On 9/9/20 6:24 AM, Andrew Jeffery wrote:
> Enable runtime debug control of whether the PEC byte is exchanged with
> the PMBus device.
>
> Some manufacturers have asked for the PEC to be disabled as part of
> debugging driver communication issues with devices.
>
> Signed-off-by: Andrew Jeffery <[email protected]>
> ---
> drivers/hwmon/pmbus/pmbus_core.c | 39 ++++++++++++++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c
> b/drivers/hwmon/pmbus/pmbus_core.c
> index 44535add3a4a..51c8502b35e9 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -2346,6 +2346,42 @@ static int pmbus_debugfs_get_status(void *data, u64
> *val)
> DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops_status, pmbus_debugfs_get_status,
> NULL, "0x%04llx\n");
>
> +static int pmbus_debugfs_get_pec(void *data, u64 *val)
> +{
> + struct i2c_client *client = data;
> +
> + *val = !!(client->flags & I2C_CLIENT_PEC);
> +
> + return 0;
> +}
> +
> +static int pmbus_debugfs_set_pec(void *data, u64 val)
> +{
> + int rc;
> + struct i2c_client *client = data;
> +
> + if (!val) {
> + client->flags &= ~I2C_CLIENT_PEC;
> + return 0;
> + }
> +
> + if (val != 1)
> + return -EINVAL;
> +
> + rc = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);
> + if (rc < 0)
> + return rc;
> +
> + if (!(rc & PB_CAPABILITY_ERROR_CHECK))
> + return -ENOTSUPP;
WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP
> +
> + client->flags |= I2C_CLIENT_PEC;
> +
> + return 0;
> +}
> +DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops_pec, pmbus_debugfs_get_pec,
> + pmbus_debugfs_set_pec, "0x%1llu\n");
ERROR: Prefixing 0x with decimal output is defective
(since the displayed value is a boolean, it is also quite useless).
> +
> static int pmbus_init_debugfs(struct i2c_client *client,
> struct pmbus_data *data)
> {
> @@ -2374,6 +2410,9 @@ static int pmbus_init_debugfs(struct i2c_client *client,
> if (!entries)
> return -ENOMEM;
>
> + debugfs_create_file("pec", 0664, data->debugfs, client,
> + &pmbus_debugfs_ops_pec);
> +
> for (i = 0; i < data->info->pages; ++i) {
> /* Check accessibility of status register if it's not page 0 */
> if (!i || pmbus_check_status_register(client, i)) {
>
