From d82ab2931d14c1d8aa27a330b03fe5bf944130cf Mon Sep 17 00:00:00 2001 From: =?utf8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Tue, 23 Jun 2020 09:27:22 +0200 Subject: [PATCH] hw/misc/pca9552: Trace GPIO change events MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Emit a trace event when a GPIO change its state. Example booting obmc-phosphor-image: $ qemu-system-arm -M witherspoon-bmc -trace pca955x_gpio_change 1592690552.687372:pca955x_gpio_change pca1 GPIO id:0 status: 0 -> 1 1592690552.690169:pca955x_gpio_change pca1 GPIO id:1 status: 0 -> 1 1592690552.691673:pca955x_gpio_change pca1 GPIO id:2 status: 0 -> 1 1592690552.696886:pca955x_gpio_change pca1 GPIO id:3 status: 0 -> 1 1592690552.698614:pca955x_gpio_change pca1 GPIO id:13 status: 0 -> 1 1592690552.699833:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1 1592690552.700842:pca955x_gpio_change pca1 GPIO id:15 status: 0 -> 1 1592690683.841921:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0 1592690683.861660:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1 1592690684.371460:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0 1592690684.882115:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1 1592690685.391411:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0 1592690685.901391:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1 1592690686.411678:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0 1592690686.921279:pca955x_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 Reviewed-by: Cédric Le Goater Signed-off-by: Philippe Mathieu-Daudé Tested-by: Cédric Le Goater Message-id: 20200623072723.6324-9-f4bug@amsat.org Signed-off-by: Peter Maydell --- 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 41f8ad213d..1c3ad57432 100644 --- a/hw/misc/pca9552.c +++ b/hw/misc/pca9552.c @@ -82,6 +82,21 @@ static void pca955x_display_pins_status(PCA955xState *s, buf[i] = '\0'; trace_pca955x_gpio_status(s->description, buf); } + if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_CHANGE)) { + for (i = 0; i < k->pin_count; 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_pca955x_gpio_change(s->description, i, + !new_state, new_state); + } + } + } } static void pca955x_update_pin_input(PCA955xState *s) diff --git a/hw/misc/trace-events b/hw/misc/trace-events index bd7bd37ea8..ebea53735c 100644 --- a/hw/misc/trace-events +++ b/hw/misc/trace-events @@ -212,3 +212,4 @@ grlib_apb_pnp_read(uint64_t addr, uint32_t value) "APB PnP read addr:0x%03"PRIx6 # pca9552.c pca955x_gpio_status(const char *description, const char *buf) "%s GPIOs 0-15 [%s]" +pca955x_gpio_change(const char *description, unsigned id, unsigned prev_state, unsigned current_state) "%s GPIO id:%u status: %u -> %u" -- 2.11.0