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drivers/bcm2835gpio: Fully restore GPIOs after use 

Restore outputs to their initial output level.

Signed-off-by: Steve Marple <stevemarple@googlemail.com>
Change-Id: I82402fd7b59d944f81c0ea7859ac499943901f82
Reviewed-on: https://review.openocd.org/c/openocd/+/7125
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
This commit is contained in:
Steve Marple 2022-08-15 15:45:02 +01:00 committed by Antonio Borneo
parent 24e801d5d6
commit fed16496ab
1 changed files with 21 additions and 5 deletions
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26
src/jtag/drivers/bcm2835gpio.c
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@ -51,7 +51,11 @@ static int speed_offset = 28;
static unsigned int jtag_delay; static unsigned int jtag_delay;
static const struct adapter_gpio_config *adapter_gpio_config; static const struct adapter_gpio_config *adapter_gpio_config;
static int initial_gpio_mode[ADAPTER_GPIO_IDX_NUM]; static struct initial_gpio_state {
unsigned int mode;
unsigned int output_level;
} initial_gpio_state[ADAPTER_GPIO_IDX_NUM];
static uint32_t initial_drive_strength_etc;
static bool is_gpio_config_valid(enum adapter_gpio_config_index idx) static bool is_gpio_config_valid(enum adapter_gpio_config_index idx)
{ {
@ -96,8 +100,15 @@ static void set_gpio_value(const struct adapter_gpio_config *gpio_config, int va
static void restore_gpio(enum adapter_gpio_config_index idx) static void restore_gpio(enum adapter_gpio_config_index idx)
{ {
if (is_gpio_config_valid(idx)) if (is_gpio_config_valid(idx)) {
SET_MODE_GPIO(adapter_gpio_config[idx].gpio_num, initial_gpio_mode[idx]); SET_MODE_GPIO(adapter_gpio_config[idx].gpio_num, initial_gpio_state[idx].mode);
if (initial_gpio_state[idx].mode == BCM2835_GPIO_MODE_OUTPUT) {
if (initial_gpio_state[idx].output_level)
GPIO_SET = 1 << adapter_gpio_config[idx].gpio_num;
else
GPIO_CLR = 1 << adapter_gpio_config[idx].gpio_num;
}
}
} }
static void initialize_gpio(enum adapter_gpio_config_index idx) static void initialize_gpio(enum adapter_gpio_config_index idx)
@ -105,10 +116,12 @@ static void initialize_gpio(enum adapter_gpio_config_index idx)
if (!is_gpio_config_valid(idx)) if (!is_gpio_config_valid(idx))
return; return;
initial_gpio_mode[idx] = MODE_GPIO(adapter_gpio_config[idx].gpio_num); initial_gpio_state[idx].mode = MODE_GPIO(adapter_gpio_config[idx].gpio_num);
unsigned int shift = adapter_gpio_config[idx].gpio_num;
initial_gpio_state[idx].output_level = (GPIO_LEV >> shift) & 1;
LOG_DEBUG("saved GPIO mode for %s (GPIO %d %d): %d", LOG_DEBUG("saved GPIO mode for %s (GPIO %d %d): %d",
adapter_gpio_get_name(idx), adapter_gpio_config[idx].chip_num, adapter_gpio_config[idx].gpio_num, adapter_gpio_get_name(idx), adapter_gpio_config[idx].chip_num, adapter_gpio_config[idx].gpio_num,
initial_gpio_mode[idx]); initial_gpio_state[idx].mode);
if (adapter_gpio_config[idx].pull != ADAPTER_GPIO_PULL_NONE) { if (adapter_gpio_config[idx].pull != ADAPTER_GPIO_PULL_NONE) {
LOG_WARNING("BCM2835 GPIO does not support pull-up or pull-down settings (signal %s)", LOG_WARNING("BCM2835 GPIO does not support pull-up or pull-down settings (signal %s)",
@ -407,6 +420,7 @@ static int bcm2835gpio_init(void)
close(dev_mem_fd); close(dev_mem_fd);
/* set 4mA drive strength, slew rate limited, hysteresis on */ /* set 4mA drive strength, slew rate limited, hysteresis on */
initial_drive_strength_etc = pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] & 0x1f;
pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1; pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
/* Configure JTAG/SWD signals. Default directions and initial states are handled /* Configure JTAG/SWD signals. Default directions and initial states are handled
@ -478,6 +492,8 @@ static int bcm2835gpio_quit(void)
restore_gpio(ADAPTER_GPIO_IDX_SRST); restore_gpio(ADAPTER_GPIO_IDX_SRST);
restore_gpio(ADAPTER_GPIO_IDX_LED); restore_gpio(ADAPTER_GPIO_IDX_LED);
/* Restore drive strength. MSB is password ("5A") */
pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5A000000 | initial_drive_strength_etc;
bcm2835gpio_munmap(); bcm2835gpio_munmap();
return ERROR_OK; return ERROR_OK;