scsi: ufs: ufs-qcom: Align programming sequence of Shared ICE for UFS controller v5

Disabling the AES core in Shared ICE is not supported during power
collapse for UFS Host Controller v5.0, which may lead to data errors
after Hibern8 exit. To comply with hardware programming guidelines and
avoid this issue, issue a sync reset to ICE upon power collapse exit.

Hence follow below steps to reset the ICE upon exiting power collapse
and align with Hw programming guide.

a. Assert the ICE sync reset by setting both SYNC_RST_SEL and
   SYNC_RST_SW bits in UFS_MEM_ICE_CFG

b. Deassert the reset by clearing SYNC_RST_SW in  UFS_MEM_ICE_CFG

Signed-off-by: Palash Kambar <quic_pkambar@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: Palash Kambar

drivers/ufs/host/ufs-qcom.c

@@ -38,6 +38,9 @@
 #define DEEMPHASIS_3_5_dB	0x04
 #define NO_DEEMPHASIS		0x0
 
+#define UFS_ICE_SYNC_RST_SEL	BIT(3)
+#define UFS_ICE_SYNC_RST_SW	BIT(4)
+
 enum {
 	TSTBUS_UAWM,
 	TSTBUS_UARM,
@@ -751,11 +754,29 @@ static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 	int err;
+	u32 reg_val;
 
 	err = ufs_qcom_enable_lane_clks(host);
 	if (err)
 		return err;
 
+	if ((!ufs_qcom_is_link_active(hba)) &&
+	    host->hw_ver.major == 5 &&
+	    host->hw_ver.minor == 0 &&
+	    host->hw_ver.step == 0) {
+		ufshcd_writel(hba, UFS_ICE_SYNC_RST_SEL | UFS_ICE_SYNC_RST_SW, UFS_MEM_ICE_CFG);
+		reg_val = ufshcd_readl(hba, UFS_MEM_ICE_CFG);
+		reg_val &= ~(UFS_ICE_SYNC_RST_SEL | UFS_ICE_SYNC_RST_SW);
+		/*
+		 * HW documentation doesn't recommend any delay between the
+		 * reset set and clear. But we are enforcing an arbitrary delay
+		 * to give flops enough time to settle in.
+		 */
+		usleep_range(50, 100);
+		ufshcd_writel(hba, reg_val, UFS_MEM_ICE_CFG);
+		ufshcd_readl(hba, UFS_MEM_ICE_CFG);
+	}
+
 	return ufs_qcom_ice_resume(host);
 }
 

drivers/ufs/host/ufs-qcom.h

@@ -60,7 +60,7 @@ enum {
 	UFS_AH8_CFG				= 0xFC,
 
 	UFS_RD_REG_MCQ				= 0xD00,
-
+	UFS_MEM_ICE_CFG				= 0x2600,
 	REG_UFS_MEM_ICE_CONFIG			= 0x260C,
 	REG_UFS_MEM_ICE_NUM_CORE		= 0x2664,