[PATCH 09/10] mmc: msm_sdhci: Reset clocks before reconfiguration

[Caleb Connolly]

On 26/02/2024 10:08, Varadarajan Narayanan wrote:
> U-Boot has to reconfigure the clocks that were set in the boot
> loaders. However, in IPQ9574, the clocks have to be reset before
> they can be reconfigured. Hence add code to do the relevant
> resets.
> 
> Signed-off-by: Varadarajan Narayanan <quic_varada at quicinc.com>
With below feedback addressed, please add

Reviewed-by: Caleb Connolly <caleb.connolly at linaro.org>
> ---
> 
>  drivers/mmc/msm_sdhci.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/mmc/msm_sdhci.c b/drivers/mmc/msm_sdhci.c
> index 9285d412fe..2e9d521159 100644
> --- a/drivers/mmc/msm_sdhci.c
> +++ b/drivers/mmc/msm_sdhci.c
> @@ -16,6 +16,7 @@
>  #include <asm/global_data.h>
>  #include <asm/io.h>
>  #include <linux/bitops.h>
> +#include <reset.h>
>  
>  /* Non-standard registers needed for SDHCI startup */
>  #define SDCC_MCI_POWER   0x0
> @@ -122,10 +123,19 @@ static int msm_sdc_probe(struct udevice *dev)
>  	struct msm_sdhc *prv = dev_get_priv(dev);
>  	const struct msm_sdhc_variant_info *var_info;
>  	struct sdhci_host *host = &prv->host;
> +	struct reset_ctl bcr_rst;
>  	u32 core_version, core_minor, core_major;
>  	u32 caps;
>  	int ret;
>  
> +	ret = reset_get_by_name(dev, "bcr_rst", &bcr_rst);
reset-names is not not valid according to the DT bindings, please use
reset_get_by_index() instead.
> +	if (!ret) {
> +		reset_assert(&bcr_rst);
> +		mdelay(10);
Is 10ms really necessary here? The equivalent code in Linux suggests
that only 125us are needed (with a 32.7KHz sleep clock) and uses 200us
to be "on the safe side". So maybe udelay(200) here instead?
> +		reset_deassert(&bcr_rst);
> +		mdelay(10);
> +	}
> +
>  	host->quirks = SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_BROKEN_R1B;
>  
>  	host->max_clk = 0;

-- 
// Caleb (they/them)