From 138d45d96758db803b50761297f3331c9170bc87 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Fri, 7 Jun 2024 06:32:04 -0700 Subject: [PATCH] hwmon: (pmbus/max31827) Explain why enum chips must not start with 0 If a driver calls device_get_match_data(), the .data pointer in its id data structures must not be NULL/0 because device_get_match_data() returns NULL if an entry is not found. Explain that in a comment to avoid confusion why this is required in this driver but not in other drivers. Cc: Daniel Matyas Acked-by: Nuno Sa Signed-off-by: Guenter Roeck --- drivers/hwmon/max31827.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c index 4d89b6a7060b..48e8f8ba4d05 100644 --- a/drivers/hwmon/max31827.c +++ b/drivers/hwmon/max31827.c @@ -47,6 +47,11 @@ #define MAX31827_M_DGR_TO_16_BIT(x) (((x) << 4) / 1000) #define MAX31827_DEVICE_ENABLE(x) ((x) ? 0xA : 0x0) +/* + * The enum passed in the .data pointer of struct of_device_id must + * start with a value != 0 since that is a requirement for using + * device_get_match_data(). + */ enum chips { max31827 = 1, max31828, max31829 }; enum max31827_cnv {