lkml.org 
[lkml]   [2018]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v2 2/2] eeprom: at24: Add support for address-width property
Date
Hi Sakari,

> -----Original Message-----
> From: Sakari Ailus [mailto:sakari.ailus@linux.intel.com]
> Sent: Tuesday, June 26, 2018 2:48 PM
> To: Chiang, AlanX <alanx.chiang@intel.com>
> Cc: linux-i2c@vger.kernel.org; Yeh, Andy <andy.yeh@intel.com>;
> Shevchenko, Andriy <andriy.shevchenko@intel.com>; Mani, Rajmohan
> <rajmohan.mani@intel.com>; andy.shevchenko@gmail.com; brgl@bgdev.pl;
> robh+dt@kernel.org; mark.rutland@arm.com; arnd@arndb.de;
> gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org
> 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, alanx.chiang@intel.com wrote:
> > From: "alanx.chiang" <alanx.chiang@intel.com>
> >
> > 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 <alanx.chiang@intel.com>
> > Signed-off-by: Andy Yeh <andy.yeh@intel.com>
> >
> > ---
> > 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
> sakari.ailus@linux.intel.com

\
 
 \ /
  Last update: 2018-06-26 09:12    [W:0.072 / U:0.652 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site