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| author | Philippe Mathieu-Daudé <f4bug@amsat.org> | 2020-06-23 09:27:22 +0200 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2020-06-26 14:30:28 +0100 |
| commit | d82ab2931d14c1d8aa27a330b03fe5bf944130cf (patch) | |
| tree | ab28dc10d299d6c4bebe65cb6e33f2d89c086e08 /hw/misc | |
| parent | 15ce12cfdd3740d38a7ab19ad0f5c812ff649fed (diff) | |
| download | qemu-d82ab2931d14c1d8aa27a330b03fe5bf944130cf.zip qemu-d82ab2931d14c1d8aa27a330b03fe5bf944130cf.tar.gz qemu-d82ab2931d14c1d8aa27a330b03fe5bf944130cf.tar.bz2 | |
hw/misc/pca9552: Trace GPIO change events
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 <clg@kaod.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20200623072723.6324-9-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'hw/misc')
| -rw-r--r-- | hw/misc/pca9552.c | 15 | ||||
| -rw-r--r-- | hw/misc/trace-events | 1 |
2 files changed, 16 insertions, 0 deletions
diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c index 41f8ad2..1c3ad57 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 bd7bd37..ebea537 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" |