Re: [PATCH] hw/arm: sabrelite: Connect SPI flash CS line to GPIO3_19

[Philippe Mathieu-Daudé]

On 9/26/21 04:56, Xuzhou Cheng wrote:
> From: Xuzhou Cheng <xuzhou.cheng@windriver.com>
> 
> The Linux spi-imx driver does not work on QEMU. The reason is that the
> state of m25p80 loops in STATE_READING_DATA state after receiving
> RDSR command, the new command is ignored. Before sending a new command,
> CS line should be pulled high to make the state of m25p80 back to IDLE.
> 
> Currently the SPI flash CS line is connected to the SPI controller, but
> on the real board, it's connected to GPIO3_19.

Maybe worth mentioning this matches the board dts:

arch/arm/boot/dts/imx6qdl-sabrelite.dtsi:

310 &ecspi1 {
311     cs-gpios = <&gpio3 19 GPIO_ACTIVE_LOW>;
312     pinctrl-names = "default";
313     pinctrl-0 = <&pinctrl_ecspi1>;
314     status = "okay";
315
316     flash: m25p80@0 {
317         compatible = "sst,sst25vf016b", "jedec,spi-nor";
318         spi-max-frequency = <20000000>;
319         reg = <0>;
320     };
321 };

> Should connect the SSI_GPIO_CS to GPIO3_19 when adding a spi-nor to
> spi1 on sabrelite machine.
> 
> Verified this patch on Linux v5.14.
> 
> Logs:
>   # echo "01234567899876543210" > test
>   # mtd_debug erase /dev/mtd0 0x0 0x1000
>   Erased 4096 bytes from address 0x00000000 in flash
>   # mtd_debug write /dev/mtdblock0 0x0 20 test
>   Copied 20 bytes from test to address 0x00000000 in flash
>   # mtd_debug read /dev/mtdblock0 0x0 20 test_out
>   Copied 20 bytes from address 0x00000000 in flash to test_out
>   # cat test_out
>   01234567899876543210#
> 
> Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Reviewed-by: Bin Meng <bin.meng@windriver.com>
> ---
>  hw/arm/sabrelite.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/arm/sabrelite.c b/hw/arm/sabrelite.c
> index 29fc777b61..553608e583 100644
> --- a/hw/arm/sabrelite.c
> +++ b/hw/arm/sabrelite.c
> @@ -87,7 +87,7 @@ static void sabrelite_init(MachineState *machine)
>                  qdev_realize_and_unref(flash_dev, BUS(spi_bus), 
> &error_fatal);
>  
>                  cs_line = qdev_get_gpio_in_named(flash_dev, SSI_GPIO_CS, 0);
> -                sysbus_connect_irq(SYS_BUS_DEVICE(spi_dev), 1, cs_line);
> +                qdev_connect_gpio_out(DEVICE(&s->gpio[2]), 19, cs_line);
>              }
>          }
>      }
> 

Thank for using an oscilloscope to verify, it reminded me
some SDcard debugging 4 years ago =)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>