TI AM62x SoC requires a wakeup flag being set in pinctrl when mcan pins
act as a wakeup source. Add support to select the wakeup state if WOL
is enabled.

Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp@baylibre.com>
---
 drivers/net/can/m_can/m_can.c | 69 +++++++++++++++++++++++++++++++++++++++++--
 drivers/net/can/m_can/m_can.h |  3 ++
 2 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 835b03db1003db6ffa21044ac756676fb193f64d..beb79403611b61d0643da960dfe5301e9dba579b 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -2247,7 +2247,26 @@ static int m_can_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
 		return ret;
 	}
 
+	if (!IS_ERR_OR_NULL(cdev->pinctrl_state_wakeup)) {
+		if (wol_enable)
+			ret = pinctrl_select_state(cdev->pinctrl, cdev->pinctrl_state_wakeup);
+		else
+			ret = pinctrl_pm_select_default_state(cdev->dev);
+
+		if (ret) {
+			netdev_err(cdev->net, "Failed to select pinctrl state %pE\n",
+				   ERR_PTR(ret));
+			goto err_wakeup_enable;
+		}
+	}
+
 	return 0;
+
+err_wakeup_enable:
+	/* Revert wakeup enable */
+	device_set_wakeup_enable(cdev->dev, !wol_enable);
+
+	return ret;
 }
 
 static const struct ethtool_ops m_can_ethtool_ops_coalescing = {
@@ -2375,6 +2394,42 @@ int m_can_class_get_clocks(struct m_can_classdev *cdev)
 }
 EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
 
+static bool m_can_class_wakeup_pinctrl_enabled(struct m_can_classdev *class_dev)
+{
+	return device_may_wakeup(class_dev->dev) && class_dev->pinctrl_state_wakeup;
+}
+
+static int m_can_class_parse_pinctrl(struct m_can_classdev *class_dev)
+{
+	struct device *dev = class_dev->dev;
+	int ret;
+
+	class_dev->pinctrl = devm_pinctrl_get(dev);
+	if (IS_ERR(class_dev->pinctrl)) {
+		ret = PTR_ERR(class_dev->pinctrl);
+		class_dev->pinctrl = NULL;
+
+		if (ret == -ENODEV)
+			return 0;
+
+		return dev_err_probe(dev, ret, "Failed to get pinctrl\n");
+	}
+
+	class_dev->pinctrl_state_wakeup =
+		pinctrl_lookup_state(class_dev->pinctrl, "wakeup");
+	if (IS_ERR(class_dev->pinctrl_state_wakeup)) {
+		ret = PTR_ERR(class_dev->pinctrl_state_wakeup);
+		class_dev->pinctrl_state_wakeup = NULL;
+
+		if (ret == -ENODEV)
+			return 0;
+
+		return dev_err_probe(dev, ret, "Failed to lookup pinctrl wakeup state\n");
+	}
+
+	return 0;
+}
+
 struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
 						int sizeof_priv)
 {
@@ -2416,7 +2471,15 @@ struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
 	m_can_of_parse_mram(class_dev, mram_config_vals);
 	spin_lock_init(&class_dev->tx_handling_spinlock);
 
+	ret = m_can_class_parse_pinctrl(class_dev);
+	if (ret)
+		goto err_free_candev;
+
 	return class_dev;
+
+err_free_candev:
+	free_candev(net_dev);
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
 
@@ -2531,7 +2594,8 @@ int m_can_class_suspend(struct device *dev)
 		m_can_clk_stop(cdev);
 	}
 
-	pinctrl_pm_select_sleep_state(dev);
+	if (!m_can_class_wakeup_pinctrl_enabled(cdev))
+		pinctrl_pm_select_sleep_state(dev);
 
 	cdev->can.state = CAN_STATE_SLEEPING;
 
@@ -2545,7 +2609,8 @@ int m_can_class_resume(struct device *dev)
 	struct net_device *ndev = cdev->net;
 	int ret = 0;
 
-	pinctrl_pm_select_default_state(dev);
+	if (!m_can_class_wakeup_pinctrl_enabled(cdev))
+		pinctrl_pm_select_default_state(dev);
 
 	cdev->can.state = CAN_STATE_ERROR_ACTIVE;
 
diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
index bd4746c63af3f0a032910644dfd48a9ebb3a6168..583c7f1d005d61b3fc8587697388522993ff11a8 100644
--- a/drivers/net/can/m_can/m_can.h
+++ b/drivers/net/can/m_can/m_can.h
@@ -128,6 +128,9 @@ struct m_can_classdev {
 	struct mram_cfg mcfg[MRAM_CFG_NUM];
 
 	struct hrtimer hrtimer;
+
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pinctrl_state_wakeup;
 };
 
 struct m_can_classdev *m_can_class_allocate_dev(struct device *dev, int sizeof_priv);

-- 
2.51.0