From fcfed1be53e014b9d707ca4520bb1591c2700f2e Mon Sep 17 00:00:00 2001
From: Anson Huang <Anson.Huang@nxp.com>
Date: Wed, 5 Sep 2018 09:24:27 +0800
Subject: [PATCH] tty: serial: imx: add pinctrl sleep/default mode switch for
 suspend
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On some i.MX SoCs' low power mode, such as i.MX7D's LPSR(low power
state retention), UART iomux settings will be lost, need to add
pinctrl sleep/default mode switch during suspend/resume to make
sure UART iomux settings are correct after resume.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/imx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 2634272ad0fb..4341589e0aab 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -24,6 +24,7 @@
 #include <linux/serial.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/rational.h>
 #include <linux/slab.h>
 #include <linux/of.h>
@@ -2444,6 +2445,8 @@ static int imx_uart_suspend_noirq(struct device *dev)
 
 	clk_disable(sport->clk_ipg);
 
+	pinctrl_pm_select_sleep_state(dev);
+
 	return 0;
 }
 
@@ -2452,6 +2455,8 @@ static int imx_uart_resume_noirq(struct device *dev)
 	struct imx_port *sport = dev_get_drvdata(dev);
 	int ret;
 
+	pinctrl_pm_select_default_state(dev);
+
 	ret = clk_enable(sport->clk_ipg);
 	if (ret)
 		return ret;