scsi: ufs: add quirk to handle broken UFS HCI version

Some host controller hardware controllers may not advertise correct
version in UFS HCI VER register. To workaround this, add new quirk
and call the host controller hardware vendor specific callback to
get the correct UFS HCI version register value.
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

drivers/scsi/ufs/ufshcd.c

@@ -271,6 +271,11 @@ static inline u32 ufshcd_get_intr_mask(struct ufs_hba *hba)
  */
 static inline u32 ufshcd_get_ufs_version(struct ufs_hba *hba)
 {
+	if (hba->quirks & UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION) {
+		if (hba->vops && hba->vops->get_ufs_hci_version)
+			return hba->vops->get_ufs_hci_version(hba);
+	}
+
 	return ufshcd_readl(hba, REG_UFS_VERSION);
 }
 

drivers/scsi/ufs/ufshcd.h

@@ -246,6 +246,7 @@ struct ufs_pwr_mode_info {
  * @name: variant name
  * @init: called when the driver is initialized
  * @exit: called to cleanup everything done in init
+ * @get_ufs_hci_version: called to get UFS HCI version
  * @clk_scale_notify: notifies that clks are scaled up/down
  * @setup_clocks: called before touching any of the controller registers
  * @setup_regulators: called before accessing the host controller
@@ -263,6 +264,7 @@ struct ufs_hba_variant_ops {
 	const char *name;
 	int	(*init)(struct ufs_hba *);
 	void    (*exit)(struct ufs_hba *);
+	u32	(*get_ufs_hci_version)(struct ufs_hba *);
 	void    (*clk_scale_notify)(struct ufs_hba *);
 	int     (*setup_clocks)(struct ufs_hba *, bool);
 	int     (*setup_regulators)(struct ufs_hba *, bool);
@@ -449,6 +451,14 @@ struct ufs_hba {
 	 */
 	#define UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE		UFS_BIT(4)
 
+	/*
+	 * This quirk needs to be enabled if the host contoller doesn't
+	 * advertise the correct version in UFS_VER register. If this quirk
+	 * is enabled, standard UFS host driver will call the vendor specific
+	 * ops (get_ufs_hci_version) to get the correct version.
+	 */
+	#define UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION		UFS_BIT(5)
+
 	unsigned int quirks;	/* Deviations from standard UFSHCI spec. */
 
 	wait_queue_head_t tm_wq;

drivers/scsi/ufs/ufshci.h

@@ -89,8 +89,9 @@ enum {
 
 /* Controller UFSHCI version */
 enum {
-	UFSHCI_VERSION_10 = 0x00010000,
-	UFSHCI_VERSION_11 = 0x00010100,
+	UFSHCI_VERSION_10 = 0x00010000, /* 1.0 */
+	UFSHCI_VERSION_11 = 0x00010100, /* 1.1 */
+	UFSHCI_VERSION_20 = 0x00000200, /* 2.0 */
 };
 
 /*