From:   Aswath Govindraju <a-govindraju@ti.com>
CC:     Nishanth Menon <nm@ti.com>, Vignesh Raghavendra <vigneshr@ti.com>,
        Aswath Govindraju <a-govindraju@ti.com>,
        Peter Rosin <peda@axentia.se>,
        Rob Herring <robh+dt@kernel.org>,
        Wolfgang Grandegger <wg@grandegger.com>,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-can@vger.kernel.org>,
        <linux-phy@lists.infradead.org>
Subject: [PATCH RFC v2 4/4] phy: phy-can-transceiver: Add support for setting mux
Date:   Mon, 22 Nov 2021 18:26:24 +0530
Message-ID: <20211122125624.6431-5-a-govindraju@ti.com>
In-Reply-To: <20211122125624.6431-1-a-govindraju@ti.com>
References: <20211122125624.6431-1-a-govindraju@ti.com>
MIME-Version: 1.0
Content-Type: text/plain
To:     unlisted-recipients:; (no To-header on input)
Precedence: bulk

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@ti.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