stm32f4: Add support for GPIO

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2019-07-25 14:55:10 -04:00
parent d501ca6b0b
commit 1487f8a257
3 changed files with 133 additions and 0 deletions

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@ -5,6 +5,7 @@ if MACH_STM32F4
config STM32F4_SELECT
bool
default y
select HAVE_GPIO
config BOARD_DIRECTORY
string

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@ -4,7 +4,16 @@
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include <string.h> // ffs
#include "board/irq.h" // irq_save
#include "command.h" // DECL_ENUMERATION_RANGE
#include "gpio.h" // gpio_out_setup
#include "internal.h" // gpio_peripheral
#include "sched.h" // sched_shutdown
DECL_ENUMERATION_RANGE("pin", "PA0", GPIO('A', 0), 32);
DECL_ENUMERATION_RANGE("pin", "PB0", GPIO('B', 0), 32);
DECL_ENUMERATION_RANGE("pin", "PC0", GPIO('C', 0), 32);
static GPIO_TypeDef * const digital_regs[] = {
GPIOA, GPIOB, GPIOC
@ -25,3 +34,102 @@ gpio_peripheral(uint32_t gpio, uint32_t mode, uint32_t func, int pullup)
regs->PUPDR = (regs->PUPDR & ~m_msk) | (pup << m_shift);
regs->OSPEEDR = (regs->OSPEEDR & ~m_msk) | (0x02 << m_shift);
}
// Convert a register and bit location back to an integer pin identifier
static int
regs_to_pin(GPIO_TypeDef *regs, uint32_t bit)
{
int i;
for (i=0; i<ARRAY_SIZE(digital_regs); i++)
if (digital_regs[i] == regs)
return GPIO('A' + i, ffs(bit)-1);
return 0;
}
/****************************************************************
* General Purpose Input Output (GPIO) pins
****************************************************************/
struct gpio_out
gpio_out_setup(uint32_t pin, uint32_t val)
{
if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs))
goto fail;
GPIO_TypeDef *regs = digital_regs[GPIO2PORT(pin)];
struct gpio_out g = { .regs=regs, .bit=GPIO2BIT(pin) };
gpio_out_reset(g, val);
return g;
fail:
shutdown("Not an output pin");
}
void
gpio_out_reset(struct gpio_out g, uint32_t val)
{
GPIO_TypeDef *regs = g.regs;
int pin = regs_to_pin(regs, g.bit);
irqstatus_t flag = irq_save();
if (val)
regs->BSRR = g.bit;
else
regs->BSRR = g.bit << 16;
gpio_peripheral(pin, GPIO_OUTPUT, 0, 0);
irq_restore(flag);
}
void
gpio_out_toggle_noirq(struct gpio_out g)
{
GPIO_TypeDef *regs = g.regs;
regs->ODR ^= g.bit;
}
void
gpio_out_toggle(struct gpio_out g)
{
irqstatus_t flag = irq_save();
gpio_out_toggle_noirq(g);
irq_restore(flag);
}
void
gpio_out_write(struct gpio_out g, uint32_t val)
{
GPIO_TypeDef *regs = g.regs;
if (val)
regs->BSRR = g.bit;
else
regs->BSRR = g.bit << 16;
}
struct gpio_in
gpio_in_setup(uint32_t pin, int32_t pull_up)
{
if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs))
goto fail;
GPIO_TypeDef *regs = digital_regs[GPIO2PORT(pin)];
struct gpio_in g = { .regs=regs, .bit=GPIO2BIT(pin) };
gpio_in_reset(g, pull_up);
return g;
fail:
shutdown("Not a valid input pin");
}
void
gpio_in_reset(struct gpio_in g, int32_t pull_up)
{
GPIO_TypeDef *regs = g.regs;
int pin = regs_to_pin(regs, g.bit);
irqstatus_t flag = irq_save();
gpio_peripheral(pin, GPIO_INPUT, 0, pull_up);
irq_restore(flag);
}
uint8_t
gpio_in_read(struct gpio_in g)
{
GPIO_TypeDef *regs = g.regs;
return !!(regs->IDR & g.bit);
}

24
src/stm32f4/gpio.h Normal file
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@ -0,0 +1,24 @@
#ifndef __STM32F4_GPIO_H
#define __STM32F4_GPIO_H
#include <stdint.h> // uint32_t
struct gpio_out {
void *regs;
uint32_t bit;
};
struct gpio_out gpio_out_setup(uint32_t pin, uint32_t val);
void gpio_out_reset(struct gpio_out g, uint32_t val);
void gpio_out_toggle_noirq(struct gpio_out g);
void gpio_out_toggle(struct gpio_out g);
void gpio_out_write(struct gpio_out g, uint32_t val);
struct gpio_in {
void *regs;
uint32_t bit;
};
struct gpio_in gpio_in_setup(uint32_t pin, int32_t pull_up);
void gpio_in_reset(struct gpio_in g, int32_t pull_up);
uint8_t gpio_in_read(struct gpio_in g);
#endif // gpio.h