[PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Amelie Delaunay]

On some boards, especially when vbus supply requires large current,
and the charge pump on the PHY isn't enough, an external vbus power switch
may be used.
Add support for this optional external vbus supply in ehci-platform.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>

---
Changes in v2:
 * Address Roger Quadros comments: move regulator_enable/disable from
ehci_platform_power_on/off to ehci_platform_port_power.
---
 Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
 drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
index 3efde12..fc480cd 100644
--- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
@@ -19,6 +19,7 @@ Optional properties:
  - phys : phandle + phy specifier pair
  - phy-names : "usb"
  - resets : phandle + reset specifier pair
+ - vbus-supply : phandle of regulator supplying vbus
 
 Example (Sequoia 440EPx):
     ehci@e0000300 {
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index b065a96..05be100 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -29,6 +29,7 @@
 #include <linux/of.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
@@ -46,6 +47,7 @@ struct ehci_platform_priv {
 	struct reset_control *rsts;
 	struct phy **phys;
 	int num_phys;
+	struct regulator *vbus_supply;
 	bool reset_on_resume;
 };
 
@@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
 	return 0;
 }
 
+static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
+				    bool enable)
+{
+	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+	int ret = 0;
+
+	if (priv->vbus_supply) {
+		if (enable)
+			ret = regulator_enable(priv->vbus_supply);
+		else
+			ret = regulator_disable(priv->vbus_supply);
+		if (ret)
+			dev_err(hcd->self.controller,
+				"failed to %s vbus supply: %d\n",
+				enable ? "enable" : "disable", ret);
+	}
+	return ret;
+}
+
 static int ehci_platform_power_on(struct platform_device *dev)
 {
 	struct usb_hcd *hcd = platform_get_drvdata(dev);
@@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
 static const struct ehci_driver_overrides platform_overrides __initconst = {
 	.reset =		ehci_platform_reset,
 	.extra_priv_size =	sizeof(struct ehci_platform_priv),
+	.port_power =		ehci_platform_port_power,
 };
 
 static struct usb_ehci_pdata ehci_platform_defaults = {
@@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
 	if (err)
 		goto err_put_clks;
 
+	priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
+	if (IS_ERR(priv->vbus_supply)) {
+		err = PTR_ERR(priv->vbus_supply);
+		if (err == -ENODEV)
+			priv->vbus_supply = NULL;
+		else
+			goto err_reset;
+	}
+
 	if (pdata->big_endian_desc)
 		ehci->big_endian_desc = 1;
 	if (pdata->big_endian_mmio)
-- 
2.7.4

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Felipe Balbi]

Hi,

Amelie Delaunay <amelie.delaunay@st.com> writes:
> On some boards, especially when vbus supply requires large current,
> and the charge pump on the PHY isn't enough, an external vbus power switch
> may be used.
> Add support for this optional external vbus supply in ehci-platform.
>
> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>
> ---
> Changes in v2:
>  * Address Roger Quadros comments: move regulator_enable/disable from
> ehci_platform_power_on/off to ehci_platform_port_power.
> ---
>  Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
>  drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> index 3efde12..fc480cd 100644
> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> @@ -19,6 +19,7 @@ Optional properties:
>   - phys : phandle + phy specifier pair
>   - phy-names : "usb"
>   - resets : phandle + reset specifier pair
> + - vbus-supply : phandle of regulator supplying vbus
>  
>  Example (Sequoia 440EPx):
>      ehci@e0000300 {
> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> index b065a96..05be100 100644
> --- a/drivers/usb/host/ehci-platform.c
> +++ b/drivers/usb/host/ehci-platform.c
> @@ -29,6 +29,7 @@
>  #include <linux/of.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
>  #include <linux/reset.h>
>  #include <linux/usb.h>
>  #include <linux/usb/hcd.h>
> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
>  	struct reset_control *rsts;
>  	struct phy **phys;
>  	int num_phys;
> +	struct regulator *vbus_supply;
>  	bool reset_on_resume;
>  };
>  
> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>  	return 0;
>  }
>  
> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
> +				    bool enable)
> +{
> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
> +	int ret = 0;
> +
> +	if (priv->vbus_supply) {

you can reduce indentation here:

	if (!priv->vbus_supply)
        	return 0;

-- 
balbi

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Amelie DELAUNAY]

