scsi: ufs: add auto hibern8 support

UFS HCI v2.0 specification adds support for auto hibern8.
Add support to enable this in the ufs host controller driver.

Change-Id: I57e5be8eae4b2cf70a2a9d9c81c9a54a24e03e71
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>

drivers/scsi/ufs/ufshcd.c

@@ -1570,6 +1570,16 @@ static void ufshcd_exit_clk_gating(struct ufs_hba *hba)
 	cancel_delayed_work_sync(&hba->clk_gating.gate_work);
 }
 
+static void ufshcd_set_auto_hibern8_timer(struct ufs_hba *hba, u32 delay)
+{
+	ufshcd_rmwl(hba, AUTO_HIBERN8_TIMER_SCALE_MASK |
+			 AUTO_HIBERN8_IDLE_TIMER_MASK,
+			AUTO_HIBERN8_TIMER_SCALE_1_MS | delay,
+			REG_AUTO_HIBERN8_IDLE_TIMER);
+	/* Make sure the timer gets applied before further operations */
+	mb();
+}
+
 /**
  * ufshcd_hibern8_hold - Make sure that link is not in hibern8.
  *
@@ -1799,6 +1809,13 @@ static ssize_t ufshcd_hibern8_on_idle_delay_store(struct device *dev,
 	spin_lock_irqsave(hba->host->host_lock, flags);
 	hba->hibern8_on_idle.delay_ms = value;
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/* Update auto hibern8 timer value if supported */
+	if (ufshcd_is_auto_hibern8_supported(hba) &&
+	    hba->hibern8_on_idle.is_enabled)
+		ufshcd_set_auto_hibern8_timer(hba,
+					      hba->hibern8_on_idle.delay_ms);
+
 	return count;
 }
 
@@ -1825,6 +1842,13 @@ static ssize_t ufshcd_hibern8_on_idle_enable_store(struct device *dev,
 	if (value == hba->hibern8_on_idle.is_enabled)
 		goto out;
 
+	/* Update auto hibern8 timer value if supported */
+	if (ufshcd_is_auto_hibern8_supported(hba)) {
+		ufshcd_set_auto_hibern8_timer(hba,
+			value ? hba->hibern8_on_idle.delay_ms : value);
+		goto update;
+	}
+
 	if (value) {
 		/*
 		 * As clock gating work would wait for the hibern8 enter work
@@ -1838,6 +1862,7 @@ static ssize_t ufshcd_hibern8_on_idle_enable_store(struct device *dev,
 		spin_unlock_irqrestore(hba->host->host_lock, flags);
 	}
 
+update:
 	hba->hibern8_on_idle.is_enabled = value;
 out:
 	return count;
@@ -1848,12 +1873,23 @@ static void ufshcd_init_hibern8_on_idle(struct ufs_hba *hba)
 	/* initialize the state variable here */
 	hba->hibern8_on_idle.state = HIBERN8_EXITED;
 
-	if (!ufshcd_is_hibern8_on_idle_allowed(hba))
+	if (!ufshcd_is_hibern8_on_idle_allowed(hba) &&
+	    !ufshcd_is_auto_hibern8_supported(hba))
 		return;
 
-	INIT_DELAYED_WORK(&hba->hibern8_on_idle.enter_work,
-			  ufshcd_hibern8_enter_work);
-	INIT_WORK(&hba->hibern8_on_idle.exit_work, ufshcd_hibern8_exit_work);
+	if (ufshcd_is_auto_hibern8_supported(hba)) {
+		hba->hibern8_on_idle.state = AUTO_HIBERN8;
+		/*
+		 * Disable SW hibern8 enter on idle in case
+		 * auto hibern8 is supported
+		 */
+		hba->caps &= ~UFSHCD_CAP_HIBERN8_ENTER_ON_IDLE;
+	} else {
+		INIT_DELAYED_WORK(&hba->hibern8_on_idle.enter_work,
+				  ufshcd_hibern8_enter_work);
+		INIT_WORK(&hba->hibern8_on_idle.exit_work,
+			  ufshcd_hibern8_exit_work);
+	}
 
 	hba->hibern8_on_idle.delay_ms = 10;
 	hba->hibern8_on_idle.is_enabled = true;
@@ -1881,7 +1917,8 @@ static void ufshcd_init_hibern8_on_idle(struct ufs_hba *hba)
 
 static void ufshcd_exit_hibern8_on_idle(struct ufs_hba *hba)
 {
-	if (!ufshcd_is_hibern8_on_idle_allowed(hba))
+	if (!ufshcd_is_hibern8_on_idle_allowed(hba) &&
+	    !ufshcd_is_auto_hibern8_supported(hba))
 		return;
 	device_remove_file(hba->dev, &hba->hibern8_on_idle.delay_attr);
 	device_remove_file(hba->dev, &hba->hibern8_on_idle.enable_attr);
@@ -6702,6 +6739,11 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	if (ret)
 		goto out;
 
