[PATCH v2 1/2] pinctrl: bcm2835: Change init order for gpio hogs

From: Phil Elwell <phil@raspberrypi.com>
To: Rob Herring <robh+dt@kernel.org>,
	Nicolas Saenz Julienne <nsaenz@kernel.org>,
	Florian Fainelli <f.fainelli@gmail.com>,
	bcm-kernel-feedback-list@broadcom.com,
	Linus Walleij <linus.walleij@linaro.org>,
	Phil Elwell <phil@raspberrypi.com>,
	Thierry Reding <treding@nvidia.com>,
	devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
	linux-gpio@vger.kernel.org
Subject: [PATCH v2 1/2] pinctrl: bcm2835: Change init order for gpio hogs
Date: Mon,  6 Dec 2021 09:22:36 +0000	[thread overview]
Message-ID: <20211206092237.4105895-2-phil@raspberrypi.com> (raw)
In-Reply-To: <20211206092237.4105895-1-phil@raspberrypi.com>

...and gpio-ranges

pinctrl-bcm2835 is a combined pinctrl/gpio driver. Currently the gpio
side is registered first, but this breaks gpio hogs (which are
configured during gpiochip_add_data). Part of the hog initialisation
is a call to pinctrl_gpio_request, and since the pinctrl driver hasn't
yet been registered this results in an -EPROBE_DEFER from which it can
never recover.

Change the initialisation sequence to register the pinctrl driver
first.

This also solves a similar problem with the gpio-ranges property, which
is required in order for released pins to be returned to inputs.

Fixes: 73345a18d464b ("pinctrl: bcm2835: Pass irqchip when adding gpiochip")
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
 drivers/pinctrl/bcm/pinctrl-bcm2835.c | 29 +++++++++++++++------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
index 2abcc6ce4eba3..b607d10e4cbd8 100644
--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
@@ -1244,6 +1244,18 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
 		raw_spin_lock_init(&pc->irq_lock[i]);
 	}
 
+	pc->pctl_desc = *pdata->pctl_desc;
+	pc->pctl_dev = devm_pinctrl_register(dev, &pc->pctl_desc, pc);
+	if (IS_ERR(pc->pctl_dev)) {
+		gpiochip_remove(&pc->gpio_chip);
+		return PTR_ERR(pc->pctl_dev);
+	}
+
+	pc->gpio_range = *pdata->gpio_range;
+	pc->gpio_range.base = pc->gpio_chip.base;
+	pc->gpio_range.gc = &pc->gpio_chip;
+	pinctrl_add_gpio_range(pc->pctl_dev, &pc->gpio_range);
+
 	girq = &pc->gpio_chip.irq;
 	girq->chip = &bcm2835_gpio_irq_chip;
 	girq->parent_handler = bcm2835_gpio_irq_handler;
@@ -1251,8 +1263,10 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
 	girq->parents = devm_kcalloc(dev, BCM2835_NUM_IRQS,
 				     sizeof(*girq->parents),
 				     GFP_KERNEL);
-	if (!girq->parents)
+	if (!girq->parents) {
+		pinctrl_remove_gpio_range(pc->pctl_dev, &pc->gpio_range);
 		return -ENOMEM;
+	}
 
 	if (is_7211) {
 		pc->wake_irq = devm_kcalloc(dev, BCM2835_NUM_IRQS,
@@ -1307,21 +1321,10 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
 	err = gpiochip_add_data(&pc->gpio_chip, pc);
 	if (err) {
 		dev_err(dev, "could not add GPIO chip\n");
+		pinctrl_remove_gpio_range(pc->pctl_dev, &pc->gpio_range);
 		return err;
 	}
 
-	pc->pctl_desc = *pdata->pctl_desc;
-	pc->pctl_dev = devm_pinctrl_register(dev, &pc->pctl_desc, pc);
-	if (IS_ERR(pc->pctl_dev)) {
-		gpiochip_remove(&pc->gpio_chip);
-		return PTR_ERR(pc->pctl_dev);
-	}
-
-	pc->gpio_range = *pdata->gpio_range;
-	pc->gpio_range.base = pc->gpio_chip.base;
-	pc->gpio_range.gc = &pc->gpio_chip;
-	pinctrl_add_gpio_range(pc->pctl_dev, &pc->gpio_range);
-
 	return 0;
 }
 
-- 
2.25.1

