Re: [PATCH v6 6/7] hw/misc/mps2-scc: Use the LED device

[Luc Michel <luc.michel@greensocs.com>]

On 9/12/20 3:40 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 8 LEDs connected to the MCC.
> 
> This replaces the 'mps2_scc_leds' trace events by the generic
> 'led_set_intensity' event.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Luc Michel <luc.michel@greensocs.com>

> ---
>   include/hw/misc/mps2-scc.h |  2 ++
>   hw/misc/mps2-scc.c         | 27 ++++++++++++++++-----------
>   hw/misc/Kconfig            |  1 +
>   hw/misc/trace-events       |  1 -
>   4 files changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/include/hw/misc/mps2-scc.h b/include/hw/misc/mps2-scc.h
> index 445e268b1fd..0009479ae83 100644
> --- a/include/hw/misc/mps2-scc.h
> +++ b/include/hw/misc/mps2-scc.h
> @@ -13,6 +13,7 @@
>   #define MPS2_SCC_H
>   
>   #include "hw/sysbus.h"
> +#include "hw/misc/led.h"
>   #include "qom/object.h"
>   
>   #define TYPE_MPS2_SCC "mps2-scc"
> @@ -28,6 +29,7 @@ struct MPS2SCC {
>   
>       /*< public >*/
>       MemoryRegion iomem;
> +    LEDState *led[8];
>   
>       uint32_t cfg0;
>       uint32_t cfg1;
> diff --git a/hw/misc/mps2-scc.c b/hw/misc/mps2-scc.c
> index 9d0909e7b35..ce1dfe93562 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(s->led[i], extract32(value, i, 1));
> +        }
>           break;
>       case A_CFGDATA_OUT:
>           s->cfgdata_out = value;
> @@ -236,6 +230,9 @@ static void mps2_scc_reset(DeviceState *dev)
>       for (i = 0; i < NUM_OSCCLK; i++) {
>           s->oscclk[i] = s->oscclk_reset[i];
>       }
> +    for (i = 0; i < ARRAY_SIZE(s->led); i++) {
> +        device_cold_reset(DEVICE(s->led[i]));
> +    }
>   }
>   
>   static void mps2_scc_init(Object *obj)
> @@ -249,6 +246,14 @@ static void mps2_scc_init(Object *obj)
>   
>   static void mps2_scc_realize(DeviceState *dev, Error **errp)
>   {
> +    MPS2SCC *s = MPS2_SCC(dev);
> +
> +    for (size_t i = 0; i < ARRAY_SIZE(s->led); i++) {
> +        char *name = g_strdup_printf("SCC LED%zu", i);
> +        s->led[i] = led_create_simple(OBJECT(dev), GPIO_POLARITY_ACTIVE_HIGH,
> +                                      LED_COLOR_GREEN, name);
> +        g_free(name);
> +    }
>   }
>   
>   static const VMStateDescription mps2_scc_vmstate = {
> diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
> index 0cecad45aad..7557a3e7b46 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 908272e8593..97f511aa58c 100644
> --- a/hw/misc/trace-events
> +++ b/hw/misc/trace-events
> @@ -84,7 +84,6 @@ 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
>   
>