Re: Re: [PATCH 2/2] gpio: rockchip: get pinctrl node from 'gpio-ranges' property

From: "jay.xu@rock-chips.com" <jay.xu@rock-chips.com>
To: "Heiko Stübner" <heiko@sntech.de>
Cc: linus.walleij <linus.walleij@linaro.org>,
	 "open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	 linux-gpio <linux-gpio@vger.kernel.org>
Subject: Re: Re: [PATCH 2/2] gpio: rockchip: get pinctrl node from 'gpio-ranges' property
Date: Mon, 7 Mar 2022 16:08:09 +0800	[thread overview]
Message-ID: <2022030716080935094010@rock-chips.com> (raw)
In-Reply-To: 2004737.KQk8vJUODO@diego

--------------
jay.xu@rock-chips.com
>Hi Jianqun,
>
>Am Donnerstag, 3. März 2022, 07:22:11 CET schrieb Jianqun Xu:
>> The dt nodes for rockchip soc designes as
>>
>> pinctrl: pinctrl {
>> gpio {
>> gpio-ranges = <&pinctrl xxx>;
>> };
>> };
>>
>> Currently, we get the pinctrl dt node from parent of gpio, this patch
>> try to get pinctrl dt node from 'gpio-ranges' property.
>>
>> After this patch, the dt nodes possible to be
>>
>> gpio {
>> gpio-ranges = <&pinctrl xxx>;
>> };
>>
>> pinctrl: pinctrl {
>>
>> };
>>
>> then the gpio driver could register as platform device itself, but not
>> populate from pinctrl driver.
>
>The change looks interesting, as it would solve that long-standing
>design-issue I "created" back in 2013 ;-) .
>
>Though you need to keep some things in mind:
>
>(1) Such a change should be reflected in the devicetree binding
>    as it involves a different form of nodes and introduces.
>
>    Looking at the binding description, using gpio-ranges to map
>    to specific pinctrl pins really seems to be a valid use for this.
>
>
>(2) Keep things backwards compatible.
>    Old devicetrees should stay working with new kernel versions
>
>    A common pattern is to try the new approach and if that fails
>    try the "deprecated" method, which should be nicely doable
>    when looking at the code change below.
> 
Hi heiko

could i get pinctrl device from name ? like this:

pctldev = get_pinctrl_dev_from_devname(ROCKCHIP_PINCTRL_DEV_NAME);

the ROCKCHIP_PINCTRL_DEV_NAME is a const string from pinctrl head file.

>
>Heiko
>
>> Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
>> ---
>>  drivers/gpio/gpio-rockchip.c | 10 +++++++---
>>  1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
>> index 1da0324445cc..46c54dff92db 100644
>> --- a/drivers/gpio/gpio-rockchip.c
>> +++ b/drivers/gpio/gpio-rockchip.c
>> @@ -690,6 +690,9 @@ rockchip_gpio_find_bank(struct pinctrl_dev *pctldev, int id)
>>  int i, found = 0;
>> 
>>  info = pinctrl_dev_get_drvdata(pctldev);
>> +	if (!info)
>> +	return NULL;
>> +
>>  bank = info->ctrl->pin_banks;
>>  for (i = 0; i < info->ctrl->nr_banks; i++, bank++) {
>>  if (bank->bank_num == id) {
>> @@ -705,15 +708,16 @@ static int rockchip_gpio_probe(struct platform_device *pdev)
>>  {
>>  struct device *dev = &pdev->dev;
>>  struct device_node *np = dev->of_node;
>> -	struct device_node *pctlnp = of_get_parent(np);
>> +	struct device_node *pctlnp = NULL;
>>  struct pinctrl_dev *pctldev = NULL;
>>  struct rockchip_pin_bank *bank = NULL;
>>  struct rockchip_pin_output_deferred *cfg;
>>  static int gpio;
>>  int id, ret;
>> 
>> -	if (!np || !pctlnp)
>> -	return -ENODEV;
>> +	pctlnp = of_parse_phandle(np, "gpio-ranges", 0);
>> +	if (!pctlnp)
>> +	pctlnp = of_get_parent(np);
>> 
>>  pctldev = of_pinctrl_get(pctlnp);
>>  if (!pctldev)
>>
>
>
>
>
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