On 28 August 2012 13:25, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> 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 <jh80.chung@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> 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) {
> + /*
> + * 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;
> + }
> + }
> +
> 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;
> +
The presence of DW_MCI_QUIRK_USE_CLKSEL_REG quirk should be sufficient
condition to know if HOLD_REG bit is supported on not. The setting of
host->use_hold_reg as above creates a dependency on the boot loader to
setup the controller appropriately.
Thanks,
Thomas.
> /* 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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