[PATCH 06/13] thermal: imx_tmu: Check the TEMP range for iMX8MM

[Peng Fan]

On iMX8MM, the V flag in TRISTR register only reflect the state of SNSR
value, not the calibrated TEMP value. So checking this flag is not
reliable. Per IC suggestion, change to read the TEMP/AVG_TEMP directly
and check whether it in valid range 10-125C.

Signed-off-by: Ye Li <ye.li at nxp.com>
Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
 drivers/thermal/imx_tmu.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/imx_tmu.c b/drivers/thermal/imx_tmu.c
index 2a08d5085c..c577b0bd6c 100644
--- a/drivers/thermal/imx_tmu.c
+++ b/drivers/thermal/imx_tmu.c
@@ -106,16 +106,24 @@ static int read_temperature(struct udevice *dev, int *temp)
 	ulong drv_data = dev_get_driver_data(dev);
 	u32 val;
 	u32 retry = 10;
+	u32 valid = 0;
 
 	do {
 		mdelay(100);
 		retry--;
 
-		if (drv_data & FLAGS_VER2)
+		if (drv_data & FLAGS_VER2) {
 			val = readl(&pdata->regs->regs_v2.tritsr);
-		else
+			/*
+			 * Check if TEMP is in valid range, the V bit in TRITSR
+			 * only reflects the RAW uncalibrated data
+			 */
+			valid =  ((val & 0xff) < 10 || (val & 0xff) > 125) ? 0 : 1;
+		} else {
 			val = readl(&pdata->regs->regs_v1.site[pdata->id].tritsr);
-	} while (!(val & 0x80000000) && retry > 0);
+			valid = val & 0x80000000;
+		}
+	} while (!valid && retry > 0);
 
 	if (retry > 0)
 		*temp = (val & 0xff) * 1000;
-- 
2.16.4