diff options
Diffstat (limited to 'drivers/gpio/tegra2_gpio.c')
| -rw-r--r-- | drivers/gpio/tegra2_gpio.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/gpio/tegra2_gpio.c b/drivers/gpio/tegra2_gpio.c new file mode 100644 index 0000000..f686e80 --- /dev/null +++ b/drivers/gpio/tegra2_gpio.c @@ -0,0 +1,255 @@ +/* + * NVIDIA Tegra2 GPIO handling. + * (C) Copyright 2010,2011 + * 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 'gp' as GPIO (1) or SFPIO (0) */ +static int get_config(int gp) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + u32 u; + int type; + + u = readl(&bank->gpio_config[GPIO_PORT(gp)]); + type = (u >> GPIO_BIT(gp)) & 1; + + debug("get_config: port = %d, bit = %d is %s\n", + GPIO_FULLPORT(gp), GPIO_BIT(gp), type ? "GPIO" : "SFPIO"); + + return type; +} + +/* Config pin 'gp' as GPIO or SFPIO, based on 'type' */ +static void set_config(int gp, int type) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + u32 u; + + debug("set_config: port = %d, bit = %d, %s\n", + GPIO_FULLPORT(gp), GPIO_BIT(gp), type ? "GPIO" : "SFPIO"); + + u = readl(&bank->gpio_config[GPIO_PORT(gp)]); + if (type) /* GPIO */ + u |= 1 << GPIO_BIT(gp); + else + u &= ~(1 << GPIO_BIT(gp)); + writel(u, &bank->gpio_config[GPIO_PORT(gp)]); +} + +/* Return GPIO pin 'gp' direction - 0 = input or 1 = output */ +static int get_direction(int gp) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + u32 u; + int dir; + + u = readl(&bank->gpio_dir_out[GPIO_PORT(gp)]); + dir = (u >> GPIO_BIT(gp)) & 1; + + debug("get_direction: port = %d, bit = %d, %s\n", + GPIO_FULLPORT(gp), GPIO_BIT(gp), dir ? "OUT" : "IN"); + + return dir; +} + +/* Config GPIO pin 'gp' as input or output (OE) as per 'output' */ +static void set_direction(int gp, int output) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + u32 u; + + debug("set_direction: port = %d, bit = %d, %s\n", + GPIO_FULLPORT(gp), GPIO_BIT(gp), output ? "OUT" : "IN"); + + u = readl(&bank->gpio_dir_out[GPIO_PORT(gp)]); + if (output) + u |= 1 << GPIO_BIT(gp); + else + u &= ~(1 << GPIO_BIT(gp)); + writel(u, &bank->gpio_dir_out[GPIO_PORT(gp)]); +} + +/* set GPIO pin 'gp' output bit as 0 or 1 as per 'high' */ +static void set_level(int gp, int high) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + u32 u; + + debug("set_level: port = %d, bit %d == %d\n", + GPIO_FULLPORT(gp), GPIO_BIT(gp), high); + + u = readl(&bank->gpio_out[GPIO_PORT(gp)]); + if (high) + u |= 1 << GPIO_BIT(gp); + else + u &= ~(1 << GPIO_BIT(gp)); + writel(u, &bank->gpio_out[GPIO_PORT(gp)]); +} + +/* + * Generic_GPIO primitives. + */ + +int gpio_request(int gp, const char *label) +{ + if (gp >= MAX_NUM_GPIOS) + return -1; + + strncpy(gpio_names[gp].name, label, GPIO_NAME_SIZE); + gpio_names[gp].name[GPIO_NAME_SIZE - 1] = '\0'; + + /* Configure as a GPIO */ + set_config(gp, 1); + + return 0; +} + +void gpio_free(int gp) +{ +} + +/* read GPIO OUT value of pin 'gp' */ +static int gpio_get_output_value(int gp) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + int val; + + debug("gpio_get_output_value: pin = %d (port %d:bit %d)\n", + gp, GPIO_FULLPORT(gp), GPIO_BIT(gp)); + + val = readl(&bank->gpio_out[GPIO_PORT(gp)]); + + return (val >> GPIO_BIT(gp)) & 1; +} + +void gpio_toggle_value(int gp) +{ + gpio_set_value(gp, !gpio_get_output_value(gp)); +} + +/* set GPIO pin 'gp' as an input */ +int gpio_direction_input(int gp) +{ + debug("gpio_direction_input: pin = %d (port %d:bit %d)\n", + gp, GPIO_FULLPORT(gp), GPIO_BIT(gp)); + + /* Configure GPIO direction as input. */ + set_direction(gp, 0); + + return 0; +} + +/* set GPIO pin 'gp' as an output, with polarity 'value' */ +int gpio_direction_output(int gp, int value) +{ + debug("gpio_direction_output: pin = %d (port %d:bit %d) = %s\n", + gp, GPIO_FULLPORT(gp), GPIO_BIT(gp), value ? "HIGH" : "LOW"); + + /* Configure GPIO output value. */ + set_level(gp, value); + + /* Configure GPIO direction as output. */ + set_direction(gp, 1); + + return 0; +} + +/* read GPIO IN value of pin 'gp' */ +int gpio_get_value(int gp) +{ + struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE; + struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)]; + int val; + + debug("gpio_get_value: pin = %d (port %d:bit %d)\n", + gp, GPIO_FULLPORT(gp), GPIO_BIT(gp)); + + val = readl(&bank->gpio_in[GPIO_PORT(gp)]); + + return (val >> GPIO_BIT(gp)) & 1; +} + +/* write GPIO OUT value to pin 'gp' */ +void gpio_set_value(int gp, int value) +{ + debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n", + gp, GPIO_FULLPORT(gp), GPIO_BIT(gp), value); + + /* Configure GPIO output value. */ + set_level(gp, value); +} + +/* + * Display Tegra GPIO information + */ +void gpio_info(void) +{ + int c, 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; + } +} |