On 08/30/2012 10:36 AM, Seungwon Jeon wrote:
> On Tuesday, August 29, 2012, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
>> On 08/29/2012 10:21 AM, Seungwon Jeon wrote:
>>> On Tuesday, August 28, 2012, 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) {
>>> 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.
The quirks could be removed.
> You wrapped the access to the CLKSEL register by callback function?
> CLKSEL is just implementation for Synopsys's phase-shift technique in Exynos
Right, CLKSEL register is used at EXYNOS.
But it could be presented other clock-phase method at other-SoC
> We don't need to consider this register.
> Perhaps, below conditions for hold_reg are only for Exynos?
No, that's generic condition that synopsys manual is mentioned.
> Which manual did you refer to?
i refer to dwc_mobile_storage(version 2.50a).
Best regards,
Jaehoon Chung
>
>>> 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.
> Yes, use_hold_regs shoud be set to CMD, whenever sending command.
> But cmd_flags for use_hold_reg can be set a time.
>
> Thanks,
> Seungwon Jeon
>
>>
>> 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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>>
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