diff options
Diffstat (limited to 'drivers/gpio/tegra_gpio.c')
-rw-r--r-- | drivers/gpio/tegra_gpio.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/gpio/tegra_gpio.c b/drivers/gpio/tegra_gpio.c new file mode 100644 index 0000000..60ec6e3 --- /dev/null +++ b/drivers/gpio/tegra_gpio.c @@ -0,0 +1,262 @@ +/* + * NVIDIA Tegra2 GPIO handling. + * (C) Copyright 2010-2012 + * NVIDIA Corporation <www.nvidia.com> + * + * 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 + */ + +/* + * Based on (mostly copied from) kw_gpio.c based Linux 2.6 kernel driver. + * Tom Warren (twarren@nvidia.com) + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/bitops.h> +#include <asm/arch/tegra2.h> +#include <asm/gpio.h> + +enum { + TEGRA2_CMD_INFO, + TEGRA2_CMD_PORT, + TEGRA2_CMD_OUTPUT, + TEGRA2_CMD_INPUT, +}; + +static struct gpio_names { + char name[GPIO_NAME_SIZE]; +} gpio_names[MAX_NUM_GPIOS]; + +static char *get_name(int i) +{ + return *gpio_names[i].name ? gpio_names[i].name : "UNKNOWN"; +} + +/* Return config of pin 'gpio' as GPIO (1) or SFPIO (0) */ +static int get_config(unsigned gpio) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + u32 u; + int type; + + u = readl(&bank->gpio_config[GPIO_PORT(gpio)]); + type = (u >> GPIO_BIT(gpio)) & 1; + + debug("get_config: port = %d, bit = %d is %s\n", + GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO"); + + return type; +} + +/* Config pin 'gpio' as GPIO or SFPIO, based on 'type' */ +static void set_config(unsigned gpio, int type) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + u32 u; + + debug("set_config: port = %d, bit = %d, %s\n", + GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO"); + + u = readl(&bank->gpio_config[GPIO_PORT(gpio)]); + if (type) /* GPIO */ + u |= 1 << GPIO_BIT(gpio); + else + u &= ~(1 << GPIO_BIT(gpio)); + writel(u, &bank->gpio_config[GPIO_PORT(gpio)]); +} + +/* Return GPIO pin 'gpio' direction - 0 = input or 1 = output */ +static int get_direction(unsigned gpio) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + u32 u; + int dir; + + u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]); + dir = (u >> GPIO_BIT(gpio)) & 1; + + debug("get_direction: port = %d, bit = %d, %s\n", + GPIO_FULLPORT(gpio), GPIO_BIT(gpio), dir ? "OUT" : "IN"); + + return dir; +} + +/* Config GPIO pin 'gpio' as input or output (OE) as per 'output' */ +static void set_direction(unsigned gpio, int output) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + u32 u; + + debug("set_direction: port = %d, bit = %d, %s\n", + GPIO_FULLPORT(gpio), GPIO_BIT(gpio), output ? "OUT" : "IN"); + + u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]); + if (output) + u |= 1 << GPIO_BIT(gpio); + else + u &= ~(1 << GPIO_BIT(gpio)); + writel(u, &bank->gpio_dir_out[GPIO_PORT(gpio)]); +} + +/* set GPIO pin 'gpio' output bit as 0 or 1 as per 'high' */ +static void set_level(unsigned gpio, int high) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + u32 u; + + debug("set_level: port = %d, bit %d == %d\n", + GPIO_FULLPORT(gpio), GPIO_BIT(gpio), high); + + u = readl(&bank->gpio_out[GPIO_PORT(gpio)]); + if (high) + u |= 1 << GPIO_BIT(gpio); + else + u &= ~(1 << GPIO_BIT(gpio)); + writel(u, &bank->gpio_out[GPIO_PORT(gpio)]); +} + +/* + * Generic_GPIO primitives. + */ + +int gpio_request(unsigned gpio, const char *label) +{ + if (gpio >= MAX_NUM_GPIOS) + return -1; + + if (label != NULL) { + strncpy(gpio_names[gpio].name, label, GPIO_NAME_SIZE); + gpio_names[gpio].name[GPIO_NAME_SIZE - 1] = '\0'; + } + + /* Configure as a GPIO */ + set_config(gpio, 1); + + return 0; +} + +int gpio_free(unsigned gpio) +{ + if (gpio >= MAX_NUM_GPIOS) + return -1; + + gpio_names[gpio].name[0] = '\0'; + /* Do not configure as input or change pin mux here */ + return 0; +} + +/* read GPIO OUT value of pin 'gpio' */ +static int gpio_get_output_value(unsigned gpio) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + int val; + + debug("gpio_get_output_value: pin = %d (port %d:bit %d)\n", + gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio)); + + val = readl(&bank->gpio_out[GPIO_PORT(gpio)]); + + return (val >> GPIO_BIT(gpio)) & 1; +} + +/* set GPIO pin 'gpio' as an input */ +int gpio_direction_input(unsigned gpio) +{ + debug("gpio_direction_input: pin = %d (port %d:bit %d)\n", + gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio)); + + /* Configure GPIO direction as input. */ + set_direction(gpio, 0); + + return 0; +} + +/* set GPIO pin 'gpio' as an output, with polarity 'value' */ +int gpio_direction_output(unsigned gpio, int value) +{ + debug("gpio_direction_output: pin = %d (port %d:bit %d) = %s\n", + gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), + value ? "HIGH" : "LOW"); + + /* Configure GPIO output value. */ + set_level(gpio, value); + + /* Configure GPIO direction as output. */ + set_direction(gpio, 1); + + return 0; +} + +/* read GPIO IN value of pin 'gpio' */ +int gpio_get_value(unsigned gpio) +{ + struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)]; + int val; + + debug("gpio_get_value: pin = %d (port %d:bit %d)\n", + gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio)); + + val = readl(&bank->gpio_in[GPIO_PORT(gpio)]); + + return (val >> GPIO_BIT(gpio)) & 1; +} + +/* write GPIO OUT value to pin 'gpio' */ +int gpio_set_value(unsigned gpio, int value) +{ + debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n", + gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), value); + + /* Configure GPIO output value. */ + set_level(gpio, value); + + return 0; +} + +/* + * Display Tegra GPIO information + */ +void gpio_info(void) +{ + unsigned c; + int type; + + for (c = 0; c < MAX_NUM_GPIOS; c++) { + type = get_config(c); /* GPIO, not SFPIO */ + if (type) { + printf("GPIO_%d:\t%s is an %s, ", c, + get_name(c), + get_direction(c) ? "OUTPUT" : "INPUT"); + if (get_direction(c)) + printf("value = %d", gpio_get_output_value(c)); + else + printf("value = %d", gpio_get_value(c)); + printf("\n"); + } else + continue; + } +} |