Re: [v5.5] mmc: sdhci-of-esdhc: fix esdhc_reset() for different controller versions

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Apr 15, 2020 at 11:52:12AM +0800, Yangbo Lu wrote:
> commit 2aa3d826adb578b26629a79b775a552cfe3fedf7 upstream.
> 
> This patch is to fix operating in esdhc_reset() for different
> controller versions, and to add bus-width restoring after data
> reset for eSDHC (verdor version <= 2.2).
> 
> Also add annotation for understanding.
> 
> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> Link: https://lore.kernel.org/r/20200108040713.38888-1-yangbo.lu@nxp.com
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/mmc/host/sdhci-of-esdhc.c | 43 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 39 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> index fcfb50f..fd1251e 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -734,23 +734,58 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
> -	u32 val;
> +	u32 val, bus_width = 0;
>  
> +	/*
> +	 * Add delay to make sure all the DMA transfers are finished
> +	 * for quirk.
> +	 */
>  	if (esdhc->quirk_delay_before_data_reset &&
>  	    (mask & SDHCI_RESET_DATA) &&
>  	    (host->flags & SDHCI_REQ_USE_DMA))
>  		mdelay(5);
>  
> +	/*
> +	 * Save bus-width for eSDHC whose vendor version is 2.2
> +	 * or lower for data reset.
> +	 */
> +	if ((mask & SDHCI_RESET_DATA) &&
> +	    (esdhc->vendor_ver <= VENDOR_V_22)) {
> +		val = sdhci_readl(host, ESDHC_PROCTL);
> +		bus_width = val & ESDHC_CTRL_BUSWIDTH_MASK;
> +	}
> +
>  	sdhci_reset(host, mask);
>  
> -	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> -	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
> +	/*
> +	 * Restore bus-width setting and interrupt registers for eSDHC
> +	 * whose vendor version is 2.2 or lower for data reset.
> +	 */
> +	if ((mask & SDHCI_RESET_DATA) &&
> +	    (esdhc->vendor_ver <= VENDOR_V_22)) {
> +		val = sdhci_readl(host, ESDHC_PROCTL);
> +		val &= ~ESDHC_CTRL_BUSWIDTH_MASK;
> +		val |= bus_width;
> +		sdhci_writel(host, val, ESDHC_PROCTL);
> +
> +		sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> +		sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
> +	}
>  
> -	if (mask & SDHCI_RESET_ALL) {
> +	/*
> +	 * Some bits have to be cleaned manually for eSDHC whose spec
> +	 * version is higher than 3.0 for all reset.
> +	 */
> +	if ((mask & SDHCI_RESET_ALL) &&
> +	    (esdhc->spec_ver >= SDHCI_SPEC_300)) {
>  		val = sdhci_readl(host, ESDHC_TBCTL);
>  		val &= ~ESDHC_TB_EN;
>  		sdhci_writel(host, val, ESDHC_TBCTL);
>  
> +		/*
> +		 * Initialize eSDHC_DLLCFG1[DLL_PD_PULSE_STRETCH_SEL] to
> +		 * 0 for quirk.
> +		 */
>  		if (esdhc->quirk_unreliable_pulse_detection) {
>  			val = sdhci_readl(host, ESDHC_DLLCFG1);
>  			val &= ~ESDHC_DLL_PD_PULSE_STRETCH_SEL;
> -- 
> 2.7.4
> 

Now applied to 5.5.y and 5.4.y, thanks.

greg k-h