pinctrl: imx8mq: Add suspend/resume ops

To support pinctl hog restore after LPSR resume back,
add the generic suspend/resume in pinctrl-imx along with the
generic pm ops to be used by platform specific drivers. Then
make use of the newly added ops in i.MX8MQ platform specific
driver.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/freescale/pinctrl-imx.c

@@ -885,3 +885,22 @@ free:
 
 	return ret;
 }
+
+static int __maybe_unused imx_pinctrl_suspend(struct device *dev)
+{
+	struct imx_pinctrl *ipctl = dev_get_drvdata(dev);
+
+	return pinctrl_force_sleep(ipctl->pctl);
+}
+
+static int __maybe_unused imx_pinctrl_resume(struct device *dev)
+{
+	struct imx_pinctrl *ipctl = dev_get_drvdata(dev);
+
+	return pinctrl_force_default(ipctl->pctl);
+}
+
+const struct dev_pm_ops imx_pinctrl_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(imx_pinctrl_suspend,
+					imx_pinctrl_resume)
+};

drivers/pinctrl/freescale/pinctrl-imx.h

@@ -17,6 +17,7 @@
 struct platform_device;
 
 extern struct pinmux_ops imx_pmx_ops;
+extern const struct dev_pm_ops imx_pinctrl_pm_ops;
 
 /**
  * struct imx_pin_mmio - MMIO pin configurations

drivers/pinctrl/freescale/pinctrl-imx8mq.c

@@ -339,6 +339,7 @@ static struct platform_driver imx8mq_pinctrl_driver = {
 	.driver = {
 		.name = "imx8mq-pinctrl",
 		.of_match_table = of_match_ptr(imx8mq_pinctrl_of_match),
+		.pm = &imx_pinctrl_pm_ops,
 		.suppress_bind_attrs = true,
 	},
 	.probe = imx8mq_pinctrl_probe,