Re: [PATCH] usb: imx-us-phy: add vbus_valid ro parameter

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 24.08.21 13:13, Marco Felsch wrote:
> Hi Ahmad,
> 
> On 21-08-24 13:01, Ahmad Fatoum wrote:
>> Hello Marco,
>>
>> On 24.08.21 12:46, Marco Felsch wrote:
>>> The parameter can be used by init scripts to detect a plugged usb cable.
>>> Upon a plugged usb cable the barebox behaviour can be changed which can
>>> be useful e.g. during production to apply a special production
>>> environment.
>>>
>>> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
>>> ---
>>>  drivers/usb/imx/imx-usb-phy.c | 34 +++++++++++++++++++++++++++++++++-
>>>  1 file changed, 33 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/usb/imx/imx-usb-phy.c b/drivers/usb/imx/imx-usb-phy.c
>>> index 32098ef248..9420c8c109 100644
>>> --- a/drivers/usb/imx/imx-usb-phy.c
>>> +++ b/drivers/usb/imx/imx-usb-phy.c
>>> @@ -37,9 +37,12 @@
>>>  #define BM_USBPHY_CTRL_ENHOSTDISCONDETECT	BIT(1)
>>>  
>>>  #define ANADIG_USB1_CHRG_DETECT_SET		0x1b4
>>> -#define ANADIG_USB2_CHRG_DETECT_SET		0x214
>>>  #define ANADIG_USB1_CHRG_DETECT_EN_B		BIT(20)
>>>  #define ANADIG_USB1_CHRG_DETECT_CHK_CHRG_B	BIT(19)
>>> +#define ANADIG_USB1_VBUS_DETECT_STAT		0x1c0
>>> +#define ANADIG_USB1_VBUS_DETECT_STAT_VBUS_VALID	BIT(3)
>>> +#define ANADIG_USB2_CHRG_DETECT_SET		0x214
>>> +#define ANADIG_USB2_VBUS_DETECT_STAT		0x220
>>>  
>>>  struct imx_usbphy {
>>>  	struct usb_phy usb_phy;
>>> @@ -132,6 +135,27 @@ static const struct phy_ops imx_phy_ops = {
>>>  	.to_usbphy = imx_usbphy_to_usbphy,
>>>  };
>>>  
>>> +/* Albeit the access can only happen serial use two variables */
>>> +unsigned int vbus_valid_usb1;
>>> +unsigned int vbus_valid_usb2;
>>> +
>>> +static int imx_usbphy_get_vbus_state(struct param_d *p, void *priv)
>>> +{
>>> +	struct imx_usbphy *imxphy = priv;
>>> +	unsigned int *vbus_valid;
>>> +	unsigned int reg, val;
>>> +
>>> +	reg = imxphy->port_id ?
>>> +		ANADIG_USB1_VBUS_DETECT_STAT :
>>> +		ANADIG_USB2_VBUS_DETECT_STAT;
>>> +	val = readl(imxphy->anatop + reg);
>>> +
>>> +	vbus_valid = imxphy->port_id ? &vbus_valid_usb1 : &vbus_valid_usb2;
>>> +	*vbus_valid = !!(val & ANADIG_USB1_VBUS_DETECT_STAT_VBUS_VALID);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>>  static int imx_usbphy_probe(struct device_d *dev)
>>>  {
>>>  	struct resource *iores;
>>> @@ -149,11 +173,19 @@ static int imx_usbphy_probe(struct device_d *dev)
>>>  	imxphy->port_id = ret;
>>>  
>>>  	if (of_get_property(np, "fsl,anatop", NULL)) {
>>> +		unsigned int *vbus_valid = imxphy->port_id ?
>>> +			&vbus_valid_usb1 :
>>> +			&vbus_valid_usb2;
>>
>> Can you allocate this in imxphy? That way you avoid globals
>> and don't hardcode the existance of only two phys into the driver.
> 
> You're right, good point.
> 
>>> +
>>>  		imxphy->anatop =
>>>  			syscon_base_lookup_by_phandle(np, "fsl,anatop");
>>>  		ret = PTR_ERR_OR_ZERO(imxphy->anatop);
>>>  		if (ret)
>>>  			goto err_free;
>>> +
>>> +		dev_add_param_bool(dev, "vbus_valid", param_set_readonly,
>>> +				   imx_usbphy_get_vbus_state, vbus_valid,
>>> +				   imxphy);
>>
>> I assume valid == usb port is in gadget mode and host is supplying vbus?
> 
> Your're right.
> 
>> What happens when port is in host mode? A comment explaining this would
>> be nice.
> 
> That's a good question didn't checked this and the datasheet don't
> distinguish between those modes. I will test it and add a comment.

prt_imx6_check_usb_boot may also be interesting to you. The protonic boards
use this to detect whether a USB drive is connected or not.

Combining those could give you a usb.connected_to={gadget,host,none}

(or some other better name)

Cheers,
Ahmad

> 
> Regards,
>   Marco
> 
>>
>>>  	}
>>>  
>>>  	iores = dev_request_mem_resource(dev, 0);
>>>
>>
>>
>> -- 
>> Pengutronix e.K.                           |                             |
>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>
> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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