Signed-off-by: Vikram Narayanan vikram186@gmail.com Cc: Stephen Warren swarren@wwwdotorg.org Cc: Albert Aribaud albert.u.boot@aribaud.net --- arch/arm/include/asm/arch-bcm2835/gpio.h | 49 +++++++++++ drivers/gpio/Makefile | 1 + drivers/gpio/rpi_gpio.c | 128 ++++++++++++++++++++++++++++++ 3 files changed, 178 insertions(+), 0 deletions(-) create mode 100644 arch/arm/include/asm/arch-bcm2835/gpio.h create mode 100644 drivers/gpio/rpi_gpio.c
diff --git a/arch/arm/include/asm/arch-bcm2835/gpio.h b/arch/arm/include/asm/arch-bcm2835/gpio.h new file mode 100644 index 0000000..3cba0fb --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/gpio.h @@ -0,0 +1,49 @@ +/* + * Copyright (C) 2012 Vikram Narayananan + * vikram186@gmail.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 + */ + +#ifndef _BCM2835_GPIO_H_ +#define _BCM2835_GPIO_H_ + +#define BCM2835_GPIO_BASE (0x7E200000) +#define BCM2835_MAX_GPIOS 53 + +#define BCM2835_GPIO_FSEL_CLR_MASK (0x7) +#define BCM2835_GPIO_OUTPUT (0x1) + +#define GPIO_TO_BANK(n) (n / 10) +#define GPIO_TO_PIN(n) (n % 10) + +struct bcm_gpio_regs { + u32 gpfsel[6]; + u32 reserved1; + u32 gpset0; + u32 gpset1; + u32 reserved2; + u32 gpclr0; + u32 gpclr1; + u32 reserved3; + u32 gplev0; + u32 gplev1; +}; + +#endif /* _BCM2835_GPIO_H_ */ diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index fb3b09a..b042c46 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -39,6 +39,7 @@ COBJS-$(CONFIG_TEGRA2_GPIO) += tegra2_gpio.o COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o COBJS-$(CONFIG_ALTERA_PIO) += altera_pio.o COBJS-$(CONFIG_MPC83XX_GPIO) += mpc83xx_gpio.o +COBJS-$(CONFIG_BCM2835_GPIO) += rpi_gpio.o
COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/gpio/rpi_gpio.c b/drivers/gpio/rpi_gpio.c new file mode 100644 index 0000000..c2b547f --- /dev/null +++ b/drivers/gpio/rpi_gpio.c @@ -0,0 +1,128 @@ +/* + * Copyright (C) 2012 Vikram Narayananan + * vikram186@gmail.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 + */ + +#include <common.h> +#include <asm/gpio.h> +#include <asm/io.h> + +struct bcm_gpio { + u32 bank; + u32 pin; +}; + +inline int gpio_is_valid(unsigned gpio) +{ + return (gpio > BCM2835_MAX_GPIOS) ? 0 : 1; +} + +static int get_bank_pin(unsigned gpio, struct bcm_gpio *pio) +{ + int bank = GPIO_TO_BANK(gpio); + int pin = GPIO_TO_PIN(gpio); + + if (!gpio_is_valid(gpio)) + return -1; + + pin &= 0x09; + pio->pin = pin; + pio->bank = bank; + return 0; +} + +int gpio_request(unsigned gpio, const char *label) +{ + return (gpio_is_valid(gpio)) ? 1 : 0; +} + +int gpio_free(unsigned gpio) +{ + return 0; +} + +int gpio_direction_input(unsigned gpio) +{ + struct bcm_gpio pio; + struct bcm_gpio_regs *reg = (struct bcm_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val = 0; + + if (get_bank_pin(gpio, &pio)) + return -1; + + val = readl(®->gpfsel[pio.bank]); + val &= ~(BCM2835_GPIO_FSEL_CLR_MASK << (pio.pin * 3)); + writel(val, reg->gpfsel[pio.bank]); +} + +int gpio_direction_output(unsigned gpio, int value) +{ + struct bcm_gpio pio; + struct bcm_gpio_regs *reg = (struct bcm_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val = 0; + + if (get_bank_pin(gpio, &pio)) + return -1; + + val = readl(®->gpfsel[pio.bank]); + val &= ~(BCM2835_GPIO_FSEL_CLR_MASK << (pio.pin * 3)); + val |= (BCM2835_GPIO_OUTPUT << (pio.pin * 3)); + writel(val, reg->gpfsel[pio.bank]); + + if (value) + gpio_set_value(gpio, value); +} + +int gpio_get_value(unsigned gpio) +{ + struct bcm_gpio_regs *reg = (struct bcm_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val = 0; + + if (!gpio_is_valid(gpio)) + return -1; + + val = (gpio < 32) ? readl(®->gplev0) : readl(®->gplev1); + gpio &= 0x1f; + + return (val & (1 << gpio)) >> gpio; +} + +int gpio_set_value(unsigned gpio, int value) +{ + struct bcm_gpio_regs *reg = (struct bcm_gpio_regs *)BCM2835_GPIO_BASE; + + if (!gpio_is_valid(gpio)) + return -1; + + if (gpio < 32) { + if (value) + writel((1 << gpio), reg->gpset0); + else + writel((1 << gpio), reg->gpclr0); + } else { + gpio &= 0x1f; + if (value) + writel((1 << pin), reg->gpset1); + else + writel((1 << pin), reg->gpclr1); + } + return 0; +}