[PATCH] gpio: mpc8xxx: Add platform device to gpiochip->parent

From: "Johnson CH Chen (陳昭勳)" <JohnsonCH.Chen@moxa.com>
To: Linus Walleij <linus.walleij@linaro.org>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "zero19850401@gmail.com" <zero19850401@gmail.com>
Subject: [PATCH] gpio: mpc8xxx: Add platform device to gpiochip->parent
Date: Tue, 26 Nov 2019 06:51:11 +0000	[thread overview]
Message-ID: <HK0PR01MB3521489269F76467DFD7843FFA450@HK0PR01MB3521.apcprd01.prod.exchangelabs.com> (raw)

Dear Linus Walleij,

In old kernels, some APIs still try to use parent->of_node from struct gpio_chip,
and it could be resulted in kernel panic because parent is NULL. Adding platform
device to gpiochip->parent can fix this problem.

Signed-off-by: Johnson Chen <johnsonch.chen@moxa.com>
Link: https://patchwork.kernel.org/patch/11234609

---
 drivers/gpio/gpio-mpc8xxx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
index 16a47de29c94..161e3ff4106a 100644
--- a/drivers/gpio/gpio-mpc8xxx.c
+++ b/drivers/gpio/gpio-mpc8xxx.c
@@ -346,6 +346,7 @@ static int mpc8xxx_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	gc = &mpc8xxx_gc->gc;
+	gc->parent = &pdev->dev;
 
 	if (of_property_read_bool(np, "little-endian")) {
 		ret = bgpio_init(gc, &pdev->dev, 4,
-- 
2.11.0

Best regards,
Johnson

Moxa Inc.
Fl. 4, No. 135, Lane 235, Baoqiao Rd.
Xindian Dist., New Taipei City, Taiwan, R.O.C.
Tel : +886-2-8919-1230 ext.1075
JohnsonCH.Chen@moxa.com 
