diff options
author | Stephen Warren <swarren@wwwdotorg.org> | 2012-08-05 16:07:21 (GMT) |
---|---|---|
committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2012-09-01 12:58:21 (GMT) |
commit | efad6cf8818620b0d85405df2b810760b62acbb8 (patch) | |
tree | 45fa8ee97e49c985752e31cc7dfe84db4f6cf18d /drivers/gpio | |
parent | 86c632651d317fbb9de92489b7a5febece3c4436 (diff) | |
download | u-boot-fsl-qoriq-efad6cf8818620b0d85405df2b810760b62acbb8.tar.xz |
ARM: add basic support for the Broadcom BCM2835 SoC
This SoC is used in the Raspberry Pi, for example.
For more details, see:
http://www.broadcom.com/products/BCM2835
http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf.
Initial support is enough to boot to a serial console, execute a minimal
set of U-Boot commands, download data over a serial port, and boot a
Linux kernel. No storage or network drivers are implemented.
GPIO driver originally by Vikram Narayanan <vikram186@gmail.com>
with many fixes from myself.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
-rw-r--r-- | drivers/gpio/bcm2835_gpio.c | 89 |
2 files changed, 90 insertions, 0 deletions
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 3c67599..17f4b73 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -43,6 +43,7 @@ COBJS-$(CONFIG_MPC83XX_GPIO) += mpc83xx_gpio.o COBJS-$(CONFIG_SH_GPIO_PFC) += sh_pfc.o COBJS-$(CONFIG_OMAP_GPIO) += omap_gpio.o COBJS-$(CONFIG_DB8500_GPIO) += db8500_gpio.o +COBJS-$(CONFIG_BCM2835_GPIO) += bcm2835_gpio.o COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c new file mode 100644 index 0000000..1d50dbd --- /dev/null +++ b/drivers/gpio/bcm2835_gpio.c @@ -0,0 +1,89 @@ +/* + * 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. + */ + +#include <common.h> +#include <asm/gpio.h> +#include <asm/io.h> + +inline int gpio_is_valid(unsigned gpio) +{ + return (gpio < BCM2835_GPIO_COUNT); +} + +int gpio_request(unsigned gpio, const char *label) +{ + return !gpio_is_valid(gpio); +} + +int gpio_free(unsigned gpio) +{ + return 0; +} + +int gpio_direction_input(unsigned gpio) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); + val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); + writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return 0; +} + +int gpio_direction_output(unsigned gpio, int value) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + gpio_set_value(gpio, value); + + val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); + val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); + writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return 0; +} + +int gpio_get_value(unsigned gpio) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + val = readl(®->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]); + + return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1; +} + +int gpio_set_value(unsigned gpio, int value) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + u32 *output_reg = value ? reg->gpset : reg->gpclr; + + writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio), + &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]); + + return 0; +} |