Re: [RFC PATCH] SPI/ACPI: DesignWare: Add ACPI support for Designware SPI driver

[Jiang Qiu]

Hi Andy,

Sorry for late relpy because Chinese new year holiday. See my replies below.


Best Regards
Jiang

å 2016/2/5 23:55, Andy Shevchenko åé:
> On Fri, Feb 5, 2016 at 9:11 AM, qiujiang <qiujiang@xxxxxxxxxx> wrote:
> > This patch added ACPI support for DesignWare SPI mmio driver. It
> > was based the corresponding DT driver and compatible for this two
> > way. This patch has been tested on Hisilicon D02 board. It relies
> > on the GPIO patchset.
> My comments below.
As Mark mentioned, I want to ask you how to use this spi-dw-mmio driver for
ACPI binding? Dose it need any other extra patchset?
> > @@ -84,8 +87,6 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
> >          dws->num_cs = num_cs;
> >
> >          if (pdev->dev.of_node) {
> > -               int i;
> > -
> >                  for (i = 0; i < dws->num_cs; i++) {
> >                          int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
> >                                          "cs-gpios", i);
> It seems the driver was never validated with more than one chip select.
> Perhaps someone has to switch to use of_spi_register_master() here.
of_spi_register_master() will be executed in the spi_register_master(), 
but it just saved the
cs_gpios to the spi_master and not used it any more.
> > @@ -104,6 +105,18 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
> >                  }
> >          }
> >
> > +       if (ACPI_COMPANION(&pdev->dev)) {
> > +               for (i = 0; i < dws->num_cs; i++) {
> > +                       snprintf(propname, sizeof(propname), "cs%d", i);
> > +                       gpiod = devm_gpiod_get(&pdev->dev,
> > +                               propname, GPIOD_ASIS);
> > +                       if (IS_ERR(gpiod)) {
> > +                               dev_err(&pdev->dev, "Get gpio desc failed!\n");
> > +                               return PTR_ERR(gpiod);
> > +                       }
> > +               }
> > +       }
> Like Mark noticed there is also same issue. Do you indeed check the
> configuration with different chip select signals?
As a spi master driver, it seems that multi-chip select must be 
supported, so this check is
necessary, I think.
>