scsi: ufs: add new get_scale_down_gear vops

Each ufs controller variant can work with various gear speeds that
can be supported at a low voltage corner. Add an ops function to
query the gear supported to scale down.

Also make the hibern8 entry/exit function non static as the variant
drivers might need to call hibern8 entry/exit when scaling down to
a lower gear.

Change-Id: I50008a892c8c21a4a3361998d76a2f8cbc2995bb
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>

2 files changed, 20 insertions, 9 deletions

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 607ed45742c4..54689aa4139f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -362,8 +362,6 @@ static int ufshcd_disable_clocks(struct ufs_hba *hba,
 static int ufshcd_disable_clocks_skip_ref_clk(struct ufs_hba *hba,
 					      bool is_gating_context);
 static int ufshcd_set_vccq_rail_unused(struct ufs_hba *hba, bool unused);
-static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
-static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
 static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
 static inline void ufshcd_save_tstamp_of_last_dme_cmd(struct ufs_hba *hba);
 static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
@@ -4019,7 +4017,7 @@ static int __ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 	return ret;
 }
 
-static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
+int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 {
 	int ret = 0, retries;
 
@@ -4032,7 +4030,7 @@ out:
 	return ret;
 }
 
-static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
+int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
 {
 	struct uic_command uic_cmd = {0};
 	int ret;
@@ -8573,9 +8571,9 @@ static bool ufshcd_is_devfreq_scaling_required(struct ufs_hba *hba,
  */
 static int ufshcd_scale_gear(struct ufs_hba *hba, bool scale_up)
 {
-	#define UFS_MIN_GEAR_TO_SCALE_DOWN	UFS_HS_G2
 	int ret = 0;
 	struct ufs_pa_layer_attr new_pwr_info;
+	u32 scale_down_gear = ufshcd_vops_get_scale_down_gear(hba);
 
 	BUG_ON(!hba->clk_scaling.saved_pwr_info.is_valid);
 
@@ -8586,16 +8584,16 @@ static int ufshcd_scale_gear(struct ufs_hba *hba, bool scale_up)
 		memcpy(&new_pwr_info, &hba->pwr_info,
 		       sizeof(struct ufs_pa_layer_attr));
 
-		if (hba->pwr_info.gear_tx > UFS_MIN_GEAR_TO_SCALE_DOWN
-		    || hba->pwr_info.gear_rx > UFS_MIN_GEAR_TO_SCALE_DOWN) {
+		if (hba->pwr_info.gear_tx > scale_down_gear
+		    || hba->pwr_info.gear_rx > scale_down_gear) {
 			/* save the current power mode */
 			memcpy(&hba->clk_scaling.saved_pwr_info.info,
 				&hba->pwr_info,
 				sizeof(struct ufs_pa_layer_attr));
 
 			/* scale down gear */
-			new_pwr_info.gear_tx = UFS_MIN_GEAR_TO_SCALE_DOWN;
-			new_pwr_info.gear_rx = UFS_MIN_GEAR_TO_SCALE_DOWN;
+			new_pwr_info.gear_tx = scale_down_gear;
+			new_pwr_info.gear_rx = scale_down_gear;
 			if (!(hba->dev_quirks & UFS_DEVICE_NO_FASTAUTO)) {
 				new_pwr_info.pwr_tx = FASTAUTO_MODE;
 				new_pwr_info.pwr_rx = FASTAUTO_MODE;
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 1e5eb3ddd7c4..84bf9d59ad50 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -307,6 +307,8 @@ struct ufs_pwr_mode_info {
  *		 implementations of resetting the hci
  * @dbg_register_dump: used to dump controller debug information
  * @update_sec_cfg: called to restore host controller secure configuration
+ * @get_scale_down_gear: called to get the minimum supported gear to
+ *			 scale down
  * @add_debugfs: used to add debugfs entries
  * @remove_debugfs: used to remove debugfs entries
  */
@@ -332,6 +334,7 @@ struct ufs_hba_variant_ops {
 	int	(*full_reset)(struct ufs_hba *);
 	void	(*dbg_register_dump)(struct ufs_hba *hba);
 	int	(*update_sec_cfg)(struct ufs_hba *hba, bool restore_sec_cfg);
+	u32	(*get_scale_down_gear)(struct ufs_hba *);
 #ifdef CONFIG_DEBUG_FS
 	void	(*add_debugfs)(struct ufs_hba *hba, struct dentry *root);
 	void	(*remove_debugfs)(struct ufs_hba *hba);
@@ -970,6 +973,8 @@ void ufshcd_remove(struct ufs_hba *);
 int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
 				u32 val, unsigned long interval_us,
 				unsigned long timeout_ms, bool can_sleep);
+int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
+int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
 
 /**
  * ufshcd_set_variant - set variant specific data to the hba
@@ -1239,6 +1244,14 @@ static inline int ufshcd_vops_update_sec_cfg(struct ufs_hba *hba,
 	return 0;
 }
 
+static inline u32 ufshcd_vops_get_scale_down_gear(struct ufs_hba *hba)
+{
+	if (hba->var && hba->var->vops && hba->var->vops->get_scale_down_gear)
+		return hba->var->vops->get_scale_down_gear(hba);
+	/* Default to lowest high speed gear */
+	return UFS_HS_G1;
+}
+
 #ifdef CONFIG_DEBUG_FS
 static inline void ufshcd_vops_add_debugfs(struct ufs_hba *hba,
 						struct dentry *root)