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 <daniel.matyas@analog.com>
Acked-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2024-06-07 06:32:04 -07:00
parent 71ac69e089
commit 138d45d967

View File

@ -47,6 +47,11 @@
#define MAX31827_M_DGR_TO_16_BIT(x) (((x) << 4) / 1000) #define MAX31827_M_DGR_TO_16_BIT(x) (((x) << 4) / 1000)
#define MAX31827_DEVICE_ENABLE(x) ((x) ? 0xA : 0x0) #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 chips { max31827 = 1, max31828, max31829 };
enum max31827_cnv { enum max31827_cnv {