Re: [PATCH v2] hw/misc/pca9552: Trace LED On/Off events

[Cédric Le Goater]

On 6/17/20 9:52 AM, Philippe Mathieu-Daudé wrote:
> On 6/17/20 9:39 AM, Cédric Le Goater wrote:
>> On 6/17/20 8:47 AM, Philippe Mathieu-Daudé wrote:
>>> Example booting obmc-phosphor-image:
>>>
>>>   $ qemu-system-arm -M witherspoon-bmc -trace pca\*
>>>   26033@1592376001.873828:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> ........]
>>>   26033@1592376001.874169:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> ........]
>>>   26033@1592376001.874348:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> ........]
>>>   26033@1592376001.874514:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> ........]
>>>   26033@1592376001.879601:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> .......*]
>>>   26033@1592376001.880507:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> ......**]
>>>   26033@1592376001.880885:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> .....***]
>>>   26033@1592376001.881228:pca9552_led_state 0x5594a9f57560 LEDs [........ 
>>> ....****]
>>>   26033@1592376001.881601:pca9552_led_state 0x5594a9f57560 LEDs [..*..... 
>>> ....****]
>>>   26033@1592376001.881952:pca9552_led_state 0x5594a9f57560 LEDs [.**..... 
>>> ....****]
>>>   26033@1592376001.882299:pca9552_led_state 0x5594a9f57560 LEDs [***..... 
>>> ....****]
>>>   26033@1592376065.090910:pca9552_led_state 0x5594a9f57560 LEDs [*.*..... 
>>> ....****]
>>>   26033@1592376065.600649:pca9552_led_state 0x5594a9f57560 LEDs [***..... 
>>> ....****]
>>>   26033@1592376066.110565:pca9552_led_state 0x5594a9f57560 LEDs [*.*..... 
>>> ....****]
>>>   26033@1592376066.620390:pca9552_led_state 0x5594a9f57560 LEDs [***..... 
>>> ....****]
>>
>> It looks better but the ordering is wrong.
> 
> The order is [15, 14, ..., 3, 2, 1, 0].

I am contaminated by PowerPC specs.  
 
> This one is blinking?
> 
>     front-power {
>         retain-state-shutdown;
>         default-state = "keep";
>         gpios = <&pca0 14 GPIO_ACTIVE_LOW>;
>     };

yes. 

Let it be then,

Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C. 

>>
>>> Suggested-by: Cédric Le Goater <clg@kaod.org>
>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>>> ---
>>>  hw/misc/pca9552.c    | 18 ++++++++++++++++++
>>>  hw/misc/trace-events |  3 +++
>>>  2 files changed, 21 insertions(+)
>>>
>>> diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
>>> index cac729e35a..693f6c3b24 100644
>>> --- a/hw/misc/pca9552.c
>>> +++ b/hw/misc/pca9552.c
>>> @@ -17,6 +17,7 @@
>>>  #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
>>> @@ -95,6 +96,23 @@ static void pca9552_write(PCA9552State *s, uint8_t reg, 
>>> uint8_t data)
>>>      case PCA9552_LS3:
>>>          s->regs[reg] = data;
>>>          pca9552_update_pin_input(s);
>>> +        if (trace_event_get_state_backends(TRACE_PCA9552_LED_STATE)) {
>>> +            char buf[2][9];
>>> +
>>> +            for (int i = 0; i < 2; i++) {
>>> +                uint8_t val = s->regs[PCA9552_INPUT0 + i];
>>> +                sprintf(buf[i], "%c%c%c%c%c%c%c%c",
>>> +                        val & 0x80 ? '*' : '.',
>>> +                        val & 0x40 ? '*' : '.',
>>> +                        val & 0x20 ? '*' : '.',
>>> +                        val & 0x10 ? '*' : '.',
>>> +                        val & 0x08 ? '*' : '.',
>>> +                        val & 0x04 ? '*' : '.',
>>> +                        val & 0x02 ? '*' : '.',
>>> +                        val & 0x01 ? '*' : '.');
>>> +            }
>>> +            trace_pca9552_led_state(s, buf[1], buf[0]);
>>> +        }
>>>          break;
>>
>> or something like this : 
>>
>>  static void pca9552_update_pin_input(PCA9552State *s)
>>  {
>>      int i;
>> +    char state[s->nr_leds + 1];
>>  
>>      for (i = 0; i < s->nr_leds; i++) {
>>          uint8_t input_reg = PCA9552_INPUT0 + (i / 8);
>> @@ -45,9 +47,11 @@ static void pca9552_update_pin_input(PCA
>>          switch (config) {
>>          case PCA9552_LED_ON:
>>              s->regs[input_reg] |= 1 << input_shift;
>> +            state[i] = '*';
>>              break;
>>          case PCA9552_LED_OFF:
>>              s->regs[input_reg] &= ~(1 << input_shift);
>> +            state[i] = '.';
>>              break;
>>          case PCA9552_LED_PWM0:
>>          case PCA9552_LED_PWM1:
>> @@ -56,6 +60,9 @@ static void pca9552_update_pin_input(PCA
>>              break;
>>          }
>>      }
>> +    state[i] = 0;
>> +
>> +    trace_pca9552_led_state(s, state);
>>  }
>>
>>
>>
>> The pin usage is described in the witherspoon DTS : 
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts?id=b1f9be9392f0#n78
>>
>> The front-power led is blinking. I suppose it means the BMC is on but not 
>> the host.
>>
>>
>> Cheers,
>>
>> C. 
>>
>>>  
>>>      case PCA9552_INPUT0:
>>> diff --git a/hw/misc/trace-events b/hw/misc/trace-events
>>> index 5561746866..21e52f192d 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_led_state(void *object, const char *bufhi, const char *buflo) "%p 
>>> LEDs [%s %s]"
>>>
>>
>>