Re: [PATCH 3/5] hwmon: (pmbus/core) Add mapping function to pmbus_read_block_data()

On 7/28/26 09:03, Nuno Sá via B4 Relay wrote:
> From: Nuno Sá <[email protected]>
> 
> This is in preparation for adding support to a device which needs to
> use it's own read_block implementation.
> 

The chip-specific implementation calls i2c_smbus_read_i2c_block_data().
I'll need to know if this is a chip limit or a controller limit.
If it is a controller limit, a chip specific override would be
inappropriate.

Guenter

> Signed-off-by: Nuno Sá <[email protected]>
> ---
>   drivers/hwmon/pmbus/pmbus.h      |  3 +++
>   drivers/hwmon/pmbus/pmbus_core.c | 24 ++++++++++++++++++++++--
>   2 files changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
> index 3d5586c67f84..d697939ec892 100644
> --- a/drivers/hwmon/pmbus/pmbus.h
> +++ b/drivers/hwmon/pmbus/pmbus.h
> @@ -459,6 +459,9 @@ struct pmbus_driver_info {
>   	int (*read_byte_data)(struct i2c_client *client, int page, int reg);
>   	int (*read_word_data)(struct i2c_client *client, int page, int phase,
>   			      int reg);
> +	/* size of data_buf is I2C_SMBUS_BLOCK_MAX + 2 */
> +	int (*read_block_data)(struct i2c_client *client, int page, u8 reg,
> +			       char *data_buf);
>   	int (*write_byte_data)(struct i2c_client *client, int page, int reg,
>   			      u8 byte);
>   	int (*write_word_data)(struct i2c_client *client, int page, int reg,
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 7b58f7198574..ff4572c473b7 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -533,6 +533,26 @@ static int pmbus_read_block_data(struct i2c_client *client, int page, u8 reg,
>   	return rv;
>   }
>   
> +/*
> + * _pmbus_read_block_data() is similar to pmbus_read_block_data(), but checks if
> + * a device specific mapping function exists and calls it if necessary.
> + */
> +static int _pmbus_read_block_data(struct i2c_client *client, int page, u8 reg,
> +				  char *data_buf)
> +{
> +	struct pmbus_data *data = i2c_get_clientdata(client);
> +	const struct pmbus_driver_info *info = data->info;
> +	int status;
> +
> +	if (info->read_block_data) {
> +		status = info->read_block_data(client, page, reg, data_buf);
> +		if (status != -ENODATA)
> +			return status;
> +	}
> +
> +	return pmbus_read_block_data(client, page, reg, data_buf);
> +}
> +
>   static struct pmbus_sensor *pmbus_find_sensor(struct pmbus_data *data, int page,
>   					      int reg)
>   {
> @@ -678,7 +698,7 @@ static bool __maybe_unused pmbus_check_block_register(struct i2c_client *client,
>   	struct pmbus_data *data = i2c_get_clientdata(client);
>   	char data_buf[I2C_SMBUS_BLOCK_MAX + 2];
>   
> -	rv = pmbus_read_block_data(client, page, reg, data_buf);
> +	rv = _pmbus_read_block_data(client, page, reg, data_buf);
>   	if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
>   		rv = pmbus_check_status_cml(client);
>   	if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK))
> @@ -3564,7 +3584,7 @@ static ssize_t pmbus_debugfs_block_read(struct file *file, char __user *buf,
>   	char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
>   
>   	scoped_guard(pmbus_lock, client) {
> -		rc = pmbus_read_block_data(client, entry->page, entry->reg, data);
> +		rc = _pmbus_read_block_data(client, entry->page, entry->reg, data);
>   		if (rc < 0)
>   			return rc;
>   	}
>