scsi: ufs: Add dev ref clock gating wait time support

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.

Link: https://lore.kernel.org/r/1581392451-28743-7-git-send-email-cang@codeaurora.org
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index cfe380348bf0fbea3d30f0009ade6f54f5e910d8..990cb48e2403042863e57b89114768ff7f7900f6 100644 (file)
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -167,6 +167,7 @@ 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 */
@@ -534,6 +535,8 @@ struct ufs_dev_info {
        u16 wmanufacturerid;
        /*UFS device Product Name */
        u8 *model;
+       u16 wspecversion;
+       u32 clk_gating_wait_us;
 };
 
 /**

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 19270748ecd41bab183d70aac041d9987eb83898..f4aa10fdbb0c3aba816e48344ea91e2b1ad76c62 100644 (file)
--- 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;                                               \
@@ -3281,6 +3284,31 @@ 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.wspecversion >= 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);
+               }
+
+               hba->dev_info.clk_gating_wait_us = gating_wait;
+       }
+
+       return err;
+}
+
 /**
  * ufshcd_memory_alloc - allocate memory for host memory space data structures
  * @hba: per adapter instance
@@ -6627,6 +6655,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
        dev_info->wmanufacturerid = desc_buf[DEVICE_DESC_PARAM_MANF_ID] << 8 |
                                     desc_buf[DEVICE_DESC_PARAM_MANF_ID + 1];
 
+       /* getting Specification Version in big endian format */
+       dev_info->wspecversion = 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_info->model, SD_ASCII_STD);
@@ -7004,6 +7036,8 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
                goto out;
        }
 
+       ufshcd_get_ref_clk_gating_wait(hba);
+
        ufs_fixup_device_setup(hba);
 
        if (!ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,