On 6/21/20 12:58 AM, Philippe Mathieu-Daudé wrote:
> Add a trivial representation of the PCA9552 GPIOs.
>
> Example booting obmc-phosphor-image:
>
> $ qemu-system-arm -M witherspoon-bmc -trace pca9552_gpio_status
> 1592689902.327837:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [*...............]
> 1592689902.329934:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [**..............]
> 1592689902.330717:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [***.............]
> 1592689902.331431:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****............]
> 1592689902.332163:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........*..]
> 1592689902.332888:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........**.]
> 1592689902.333629:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........***]
> 1592690032.793289:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........*.*]
> 1592690033.303163:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........***]
> 1592690033.812962:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........*.*]
> 1592690034.323234:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........***]
> 1592690034.832922:pca9552_gpio_status pca-unspecified GPIOs 0-15
> [****.........*.*]
>
> 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
>
> Suggested-by: Cédric Le Goater <c...@kaod.org>
> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> ---
> include/hw/misc/pca9552.h | 1 +
> hw/misc/pca9552.c | 29 +++++++++++++++++++++++++++++
> hw/misc/trace-events | 3 +++
> 3 files changed, 33 insertions(+)
>
> diff --git a/include/hw/misc/pca9552.h b/include/hw/misc/pca9552.h
> index c5be7f1c5e..755be2e8e5 100644
> --- a/include/hw/misc/pca9552.h
> +++ b/include/hw/misc/pca9552.h
> @@ -26,6 +26,7 @@ typedef struct PCA9552State {
> uint8_t pointer;
>
> uint8_t regs[PCA9552_NR_REGS];
> + uint16_t pins_status; /* Holds latest INPUT0 & INPUT1 status */
Hmm, that is an extra state redundant with regs.
> uint8_t max_reg;
> char *description; /* For debugging purpose only */
> uint8_t nr_leds;
> diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
> index 54ccdcf6d4..f0d435e310 100644
> --- a/hw/misc/pca9552.c
> +++ b/hw/misc/pca9552.c
> @@ -12,12 +12,14 @@
> #include "qemu/osdep.h"
> #include "qemu/log.h"
> #include "qemu/module.h"
> +#include "qemu/bitops.h"
> #include "hw/qdev-properties.h"
> #include "hw/misc/pca9552.h"
> #include "hw/misc/pca9552_regs.h"
> #include "migration/vmstate.h"
> #include "qapi/error.h"
> #include "qapi/visitor.h"
> +#include "trace.h"
>
> #define PCA9552_LED_ON 0x0
> #define PCA9552_LED_OFF 0x1
> @@ -34,6 +36,32 @@ static uint8_t pca9552_pin_get_config(PCA9552State *s, int
> pin)
> return extract32(s->regs[reg], shift, 2);
> }
>
> +static void pca9552_display_pins_status(PCA9552State *s)
> +{
> + uint16_t pins_status, pins_changed;
> + int i;
> +
> + pins_status = (s->regs[PCA9552_INPUT1] << 8) | s->regs[PCA9552_INPUT0];
> + pins_changed = s->pins_status ^ pins_status;
> + if (!pins_changed) {
> + return;
> + }
> + s->pins_status = pins_status;
It's nice to have but it won't kill puppies if we recompute the
state each time when traces are on.
> + if (trace_event_get_state_backends(TRACE_PCA9552_GPIO_STATUS)) {
> + char buf[PCA9552_PIN_COUNT + 1];
> +
> + for (i = 0; i < s->nr_leds; i++) {
> + if (extract32(pins_status, i, 1)) {
> + buf[i] = '*';
> + } else {
> + buf[i] = '.';
> + }
> + }
> + buf[i] = '\0';
> + trace_pca9552_gpio_status(s->description, buf);
> + }
> +}
> +
> static void pca9552_update_pin_input(PCA9552State *s)
> {
> int i;
> @@ -57,6 +85,7 @@ static void pca9552_update_pin_input(PCA9552State *s)
> break;
> }
and we could test TRACE_PCA9552_GPIO_STATUS here :
> }
> + pca9552_display_pins_status(s);
> }
>
> static uint8_t pca9552_read(PCA9552State *s, uint8_t reg)
> diff --git a/hw/misc/trace-events b/hw/misc/trace-events
> index 5561746866..7630e59652 100644
> --- a/hw/misc/trace-events
> +++ b/hw/misc/trace-events
> @@ -206,3 +206,6 @@ via1_rtc_cmd_pram_sect_write(int sector, int offset, int
> addr, int value) "secto
> # grlib_ahb_apb_pnp.c
> grlib_ahb_pnp_read(uint64_t addr, uint32_t value) "AHB PnP read
> addr:0x%03"PRIx64" data:0x%08x"
> grlib_apb_pnp_read(uint64_t addr, uint32_t value) "APB PnP read
> addr:0x%03"PRIx64" data:0x%08x"
> +
> +# pca9552.c
> +pca9552_gpio_status(const char *description, const char *buf) "%s GPIOs 0-15
> [%s]"
>
