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SubjectRe: [PATCH v4 6/8] scsi: ufs: Add dev ref clock gating wait time support
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On 1/22/2020 11:25 PM, Can Guo wrote:
> In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime defines
> the minimum time for which the reference clock is required by device during
> transition to LS-MODE or HIBERN8 state. Make this change to reflect the new
> requirement by adding delays before turning off the clock.
>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---

Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>

> drivers/scsi/ufs/ufs.h | 3 +++
> drivers/scsi/ufs/ufshcd.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 44 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 3327981..385bac8 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -168,6 +168,7 @@ enum attr_idn {
> QUERY_ATTR_IDN_FFU_STATUS = 0x14,
> QUERY_ATTR_IDN_PSA_STATE = 0x15,
> QUERY_ATTR_IDN_PSA_DATA_SIZE = 0x16,
> + QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME = 0x17,
> };
>
> /* Descriptor idn for Query requests */
> @@ -530,6 +531,8 @@ struct ufs_dev_info {
> bool f_power_on_wp_en;
> /* Keeps information if any of the LU is power on write protected */
> bool is_lu_power_on_wp;
> + u16 spec_version;
> + u32 clk_gating_wait_us;
> };
>
> #define MAX_MODEL_LEN 16
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index c316a07..1ee2187 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -91,6 +91,9 @@
> /* default delay of autosuspend: 2000 ms */
> #define RPM_AUTOSUSPEND_DELAY_MS 2000
>
> +/* Default value of wait time before gating device ref clock */
> +#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */
> +
> #define ufshcd_toggle_vreg(_dev, _vreg, _on) \
> ({ \
> int _ret; \
> @@ -3357,6 +3360,37 @@ static inline int ufshcd_read_unit_desc_param(struct ufs_hba *hba,
> param_offset, param_read_buf, param_size);
> }
>
> +static int ufshcd_get_ref_clk_gating_wait(struct ufs_hba *hba)
> +{
> + int err = 0;
> + u32 gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
> +
> + if (hba->dev_info.spec_version >= 0x300) {
> + err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> + QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME, 0, 0,
> + &gating_wait);
> + if (err)
> + dev_err(hba->dev, "Failed reading bRefClkGatingWait. err = %d, use default %uus\n",
> + err, gating_wait);
> +
> + if (gating_wait == 0) {
> + gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
> + dev_err(hba->dev, "Undefined ref clk gating wait time, use default %uus\n",
> + gating_wait);
> + }
> +
> + /*
> + * bRefClkGatingWaitTime defines the minimum time for which the
> + * reference clock is required by device during transition from
> + * HS-MODE to LS-MODE or HIBERN8 state. Give it more time to be
> + * on the safe side.
> + */
> + hba->dev_info.clk_gating_wait_us = gating_wait + 50;
> + }
> +
> + return err;
> +}
> +
> /**
> * ufshcd_memory_alloc - allocate memory for host memory space data structures
> * @hba: per adapter instance
> @@ -6628,6 +6662,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba,
> dev_desc->wmanufacturerid = desc_buf[DEVICE_DESC_PARAM_MANF_ID] << 8 |
> desc_buf[DEVICE_DESC_PARAM_MANF_ID + 1];
>
> + /* getting Specification Version in big endian format */
> + hba->dev_info.spec_version = desc_buf[DEVICE_DESC_PARAM_SPEC_VER] << 8 |
> + desc_buf[DEVICE_DESC_PARAM_SPEC_VER + 1];
> +
> model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
> err = ufshcd_read_string_desc(hba, model_index,
> &dev_desc->model, SD_ASCII_STD);
> @@ -7046,6 +7084,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
>
> /* clear any previous UFS device information */
> memset(&hba->dev_info, 0, sizeof(hba->dev_info));
> +
> + ufshcd_get_ref_clk_gating_wait(hba);
> +
> if (!ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,
> QUERY_FLAG_IDN_PWR_ON_WPE, &flag))
> hba->dev_info.f_power_on_wp_en = flag;
>


--
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