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SubjectRe: [PATCH V4 4/7] mmc: sdhci: add 32-bit block count support for v4 mode
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On 24/07/18 05:51, 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.
>
> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
> ---
> drivers/mmc/host/sdhci.c | 14 +++++++++++++-
> drivers/mmc/host/sdhci.h | 1 +
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 920d8ec..c272a2b 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1070,7 +1070,19 @@ 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, 16-bit Block Count
> + * register need to be set to zero, 32-bit Block Count register would
> + * be selected.
> + */
> + if (host->version >= SDHCI_SPEC_410 && host->v4_mode) {
> + if (sdhci_readw(host, SDHCI_BLOCK_COUNT))
> + sdhci_writew(host, 0, SDHCI_BLOCK_COUNT);
> + sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT);

So this is also SDHCI_ARGUMENT2 which is why there is a conflict with
auto-CMD23. We need to write SDHCI_32BIT_BLK_CNT only once, but also cater
for eMMC which uses the CMD23 argument for more than just block count.

> + } 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 23318ff..81aae07 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))
>

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