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SubjectRe: [PATCH V3 4/7] mmc: sdhci: add 32-bit block count support for v4 mode
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On 17/07/18 12:14, Chunyan Zhang wrote:
> Hi,
>
> On 17 July 2018 at 16:29, Adrian Hunter <adrian.hunter@intel.com> wrote:
>> On 09/07/18 06:19, Chunyan Zhang wrote:
>>> When Host Version 4 is enabled, SDMA System Address register is
>>> re-defined as 32-bit Block Count, and SDMA uses ADMA System
>>> Address register (05Fh-058h) instead.
>>>
>>> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
>>> ---
>>> drivers/mmc/host/sdhci.c | 4 +++-
>>> drivers/mmc/host/sdhci.h | 1 +
>>> 2 files changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 7871ae2..f64e766 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -889,6 +889,7 @@ static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
>>> static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
>>> {
>>> u8 ctrl;
>>> + u32 reg;
>>> struct mmc_data *data = cmd->data;
>>>
>>> host->data_timeout = 0;
>>> @@ -1021,7 +1022,8 @@ 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);
>>> + reg = host->v4_mode ? SDHCI_32BIT_BLK_CNT : SDHCI_BLOCK_COUNT;
>>> + sdhci_writew(host, data->blocks, reg);
>>
>> The specification says to set 16-bit block count register to zero when using
>> 32-bit block count. It also says it is valid for V4.1 onwards and also for
>> V4 with SDMA and auto-CMD23.
>>
>> So maybe we should continue to use the 16-bit block count register with V4.0
>
> Ok.
>
> Where can I get a V4.0 specification? I only have V4.10 on hands.

I do not have a copy I can share, but the 4.1 specification already
indicates what is V4.1 (onwards) and what only requires Host Version 4 Enable.

>
>>
>>> }
>>>
>>> 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 24fa58a..889e48b 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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