On 6/22/20 9:01 AM, Cédric Le Goater wrote: > On 6/21/20 12:58 AM, Philippe Mathieu-Daudé wrote: >> Emit a trace event when a GPIO change its state. > > I understand now why you need 'pin_status'. > > We could compute 'pin_status' and 'pin_changed' in routine > pca9552_update_pin_input() when updating the PCA9552_INPUT0/1 > register values and pass them to pca9552_display_pins_status() > or something like that.
Good idea, thanks! > > Maybe add two different display routines also. > >> >> Example booting obmc-phosphor-image: >> >> $ qemu-system-arm -M witherspoon-bmc -trace pca9552_gpio_change >> 1592690552.687372:pca9552_gpio_change pca1 GPIO id:0 status: 0 -> 1 >> 1592690552.690169:pca9552_gpio_change pca1 GPIO id:1 status: 0 -> 1 >> 1592690552.691673:pca9552_gpio_change pca1 GPIO id:2 status: 0 -> 1 >> 1592690552.696886:pca9552_gpio_change pca1 GPIO id:3 status: 0 -> 1 >> 1592690552.698614:pca9552_gpio_change pca1 GPIO id:13 status: 0 -> 1 >> 1592690552.699833:pca9552_gpio_change pca1 GPIO id:14 status: 0 -> 1 >> 1592690552.700842:pca9552_gpio_change pca1 GPIO id:15 status: 0 -> 1 >> 1592690683.841921:pca9552_gpio_change pca1 GPIO id:14 status: 1 -> 0 >> 1592690683.861660:pca9552_gpio_change pca1 GPIO id:14 status: 0 -> 1 >> 1592690684.371460:pca9552_gpio_change pca1 GPIO id:14 status: 1 -> 0 >> 1592690684.882115:pca9552_gpio_change pca1 GPIO id:14 status: 0 -> 1 >> 1592690685.391411:pca9552_gpio_change pca1 GPIO id:14 status: 1 -> 0 >> 1592690685.901391:pca9552_gpio_change pca1 GPIO id:14 status: 0 -> 1 >> 1592690686.411678:pca9552_gpio_change pca1 GPIO id:14 status: 1 -> 0 >> 1592690686.921279:pca9552_gpio_change pca1 GPIO id:14 status: 0 -> 1 >> >> We notice the GPIO #14 (front-power LED) starts to blink. >> >> This LED is described in the witherspoon device-tree [*]: >> >> front-power { >> retain-state-shutdown; >> default-state = "keep"; >> gpios = <&pca0 14 GPIO_ACTIVE_LOW>; >> }; >> >> [*] >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts?id=b1f9be9392f0#n140 >> >> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org> >> --- >> hw/misc/pca9552.c | 15 +++++++++++++++ >> hw/misc/trace-events | 1 + >> 2 files changed, 16 insertions(+) >> >> diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c >> index f0d435e310..85557b78d9 100644 >> --- a/hw/misc/pca9552.c >> +++ b/hw/misc/pca9552.c >> @@ -60,6 +60,21 @@ static void pca9552_display_pins_status(PCA9552State *s) >> buf[i] = '\0'; >> trace_pca9552_gpio_status(s->description, buf); >> } >> + if (trace_event_get_state_backends(TRACE_PCA9552_GPIO_CHANGE)) { >> + for (i = 0; i < s->nr_leds; i++) { >> + if (extract32(pins_changed, i, 1)) { >> + unsigned new_state = extract32(pins_status, i, 1); >> + >> + /* >> + * We display the state using the PCA logic ("active-high"). >> + * This is not the state of the LED, which signal might be >> + * wired "active-low" on the board. >> + */ >> + trace_pca9552_gpio_change(s->description, i, >> + !new_state, new_state); >> + } >> + } >> + } >> } >> >> static void pca9552_update_pin_input(PCA9552State *s) >> diff --git a/hw/misc/trace-events b/hw/misc/trace-events >> index 7630e59652..805d2110e0 100644 >> --- a/hw/misc/trace-events >> +++ b/hw/misc/trace-events >> @@ -209,3 +209,4 @@ grlib_apb_pnp_read(uint64_t addr, uint32_t value) "APB >> PnP read addr:0x%03"PRIx6 >> >> # pca9552.c >> pca9552_gpio_status(const char *description, const char *buf) "%s GPIOs >> 0-15 [%s]" >> +pca9552_gpio_change(const char *description, unsigned id, unsigned >> prev_state, unsigned current_state) "%s GPIO id:%u status: %u -> %u" >> > >