[U-Boot] [EXT] Re: [PATCH v2 1/3] dm: i2c: Add a flag that needs to generate a stop bit

[Simon Glass]

Hi Chuanhua,

On Sun, 23 Jun 2019 at 22:46, Chuanhua Han <chuanhua.han at nxp.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Simon Glass <sjg at chromium.org>
> > Sent: 2019年6月23日 3:10
> > To: Chuanhua Han <chuanhua.han at nxp.com>
> > Cc: Heiko Schocher <hs at denx.de>; U-Boot Mailing List <u-boot at lists.denx.de>;
> > Biwen Li <biwen.li at nxp.com>; Lukasz Majewski <lukma at denx.de>
> > Subject: [EXT] Re: [PATCH v2 1/3] dm: i2c: Add a flag that needs to generate a
> > stop bit
> >
> > Caution: EXT Email
> >
> > Hi,
> >
> > On Fri, 24 May 2019 at 03:23, Chuanhua Han <chuanhua.han at nxp.com> wrote:
> > >
> > > Usually the i2c bus needs to write the address of the register before
> > > reading the internal register data of the device (ignoring the
> > > transmission of the slave address).
> > >
> > > Generally, the stop signal is not needed before the register is read,
> > > but there is a special chip that needs this stop signal (such as
> > > pcf2127), this patch adds a flag that needs to generate a stop bit to
> > > determine whether the i2c host needs to generate a stop signal before
> > > reading the register data.
> >
> > Does this mean that the chip does not comply with the i2c protocol?
> >
> > Is it possible instead to so a write and then a read?
> >
> > See dm_i2c_xfer().
> Please see the fourth version of the patch, use the dm_i2c_xfer () function to do and I use a flag to limit the dm_i2c_read function
> It is the same to transmit only one msg. Since the core layer already provides the dm_i2c_read function, it is appropriate to use this function.
> Only condition flag is required to limit

I cannot find that patch. On another thread you pointed me to a v4
patch but when I looked it was not v4.

Can you please link to the v4 patch in patchwork?

I found a v2 that I will reply to in any case.

Regards,
Simon