[PATCH v2 2/2] net: flexcan: add transceiver switch gpios support

Marc Kleine-Budde mkl at pengutronix.de
Thu Jun 28 08:05:14 EDT 2012


On 06/28/2012 01:46 PM, Shawn Guo wrote:
> On Thu, Jun 28, 2012 at 07:33:28PM +0800, Dong Aisheng wrote:
>>> +		phy_stby_gpio = of_get_named_gpio_flags(pdev->dev.of_node,
>>> +							"phy-standby-gpios",
>>> +							0, &flags);
>>> +		if (gpio_is_valid(phy_stby_gpio)) {
>>> +			if (flags == OF_GPIO_ACTIVE_LOW)
>>> +				phy_stby_high = false;
>>> +			err = devm_gpio_request_one(&pdev->dev, phy_stby_gpio,
>>> +						    GPIOF_DIR_OUT,
>>> +						    "phy-standby");
>>> +			if (err) {
>>> +				dev_err(&pdev->dev,
>>> +					"failed to request gpio %d: %d\n",
>>> +					phy_stby_gpio, err);
>>> +				goto failed_gpio;
>> I checked mx28 evk, it seems the phy only has a STB gpio and shared by both CAN0&CAN1.
>> I wonder the CAN1 probe may fail here.
>>
> It can be managed by dts.  Here is what I have in imx28-evk.dts, where
> only can0 has phy-enable-gpios property.
> 
> 
> 	can0: can at 80032000 {
> 		pinctrl-names = "default";
> 		pinctrl-0 = <&can0_pins_a>;
> 		phy-enable-gpios = <&gpio2 13 0>;
> 		status = "okay";
> 	};
> 
> 	can1: can at 80034000 {
> 		pinctrl-names = "default";
> 		pinctrl-0 = <&can1_pins_a>;
> 		status = "okay";
> 	};

Will this work if can0 is down and can1 is up?

Can we abstract the transceiver power as a regulator? Or a clock? :P

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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