Re: [PATCH v3] hwmon: corsair-psu: add reporting of rail mode via debugfs

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Aug 11, 2022 at 08:26:37AM +0000, Wilken Gottwalt wrote:
> Add reporting if the PSU is running in single or multi rail mode via
> ocpmode debugfs entry. Also update the documentation and driver comments
> accordingly.
> 
> Signed-off-by: Wilken Gottwalt <wilken.gottwalt@posteo.net>

Applied to hwmon-next.

Thanks,
Guenter

> ---
> Changes in v3:
>   - added more explanations in the driver
> 
> Changes in v2:
>   - fixed spelling issues in commit message
> ---
>  Documentation/hwmon/corsair-psu.rst |  5 +++--
>  drivers/hwmon/corsair-psu.c         | 29 ++++++++++++++++++++++++++++-
>  2 files changed, 31 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/hwmon/corsair-psu.rst b/Documentation/hwmon/corsair-psu.rst
> index e8378e7a1d8c..c3a76305c587 100644
> --- a/Documentation/hwmon/corsair-psu.rst
> +++ b/Documentation/hwmon/corsair-psu.rst
> @@ -86,8 +86,9 @@ Debugfs entries
>  ---------------
>  
>  =======================	========================================================
> -uptime			Current uptime of the psu
> +ocpmode                 Single or multi rail mode of the PCIe power connectors
> +product                 Product name of the psu
> +uptime			Session uptime of the psu
>  uptime_total		Total uptime of the psu
>  vendor			Vendor name of the psu
> -product			Product name of the psu
>  =======================	========================================================
> diff --git a/drivers/hwmon/corsair-psu.c b/drivers/hwmon/corsair-psu.c
> index 14389fd7afb8..c99e4c6afc2d 100644
> --- a/drivers/hwmon/corsair-psu.c
> +++ b/drivers/hwmon/corsair-psu.c
> @@ -55,6 +55,7 @@
>  #define SECONDS_PER_DAY		(SECONDS_PER_HOUR * 24)
>  #define RAIL_COUNT		3 /* 3v3 + 5v + 12v */
>  #define TEMP_COUNT		2
> +#define OCP_MULTI_RAIL		0x02
>  
>  #define PSU_CMD_SELECT_RAIL	0x00 /* expects length 2 */
>  #define PSU_CMD_RAIL_VOLTS_HCRIT 0x40 /* the rest of the commands expect length 3 */
> @@ -71,9 +72,10 @@
>  #define PSU_CMD_RAIL_WATTS	0x96
>  #define PSU_CMD_VEND_STR	0x99
>  #define PSU_CMD_PROD_STR	0x9A
> -#define PSU_CMD_TOTAL_WATTS	0xEE
>  #define PSU_CMD_TOTAL_UPTIME	0xD1
>  #define PSU_CMD_UPTIME		0xD2
> +#define PSU_CMD_OCPMODE		0xD8
> +#define PSU_CMD_TOTAL_WATTS	0xEE
>  #define PSU_CMD_INIT		0xFE
>  
>  #define L_IN_VOLTS		"v_in"
> @@ -268,6 +270,7 @@ static int corsairpsu_get_value(struct corsairpsu_data *priv, u8 cmd, u8 rail, l
>  		break;
>  	case PSU_CMD_TOTAL_UPTIME:
>  	case PSU_CMD_UPTIME:
> +	case PSU_CMD_OCPMODE:
>  		*val = tmp;
>  		break;
>  	default:
> @@ -660,6 +663,29 @@ static int product_show(struct seq_file *seqf, void *unused)
>  }
>  DEFINE_SHOW_ATTRIBUTE(product);
>  
> +static int ocpmode_show(struct seq_file *seqf, void *unused)
> +{
> +	struct corsairpsu_data *priv = seqf->private;
> +	long val;
> +	int ret;
> +
> +	/*
> +	 * The rail mode is switchable on the fly. The RAW interface can be used for this. But it
> +	 * will not be included here, because I consider it somewhat dangerous for the health of the
> +	 * PSU. The returned value can be a bogus one, if the PSU is in the process of switching and
> +	 * getting of the value itself can also fail during this. Because of this every other value
> +	 * than OCP_MULTI_RAIL can be considered as "single rail".
> +	 */
> +	ret = corsairpsu_get_value(priv, PSU_CMD_OCPMODE, 0, &val);
> +	if (ret < 0)
> +		seq_puts(seqf, "N/A\n");
> +	else
> +		seq_printf(seqf, "%s\n", (val == OCP_MULTI_RAIL) ? "multi rail" : "single rail");
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(ocpmode);
> +
>  static void corsairpsu_debugfs_init(struct corsairpsu_data *priv)
>  {
>  	char name[32];
> @@ -671,6 +697,7 @@ static void corsairpsu_debugfs_init(struct corsairpsu_data *priv)
>  	debugfs_create_file("uptime_total", 0444, priv->debugfs, priv, &uptime_total_fops);
>  	debugfs_create_file("vendor", 0444, priv->debugfs, priv, &vendor_fops);
>  	debugfs_create_file("product", 0444, priv->debugfs, priv, &product_fops);
> +	debugfs_create_file("ocpmode", 0444, priv->debugfs, priv, &ocpmode_fops);
>  }
>  
>  #else