void gpio_pre_init(void)
{
const struct gpio_info *g = gpio_list;
int is_warm = system_is_reboot_warm();
int i;
/* Required to configure external IRQ lines (SYSCFG_EXTICRn) */
STM32_RCC_APB2ENR |= 1 << 0;
/* Delay 1 APB clock cycle after the clock is enabled */
clock_wait_bus_cycles(BUS_APB, 1);
if (!is_warm)
gpio_enable_clocks();
/* Set all GPIOs to defaults */
for (i = 0; i < GPIO_COUNT; i++, g++) {
int flags = g->flags;
if (flags & GPIO_DEFAULT)
continue;
/*
* If this is a warm reboot, don't set the output levels or
* we'll shut off the AP.
*/
if (is_warm)
flags &= ~(GPIO_LOW | GPIO_HIGH);
/* Set up GPIO based on flags */
gpio_set_flags_by_mask(g->port, g->mask, flags);
}
}
void gpio_enable_clocks(void)
{
/*
* Enable all GPIOs clocks
*
* TODO(crosbug.com/p/23770): only enable the banks we need to,
* and support disabling some of them in low-power idle.
*/
STM32_RCC_AHBENR |= 0x3f;
/* Delay 1 AHB clock cycle after the clock is enabled */
clock_wait_bus_cycles(BUS_AHB, 1);
}
