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

From: Amit Kucheria
Date: Mon Jul 02 2018 - 08:45:12 EST


Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
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