to the specified bank. + */ +static int _get_gpio_direction(const struct gpio_bank *bank, int gpio) +{ + void *reg = bank->base; + u32 v; + + switch (bank->method) { + case METHOD_GPIO_24XX: + reg += OMAP_GPIO_OE; + break; + default: + return -1; + } + + v = __raw_readl(reg); + + if (v & (1 << gpio)) + return OMAP_GPIO_DIR_IN; + else + return OMAP_GPIO_DIR_OUT; +} + +static void _set_gpio_dataout(const struct gpio_bank *bank, int gpio, + int enable) +{ + void *reg = bank->base; + u32 l = 0; + + switch (bank->method) { + case METHOD_GPIO_24XX: + if (enable) + reg += OMAP_GPIO_SETDATAOUT; + else + reg += OMAP_GPIO_CLEARDATAOUT; + l = 1 << gpio; + break; + default: + printf("omap3-gpio unknown bank method %s %d\n", + __FILE__, __LINE__); + return; + } + __raw_writel(l, reg); +} + +/** + * Set value of the specified gpio + */ +int gpio_set_value(unsigned gpio, int value) +{ + const struct gpio_bank *bank; + + if (check_gpio(gpio) < 0) + return -1; + bank = get_gpio_bank(gpio); + _set_gpio_dataout(bank, get_gpio_index(gpio), value); + + return 0; +} + +/** + * Get value of the specified gpio + */ +int gpio_get_value(unsigned gpio) +{ + const struct gpio_bank *bank; + void *reg; + int input; + + if (check_gpio(gpio) < 0) + return -1; + bank = get_gpio_bank(gpio); + reg = bank->base; + switch (bank->method) { + case METHOD_GPIO_24XX: + input = _get_gpio_direction(bank, get_gpio_index(gpio)); + switch (input) { + case OMAP_GPIO_DIR_IN: + reg += OMAP_GPIO_DATAIN; + break; + case OMAP_GPIO_DIR_OUT: + reg += OMAP_GPIO_DATAOUT; + break; + default: + return -1; + } + break; + default: + return -1; + } + return (__raw_readl(reg) + & (1 << get_gpio_index(gpio))) != 0; +} + +/** + * Set gpio direction as input + */ +int gpio_direction_input(unsigned gpio) +{ + const struct gpio_bank *bank; + + if (check_gpio(gpio) < 0) + return -1; + + bank = get_gpio_bank(gpio); + _set_gpio_direction(bank, get_gpio_index(gpio), 1); + + return 0; +} + +/** + * Set gpio direction as output + */ +int gpio_direction_output(unsigned gpio, int value) +{ + const struct gpio_bank *bank; + + if (check_gpio(gpio) < 0) + return -1; + + bank = get_gpio_bank(gpio); + _set_gpio_dataout(bank, get_gpio_index(gpio), value); + _set_gpio_direction(bank, get_gpio_index(gpio), 0); + + return 0; +} + +/** + * Request a gpio before using it. + * + * NOTE: Argument 'label' is unused. + */ +int gpio_request(unsigned gpio, const char *label) +{ + if (check_gpio(gpio) < 0) + return -1; + + return 0; +} + +/** + * Reset and free the gpio after using it. + */ +int gpio_free(unsigned gpio) +{ + return 0; +} |