ti_bandgap_get_sensor_data() returns an ERR_PTR() if the bandgap
instance or sensor ID is invalid. Otherwise it returns the stored sensor
data, which can be NULL if no data has been set or the stored value has
been cleared.

This mismatch was already present in omap_bandgap_get_sensor_data() when
the driver was introduced in staging.

Document the validation errors while retaining NULL as a possible stored
value.

Fixes: 8feaf0ce1a04 ("staging: OMAP4+: thermal: introduce bandgap temperature sensor")
Assisted-by: LLM
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
---
 drivers/thermal/ti-soc-thermal/ti-bandgap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
index ba43399d0b384cf86d12642cc184c5f14066f431..2e8fe7daedb80b7ca4a24f2c89fc5ef44a0a9ebb 100644
--- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
+++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
@@ -576,7 +576,8 @@ int ti_bandgap_set_sensor_data(struct ti_bandgap *bgp, int id, void *data)
  * @bgp: pointer to bandgap instance
  * @id: sensor id
  *
- * Return: data stored by set function with sensor id on success or NULL
+ * Return: the stored sensor data, which may be %NULL, or an ERR_PTR()
+ * if @bgp or @id is invalid.
  */
 void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id)
 {
-- 
2.39.5 (Apple Git-154)