Re: [PATCH v1 2/9] misc: Support Asus Transformer's EC access device

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Feb 03, 2026 at 06:28:11PM +0200, Svyatoslav Ryhel wrote:
> вт, 3 лют. 2026 р. о 14:00 Greg Kroah-Hartman <gregkh@linuxfoundation.org> пише:
> >
> > On Tue, Feb 03, 2026 at 01:54:58PM +0200, Svyatoslav Ryhel wrote:
> > > вт, 3 лют. 2026 р. о 13:41 Greg Kroah-Hartman <gregkh@linuxfoundation.org> пише:
> > > >
> > > > On Sun, Feb 01, 2026 at 12:43:36PM +0200, Svyatoslav Ryhel wrote:
> > > > > --- /dev/null
> > > > > +++ b/drivers/misc/asus-dockram.c
> > > > > @@ -0,0 +1,327 @@
> > > > > +// SPDX-License-Identifier: GPL-2.0-or-later
> > > > > +/*
> > > > > + * ASUS EC: DockRAM
> > > > > + */
> > > > > +
> > > > > +#include <linux/device.h>
> > > > > +#include <linux/err.h>
> > > > > +#include <linux/i2c.h>
> > > > > +#include <linux/mfd/asus-ec.h>
> > > > > +#include <linux/mod_devicetable.h>
> > > > > +#include <linux/module.h>
> > > > > +#include <linux/mutex.h>
> > > > > +#include <linux/slab.h>
> > > > > +#include <linux/string.h>
> > > > > +#include <linux/sysfs.h>
> > > > > +#include <linux/types.h>
> > > > > +#include <linux/unaligned.h>
> > > > > +
> > > > > +struct dockram_ec_data {
> > > > > +     struct mutex ctl_lock; /* prevent simultaneous access */
> > > > > +     char ctl_data[DOCKRAM_ENTRY_BUFSIZE];
> > > > > +};
> > > > > +
> > > > > +int asus_dockram_read(struct i2c_client *client, int reg, char *buf)
> > > > > +{
> > > > > +     int rc;
> > > > > +
> > > > > +     memset(buf, 0, DOCKRAM_ENTRY_BUFSIZE);
> > > > > +     rc = i2c_smbus_read_i2c_block_data(client, reg, DOCKRAM_ENTRY_BUFSIZE, buf);
> > > > > +     if (rc < 0)
> > > > > +             return rc;
> > > > > +
> > > > > +     if (buf[0] > DOCKRAM_ENTRY_SIZE) {
> > > > > +             dev_err(&client->dev, "bad data len; buffer: %*ph; rc: %d\n",
> > > > > +                     DOCKRAM_ENTRY_BUFSIZE, buf, rc);
> > > > > +             return -EPROTO;
> > > > > +     }
> > > > > +
> > > > > +     dev_dbg(&client->dev, "got data; buffer: %*ph; rc: %d\n",
> > > > > +             DOCKRAM_ENTRY_BUFSIZE, buf, rc);
> > > > > +
> > > > > +     return 0;
> > > > > +}
> > > > > +EXPORT_SYMBOL_GPL(asus_dockram_read);
> > > >
> > > > No documentation for these new public symbols?
> > > >
> > >
> > > These functions are mainly used in communication between the dockram
> > > device, asus-ec and its subdevices. Export is used here because all
> > > mentioned devices can be built as modules. I can add descriptions of
> > > functions into header if needed, but they should never be used outside
> > > of dockram-EC complex. Same applies to 2 export functions in the EC
> > > MFD.
> >
> > Then you should properly document this :)
> >
> > > > > +static BIN_ATTR_RW(dockram, DOCKRAM_ENTRIES * DOCKRAM_ENTRY_SIZE);
> > > > > +static DEVICE_ATTR_RW(control_reg);
> > > >
> > > > You did not document your new sysfs files in Documentation/ABI/ which is
> > > > required.
> > > >
> > > > Also, why do you need a brand new user/kernel api at all?  Who is going
> > > > to use this and for what?
> > > >
> > >
> > > These api were used mainly for debugging/logging purposes and descend
> > > from original downstream EC driver. I can both add documentation into
> > > ABI or remove them if that is absolutely necessary.
> >
> > Debugging should not be in sysfs, please put this type of stuff into
> > debugfs instead if you really need it.
> >
> 
> There is no similar way to handle BIN_ATTR_RW in the debugfs (), may I
> preserve  dockram_read/write with __maybe_unused instead of removing
> them? I will add comment with explanation

debugfs allows you to do much much more than simple stuff like
BIN_ATTR_RW().  Go wild there, but don't put debugging stuff in sysfs,
that is NOT what it is there for at all, but rather, that is exactly
what debugfs is for.

thanks,

greg k-h