1 files changed, 76 insertions, 2 deletions

diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
index 62a5d449c388..bc14dc874594 100644
--- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
+++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
@@ -119,6 +119,37 @@ exit:
 }
 
 /**
+ * ti_errata814_bandgap_read_temp() - helper function to read dra7 sensor temperature
+ * @bgp: pointer to ti_bandgap structure
+ * @reg: desired register (offset) to be read
+ *
+ * Function to read dra7 bandgap sensor temperature. This is done separately
+ * so as to workaround the errata "Bandgap Temperature read Dtemp can be
+ * corrupted" - Errata ID: i814".
+ * Read accesses to registers listed below can be corrupted due to incorrect
+ * resynchronization between clock domains.
+ * Read access to registers below can be corrupted :
+ * CTRL_CORE_DTEMP_MPU/GPU/CORE/DSPEVE/IVA_n (n = 0 to 4)
+ * CTRL_CORE_TEMP_SENSOR_MPU/GPU/CORE/DSPEVE/IVA_n
+ *
+ * Return: the register value.
+ */
+static u32 ti_errata814_bandgap_read_temp(struct ti_bandgap *bgp,  u32 reg)
+{
+	u32 val1, val2;
+
+	val1 = ti_bandgap_readl(bgp, reg);
+	val2 = ti_bandgap_readl(bgp, reg);
+
+	/* If both times we read the same value then that is right */
+	if (val1 == val2)
+		return val1;
+
+	/* if val1 and val2 are different read it third time */
+	return ti_bandgap_readl(bgp, reg);
+}
+
+/**
  * ti_bandgap_read_temp() - helper function to read sensor temperature
  * @bgp: pointer to ti_bandgap structure
  * @id: bandgap sensor id
@@ -148,7 +179,11 @@ static u32 ti_bandgap_read_temp(struct ti_bandgap *bgp, int id)
 	}
 
 	/* read temperature */
-	temp = ti_bandgap_readl(bgp, reg);
+	if (TI_BANDGAP_HAS(bgp, ERRATA_814))
+		temp = ti_errata814_bandgap_read_temp(bgp, reg);
+	else
+		temp = ti_bandgap_readl(bgp, reg);
+
 	temp &= tsr->bgap_dtemp_mask;
 
 	if (TI_BANDGAP_HAS(bgp, FREEZE_BIT))
@@ -410,7 +445,7 @@ static int ti_bandgap_update_alert_threshold(struct ti_bandgap *bgp, int id,
 {
 	struct temp_sensor_data *ts_data = bgp->conf->sensors[id].ts_data;
 	struct temp_sensor_registers *tsr;
-	u32 thresh_val, reg_val, t_hot, t_cold;
+	u32 thresh_val, reg_val, t_hot, t_cold, ctrl;
 	int err = 0;
 
 	tsr = bgp->conf->sensors[id].registers;
@@ -442,8 +477,47 @@ static int ti_bandgap_update_alert_threshold(struct ti_bandgap *bgp, int id,
 		  ~(tsr->threshold_thot_mask | tsr->threshold_tcold_mask);
 	reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask)) |
 		   (t_cold << __ffs(tsr->threshold_tcold_mask));
+
+	/**
+	 * Errata i813:
+	 * Spurious Thermal Alert: Talert can happen randomly while the device
+	 * remains under the temperature limit defined for this event to trig.
+	 * This spurious event is caused by a incorrect re-synchronization
+	 * between clock domains. The comparison between configured threshold
+	 * and current temperature value can happen while the value is
+	 * transitioning (metastable), thus causing inappropriate event
+	 * generation. No spurious event occurs as long as the threshold value
+	 * stays unchanged. Spurious event can be generated while a thermal
+	 * alert threshold is modified in
+	 * CONTROL_BANDGAP_THRESHOLD_MPU/GPU/CORE/DSPEVE/IVA_n.
+	 */
+
+	if (TI_BANDGAP_HAS(bgp, ERRATA_813)) {
+		/* Mask t_hot and t_cold events at the IP Level */
+		ctrl = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
+
+		if (hot)
+			ctrl &= ~tsr->mask_hot_mask;
+		else
+			ctrl &= ~tsr->mask_cold_mask;
+
+		ti_bandgap_writel(bgp, ctrl, tsr->bgap_mask_ctrl);
+	}
+
+	/* Write the threshold value */
 	ti_bandgap_writel(bgp, reg_val, tsr->bgap_threshold);
 
+	if (TI_BANDGAP_HAS(bgp, ERRATA_813)) {
+		/* Unmask t_hot and t_cold events at the IP Level */
+		ctrl = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
+		if (hot)
+			ctrl |= tsr->mask_hot_mask;
+		else
+			ctrl |= tsr->mask_cold_mask;
+
+		ti_bandgap_writel(bgp, ctrl, tsr->bgap_mask_ctrl);
+	}
+
 	if (err) {
 		dev_err(bgp->dev, "failed to reprogram thot threshold\n");
 		err = -EIO;