Re: [PATCH] hwmon: (pmbus/acbel-fsg032) Add firmware version debugfs attribute

[Eddie James]

On 6/27/23 17:19, Guenter Roeck wrote:
> On 6/27/23 11:40, Eddie James wrote:
> > Like the IBM CFFPS driver, export the PSU's firmware version to a
> > debugfs attribute as reported in the manufacturer register.
> >
> > Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx>
> > ---
> >   drivers/hwmon/pmbus/acbel-fsg032.c | 48 ++++++++++++++++++++++++++++++
> >   1 file changed, 48 insertions(+)
> >
> > diff --git a/drivers/hwmon/pmbus/acbel-fsg032.c 
> > b/drivers/hwmon/pmbus/acbel-fsg032.c
> > index 0a0ef4ce3493..4b97f108cfe3 100644
> > --- a/drivers/hwmon/pmbus/acbel-fsg032.c
> > +++ b/drivers/hwmon/pmbus/acbel-fsg032.c
> > @@ -3,6 +3,7 @@
> >    * Copyright 2023 IBM Corp.
> >    */
> >   +#include <linux/debugfs.h>
> >   #include <linux/device.h>
> >   #include <linux/fs.h>
> >   #include <linux/i2c.h>
> > @@ -11,6 +12,52 @@
> >   #include <linux/hwmon-sysfs.h>
> >   #include "pmbus.h"
> >   +#define ACBEL_MFR_FW_REVISION    0xd9
> > +
> > +static ssize_t acbel_fsg032_debugfs_read(struct file *file, char 
> > __user *buf, size_t count,
> > +                     loff_t *ppos)
> > +{
> > +    struct i2c_client *client = file->private_data;
> > +    char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
> > +    char out[8];
> > +    int rc;
> > +    int i;
> > +
> > +    rc = pmbus_lock_interruptible(client);
>
> Is that needed here ?


Good point, it's not.


> > +    if (rc)
> > +        return rc;
> > +
> > +    rc = i2c_smbus_read_block_data(client, ACBEL_MFR_FW_REVISION, 
> > data);
> > +    pmbus_unlock(client);
> > +    if (rc < 0)
> > +        return rc;
> > +
> > +    for (i = 0; i < rc && i < 3; ++i)
> > +        snprintf(&out[i * 2], 3, "%02X", data[i]);
> > +
> > +    rc = i * 2;
> > +    out[rc++] = '\n';
> > +    out[rc++] = 0;
>
> Any reason for not using one of the %*ph variants ?


Nope, that will work great, thanks.

Eddie


> Thanks,
> Guenter
>
> > +    return simple_read_from_buffer(buf, count, ppos, out, rc);
> > +}
> > +
> > +static const struct file_operations acbel_debugfs_ops = {
> > +    .llseek = noop_llseek,
> > +    .read = acbel_fsg032_debugfs_read,
> > +    .write = NULL,
> > +    .open = simple_open,
> > +};
> > +
> > +static void acbel_fsg032_init_debugfs(struct i2c_client *client)
> > +{
> > +    struct dentry *debugfs = pmbus_get_debugfs_dir(client);
> > +
> > +    if (!debugfs)
> > +        return;
> > +
> > +    debugfs_create_file("fw_version", 0444, debugfs, client, 
> > &acbel_debugfs_ops);
> > +}
> > +
> >   static const struct i2c_device_id acbel_fsg032_id[] = {
> >       { "acbel_fsg032" },
> >       {}
> > @@ -59,6 +106,7 @@ static int acbel_fsg032_probe(struct i2c_client 
> > *client)
> >       if (rc)
> >           return rc;
> >   +    acbel_fsg032_init_debugfs(client);
> >       return 0;
> >   }