Revert "Revert "FROMLIST: scsi: ufs: Add dev ref clock gating wait time support""ASB-2020-02-05_mainline

This reverts commit 8326ceb4bc09ff3430a768af227be30530b9997d which was
commit 1ddc9771d5bc0c8706438b015ba01d4dbba857f7.  It was fixed up by
hand due to the scsi upstream merge.

Bug: 143632303
Link: https://lore.kernel.org/patchwork/patch/1149892/
Cc: Can Guo <cang@codeaurora.org>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I69900cab82eb84a384db3b30c5a6311964ec9d91

2 files changed, 48 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index dde2eb02f76f..ffe68ab664dd 100644
--- 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 spec_version;
+	u32 clk_gating_wait_us;
 };
 
 /**
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 6a51eb80c3a1..9e9f1426bf39 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -92,6 +92,9 @@
 /* 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;                                               \
@@ -3338,6 +3341,37 @@ 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
@@ -6694,6 +6728,10 @@ 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 */
+	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_info->model, SD_ASCII_STD);
@@ -7073,6 +7111,8 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
 
 	ufs_fixup_device_setup(hba);
 
+	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;
@@ -7469,12 +7509,17 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 	struct ufs_clk_info *clki;
 	struct list_head *head = &hba->clk_list_head;
 	unsigned long flags;
+	unsigned long gating_wait;
 	ktime_t start = ktime_get();
 	bool clk_state_changed = false;
 
 	if (list_empty(head))
 		goto out;
 
+	gating_wait = (unsigned long)hba->dev_info.clk_gating_wait_us;
+	if (!on && !skip_ref_clk && !!gating_wait)
+		usleep_range(gating_wait, gating_wait + 10);
+
 	ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE);
 	if (ret)
 		return ret;