diff options
author | Alexandru Gagniuc <mr.nuke.me@gmail.com> | 2014-01-02 03:59:24 -0500 |
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committer | Alexandru Gagniuc <mr.nuke.me@gmail.com> | 2014-01-09 01:05:29 +0100 |
commit | 919e499a364bebd0032f2f7b92051fb4f301f66f (patch) | |
tree | 66539e60116d412e6c25fad8339b51b6fbde0206 /src/cpu/allwinner/a10/gpio.c | |
parent | 6ed574a661dcf85dea9d093fdcd4c060d51d08d2 (diff) |
cpu/allwinner/a10: Add functions for driving GPIO pins
Change-Id: I9473a6e574c3af02d154a7e30245f0dc0b238300
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4599
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Diffstat (limited to 'src/cpu/allwinner/a10/gpio.c')
-rw-r--r-- | src/cpu/allwinner/a10/gpio.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/cpu/allwinner/a10/gpio.c b/src/cpu/allwinner/a10/gpio.c new file mode 100644 index 0000000000..295cdf2054 --- /dev/null +++ b/src/cpu/allwinner/a10/gpio.c @@ -0,0 +1,98 @@ +/* + * Basic GPIO helpers for Allwinner CPUs + * + * Copyright (C) 2013 Alexandru Gagniuc <mr.nuke.me@gmail.com> + * Subject to the GNU GPL v2, or (at your option) any later version. + */ + +#include "gpio.h" + +#include <arch/io.h> + +static struct a10_gpio *const gpio = (void *)GPIO_BASE; + +/** + * \brief Set a single output pin + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @param[in] pin the pin number in the given port (1 -> 31) + */ +void gpio_set(u8 port, u8 pin) +{ + u32 reg32; + + if ((port > GPS)) + return; + + reg32 = gpio_read(port); + reg32 |= (1 << pin); + gpio_write(port, reg32); +} + +/** + * \brief Clear a single output pin + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @param[in] pin the pin number in the given port (1 -> 31) + */ +void gpio_clear(u8 port, u8 pin) +{ + u32 reg32; + if ((port > GPS)) + return; + + reg32 = gpio_read(port); + reg32 &= ~(1 << pin); + gpio_write(port, reg32); +} + +/** + * \brief Get the status of a single input pin + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @param[in] pin the pin number in the given port (1 -> 31) + * @return 1 if the pin is high, or 0 if the pin is low + */ +int gpio_get(u8 port, u8 pin) +{ + if ((port > GPS)) + return 0; + + return (gpio_read(port) & (1 << pin)) ? 1 : 0; +} + +/** + * \brief Write to a GPIO port + * + * Write the state of all output pins in the GPIO port. This only affects pins + * configured as output pins. + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @param[in] value 32-bit mask indicating which pins to set. For a set bit, the + * corresponding pin will be set. Otherwise, it will be cleared + */ +void gpio_write(u8 port, u32 val) +{ + if ((port > GPS)) + return; + + write32(val, &gpio->port[port].dat); +} + +/** + * \brief Write to a GPIO port + * + * Read the state of all input pins in the GPIO port. + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @return 32-bit mask indicating which pins are high. For each set bit, the + * corresponding pin is high. The value of bits corresponding to pins + * which are not configured as inputs is undefined. + */ +u32 gpio_read(u8 port) +{ + if ((port > GPS)) + return 0; + + return read32(&gpio->port[port].dat); +} |