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path: root/drivers/thermal/ti-soc-thermal/ti-bandgap.c
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Diffstat (limited to 'drivers/thermal/ti-soc-thermal/ti-bandgap.c')
-rw-r--r--drivers/thermal/ti-soc-thermal/ti-bandgap.c78
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;