Re: [PATCH V7 5/9] mmc: sdhci: Add 32-bit block count support for v4 mode

[Adrian Hunter]

On 29/08/18 10:03, Chunyan Zhang wrote:
> Host Controller Version 4.10 re-defines SDMA System Address register
> as 32-bit Block Count for v4 mode, and SDMA uses ADMA System
> Address register (05Fh-058h) instead if v4 mode is enabled. Also
> when using 32-bit block count, 16-bit block count register need
> to be set to zero.
> 
> Since using 32-bit Block Count would cause problems for auto-cmd23,
> it can be chosen via host->quirk2.
> 
> Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
>  drivers/mmc/host/sdhci.c | 14 +++++++++++++-
>  drivers/mmc/host/sdhci.h |  8 ++++++++
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 17345b6..604bf4c 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1073,7 +1073,19 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
>  	/* Set the DMA boundary value and block size */
>  	sdhci_writew(host, SDHCI_MAKE_BLKSZ(host->sdma_boundary, data->blksz),
>  		     SDHCI_BLOCK_SIZE);
> -	sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
> +
> +	/*
> +	 * For Version 4.10 onwards, if v4 mode is enabled, 32-bit Block Count
> +	 * can be supported, in that case 16-bit block count register must be 0.
> +	 */
> +	if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
> +	    (host->quirks2 & SDHCI_QUIRK2_USE_32BIT_BLK_CNT)) {
> +		if (sdhci_readw(host, SDHCI_BLOCK_COUNT))
> +			sdhci_writew(host, 0, SDHCI_BLOCK_COUNT);
> +		sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT);
> +	} else {
> +		sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
> +	}
>  }
>  
>  static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index c5cc513..f7a1079 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -28,6 +28,7 @@
>  
>  #define SDHCI_DMA_ADDRESS	0x00
>  #define SDHCI_ARGUMENT2		SDHCI_DMA_ADDRESS
> +#define SDHCI_32BIT_BLK_CNT	SDHCI_DMA_ADDRESS
>  
>  #define SDHCI_BLOCK_SIZE	0x04
>  #define  SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & 0xFFF))
> @@ -462,6 +463,13 @@ struct sdhci_host {
>   * obtainable timeout.
>   */
>  #define SDHCI_QUIRK2_DISABLE_HW_TIMEOUT			(1<<17)
> +/*
> + * 32-bit block count may not support eMMC where upper bits of CMD23 are used
> + * for other purposes.  Consequently we support 16-bit block count by default.
> + * Otherwise, SDHCI_QUIRK2_USE_32BIT_BLK_CNT can be selected to use 32-bit
> + * block count.
> + */
> +#define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
>  
>  	int irq;		/* Device IRQ */
>  	void __iomem *ioaddr;	/* Mapped address */
>