On 08/29/2012 10:21 AM, Seungwon Jeon wrote:
> On Tuesday, August 28, 2012, Jaehoon Chung <[email protected]> wrote:
>> This patch is added the use_hold_reg bit in CMD register.
>>
>> In upper version than 2.40a, bit[29] of CMD register is used the
>> use_hold_reg.
>> Some SoC is affected by this bit.
>> (This bit means whether use hold register when send data and cmd.
>> And related with cclk_in_drv phase)
>>
>> Now i known that HOLD-register is using only Exynos-SoC.
>> But hold-register is supported basically feature at Synopsys-IP.
>> If Other SoC is used hold regster, we can change the _CLKSEL_REG_.
>>
>> Signed-off-by: Jaehoon Chung <[email protected]>
>> Signed-off-by: Kyungmin Park <[email protected]>
>> ---
>> drivers/mmc/host/dw_mmc.c | 36 ++++++++++++++++++++++++++++++++++++
>> drivers/mmc/host/dw_mmc.h | 1 +
>> include/linux/mmc/dw_mmc.h | 3 +++
>> 3 files changed, 40 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 437fdf8..3642455 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -265,11 +265,45 @@ static u32 dw_mci_prepare_command(struct mmc_host
>> *mmc, struct mmc_command *cmd)
>> static void dw_mci_start_command(struct dw_mci *host,
>> struct mmc_command *cmd, u32 cmd_flags)
>> {
>> + struct dw_mci_slot *slot = host->cur_slot;
>> + struct mmc_ios *ios = &slot->mmc->ios;
>> +
>> host->cmd = cmd;
>> dev_vdbg(&host->dev,
>> "start command: ARGR=0x%08x CMDR=0x%08x\n",
>> cmd->arg, cmd_flags);
>>
>> + if (host->quirks & DW_MCI_QUIRK_USE_CLKSEL_REG) {
> What is this quirk for?
CLKSEL register is only used at the Exynos-SoC.
I didn't know which SoC is used. I added the quirks for Exynos using the CLKSEL
register.
> Could you explain?
>
>> + /*
>> + * If use HOLD register and SDR12/SDSR25,
>> + * CMD and DATA sent to card through HOLD regster by default.
>> + * But if mode is SDR50/DDR50/SDR104,
>> + * only use the hold register when cclk_in_drv value is greater
>> than 0.
>> + */
>> + switch (ios->timing) {
>> + case MMC_TIMING_UHS_SDR50:
>> + case MMC_TIMING_UHS_DDR50:
>> + case MMC_TIMING_UHS_SDR104:
>> + if (host->pdata->get_clk_drv &&
>> + host->pdata->get_clk_drv(host) &&
>> + host->use_hold_reg) {
>> + cmd_flags |= SDMMC_CMD_USE_HOLD_REG;
>> + break;
>> + }
>> +
>> + cmd_flags &= ~SDMMC_CMD_USE_HOLD_REG;
>> + break;
>> + case MMC_TIMING_UHS_SDR12:
>> + case MMC_TIMING_UHS_SDR25:
>> + if (host->use_hold_reg) {
>> + cmd_flags |= SDMMC_CMD_USE_HOLD_REG;
>> + break;
>> + }
>> + default:
>> + cmd_flags &= ~SDMMC_CMD_USE_HOLD_REG;
>> + }
>> + }
>> +
> Considering MMC_TIMING_MMC_HS, MMC_TIMING_SD_HS is omitted.
Sorry, i will fix.
> Didn't you consider moving this whole routine to dw_mci_set_ios?
> When deciding the timing, once seems to be enough.
Well, i considered that move the code into dw_mci_set_ios().
But cmd_flags is set before sending the command at every time.
Finally, hold_regs bit must be also set at every time.
We can prevent to set the cmd_flags at every time.
Best Regards,
Jaehoon Chung
>
> Thanks,
> Seungwon Jeon
>
>> mci_writel(host, CMDARG, cmd->arg);
>> wmb();
>>
>> @@ -2015,6 +2049,8 @@ int dw_mci_probe(struct dw_mci *host)
>> host->data_shift = 2;
>> }
>>
>> + host->use_hold_reg = (mci_readl(host, HCON) >> 22) & 0x1;
>> +
>> /* Reset all blocks */
>> if (!mci_wait_reset(&host->dev, host))
>> return -ENODEV;
>> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
>> index b6a1a78..cc905ee 100644
>> --- a/drivers/mmc/host/dw_mmc.h
>> +++ b/drivers/mmc/host/dw_mmc.h
>> @@ -111,6 +111,7 @@
>> #define SDMMC_INT_ERROR 0xbfc2
>> /* Command register defines */
>> #define SDMMC_CMD_START BIT(31)
>> +#define SDMMC_CMD_USE_HOLD_REG BIT(29)
>> #define SDMMC_CMD_CCS_EXP BIT(23)
>> #define SDMMC_CMD_CEATA_RD BIT(22)
>> #define SDMMC_CMD_UPD_CLK BIT(21)
>> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
>> index f20979c..803a80d 100644
>> --- a/include/linux/mmc/dw_mmc.h
>> +++ b/include/linux/mmc/dw_mmc.h
>> @@ -156,6 +156,7 @@ struct dw_mci {
>> u32 fifoth_val;
>> u16 verid;
>> u16 data_offset;
>> + bool use_hold_reg;
>> struct device dev;
>> struct dw_mci_board *pdata;
>> struct dw_mci_slot *slot[MAX_MCI_SLOTS];
>> @@ -201,6 +202,8 @@ struct dw_mci_dma_ops {
>> #define DW_MCI_QUIRK_HIGHSPEED BIT(2)
>> /* Unreliable card detection */
>> #define DW_MCI_QUIRK_BROKEN_CARD_DETECTION BIT(3)
>> +/* To use the CLKSEL register for phase-shift */
>> +#define DW_MCI_QUIRK_USE_CLKSEL_REG BIT(4)
>>
>>
>> struct dma_pdata;
>> --
>> 1.7.4.1
>
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