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

From: Aswath Govindraju
Date: Mon Nov 22 2021 - 07:57:05 EST


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@xxxxxx>
---
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