From: Paul Gerber <redacted>

The i.MX 8MP has a ADC_PD bit in the TMU_TER register that controls the
operating mode of the ADC:
* 0 means normal operating mode
* 1 means power down mode

When enabling/disabling the TMU, the ADC operating mode must be set
accordingly.

i.MX 8M Mini & Nano are lacking this bit.

Signed-off-by: Paul Gerber <redacted>
Signed-off-by: Alexander Stein <redacted>
---
Often this bit is set already by the bootloader, but in case this is not
done, the file /sys/class/thermal/thermal_zone0/temp will always return
-EAGAIN.

 drivers/thermal/imx8mm_thermal.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/thermal/imx8mm_thermal.c b/drivers/thermal/imx8mm_thermal.c
index 7442e013738f..af666bd9e8d4 100644
--- a/drivers/thermal/imx8mm_thermal.c
+++ b/drivers/thermal/imx8mm_thermal.c

@@ -21,6 +21,7 @@
 #define TPS			0x4
 #define TRITSR			0x20	/* TMU immediate temp */
 
+#define TER_ADC_PD		BIT(30)
 #define TER_EN			BIT(31)
 #define TRITSR_TEMP0_VAL_MASK	0xff
 #define TRITSR_TEMP1_VAL_MASK	0xff0000

@@ -113,6 +114,8 @@ static void imx8mm_tmu_enable(struct imx8mm_tmu *tmu, bool enable)
 
 	val = readl_relaxed(tmu->base + TER);
 	val = enable ? (val | TER_EN) : (val & ~TER_EN);
+	if (tmu->socdata->version == TMU_VER2)
+		val = enable ? (val & ~TER_ADC_PD) : (val | TER_ADC_PD);
 	writel_relaxed(val, tmu->base + TER);
 }
 

-- 
2.25.1