[PATCH v4 5/6] thermal: tsens: Check if we have valid data before reading

[Amit Kucheria]

Signed-off-by: Amit Kucheria <amit.kuche...@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.anders...@linaro.org>
---
 drivers/thermal/qcom/tsens-v2.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/thermal/qcom/tsens-v2.c b/drivers/thermal/qcom/tsens-v2.c
index 1871945..0473f33 100644
--- a/drivers/thermal/qcom/tsens-v2.c
+++ b/drivers/thermal/qcom/tsens-v2.c
@@ -7,6 +7,9 @@
 #include <linux/regmap.h>
 #include "tsens.h"
 
+#define TRDY_OFFSET            0xe4
+#define TRDY_READY_BIT         BIT(0)
+
 #define STATUS_OFFSET          0xa0
 #define LAST_TEMP_MASK         0xfff
 #define STATUS_VALID_BIT       BIT(21)
@@ -19,6 +22,12 @@ static int get_temp_tsens_v2(struct tsens_device *tmdev, int 
id, int *temp)
        unsigned int sensor_addr;
        int last_temp = 0, last_temp2 = 0, last_temp3 = 0, ret;
 
+       ret = regmap_read(tmdev->map, TRDY_OFFSET, &code);
+       if (ret)
+               return ret;
+       if (code & TRDY_READY_BIT)
+               return -ENODATA;
+
        sensor_addr = STATUS_OFFSET + s->hw_id * 4;
        ret = regmap_read(tmdev->map, sensor_addr, &code);
        if (ret)
-- 
2.7.4