gpio: pxa: handle corner case of unprobed device

In the corner case where the gpio driver probe fails, for whatever
reason, the suspend and resume handlers will still be called as they
have to be registered as syscore operations. This applies as well when
no probe was called while the driver has been built in the kernel.

Nicolas tracked this in :
https://bugzilla.kernel.org/show_bug.cgi?id=200905

Therefore, add a failsafe in these function, and test if a proper probe
succeeded and the driver is functional.
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Reported-by: NNicolas Chauvet <kwizart@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-pxa.c

@@ -776,6 +776,9 @@ static int pxa_gpio_suspend(void)
 	struct pxa_gpio_bank *c;
 	int gpio;
 
+	if (!pchip)
+		return 0;
+
 	for_each_gpio_bank(gpio, c, pchip) {
 		c->saved_gplr = readl_relaxed(c->regbase + GPLR_OFFSET);
 		c->saved_gpdr = readl_relaxed(c->regbase + GPDR_OFFSET);
@@ -794,6 +797,9 @@ static void pxa_gpio_resume(void)
 	struct pxa_gpio_bank *c;
 	int gpio;
 
+	if (!pchip)
+		return;
+
 	for_each_gpio_bank(gpio, c, pchip) {
 		/* restore level with set/clear */
 		writel_relaxed(c->saved_gplr, c->regbase + GPSR_OFFSET);