On Tue, 4 Apr 2023 09:23:36 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> On 04/04/2023 09:20, Herve Codina wrote:
> >> I suggest that none of this (besides the child registration, which is
> >> achieved by a simple OF API call in this case) has anything to do with
> >> MFD. We are not requesting and initialising shared resources and we are
> >> not using the MFD API to register children. The pin control
> >> functionality clearly needs moving to Pinctrl and the rest, if you
> >> cannot find a suitable home for it *may be* suitable for Misc.
> >>
> >
> > I am confused and I am not really sure to understand where to put my driver.
> >
> > The core pef2256.c needs to:
> > 1) setup the pef2256
> > 2) add the children
> >
> > To add the children it calls devm_of_platform_populate() to add the audio
> > parts as several audio children can be available with the same compatible
> > string.
> >
> > I plan to move the pinctrl part to the pinctrl subsystem. With this done,
> > the core pef2256.c will probably add the children using:
> > - a mfd_cell for the pinctrl part
> > - devm_of_platform_populate() for the audio children
> >
> > The setup (E1 lines and TDM configuration) still needs to be done by the
> > core pef2256.c. Moving this part only to Misc will break the hierarchy.
> > The audio children depends on the core pef2256.c as this one do the setup.
> > Having in the audio children and the part that do the setup in same hierarchy
> > level is not correct. Audio children should be children of the part that do
> > the setup.
> >
> > So, the structure I have in mind:
> > - pef2256.c (MFD)
> > implement and do the setup at probe()
> > Add the children at probe():
> > - pef2256-pinctrl (pinctrl) added using mfd_add_devices()
> > - pef2256-codec (ASoC codec) added using devm_of_platform_populate()
> >
> > Lee, with this in mind, can the core pef2256.c be a MFD driver ?
>
> You do not use MFD here, so why do you want to keep it in MFD? If you
> disagree, please tell me where is the MFD code in your patch?
I don't want to absolutely use MFD.
I just want to put my driver somewhere and I don't know the right location
between MFD and Misc.
Basically, the driver needs to do (little simplified and error path removed):
static const struct mfd_cell pef2256_devs[] = {
{ .name = "lantiq-pef2256-pinctrl", },
};
static int pef2256_probe(struct platform_device *pdev)
{
struct pef2256 *pef2256;
void __iomem *iomem;
int ret;
int irq;
pef2256 = devm_kzalloc(&pdev->dev, sizeof(*pef2256), GFP_KERNEL);
if (!pef2256)
return -ENOMEM;
pef2256->dev = &pdev->dev;
iomem = devm_platform_ioremap_resource(pdev, 0);
pef2256->regmap = devm_regmap_init_mmio(&pdev->dev, iomem,
&pef2256_regmap_config);
pef2256->mclk = devm_clk_get_enabled(&pdev->dev, "mclk");
pef2256->sclkr = devm_clk_get_enabled(&pdev->dev, "sclkr");
pef2256->sclkx = devm_clk_get_enabled(&pdev->dev, "sclkx");
pef2256->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
if (pef2256->reset_gpio) {
gpiod_set_value_cansleep(pef2256->reset_gpio, 1);
udelay(10);
gpiod_set_value_cansleep(pef2256->reset_gpio, 0);
udelay(10);
}
pef2556_of_parse(pef2256, np);
irq = platform_get_irq(pdev, 0);
ret = devm_request_irq(pef2256->dev, irq, pef2256_irq_handler, 0, "pef2256", pef2256);
platform_set_drvdata(pdev, pef2256);
mfd_add_devices(pef2256->dev, PLATFORM_DEVID_NONE, pef2256_devs,
ARRAY_SIZE(pef2256_devs), NULL, 0, NULL);
pef2256_setup(pef2256);
devm_of_platform_populate(pef2256->dev);
return 0;
}
>
> Best regards,
> Krzysztof
>
--
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