+	/* Enable auto hibern8 if supported */
+	if (ufshcd_is_auto_hibern8_supported(hba))
+		ufshcd_set_auto_hibern8_timer(hba,
+					      hba->hibern8_on_idle.delay_ms);
+
 	/* Debug counters initialization */
 	ufshcd_clear_dbg_ufs_stats(hba);
 	/* set the default level for urgent bkops */

drivers/scsi/ufs/ufshcd.h

@@ -74,6 +74,7 @@
 #define UFSHCD_DRIVER_VERSION "0.3"
 
 #define UFS_BIT(x)	BIT(x)
+#define UFS_MASK(x, y)	(x << ((y) % BITS_PER_LONG))
 
 struct ufs_hba;
 
@@ -429,6 +430,7 @@ enum ufshcd_hibern8_on_idle_state {
 	HIBERN8_EXITED,
 	REQ_HIBERN8_ENTER,
 	REQ_HIBERN8_EXIT,
+	AUTO_HIBERN8,
 };
 
 /**
@@ -929,6 +931,11 @@ static inline bool ufshcd_is_intr_aggr_allowed(struct ufs_hba *hba)
 		return false;
 }
 
+static inline bool ufshcd_is_auto_hibern8_supported(struct ufs_hba *hba)
+{
+	return !!(hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT);
+}
+
 static inline bool ufshcd_is_crypto_supported(struct ufs_hba *hba)
 {
 	return !!(hba->capabilities & MASK_CRYPTO_SUPPORT);

drivers/scsi/ufs/ufshci.h

@@ -48,6 +48,7 @@ enum {
 	REG_UFS_VERSION				= 0x08,
 	REG_CONTROLLER_DEV_ID			= 0x10,
 	REG_CONTROLLER_PROD_ID			= 0x14,
+	REG_AUTO_HIBERN8_IDLE_TIMER		= 0x18,
 	REG_INTERRUPT_STATUS			= 0x20,
 	REG_INTERRUPT_ENABLE			= 0x24,
 	REG_CONTROLLER_STATUS			= 0x30,
@@ -85,6 +86,7 @@ enum {
 enum {
 	MASK_TRANSFER_REQUESTS_SLOTS		= 0x0000001F,
 	MASK_TASK_MANAGEMENT_REQUEST_SLOTS	= 0x00070000,
+	MASK_AUTO_HIBERN8_SUPPORT		= 0x00800000,
 	MASK_64_ADDRESSING_SUPPORT		= 0x01000000,
 	MASK_OUT_OF_ORDER_DATA_DELIVERY_SUPPORT	= 0x02000000,
 	MASK_UIC_DME_TEST_MODE_SUPPORT		= 0x04000000,
@@ -117,6 +119,18 @@ enum {
 #define MANUFACTURE_ID_MASK	UFS_MASK(0xFFFF, 0)
 #define PRODUCT_ID_MASK		UFS_MASK(0xFFFF, 16)
 
+/*
+ * AHIT - Auto-Hibernate Idle Timer  18h
+ */
+#define AUTO_HIBERN8_IDLE_TIMER_MASK		UFS_MASK(0x3FF, 0)
+#define AUTO_HIBERN8_TIMER_SCALE_MASK		UFS_MASK(0x7, 10)
+#define AUTO_HIBERN8_TIMER_SCALE_1_US		UFS_MASK(0x0, 10)
+#define AUTO_HIBERN8_TIMER_SCALE_10_US		UFS_MASK(0x1, 10)
+#define AUTO_HIBERN8_TIMER_SCALE_100_US		UFS_MASK(0x2, 10)
+#define AUTO_HIBERN8_TIMER_SCALE_1_MS		UFS_MASK(0x3, 10)
+#define AUTO_HIBERN8_TIMER_SCALE_10_MS		UFS_MASK(0x4, 10)
+#define AUTO_HIBERN8_TIMER_SCALE_100_MS		UFS_MASK(0x5, 10)
+
 /* IS - Interrupt status (20h) / IE - Interrupt enable (24h) */
 #define UTP_TRANSFER_REQ_COMPL			UFS_BIT(0)
 #define UIC_DME_END_PT_RESET			UFS_BIT(1)