Hi Alexandre,
Thanks for the feedback.
> Subject: Re: [PATCH v3 2/4] rtc: pcf85363: Add support for NXP pcf85263 rtc
>
> On 06/12/2018 15:49:57+0000, Biju Das wrote:
> > Hi Geert,
> >
> > Thanks for the feedback.
> >
> > > Subject: Re: [PATCH v3 2/4] rtc: pcf85363: Add support for NXP
> > > pcf85263 rtc
> > >
> > > Hi Biju,
> > >
> > > On Thu, Dec 6, 2018 at 4:24 PM Biju Das <biju.das@xxxxxxxxxxxxxx>
> wrote:
> > > > > Subject: Re: [PATCH v3 2/4] rtc: pcf85363: Add support for NXP
> > > > > pcf85263 rtc CC nvmem maintainer
> > > > >
> > > > > On Thu, Dec 6, 2018 at 10:04 AM Biju Das
> > > > > <biju.das@xxxxxxxxxxxxxx>
> > > wrote:
> > > > > > Add support for NXP pcf85263 real-time clock. pcf85263 rtc is
> > > > > > compatible with pcf85363,except that pcf85363 has additional
> > > > > > 64 bytes of
> > > > > RAM.
> > >
> > > > > > --- a/drivers/rtc/rtc-pcf85363.c
> > > > > > +++ b/drivers/rtc/rtc-pcf85363.c
> > > > > > @@ -120,6 +120,11 @@ struct pcf85363 {
> > > > > > struct regmap *regmap;
> > > > > > };
> > > > > >
> > > > > > +struct pcf85x63_config {
> > > > > > + struct regmap_config regmap;
> > > > > > + unsigned int num_nvram; };
> > > > > > +
> > > > > > static int pcf85363_rtc_read_time(struct device *dev, struct
> > > > > > rtc_time
> > > > > > *tm) {
> > > > > > struct pcf85363 *pcf85363 = dev_get_drvdata(dev); @@
> > > > > > -311,25
> > > > > > +316,68 @@ static int pcf85363_nvram_write(void *priv,
> > > > > > +unsigned int
> > > > > offset, void *val,
> > > > > > val, bytes); }
> > > > > >
> > > > > > -static const struct regmap_config regmap_config = {
> > > > > > - .reg_bits = 8,
> > > > > > - .val_bits = 8,
> > > > > > - .max_register = 0x7f,
> > > > > > +static int pcf85x63_nvram_read(void *priv, unsigned int
> > > > > > +offset, void
> > > *val,
> > > > > > + size_t bytes)
> > > > >
> > > > > Given bytes should be 1, val should be a pointer to a single byte...
> > > > > What if bytes == 0?
> > > >
> > > > I doubt we get "bytes==0" because of the checks in "
> > > drivers/nvmem/core.c"
> > > > Function " bin_attr_nvmem_read/ bin_attr_nvmem_write".
> > >
> > > Depends. There are other functions calling nvmem_reg_{read,write}(),
> e.g.
> > > nvmem_device_{read,write}().
> >
> > OK. In that case, I will return (-EINVAL) for "bytes !=1"
> >
>
> I think it is probably better to ensure the nvmem core never passes an invalid
> number of bytes. All the ther RTC drivers make that assumption.
In that case, I will do following checks in nvmem_device_{read,write}() before calling nvmem_reg_{read,write}(),
nvmem_device_read
/* Stop the user from reading */
if (offset >= nvmem->size)
return 0;
if (bytes == 0)
return -EINVAL;
if (offset + bytes > nvmem->size)
bytes = nvmem->size - offset;
nvmem_device_write
/* Stop the user from writing */
if (offset >= nvmem->size)
return -EFBIG;
if (bytes == 0)
return -EINVAL;
if (offset + bytes > nvmem->size)
bytes = nvmem->size - offset;
regards,
Biju
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