On 11.11.2021 22:13:12, Aswath Govindraju wrote:
> 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 | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
> index 6f3fe37dee0e..3d8da5226e27 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 +22,22 @@ 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, 1);
Hard coding the "1" looks wrong here. I have seen some boards where you
can select between a CAN-2.0 and a single wire CAN transceiver with a
mux. So I think we cannot hard code the "1" here.
> + 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 +55,8 @@ 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 +107,15 @@ 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")) {
Is this the proper way of doing this? Looks like we need a
devm_mux_control_get_optional(), which doesn't return a -ENODEV if the
device doesn't exist.
Cc'ed Peter Rosin.
> + struct mux_control *control;
> +
> + control = devm_mux_control_get(dev, NULL);
> + if (IS_ERR(control))
> + return PTR_ERR(control);
What about making use of dev_err_probe()?
> + 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
>
>
Regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
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