linux-kernel - [PATCH RFC v2 4/4] phy: phy-can-transceiver: Add support for setting mux

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Message-ID: <20211122125624.6431-5-a-govindraju@ti.com>
Date:   Mon, 22 Nov 2021 18:26:24 +0530
From:   Aswath Govindraju <a-govindraju@...com>
To:     unlisted-recipients:; (no To-header on input)
CC:     Nishanth Menon <nm@...com>, Vignesh Raghavendra <vigneshr@...com>,
        Aswath Govindraju <a-govindraju@...com>,
        Peter Rosin <peda@...ntia.se>,
        Rob Herring <robh+dt@...nel.org>,
        Wolfgang Grandegger <wg@...ndegger.com>,
        Marc Kleine-Budde <mkl@...gutronix.de>,
        Kishon Vijay Abraham I <kishon@...com>,
        Vinod Koul <vkoul@...nel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <linux-can@...r.kernel.org>,
        <linux-phy@...ts.infradead.org>
Subject: [PATCH RFC v2 4/4] phy: phy-can-transceiver: Add support for setting mux

On some boards, for routing CAN signals from controller to transceiver,
muxes might need to be set. Therefore, add support for setting the mux by
reading the mux-controls property from the device tree node.

Signed-off-by: Aswath Govindraju <a-govindraju@...com>
---
 drivers/phy/phy-can-transceiver.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 6f3fe37dee0e..15056b9d68ba 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -10,6 +10,7 @@
 #include<linux/module.h>
 #include<linux/gpio.h>
 #include<linux/gpio/consumer.h>
+#include <linux/mux/consumer.h>
 
 struct can_transceiver_data {
 	u32 flags;
@@ -21,13 +22,23 @@ struct can_transceiver_phy {
 	struct phy *generic_phy;
 	struct gpio_desc *standby_gpio;
 	struct gpio_desc *enable_gpio;
+	struct mux_control *mux_ctrl;
 };
 
 /* Power on function */
 static int can_transceiver_phy_power_on(struct phy *phy)
 {
+	int ret;
 	struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy);
 
+	if (can_transceiver_phy->mux_ctrl) {
+		ret = mux_control_select(can_transceiver_phy->mux_ctrl,
+					 mux_control_enable_state(can_transceiver_phy->mux_ctrl));
+		if (ret) {
+			dev_err(&phy->dev, "Failed to select CAN mux: %d\n", ret);
+			return ret;
+		}
+	}
 	if (can_transceiver_phy->standby_gpio)
 		gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
 	if (can_transceiver_phy->enable_gpio)
@@ -45,6 +56,8 @@ static int can_transceiver_phy_power_off(struct phy *phy)
 		gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 1);
 	if (can_transceiver_phy->enable_gpio)
 		gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 0);
+	if (can_transceiver_phy->mux_ctrl)
+		mux_control_deselect(can_transceiver_phy->mux_ctrl);
 
 	return 0;
 }
@@ -95,6 +108,19 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 	match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
 	drvdata = match->data;
 
+	if (of_property_read_bool(dev->of_node, "mux-controls")) {
+		struct mux_control *control;
+		int ret;
+
+		control = devm_mux_control_get(dev, NULL);
+		if (IS_ERR(control)) {
+			ret = PTR_ERR(control);
+			dev_err_probe(&pdev->dev, ret, "failed to get mux\n");
+			return PTR_ERR(control);
+		}
+		can_transceiver_phy->mux_ctrl = control;
+	}
+
 	phy = devm_phy_create(dev, dev->of_node,
 			      &can_transceiver_phy_ops);
 	if (IS_ERR(phy)) {
-- 
2.17.1