stm32: Add support for configuring open drain output mode

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2019-08-20 13:32:14 -04:00
parent c930fc392b
commit e32be928dc
3 changed files with 9 additions and 2 deletions

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@ -18,6 +18,7 @@ extern GPIO_TypeDef * const digital_regs[];
#define GPIO_INPUT 0
#define GPIO_OUTPUT 1
#define GPIO_OPEN_DRAIN 0x100
#define GPIO_FUNCTION(fn) (2 | ((fn) << 4))
#define GPIO_ANALOG 3

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@ -75,10 +75,15 @@ gpio_peripheral(uint32_t gpio, uint32_t mode, int pullup)
cfg = pullup ? 0x8 : 0x4;
} else if (mode == GPIO_OUTPUT) {
cfg = 0x1;
} else if (mode == (GPIO_OUTPUT | GPIO_OPEN_DRAIN)) {
cfg = 0x5;
} else if (mode == GPIO_ANALOG) {
cfg = 0x0;
} else {
if (pullup > 0)
if (mode & GPIO_OPEN_DRAIN)
// Alternate function with open-drain mode
cfg = 0xd;
else if (pullup > 0)
// Alternate function input pins use GPIO_INPUT mode on the stm32f1
cfg = 0x8;
else

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@ -72,7 +72,7 @@ gpio_peripheral(uint32_t gpio, uint32_t mode, int pullup)
gpio_clock_enable(regs);
// Configure GPIO
uint32_t mode_bits = mode & 0x0f, func = mode >> 4;
uint32_t mode_bits = mode & 0xf, func = (mode >> 4) & 0xf, od = mode >> 8;
uint32_t pup = pullup ? (pullup > 0 ? 1 : 2) : 0;
uint32_t pos = gpio % 16, af_reg = pos / 8;
uint32_t af_shift = (pos % 8) * 4, af_msk = 0x0f << af_shift;
@ -81,6 +81,7 @@ gpio_peripheral(uint32_t gpio, uint32_t mode, int pullup)
regs->AFR[af_reg] = (regs->AFR[af_reg] & ~af_msk) | (func << af_shift);
regs->MODER = (regs->MODER & ~m_msk) | (mode_bits << m_shift);
regs->PUPDR = (regs->PUPDR & ~m_msk) | (pup << m_shift);
regs->OTYPER = (regs->OTYPER & ~(1 << pos)) | (od << pos);
regs->OSPEEDR = (regs->OSPEEDR & ~m_msk) | (0x02 << m_shift);
}