scsi: ufs-mediatek: customize the delay for enabling host

MediaTek platform and UFS controller can dynamically customize the delay
for host enabling according to different scenarios.

For example, if UniPro enters lower-power mode, such delay can be
minimized, otherwise longer delay shall be expected.

Link: https://lore.kernel.org/r/20200318104016.28049-8-stanley.chu@mediatek.comReviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufs-mediatek.c

@@ -30,11 +30,6 @@
 #define ufs_mtk_device_reset_ctrl(high, res) \
 	ufs_mtk_smc(UFS_MTK_SIP_DEVICE_RESET, high, res)
 
-#define ufs_mtk_unipro_powerdown(hba, powerdown) \
-	ufshcd_dme_set(hba, \
-		       UIC_ARG_MIB_SEL(VS_UNIPROPOWERDOWNCONTROL, 0), \
-		       powerdown)
-
 static void ufs_mtk_cfg_unipro_cg(struct ufs_hba *hba, bool enable)
 {
 	u32 tmp;
@@ -71,6 +66,21 @@ static void ufs_mtk_cfg_unipro_cg(struct ufs_hba *hba, bool enable)
 	}
 }
 
+static int ufs_mtk_hce_enable_notify(struct ufs_hba *hba,
+				     enum ufs_notify_change_status status)
+{
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+	if (status == PRE_CHANGE) {
+		if (host->unipro_lpm)
+			hba->hba_enable_delay_us = 0;
+		else
+			hba->hba_enable_delay_us = 600;
+	}
+
+	return 0;
+}
+
 static int ufs_mtk_bind_mphy(struct ufs_hba *hba)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
@@ -324,12 +334,26 @@ static int ufs_mtk_pwr_change_notify(struct ufs_hba *hba,
 	return ret;
 }
 
+static int ufs_mtk_unipro_set_pm(struct ufs_hba *hba, u32 lpm)
+{
+	int ret;
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+	ret = ufshcd_dme_set(hba,
+			     UIC_ARG_MIB_SEL(VS_UNIPROPOWERDOWNCONTROL, 0),
+			     lpm);
+	if (!ret)
+		host->unipro_lpm = lpm;
+
+	return ret;
+}
+
 static int ufs_mtk_pre_link(struct ufs_hba *hba)
 {
 	int ret;
 	u32 tmp;
 
-	ufs_mtk_unipro_powerdown(hba, 0);
+	ufs_mtk_unipro_set_pm(hba, 0);
 
 	/*
 	 * Setting PA_Local_TX_LCC_Enable to 0 before link startup
@@ -437,7 +461,7 @@ static int ufs_mtk_link_set_hpm(struct ufs_hba *hba)
 	if (err)
 		return err;
 
-	err = ufs_mtk_unipro_powerdown(hba, 0);
+	err = ufs_mtk_unipro_set_pm(hba, 0);
 	if (err)
 		return err;
 
@@ -458,10 +482,10 @@ static int ufs_mtk_link_set_lpm(struct ufs_hba *hba)
 {
 	int err;
 
-	err = ufs_mtk_unipro_powerdown(hba, 1);
+	err = ufs_mtk_unipro_set_pm(hba, 1);
 	if (err) {
 		/* Resume UniPro state for following error recovery */
-		ufs_mtk_unipro_powerdown(hba, 0);
+		ufs_mtk_unipro_set_pm(hba, 0);
 		return err;
 	}
 
@@ -552,6 +576,7 @@ static struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.name                = "mediatek.ufshci",
 	.init                = ufs_mtk_init,
 	.setup_clocks        = ufs_mtk_setup_clocks,
+	.hce_enable_notify   = ufs_mtk_hce_enable_notify,
 	.link_startup_notify = ufs_mtk_link_startup_notify,
 	.pwr_change_notify   = ufs_mtk_pwr_change_notify,
 	.apply_dev_quirks    = ufs_mtk_apply_dev_quirks,

drivers/scsi/ufs/ufs-mediatek.h

@@ -91,6 +91,7 @@ enum {
 struct ufs_mtk_host {
 	struct ufs_hba *hba;
 	struct phy *mphy;
+	bool unipro_lpm;
 	bool ref_clk_enabled;
 	u16 ref_clk_ungating_wait_us;
 	u16 ref_clk_gating_wait_us;