From 9f28e53c71d28d04e2775c59944d2887a99f1e86 Mon Sep 17 00:00:00 2001 From: Josh Rahm Date: Sun, 22 Nov 2020 01:06:30 -0700 Subject: Large reorganization. What was in core/ is now moved to arch/stm34l4xxx/peripherals. This new directory is *supposed to* to contain raw header files defining just the pertinent register structures for the various peripherals. Peripheral management belongs somewhere in the new `kern/..` directories. This is not completely the case at the moment, so more refactoring needs to be done. What was sitting in the root has now been moved into the kern/ directory. The kern/ directory is to contain everything else other than raw device register definitions. The root of the kern/ tree is reserved for standard library-esque headers. The kern/ directory contains management systems for that peripheral. (At the moment DMA is the only peripheral with a decent management system.) Preferably these peripheral systems should only include their correlating header in arch/stm34l4xxx/peripherals, and use other management systems for handling other peripherals rather than manipulating their raw registers directly. (Though this ideal will require much more critical mass of management systems.) --- 02-usart/src/arch/stm32l4xxx/peripherals/gpio.c | 52 +++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 02-usart/src/arch/stm32l4xxx/peripherals/gpio.c (limited to '02-usart/src/arch/stm32l4xxx/peripherals/gpio.c') diff --git a/02-usart/src/arch/stm32l4xxx/peripherals/gpio.c b/02-usart/src/arch/stm32l4xxx/peripherals/gpio.c new file mode 100644 index 0000000..a1e82c7 --- /dev/null +++ b/02-usart/src/arch/stm32l4xxx/peripherals/gpio.c @@ -0,0 +1,52 @@ +#include "arch/stm32l4xxx/peripherals/gpio.h" +#include "arch/stm32l4xxx/peripherals/rcc.h" + +/* + * Sets the mode of a pin on a gpio por. + */ +void set_gpio_pin_mode( + __IO gpio_port_t* gpio_port, gpio_pin_t pin, gpio_pin_mode_t mode) +{ + /* Each pin has a 2-bit mode provided at bits pin#*2 and pin#*2+1 */ + gpio_port->mode_r &= ~(0x03 << pin * 2); + gpio_port->mode_r |= mode << pin * 2; +} + +gpio_output_pin_t set_gpio_pin_output( + __IO gpio_port_t* gpio_port, gpio_pin_t pin) +{ + set_gpio_pin_mode(gpio_port, pin, MODE_OUTPUT); + + return (gpio_output_pin_t){.gpio_port = gpio_port, .pin = pin}; +} + +void set_gpio_output_pin(gpio_output_pin_t pin, bool onoff) +{ + if (onoff) { + pin.gpio_port->output_r |= 1 << pin.pin; + } else { + pin.gpio_port->output_r &= ~(1 << pin.pin); + } +} + +void set_gpio_alternate_function( + __IO gpio_port_t* port, gpio_pin_t gpio_pin, alternate_function_t afn) +{ + __IO uint32_t* reg; + if (gpio_pin < 8) { + reg = &(port->af_rl); + } else { + reg = &(port->af_rh); + gpio_pin -= 8; + } + + uint32_t tmp = *reg & (~0x0f << gpio_pin * 4); + *reg = tmp | (afn << gpio_pin * 4); +} + +#define GPIO_PORTS_BASE_ADDR ((uint8_t*)0x48000000) +__IO gpio_port_t* enable_gpio(gpio_port_number_t gpio_port_number) +{ + RCC.ahb2en_r |= 1 << gpio_port_number; /* Enable the GPIO port. */ + return (__IO gpio_port_t*)(GPIO_PORTS_BASE_ADDR + (gpio_port_number * 0x400)); +} -- cgit