linux-kernel - Re: [PATCH 2/2] phy: phy-can-transceiver: Add support for setting mux

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Message-ID: <YbhInhyZH9d0HGGf@matsya>
Date:   Tue, 14 Dec 2021 13:02:46 +0530
From:   Vinod Koul <vkoul@...nel.org>
To:     Aswath Govindraju <a-govindraju@...com>
Cc:     Wolfgang Grandegger <wg@...ndegger.com>,
        Marc Kleine-Budde <mkl@...gutronix.de>,
        Kishon Vijay Abraham I <kishon@...com>,
        Rob Herring <robh+dt@...nel.org>, linux-can@...r.kernel.org,
        linux-phy@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] phy: phy-can-transceiver: Add support for setting mux

On 02-12-21, 18:40, 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-states property from the device tree node.
> 
> Signed-off-by: Aswath Govindraju <a-govindraju@...com>
> ---
>  drivers/phy/Kconfig               |  1 +
>  drivers/phy/phy-can-transceiver.c | 22 ++++++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 82b63e60c5a2..300b0f2b5f84 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -64,6 +64,7 @@ config USB_LGM_PHY
>  config PHY_CAN_TRANSCEIVER
>  	tristate "CAN transceiver PHY"
>  	select GENERIC_PHY
> +	select MULTIPLEXER
>  	help
>  	  This option enables support for CAN transceivers as a PHY. This
>  	  driver provides function for putting the transceivers in various
> diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
> index 6f3fe37dee0e..cb91d0e94da7 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_state *mux_state;
>  };
>  
>  /* 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);

reverse christmas tree notation is typically use, so new addition at the
end here please

>  
> +	if (can_transceiver_phy->mux_state) {
> +		ret = mux_state_select(can_transceiver_phy->mux_state);
> +		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_state)
> +		mux_state_deselect(can_transceiver_phy->mux_state);
>  
>  	return 0;
>  }
> @@ -95,6 +107,16 @@ 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-states")) {
> +		struct mux_state *mux_state;
> +
> +		mux_state = devm_mux_state_get(dev, NULL);
> +		if (IS_ERR(mux_state))
> +			return dev_err_probe(&pdev->dev, PTR_ERR(mux_state),
> +					     "failed to get mux\n");
> +		can_transceiver_phy->mux_state = mux_state;
> +	}
> +
>  	phy = devm_phy_create(dev, dev->of_node,
>  			      &can_transceiver_phy_ops);
>  	if (IS_ERR(phy)) {
> -- 
> 2.17.1

-- 
~Vinod