Hi Sakari,
> -----Original Message-----
> From: Sakari Ailus [mailto:[email protected]]
> Sent: Tuesday, June 26, 2018 2:48 PM
> To: Chiang, AlanX <[email protected]>
> Cc: [email protected]; Yeh, Andy <[email protected]>;
> Shevchenko, Andriy <[email protected]>; Mani, Rajmohan
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: Re: [PATCH v2 2/2] eeprom: at24: Add support for address-width
> property
>
> Hi Alan,
>
> On Tue, Jun 26, 2018 at 02:22:08PM +0800, [email protected] wrote:
> > From: "alanx.chiang" <[email protected]>
> >
> > Provide a flexible way to determine the addressing bits of eeprom.
> > Pass the addressing bits to driver through address-width property.
> >
> > Signed-off-by: Alan Chiang <[email protected]>
> > Signed-off-by: Andy Yeh <[email protected]>
> >
> > ---
> > since v1
> > -- Add a warn message for 8-bit addressing.
> >
> > ---
> > drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> > index 0c125f2..231afcd 100644
> > --- a/drivers/misc/eeprom/at24.c
> > +++ b/drivers/misc/eeprom/at24.c
> > @@ -478,6 +478,22 @@ static void at24_properties_to_pdata(struct device
> *dev,
> > if (device_property_present(dev, "no-read-rollover"))
> > chip->flags |= AT24_FLAG_NO_RDROL;
> >
> > + err = device_property_read_u32(dev, "address-width", &val);
> > + if (!err) {
> > + switch (val) {
> > + case 8:
> > + chip->flags &= ~AT24_FLAG_ADDR16;
> > + dev_warn(dev, "address-width is 8, clear the ADD16
> bit\n");
>
> Even though the default is 8 address bits, I don't see a need to issue a
> warning if the address-width property sets that to 8 explicitly. I.e. only
> warn
> if the flag was set.
>
Do you mean I have to add a statement for checking if the bit has been set
before?
For example:
If (chip->flags & AT24_FLAG_ADDR16)
dev_warn(dev, "address-width is 8, clear the ADD16 bit\n");
If it is, I would like to modify it as below:
case 8:
If (chip->flags & AT24_FLAG_ADDR16) {
chip->flags &= ~AT24_FLAG_ADDR16;
dev_warn(dev, "address-width is 8, clear the ADDR16 bit\n");
}
break;
> > + break;
> > + case 16:
> > + chip->flags |= AT24_FLAG_ADDR16;
> > + break;
> > + default:
> > + dev_warn(dev, "Bad \"address-width\" property:
> %u\n",
> > + val);
> > + }
> > + }
> > +
> > err = device_property_read_u32(dev, "size", &val);
> > if (!err)
> > chip->byte_len = val;
>
> --
> Regards,
>
> Sakari Ailus
> [email protected]
