diff options
| author | Pavel Pisa <ppisa@pikron.com> | 2016-05-19 10:29:28 +0200 |
|---|---|---|
| committer | Pavel Pisa <ppisa@pikron.com> | 2016-05-19 13:21:40 +0200 |
| commit | 4b62192f0570427ec66b9fd57882389c9a92a459 (patch) | |
| tree | 1b434b867dad47fccb003ff994f11adb450923d8 /c | |
| parent | arm/raspberrypi: ensure that RTEMS application image can be started by U-boot. (diff) | |
| download | rtems-4b62192f0570427ec66b9fd57882389c9a92a459.tar.bz2 | |
arm/raspberrypi: correct GPIO pin function selection.
Original implementation does only bitwise-or with previous register
value for all functions except IN. Switch from one to other function
would lead to incorrect value.
Diffstat (limited to 'c')
| -rw-r--r-- | c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c | 18 | ||||
| -rw-r--r-- | c/src/lib/libbsp/arm/raspberrypi/include/rpi-gpio.h | 3 |
2 files changed, 11 insertions, 10 deletions
diff --git a/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c b/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c index 642666ab02..40acd84483 100644 --- a/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c +++ b/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c @@ -52,15 +52,15 @@ static rtems_status_code rpi_select_pin_function( uint32_t type ) { /* Calculate the pin function select register address. */ - volatile unsigned int *pin_addr = (unsigned int *) BCM2835_GPIO_REGS_BASE + - (pin / 10); - - if ( type == RPI_DIGITAL_IN ) { - *(pin_addr) &= ~SELECT_PIN_FUNCTION(RPI_DIGITAL_IN, pin); - } - else { - *(pin_addr) |= SELECT_PIN_FUNCTION(type, pin); - } + volatile uint32_t *pin_addr = (uint32_t *) BCM2835_GPIO_REGS_BASE + + (pin / 10); + uint32_t reg_old; + uint32_t reg_new; + + reg_new = reg_old = *pin_addr; + reg_new &= ~SELECT_PIN_FUNCTION(RPI_ALT_FUNC_MASK, pin); + reg_new |= SELECT_PIN_FUNCTION(type, pin); + *pin_addr = reg_new; return RTEMS_SUCCESSFUL; } diff --git a/c/src/lib/libbsp/arm/raspberrypi/include/rpi-gpio.h b/c/src/lib/libbsp/arm/raspberrypi/include/rpi-gpio.h index 7f4d802b0f..82ba4b1f2a 100644 --- a/c/src/lib/libbsp/arm/raspberrypi/include/rpi-gpio.h +++ b/c/src/lib/libbsp/arm/raspberrypi/include/rpi-gpio.h @@ -26,7 +26,7 @@ extern "C" { /** * @brief Raspberry Pi GPIO functions. */ -#define RPI_DIGITAL_IN 7 +#define RPI_DIGITAL_IN 0 #define RPI_DIGITAL_OUT 1 #define RPI_ALT_FUNC_0 4 #define RPI_ALT_FUNC_1 5 @@ -34,6 +34,7 @@ extern "C" { #define RPI_ALT_FUNC_3 7 #define RPI_ALT_FUNC_4 3 #define RPI_ALT_FUNC_5 2 +#define RPI_ALT_FUNC_MASK 7 /** * @brief Setups a JTAG interface. |