Re: [PATCH v3 6/7] hw/misc/mps2-scc: Use the LED device

[Philippe Mathieu-Daudé]

On 6/21/20 1:07 AM, 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 8 LEDs connected to the MCC.
> 
> This remplaces the 'mps2_scc_leds' trace events by the generic
> 'led_set_intensity' event.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> https://youtu.be/l9kD70uPchk?t=288
> ---
>  include/hw/misc/mps2-scc.h |  1 +
>  hw/misc/mps2-scc.c         | 23 ++++++++++++-----------
>  hw/misc/Kconfig            |  1 +
>  hw/misc/trace-events       |  1 -
>  4 files changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/include/hw/misc/mps2-scc.h b/include/hw/misc/mps2-scc.h
> index 7045473788..29e12b832b 100644
> --- a/include/hw/misc/mps2-scc.h
> +++ b/include/hw/misc/mps2-scc.h
> @@ -25,6 +25,7 @@ typedef struct {
>  
>      /*< public >*/
>      MemoryRegion iomem;
> +    DeviceState *led[8];
>  
>      uint32_t cfg0;
>      uint32_t cfg1;
> diff --git a/hw/misc/mps2-scc.c b/hw/misc/mps2-scc.c
> index 9d0909e7b3..2e59a382ec 100644
> --- a/hw/misc/mps2-scc.c
> +++ b/hw/misc/mps2-scc.c
> @@ -20,11 +20,13 @@
>  #include "qemu/osdep.h"
>  #include "qemu/log.h"
>  #include "qemu/module.h"
> +#include "qemu/bitops.h"
>  #include "trace.h"
>  #include "hw/sysbus.h"
>  #include "migration/vmstate.h"
>  #include "hw/registerfields.h"
>  #include "hw/misc/mps2-scc.h"
> +#include "hw/misc/led.h"
>  #include "hw/qdev-properties.h"
>  
>  REG32(CFG0, 0)
> @@ -152,18 +154,10 @@ static void mps2_scc_write(void *opaque, hwaddr offset, 
> uint64_t value,
>          s->cfg0 = value;
>          break;
>      case A_CFG1:
> -        /* CFG1 bits [7:0] control the board LEDs. We don't currently have
> -         * a mechanism for displaying this graphically, so use a trace event.
> -         */
> -        trace_mps2_scc_leds(value & 0x80 ? '*' : '.',
> -                            value & 0x40 ? '*' : '.',
> -                            value & 0x20 ? '*' : '.',
> -                            value & 0x10 ? '*' : '.',
> -                            value & 0x08 ? '*' : '.',
> -                            value & 0x04 ? '*' : '.',
> -                            value & 0x02 ? '*' : '.',
> -                            value & 0x01 ? '*' : '.');
>          s->cfg1 = value;
> +        for (size_t i = 0; i < ARRAY_SIZE(s->led); i++) {
> +            led_set_state(LED(s->led[i]), !!extract32(value, i, 1));
> +        }
>          break;
>      case A_CFGDATA_OUT:
>          s->cfgdata_out = value;
> @@ -245,6 +239,13 @@ static void mps2_scc_init(Object *obj)
>  
>      memory_region_init_io(&s->iomem, obj, &mps2_scc_ops, s, "mps2-scc", 
> 0x1000);
>      sysbus_init_mmio(sbd, &s->iomem);
> +
> +    for (size_t i = 0; i < ARRAY_SIZE(s->led); i++) {
> +        char *name = g_strdup_printf("SCC LED%zu", i);
> +        s->led[i] = create_led(obj, LED_COLOR_GREEN,
> +                               name, LED_RESET_INTENSITY_ACTIVE_HIGH);
> +        g_free(name);
> +    }

This has to go ...

>  }
>  
>  static void mps2_scc_realize(DeviceState *dev, Error **errp)

... here to avoid:

**
ERROR:/tmp/qemu-test/src/hw/core/qdev.c:1074:device_finalize: assertion
failed: (dev->canonical_path)
Broken pipe
/tmp/qemu-test/src/tests/qtest/libqtest.c:175: kill_qemu() detected QEMU
death from signal 6 (Aborted) (core dumped)
ERROR - too few tests run (expected 6, got 5)

> diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
> index 889757731b..f278f7f354 100644
> --- a/hw/misc/Kconfig
> +++ b/hw/misc/Kconfig
> @@ -97,6 +97,7 @@ config MPS2_FPGAIO
>  
>  config MPS2_SCC
>      bool
> +    select LED
>  
>  config TZ_MPC
>      bool
> diff --git a/hw/misc/trace-events b/hw/misc/trace-events
> index 8bc7a675e8..490a0f341a 100644
> --- a/hw/misc/trace-events
> +++ b/hw/misc/trace-events
> @@ -81,7 +81,6 @@ aspeed_scu_write(uint64_t offset, unsigned size, uint32_t 
> data) "To 0x%" PRIx64
>  mps2_scc_read(uint64_t offset, uint64_t data, unsigned size) "MPS2 SCC read: 
> offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
>  mps2_scc_write(uint64_t offset, uint64_t data, unsigned size) "MPS2 SCC 
> write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
>  mps2_scc_reset(void) "MPS2 SCC: reset"
> -mps2_scc_leds(char led7, char led6, char led5, char led4, char led3, char 
> led2, char led1, char led0) "MPS2 SCC LEDs: %c%c%c%c%c%c%c%c"
>  mps2_scc_cfg_write(unsigned function, unsigned device, uint32_t value) "MPS2 
> SCC config write: function %d device %d data 0x%" PRIx32
>  mps2_scc_cfg_read(unsigned function, unsigned device, uint32_t value) "MPS2 
> SCC config read: function %d device %d data 0x%" PRIx32
>  
>