Re: [PATCH v5 6/7] hwmon: pmbus: adm1266: debugfs for blackbox info

From: Guenter Roeck
Date: Wed Jun 24 2020 - 17:53:22 EST


On Wed, Jun 24, 2020 at 06:17:35PM +0300, alexandru.tachici@xxxxxxxxxx wrote:
> From: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
>
> Add a debugfs file to print information in the
> BLACKBOX_INFORMATION register. Contains information
> about the number of stored records, logic index and id
> of the latest record.

How is this different to the nvram method implemented in toe previous patch ?
Why do we need both ?

>
> Signed-off-by: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
> ---
> drivers/hwmon/pmbus/adm1266.c | 56 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 55 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
> index b9e92ab1e39a..ea2dc481094b 100644
> --- a/drivers/hwmon/pmbus/adm1266.c
> +++ b/drivers/hwmon/pmbus/adm1266.c
> @@ -60,6 +60,7 @@ struct adm1266_data {
> const char *gpio_names[ADM1266_GPIO_NR + ADM1266_PDIO_NR];
> struct i2c_client *client;
> struct mutex ioctl_mutex; /* lock ioctl access */
> + struct dentry *debugfs_dir;
> struct nvmem_config nvmem_config;
> struct nvmem_device *nvmem;
> u8 *dev_mem;
> @@ -406,6 +407,28 @@ static const struct proc_ops adm1266_proc_ops = {
> .proc_ioctl = adm1266_ioctl,
> };
>
> +static int adm1266_blackbox_information_read(struct seq_file *s, void *pdata)
> +{
> + struct device *dev = s->private;
> + struct i2c_client *client = to_i2c_client(dev);
> + u8 read_buf[5];
> + unsigned int latest_id;
> + int ret;
> +
> + ret = i2c_smbus_read_block_data(client, ADM1266_BLACKBOX_INFO,
> + read_buf);
> + if (ret < 0)
> + return ret;
> +
> + seq_puts(s, "BLACKBOX_INFORMATION:\n");
> + latest_id = read_buf[0] + (read_buf[1] << 8);
> + seq_printf(s, "Black box ID: %u\n", latest_id);
> + seq_printf(s, "Logic index: %u\n", read_buf[2]);
> + seq_printf(s, "Record count: %u\n", read_buf[3]);
> +
> + return 0;
> +}
> +
> static int adm1266_init_procfs(struct adm1266_data *data)
> {
> struct proc_dir_entry *proc_dir;
> @@ -423,6 +446,29 @@ static int adm1266_init_procfs(struct adm1266_data *data)
> return 0;
> }
>
> +static int adm1266_init_debugfs(struct adm1266_data *data)
> +{
> + struct dentry *entry;
> + struct dentry *root;
> +
> + root = pmbus_get_debugfs_dir(data->client);
> + if (!root)
> + return -ENOENT;
> +
> + data->debugfs_dir = debugfs_create_dir(data->client->name, root);
> + if (!data->debugfs_dir)
> + return -ENOENT;
> +
> + entry = debugfs_create_devm_seqfile(&data->client->dev,
> + "blackbox_information",
> + data->debugfs_dir,
> + adm1266_blackbox_information_read);
> + if (!entry)
> + return -ENOENT;
> +
> + return 0;
> +}
> +
> static int adm1266_nvmem_read_blackbox(struct adm1266_data *data, u8 *buf)
> {
> u8 read_buf[5];
> @@ -571,7 +617,15 @@ static int adm1266_probe(struct i2c_client *client,
> for (i = 0; i < info->pages; i++)
> info->func[i] = funcs;
>
> - return pmbus_do_probe(client, id, info);
> + ret = pmbus_do_probe(client, id, info);
> + if (ret)
> + return ret;
> +
> + ret = adm1266_init_debugfs(data);
> + if (ret)
> + dev_warn(&client->dev, "Failed to register debugfs: %d\n", ret);

debugfs functions are supposed to fail silently.

> +
> + return 0;
> }
>
> static const struct of_device_id adm1266_of_match[] = {