Re: [PATCH 10/12] spi: add support for spi_controller::set_cs_timing

[Marco Felsch <m.felsch@pengutronix.de>]

On 24-11-25, Sascha Hauer wrote:
> On Fri, Nov 15, 2024 at 08:57:45PM +0100, Marco Felsch wrote:
> > Import the spi_controller set_cs_timing() hook to make it easier to port
> > code from the Linux.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> >  include/spi/spi.h | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/include/spi/spi.h b/include/spi/spi.h
> > index 8354b7d8baa6..092eacd4a8e1 100644
> > --- a/include/spi/spi.h
> > +++ b/include/spi/spi.h
> > @@ -179,6 +179,9 @@ static inline void spi_set_ctldata(struct spi_device *spi, void *state)
> >   *	must fail if an unrecognized or unsupported mode is requested.
> >   *	It's always safe to call this unless transfers are pending on
> >   *	the device whose settings are being modified.
> > + * @set_cs_timing: optional hook for SPI devices to request SPI master
> > + * controller for configuring specific CS setup time, hold time and inactive
> > + * delay interms of clock counts
> >   * @transfer: adds a message to the controller's transfer queue.
> >   * @cleanup: frees controller-specific state
> >   * @cs_gpiods: Array of GPIO descriptors to use as chip select lines; one per CS
> > @@ -246,6 +249,16 @@ struct spi_controller {
> >  	/* setup mode and clock, etc (spi driver may call many times) */
> >  	int			(*setup)(struct spi_device *spi);
> >  
> > +	/*
> > +	 * set_cs_timing() method is for SPI controllers that supports
> > +	 * configuring CS timing.
> > +	 *
> > +	 * This hook allows SPI client drivers to request SPI controllers
> > +	 * to configure specific CS timing through spi_set_cs_timing() after
> > +	 * spi_setup().
> > +	 */
> > +	int (*set_cs_timing)(struct spi_device *spi);
> 
> You add this hook here, but it's not called from the core code changes
> in the next commit and it's not implemented in the new driver you
> introduce with this series. Is there something missing in this series?

It's checked by spi_set_cs(). I wanted to be as close as possible to the
Linux version but can drop this hook and adapt the check. Another option
is to add the Linux spi_set_cs_timing() to the barebox
spi_register_controller().

Regards,
  Marco


> 
> Sascha
> 
> 
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