[PATCH 05/13] thermal: imx_tmu: Fix for temperature out of range

[Peng Fan]

When the temperature is out of sensor's range, the Valid bit won't be
set in TRITSR register. So the polling loop won't go out.

Change the codes to retry 10 times with 100ms interval for the Valid bit.
If the timeout, we give a warning for the invalid data.

Modifed from Ye's NXP patch

Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
 drivers/thermal/imx_tmu.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/imx_tmu.c b/drivers/thermal/imx_tmu.c
index 049f32c39e..2a08d5085c 100644
--- a/drivers/thermal/imx_tmu.c
+++ b/drivers/thermal/imx_tmu.c
@@ -105,15 +105,22 @@ static int read_temperature(struct udevice *dev, int *temp)
 	struct imx_tmu_plat *pdata = dev_get_platdata(dev);
 	ulong drv_data = dev_get_driver_data(dev);
 	u32 val;
+	u32 retry = 10;
 
 	do {
-		if (drv_data & FLAGS_VER2) {
+		mdelay(100);
+		retry--;
+
+		if (drv_data & FLAGS_VER2)
 			val = readl(&pdata->regs->regs_v2.tritsr);
 		else
 			val = readl(&pdata->regs->regs_v1.site[pdata->id].tritsr);
-	} while (!(val & 0x80000000));
+	} while (!(val & 0x80000000) && retry > 0);
 
-	*temp = (val & 0xff) * 1000;
+	if (retry > 0)
+		*temp = (val & 0xff) * 1000;
+	else
+		return -EINVAL;
 
 	return 0;
 }
-- 
2.16.4