diff options
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/sandbox.c | 209 |
2 files changed, 210 insertions, 0 deletions
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 4375a55..fb3b09a 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -34,6 +34,7 @@ COBJS-$(CONFIG_MXS_GPIO) += mxs_gpio.o COBJS-$(CONFIG_PCA953X) += pca953x.o COBJS-$(CONFIG_PCA9698) += pca9698.o COBJS-$(CONFIG_S5P) += s5p_gpio.o +COBJS-$(CONFIG_SANDBOX_GPIO) += sandbox.o COBJS-$(CONFIG_TEGRA2_GPIO) += tegra2_gpio.o COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o COBJS-$(CONFIG_ALTERA_PIO) += altera_pio.o diff --git a/drivers/gpio/sandbox.c b/drivers/gpio/sandbox.c new file mode 100644 index 0000000..19d2db0 --- /dev/null +++ b/drivers/gpio/sandbox.c @@ -0,0 +1,209 @@ +/* + * Copyright (c) 2011 The Chromium OS Authors. + * 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 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 + */ + +#include <common.h> +#include <asm/gpio.h> + +/* Flags for each GPIO */ +#define GPIOF_OUTPUT (1 << 0) /* Currently set as an output */ +#define GPIOF_HIGH (1 << 1) /* Currently set high */ +#define GPIOF_RESERVED (1 << 2) /* Is in use / requested */ + +struct gpio_state { + const char *label; /* label given by requester */ + u8 flags; /* flags (GPIOF_...) */ +}; + +/* + * State of GPIOs + * TODO: Put this into sandbox state + */ +static struct gpio_state state[CONFIG_SANDBOX_GPIO_COUNT]; + +/* Access routines for GPIO state */ +static u8 *get_gpio_flags(unsigned gp) +{ + /* assert()'s could be disabled, so make sure we handle that */ + assert(gp < ARRAY_SIZE(state)); + if (gp >= ARRAY_SIZE(state)) { + static u8 invalid_flags; + printf("sandbox_gpio: error: invalid gpio %u\n", gp); + return &invalid_flags; + } + + return &state[gp].flags; +} + +static int get_gpio_flag(unsigned gp, int flag) +{ + return (*get_gpio_flags(gp) & flag) != 0; +} + +static int set_gpio_flag(unsigned gp, int flag, int value) +{ + u8 *gpio = get_gpio_flags(gp); + + if (value) + *gpio |= flag; + else + *gpio &= ~flag; + + return 0; +} + +static int check_reserved(unsigned gpio, const char *func) +{ + if (!get_gpio_flag(gpio, GPIOF_RESERVED)) { + printf("sandbox_gpio: %s: error: gpio %u not reserved\n", + func, gpio); + return -1; + } + + return 0; +} + +/* + * Back-channel sandbox-internal-only access to GPIO state + */ + +int sandbox_gpio_get_value(unsigned gp) +{ + if (get_gpio_flag(gp, GPIOF_OUTPUT)) + debug("sandbox_gpio: get_value on output gpio %u\n", gp); + return get_gpio_flag(gp, GPIOF_HIGH); +} + +int sandbox_gpio_set_value(unsigned gp, int value) +{ + return set_gpio_flag(gp, GPIOF_HIGH, value); +} + +int sandbox_gpio_get_direction(unsigned gp) +{ + return get_gpio_flag(gp, GPIOF_OUTPUT); +} + +int sandbox_gpio_set_direction(unsigned gp, int output) +{ + return set_gpio_flag(gp, GPIOF_OUTPUT, output); +} + +/* + * These functions implement the public interface within U-Boot + */ + +/* set GPIO port 'gp' as an input */ +int gpio_direction_input(unsigned gp) +{ + debug("%s: gp:%u\n", __func__, gp); + + if (check_reserved(gp, __func__)) + return -1; + + return sandbox_gpio_set_direction(gp, 0); +} + +/* set GPIO port 'gp' as an output, with polarity 'value' */ +int gpio_direction_output(unsigned gp, int value) +{ + debug("%s: gp:%u, value = %d\n", __func__, gp, value); + + if (check_reserved(gp, __func__)) + return -1; + + return sandbox_gpio_set_direction(gp, 1) | + sandbox_gpio_set_value(gp, value); +} + +/* read GPIO IN value of port 'gp' */ +int gpio_get_value(unsigned gp) +{ + debug("%s: gp:%u\n", __func__, gp); + + if (check_reserved(gp, __func__)) + return -1; + + return sandbox_gpio_get_value(gp); +} + +/* write GPIO OUT value to port 'gp' */ +int gpio_set_value(unsigned gp, int value) +{ + debug("%s: gp:%u, value = %d\n", __func__, gp, value); + + if (check_reserved(gp, __func__)) + return -1; + + if (!sandbox_gpio_get_direction(gp)) { + printf("sandbox_gpio: error: set_value on input gpio %u\n", gp); + return -1; + } + + return sandbox_gpio_set_value(gp, value); +} + +int gpio_request(unsigned gp, const char *label) +{ + debug("%s: gp:%u, label:%s\n", __func__, gp, label); + + if (gp >= ARRAY_SIZE(state)) { + printf("sandbox_gpio: error: invalid gpio %u\n", gp); + return -1; + } + + if (get_gpio_flag(gp, GPIOF_RESERVED)) { + printf("sandbox_gpio: error: gpio %u already reserved\n", gp); + return -1; + } + + state[gp].label = label; + return set_gpio_flag(gp, GPIOF_RESERVED, 1); +} + +int gpio_free(unsigned gp) +{ + debug("%s: gp:%u\n", __func__, gp); + + if (check_reserved(gp, __func__)) + return -1; + + state[gp].label = NULL; + return set_gpio_flag(gp, GPIOF_RESERVED, 0); +} + +/* Display GPIO information */ +void gpio_info(void) +{ + unsigned gpio; + + puts("Sandbox GPIOs\n"); + + for (gpio = 0; gpio < ARRAY_SIZE(state); ++gpio) { + const char *label = state[gpio].label; + + printf("%4d: %s: %d [%c] %s\n", + gpio, + sandbox_gpio_get_direction(gpio) ? "out" : " in", + sandbox_gpio_get_value(gpio), + get_gpio_flag(gpio, GPIOF_RESERVED) ? 'x' : ' ', + label ? label : ""); + } +} |