Re: [PATCH v5 5/7] hw/misc/mps2-fpgaio: Use the LED device

[Luc Michel]

Hi Phil,

On 9/10/20 10:54 PM, Philippe Mathieu-Daudé wrote:
> Per the 'ARM MPS2 and MPS2+ FPGA Prototyping Boards Technical
> Reference Manual' (100112_0200_07_en):
>
>    2.1  Overview of the MPS2 and MPS2+ hardware
>
>         The MPS2 and MPS2+ FPGA Prototyping Boards contain the
>         following components and interfaces:
>
>         * User switches and user LEDs:
>
>           - Two green LEDs and two push buttons that connect to
>             the FPGA.
>           - Eight green LEDs and one 8-way dip switch that connect
>             to the MCC.
>
> Add the 2 LEDs connected to the FPGA.
>
> This remplaces the 'mps2_fpgaio_leds' trace events by the generic
replaces
> 'led_set_intensity' event.

If I'm not mistaken the LED device being a DEVICE and not a 
SYS_BUS_DEVICE, it needs to be manually reset. So you probably need to 
reset it in mps2_fpgaio_reset so it doesn't get out of sync on system reset.

--
Luc

> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   include/hw/misc/mps2-fpgaio.h |  2 ++
>   hw/misc/mps2-fpgaio.c         | 19 ++++++++++++++-----
>   hw/misc/Kconfig               |  1 +
>   hw/misc/trace-events          |  1 -
>   4 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/include/hw/misc/mps2-fpgaio.h b/include/hw/misc/mps2-fpgaio.h
> index 69e265cd4b2..901880cc3a7 100644
> --- a/include/hw/misc/mps2-fpgaio.h
> +++ b/include/hw/misc/mps2-fpgaio.h
> @@ -22,6 +22,7 @@
>   #define MPS2_FPGAIO_H
>   
>   #include "hw/sysbus.h"
> +#include "hw/misc/led.h"
>   
>   #define TYPE_MPS2_FPGAIO "mps2-fpgaio"
>   #define MPS2_FPGAIO(obj) OBJECT_CHECK(MPS2FPGAIO, (obj), TYPE_MPS2_FPGAIO)
> @@ -32,6 +33,7 @@ typedef struct {
>   
>       /*< public >*/
>       MemoryRegion iomem;
> +    LEDState *led[2];
>   
>       uint32_t led0;
>       uint32_t prescale;
> diff --git a/hw/misc/mps2-fpgaio.c b/hw/misc/mps2-fpgaio.c
> index 2f3fbeef348..86ca78eb235 100644
> --- a/hw/misc/mps2-fpgaio.c
> +++ b/hw/misc/mps2-fpgaio.c
> @@ -24,6 +24,7 @@
>   #include "migration/vmstate.h"
>   #include "hw/registerfields.h"
>   #include "hw/misc/mps2-fpgaio.h"
> +#include "hw/misc/led.h"
>   #include "hw/qdev-properties.h"
>   #include "qemu/timer.h"
>   
> @@ -176,12 +177,9 @@ static void mps2_fpgaio_write(void *opaque, hwaddr offset, uint64_t value,
>   
>       switch (offset) {
>       case A_LED0:
> -        /* LED bits [1:0] control board LEDs. We don't currently have
> -         * a mechanism for displaying this graphically, so use a trace event.
> -         */
> -        trace_mps2_fpgaio_leds(value & 0x02 ? '*' : '.',
> -                               value & 0x01 ? '*' : '.');
>           s->led0 = value & 0x3;
> +        led_set_state(s->led[0], value & 0x01);
> +        led_set_state(s->led[1], value & 0x02);
>           break;
>       case A_PRESCALE:
>           resync_counter(s);
> @@ -251,6 +249,16 @@ static void mps2_fpgaio_init(Object *obj)
>       sysbus_init_mmio(sbd, &s->iomem);
>   }
>   
> +static void mps2_fpgaio_realize(DeviceState *dev, Error **errp)
> +{
> +    MPS2FPGAIO *s = MPS2_FPGAIO(dev);
> +
> +    s->led[0] = led_create_simple(OBJECT(dev), GPIO_POLARITY_ACTIVE_HIGH,
> +                                  LED_COLOR_GREEN, "USERLED0");
> +    s->led[1] = led_create_simple(OBJECT(dev), GPIO_POLARITY_ACTIVE_HIGH,
> +                                  LED_COLOR_GREEN, "USERLED1");
> +}
> +
>   static bool mps2_fpgaio_counters_needed(void *opaque)
>   {
>       /* Currently vmstate.c insists all subsections have a 'needed' function */
> @@ -299,6 +307,7 @@ static void mps2_fpgaio_class_init(ObjectClass *klass, void 
> *data)
>       DeviceClass *dc = DEVICE_CLASS(klass);
>   
>       dc->vmsd = &mps2_fpgaio_vmstate;
> +    dc->realize = mps2_fpgaio_realize;
>       dc->reset = mps2_fpgaio_reset;
>       device_class_set_props(dc, mps2_fpgaio_properties);
>   }
> diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
> index 5c151fa3a83..0cecad45aad 100644
> --- a/hw/misc/Kconfig
> +++ b/hw/misc/Kconfig
> @@ -93,6 +93,7 @@ config MIPS_ITU
>   
>   config MPS2_FPGAIO
>       bool
> +    select LED
>   
>   config MPS2_SCC
>       bool
> diff --git a/hw/misc/trace-events b/hw/misc/trace-events
> index 89d15f05f9a..43b9e0cf250 100644
> --- a/hw/misc/trace-events
> +++ b/hw/misc/trace-events
> @@ -93,7 +93,6 @@ mps2_scc_cfg_read(unsigned function, unsigned device, uint32_t 
> value) "MPS2 SCC
>   mps2_fpgaio_read(uint64_t offset, uint64_t data, unsigned size) "MPS2 FPGAIO read: offset 0x%" 
> PRIx64 " data 0x%" PRIx64 " size %u"
>   mps2_fpgaio_write(uint64_t offset, uint64_t data, unsigned size) "MPS2 FPGAIO write: offset 0x%" 
> PRIx64 " data 0x%" PRIx64 " size %u"
>   mps2_fpgaio_reset(void) "MPS2 FPGAIO: reset"
> -mps2_fpgaio_leds(char led1, char led0) "MPS2 FPGAIO LEDs: %c%c"
>   
>   # msf2-sysreg.c
>   msf2_sysreg_write(uint64_t offset, uint32_t val, uint32_t prev) "msf2-sysreg write: addr 0x%08" 
> PRIx64 " data 0x%" PRIx32 " prev 0x%" PRIx32