On Fri, Aug 23, 2024 at 06:23:54AM +0000, Ryan Chen wrote:
> > On Thu, Aug 22, 2024 at 02:24:26AM +0000, Ryan Chen wrote:
> > > > On Wed, Aug 21, 2024 at 06:43:01AM +0000, Ryan Chen wrote:
> > > > > > On Mon, Aug 19, 2024 at 05:28:49PM +0800, Ryan Chen wrote:
...
> > > > > > > + if (i2c_bus->mode == BUFF_MODE) {
> > > > > > > + i2c_bus->buf_base =
> > > > > > devm_platform_get_and_ioremap_resource(pdev, 1, &res);
> > > > > > > + if (!IS_ERR_OR_NULL(i2c_bus->buf_base))
> > > > > > > + i2c_bus->buf_size = resource_size(res) / 2;
> > > > > > > + else
> > > > > > > + i2c_bus->mode = BYTE_MODE;
> > > > > >
> > > > > > What's wrong with positive conditional? And is it even possible
> > > > > > to have NULL here?
> > > > > >
> > > > > Yes, if dtsi fill not following yaml example have reg 1, that will
> > > > > failure at buffer
> > > > mode.
> > > > > And I can swith to byte mode.
> > > > >
> > > > > reg = <0x80 0x80>, <0xc00 0x20>;
> > > >
> > > > I was asking about if (!IS_ERR_OR_NULL(...)) line:
> > > > 1) Why 'if (!foo) {} else {}' instead of 'if (foo) {} else {}'?
> > > I will update to following.
> > > if (IS_ERR(i2c_bus->buf_base))
> > > i2c_bus->mode = BYTE_MODE;
> > > else
> > > i2c_bus->buf_size = resource_size(res) / 2;
> > >
> > > > 2) Why _NULL?
> > > If dtsi file is claim only 1 reg offset. reg = <0x80 0x80>; that will goto byte
> > mode.
> > > reg = <0x80 0x80>, <0xc00 0x20>; can support buffer mode.
> > > due to 2nd is buffer register offset.
> >
> > I have asked why IS_ERR_OR_NULL() and not IS_ERR().
> >
> OH, I will doing by this.
> if (IS_ERR_OR_NULL(i2c_bus->buf_base))
The question about _NULL remains unanswered...
> i2c_bus->mode = BYTE_MODE;
> else
> i2c_bus->buf_size = resource_size(res) / 2;
--
With Best Regards,
Andy Shevchenko
