hw/gpio/nrf51: implement DETECT signal

Implement nRF51 DETECT signal in the GPIO peripheral.

The reference manual makes mention of a per-pin DETECT signal, but these
are not exposed to the user. See https://devzone.nordicsemi.com/f/nordic-q-a/39858/gpio-per-pin-detect-signal-available
for more information. Currently, I don't see a reason to model these.

Signed-off-by: Chris Laplante <chris@laplante.io>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230728160324.1159090-2-chris@laplante.io
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Chris Laplante 2023-08-22 17:24:15 +01:00 committed by Peter Maydell
parent b0dd9a7d6d
commit 8d6b2f947d
2 changed files with 14 additions and 1 deletions

View File

@ -78,6 +78,7 @@ static void update_state(NRF51GPIOState *s)
int pull;
size_t i;
bool connected_out, dir, connected_in, out, in, input;
bool assert_detect = false;
for (i = 0; i < NRF51_GPIO_PINS; i++) {
pull = pull_value(s->cnf[i]);
@ -99,7 +100,15 @@ static void update_state(NRF51GPIOState *s)
qemu_log_mask(LOG_GUEST_ERROR,
"GPIO pin %zu short circuited\n", i);
}
if (!connected_in) {
if (connected_in) {
uint32_t detect_config = extract32(s->cnf[i], 16, 2);
if ((detect_config == 2) && (in == 1)) {
assert_detect = true;
}
if ((detect_config == 3) && (in == 0)) {
assert_detect = true;
}
} else {
/*
* Floating input: the output stimulates IN if connected,
* otherwise pull-up/pull-down resistors put a value on both
@ -116,6 +125,8 @@ static void update_state(NRF51GPIOState *s)
}
update_output_irq(s, i, connected_out, out);
}
qemu_set_irq(s->detect, assert_detect);
}
/*
@ -291,6 +302,7 @@ static void nrf51_gpio_init(Object *obj)
qdev_init_gpio_in(DEVICE(s), nrf51_gpio_set, NRF51_GPIO_PINS);
qdev_init_gpio_out(DEVICE(s), s->output, NRF51_GPIO_PINS);
qdev_init_gpio_out_named(DEVICE(s), &s->detect, "detect", 1);
}
static void nrf51_gpio_class_init(ObjectClass *klass, void *data)

View File

@ -64,6 +64,7 @@ struct NRF51GPIOState {
uint32_t old_out_connected;
qemu_irq output[NRF51_GPIO_PINS];
qemu_irq detect;
};