linux-kernel - [PATCH v2 1/2] pinctrl: bcm: bcm2835: Switch to use ->add_pin

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Date:   Fri, 13 Jan 2023 19:10:50 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-rpi-kernel@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org
Cc:     Bartosz Golaszewski <brgl@...ev.pl>,
        Florian Fainelli <f.fainelli@...il.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@...adcom.com>,
        Ray Jui <rjui@...adcom.com>,
        Scott Branden <sbranden@...adcom.com>,
        Stefan Wahren <stefan.wahren@...e.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v2 1/2] pinctrl: bcm: bcm2835: Switch to use ->add_pin_ranges()

Yeah, while the ->add_pin_ranges() shouldn't be used by DT drivers,
this one requires it to support quite old firmware descriptions that
do not have gpio-ranges property.

The change allows to clean up GPIO library from OF specifics.
There is no functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
v2: fixed compilation issues (LKP), Cc'ed to the author of original code

Btw, the commit d2b67744fd99 ("pinctrl: bcm2835: implement hook for
missing gpio-ranges") seems problematic in the fist place due to
odd of_node_put() call. I dunno how that part had been tested, or
how it's supposed to work, i.e. where is the counterpart of_node_get().
Anyway this change drops it for good.

Perhaps we can check gpio-ranges property presence inside the GPIO
library, so this ->add_pin_ranges() won't be called at all.

Also I would like to understand the dance around checking for pin
control device. The original commit lacks of comments in the non-trivial
code.

 drivers/pinctrl/bcm/pinctrl-bcm2835.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
index 7857e612a100..29f278c49103 100644
--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
@@ -358,16 +358,17 @@ static int bcm2835_gpio_direction_output(struct gpio_chip *chip,
 	return 0;
 }
 
-static int bcm2835_of_gpio_ranges_fallback(struct gpio_chip *gc,
-					   struct device_node *np)
+static int bcm2835_add_pin_ranges_fallback(struct gpio_chip *gc)
 {
+	struct device_node *np = dev_of_node(gc->parent);
 	struct pinctrl_dev *pctldev = of_pinctrl_get(np);
 
-	of_node_put(np);
-
 	if (!pctldev)
 		return 0;
 
+	if (of_property_read_bool(np, "gpio-ranges"))
+		return 0;
+
 	gpiochip_add_pin_range(gc, pinctrl_dev_get_devname(pctldev), 0, 0,
 			       gc->ngpio);
 
@@ -388,7 +389,7 @@ static const struct gpio_chip bcm2835_gpio_chip = {
 	.base = -1,
 	.ngpio = BCM2835_NUM_GPIOS,
 	.can_sleep = false,
-	.of_gpio_ranges_fallback = bcm2835_of_gpio_ranges_fallback,
+	.add_pin_ranges = bcm2835_add_pin_ranges_fallback,
 };
 
 static const struct gpio_chip bcm2711_gpio_chip = {
@@ -405,7 +406,7 @@ static const struct gpio_chip bcm2711_gpio_chip = {
 	.base = -1,
 	.ngpio = BCM2711_NUM_GPIOS,
 	.can_sleep = false,
-	.of_gpio_ranges_fallback = bcm2835_of_gpio_ranges_fallback,
+	.add_pin_ranges = bcm2835_add_pin_ranges_fallback,
 };
 
 static void bcm2835_gpio_irq_handle_bank(struct bcm2835_pinctrl *pc,
-- 
2.39.0