Re: [PATCH v3 2/3] hwmon: (adt7475) Add support for pin configuration

From: Guenter Roeck
Date: Mon May 02 2022 - 00:36:35 EST


On Wed, Mar 23, 2022 at 04:40:55PM +1300, Chris Packham wrote:
> The adt7473, adt7475, adt7476 and adt7490 have pins that can be used for
> different functions. On the adt7473 and adt7475 this is pins 5 and 9.
> On the adt7476 and adt7490 this is pins 10 and 14.
>
> The first pin can either be PWM2(default) or SMBALERT#. The second pin
> can be TACH4(default), THERM#, SMBALERT# or GPIO.
>
> The adt7475 driver has always been able to detect the configuration if
> it had been done by an earlier boot stage. Add support for configuring
> the pins based on the hardware description in the device tree.
>
> Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Applied to hwmon-next.

Thanks,
Guenter

> ---
>
> Notes:
> Changes in v3:
> - None
> Changes in v2:
> - Use load_config{3,4} instead of load_pin{10,14}_config
> - Handle errors from adt7475_read()
> - Remove obsolete check on chip type
> - Use enum chips instead of int
> - Update error messages
>
> drivers/hwmon/adt7475.c | 96 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 96 insertions(+)
>
> diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
> index 9d5b019651f2..6de501de41b2 100644
> --- a/drivers/hwmon/adt7475.c
> +++ b/drivers/hwmon/adt7475.c
> @@ -112,6 +112,8 @@
> #define CONFIG3_THERM 0x02
>
> #define CONFIG4_PINFUNC 0x03
> +#define CONFIG4_THERM 0x01
> +#define CONFIG4_SMBALERT 0x02
> #define CONFIG4_MAXDUTY 0x08
> #define CONFIG4_ATTN_IN10 0x30
> #define CONFIG4_ATTN_IN43 0xC0
> @@ -1460,6 +1462,96 @@ static int adt7475_update_limits(struct i2c_client *client)
> return 0;
> }
>
> +static int load_config3(const struct i2c_client *client, const char *propname)
> +{
> + const char *function;
> + u8 config3;
> + int ret;
> +
> + ret = of_property_read_string(client->dev.of_node, propname, &function);
> + if (!ret) {
> + ret = adt7475_read(REG_CONFIG3);
> + if (ret < 0)
> + return ret;
> +
> + config3 = ret & ~CONFIG3_SMBALERT;
> + if (!strcmp("pwm2", function))
> + ;
> + else if (!strcmp("smbalert#", function))
> + config3 |= CONFIG3_SMBALERT;
> + else
> + return -EINVAL;
> +
> + return i2c_smbus_write_byte_data(client, REG_CONFIG3, config3);
> + }
> +
> + return 0;
> +}
> +
> +static int load_config4(const struct i2c_client *client, const char *propname)
> +{
> + const char *function;
> + u8 config4;
> + int ret;
> +
> + ret = of_property_read_string(client->dev.of_node, propname, &function);
> + if (!ret) {
> + ret = adt7475_read(REG_CONFIG4);
> + if (ret < 0)
> + return ret;
> +
> + config4 = ret & ~CONFIG4_PINFUNC;
> +
> + if (!strcmp("tach4", function))
> + ;
> + else if (!strcmp("therm#", function))
> + config4 |= CONFIG4_THERM;
> + else if (!strcmp("smbalert#", function))
> + config4 |= CONFIG4_SMBALERT;
> + else if (!strcmp("gpio", function))
> + config4 |= CONFIG4_PINFUNC;
> + else
> + return -EINVAL;
> +
> + return i2c_smbus_write_byte_data(client, REG_CONFIG4, config4);
> + }
> +
> + return 0;
> +}
> +
> +static int load_config(const struct i2c_client *client, enum chips chip)
> +{
> + int err;
> + const char *prop1, *prop2;
> +
> + switch (chip) {
> + case adt7473:
> + case adt7475:
> + prop1 = "adi,pin5-function";
> + prop2 = "adi,pin9-function";
> + break;
> + case adt7476:
> + case adt7490:
> + prop1 = "adi,pin10-function";
> + prop2 = "adi,pin14-function";
> + break;
> + }
> +
> + err = load_config3(client, prop1);
> + if (err) {
> + dev_err(&client->dev, "failed to configure %s\n", prop1);
> + return err;
> + }
> +
> + err = load_config4(client, prop2);
> + if (err) {
> + dev_err(&client->dev, "failed to configure %s\n", prop2);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> static int set_property_bit(const struct i2c_client *client, char *property,
> u8 *config, u8 bit_index)
> {
> @@ -1585,6 +1677,10 @@ static int adt7475_probe(struct i2c_client *client)
> revision = adt7475_read(REG_DEVID2) & 0x07;
> }
>
> + ret = load_config(client, chip);
> + if (ret)
> + return ret;
> +
> config3 = adt7475_read(REG_CONFIG3);
> /* Pin PWM2 may alternatively be used for ALERT output */
> if (!(config3 & CONFIG3_SMBALERT))