On 2/1/21 8:50 AM, Matthew Barth wrote:
> There was an issue in how the tach feedbacks of dual rotor fans were
> reported during any change in fan speeds with revision "A" of the
> MAX31785. When the fan speeds would transition to a new target speed,
> the rotor not wired to the TACH input when TACHSEL = 0 would report a
> speed of 0 until the new target was reached. This has been fixed,
> resulting in a revision "B" update where the MFR_REVISION of "B" is
> 0x3061.
>
Is that published somewhere ?
> Signed-off-by: Matthew Barth <msbarth@xxxxxxxxxxxxx>
> ---
> drivers/hwmon/pmbus/max31785.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/pmbus/max31785.c b/drivers/hwmon/pmbus/max31785.c
> index e5a9f4019cd5..e636a65061df 100644
> --- a/drivers/hwmon/pmbus/max31785.c
> +++ b/drivers/hwmon/pmbus/max31785.c
> @@ -17,6 +17,7 @@ enum max31785_regs {
>
> #define MAX31785 0x3030
> #define MAX31785A 0x3040
> +#define MAX31785B 0x3061
>
> #define MFR_FAN_CONFIG_DUAL_TACH BIT(12)
>
> @@ -350,12 +351,13 @@ static int max31785_probe(struct i2c_client *client)
> if (ret < 0)
> return ret;
>
> - if (ret == MAX31785A) {
> + if (ret == MAX31785A || ret == MAX31785B) {
> dual_tach = true;
> } else if (ret == MAX31785) {
> if (!strcmp("max31785a", client->name))
Probably also wants to check for max31785b,
> dev_warn(dev, "Expected max3175a, found max31785: cannot provide secondary tachometer readings\n");
and say something like "Expected max3175a/b, ..."
Thanks,
Guenter
> } else {
> + dev_err(dev, "Unrecognized MAX31785 revision: %x\n", ret);
> return -ENODEV;
> }
>
> @@ -371,6 +373,7 @@ static int max31785_probe(struct i2c_client *client)
> static const struct i2c_device_id max31785_id[] = {
> { "max31785", 0 },
> { "max31785a", 0 },
> + { "max31785b", 0 },
> { },
> };
>
> @@ -379,6 +382,7 @@ MODULE_DEVICE_TABLE(i2c, max31785_id);
> static const struct of_device_id max31785_of_match[] = {
> { .compatible = "maxim,max31785" },
> { .compatible = "maxim,max31785a" },
> + { .compatible = "maxim,max31785b" },
> { },
> };
>
>
