On Tue, 19 Jan 2021 at 13:40, Bin Meng <bmeng...@gmail.com> wrote:
>
> From: Philippe Mathieu-Daudé <f4...@amsat.org>
>
> When the block is disabled, all registers are reset with the
> exception of the ECSPI_CONREG. It is initialized to zero
> when the instance is created.
>
> Ref: i.MX 6DQ Applications Processor Reference Manual (IMX6DQRM),
> chapter 21.7.3: Control Register (ECSPIx_CONREG)
> diff --git a/hw/ssi/imx_spi.c b/hw/ssi/imx_spi.c
> index 8fb3c9b..c952a3d 100644
> --- a/hw/ssi/imx_spi.c
> +++ b/hw/ssi/imx_spi.c
> @@ -231,12 +231,23 @@ static void imx_spi_flush_txfifo(IMXSPIState *s)
> static void imx_spi_reset(DeviceState *dev)
> {
> IMXSPIState *s = IMX_SPI(dev);
> + int i;
>
> DPRINTF("\n");
>
> - memset(s->regs, 0, sizeof(s->regs));
> -
> - s->regs[ECSPI_STATREG] = 0x00000003;
> + for (i = 0; i < ARRAY_SIZE(s->regs); i++) {
> + switch (i) {
> + case ECSPI_CONREG:
> + /* CONREG is not updated on reset */
> + break;
> + case ECSPI_STATREG:
> + s->regs[i] = 0x00000003;
> + break;
> + default:
> + s->regs[i] = 0;
> + break;
> + }
> + }
This retains the CONREG register value for both:
* 'soft' reset caused by write to device register to disable
the block
-- this is corrcet as per the datasheet quote
* 'power on' reset via TYPE_DEVICE's reset method
-- but in this case we should reset CONREG, because the Device
reset method is like a complete device powercycle and should
return the device state to what it was when QEMU was first
started.
thanks
-- PMM