Hi,

On 02/20/2018 02:02 PM, Felipe Balbi wrote:
> 
> Hi,
> 
> Amelie Delaunay <amelie.delaunay@st.com> writes:
>> On some boards, especially when vbus supply requires large current,
>> and the charge pump on the PHY isn't enough, an external vbus power switch
>> may be used.
>> Add support for this optional external vbus supply in ehci-platform.
>>
>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>>
>> ---
>> Changes in v2:
>>   * Address Roger Quadros comments: move regulator_enable/disable from
>> ehci_platform_power_on/off to ehci_platform_port_power.
>> ---
>>   Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
>>   drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
>>   2 files changed, 32 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> index 3efde12..fc480cd 100644
>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> @@ -19,6 +19,7 @@ Optional properties:
>>    - phys : phandle + phy specifier pair
>>    - phy-names : "usb"
>>    - resets : phandle + reset specifier pair
>> + - vbus-supply : phandle of regulator supplying vbus
>>   
>>   Example (Sequoia 440EPx):
>>       ehci@e0000300 {
>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>> index b065a96..05be100 100644
>> --- a/drivers/usb/host/ehci-platform.c
>> +++ b/drivers/usb/host/ehci-platform.c
>> @@ -29,6 +29,7 @@
>>   #include <linux/of.h>
>>   #include <linux/phy/phy.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>>   #include <linux/reset.h>
>>   #include <linux/usb.h>
>>   #include <linux/usb/hcd.h>
>> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
>>   	struct reset_control *rsts;
>>   	struct phy **phys;
>>   	int num_phys;
>> +	struct regulator *vbus_supply;
>>   	bool reset_on_resume;
>>   };
>>   
>> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>   	return 0;
>>   }
>>   
>> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
>> +				    bool enable)
>> +{
>> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
>> +	int ret = 0;
>> +
>> +	if (priv->vbus_supply) {
> 
> you can reduce indentation here:
> 
> 	if (!priv->vbus_supply)
>          	return 0;
> 

You're right, thanks! I will fix it in upcoming v3, waiting for other 
additional comments.
Amelie

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Roger Quadros]

Hi,

On 20/02/18 14:58, Amelie Delaunay wrote:
> On some boards, especially when vbus supply requires large current,
> and the charge pump on the PHY isn't enough, an external vbus power switch
> may be used.
> Add support for this optional external vbus supply in ehci-platform.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
> 
> ---
> Changes in v2:
>  * Address Roger Quadros comments: move regulator_enable/disable from
> ehci_platform_power_on/off to ehci_platform_port_power.
> ---
>  Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
>  drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> index 3efde12..fc480cd 100644
> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> @@ -19,6 +19,7 @@ Optional properties:
>   - phys : phandle + phy specifier pair
>   - phy-names : "usb"
>   - resets : phandle + reset specifier pair
> + - vbus-supply : phandle of regulator supplying vbus
>  

Can platforms have more than one regulator e.g. one regulator per port?

>  Example (Sequoia 440EPx):
>      ehci@e0000300 {
> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> index b065a96..05be100 100644
> --- a/drivers/usb/host/ehci-platform.c
> +++ b/drivers/usb/host/ehci-platform.c
> @@ -29,6 +29,7 @@
>  #include <linux/of.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
>  #include <linux/reset.h>
>  #include <linux/usb.h>
>  #include <linux/usb/hcd.h>
> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
>  	struct reset_control *rsts;
>  	struct phy **phys;
>  	int num_phys;
> +	struct regulator *vbus_supply;
>  	bool reset_on_resume;
>  };
>  
> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>  	return 0;
>  }
>  
> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
> +				    bool enable)
> +{
> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
> +	int ret = 0;
> +
> +	if (priv->vbus_supply) {
> +		if (enable)
> +			ret = regulator_enable(priv->vbus_supply);
> +		else
> +			ret = regulator_disable(priv->vbus_supply);
> +		if (ret)
> +			dev_err(hcd->self.controller,
> +				"failed to %s vbus supply: %d\n",
> +				enable ? "enable" : "disable", ret);
> +	}
> +	return ret;
> +}
> +
>  static int ehci_platform_power_on(struct platform_device *dev)
>  {
>  	struct usb_hcd *hcd = platform_get_drvdata(dev);
> @@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
>  static const struct ehci_driver_overrides platform_overrides __initconst = {
>  	.reset =		ehci_platform_reset,
>  	.extra_priv_size =	sizeof(struct ehci_platform_priv),
> +	.port_power =		ehci_platform_port_power,
>  };
>  
>  static struct usb_ehci_pdata ehci_platform_defaults = {
> @@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
>  	if (err)
>  		goto err_put_clks;
>  
> +	priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
> +	if (IS_ERR(priv->vbus_supply)) {
> +		err = PTR_ERR(priv->vbus_supply);
> +		if (err == -ENODEV)
> +			priv->vbus_supply = NULL;
> +		else
> +			goto err_reset;
> +	}
> +
>  	if (pdata->big_endian_desc)
>  		ehci->big_endian_desc = 1;
>  	if (pdata->big_endian_mmio)
> 

-- 
cheers,
-roger

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Amelie DELAUNAY]

Hi,

On 02/20/2018 03:00 PM, Roger Quadros wrote:
> Hi,
> 
> On 20/02/18 14:58, Amelie Delaunay wrote:
>> On some boards, especially when vbus supply requires large current,
>> and the charge pump on the PHY isn't enough, an external vbus power switch
>> may be used.
>> Add support for this optional external vbus supply in ehci-platform.
>>
>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>>
>> ---
>> Changes in v2:
>>   * Address Roger Quadros comments: move regulator_enable/disable from
>> ehci_platform_power_on/off to ehci_platform_port_power.
>> ---
>>   Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
>>   drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
>>   2 files changed, 32 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> index 3efde12..fc480cd 100644
>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> @@ -19,6 +19,7 @@ Optional properties:
>>    - phys : phandle + phy specifier pair
>>    - phy-names : "usb"
>>    - resets : phandle + reset specifier pair
>> + - vbus-supply : phandle of regulator supplying vbus
>>   
> 
> Can platforms have more than one regulator e.g. one regulator per port?
> 

I imagine that yes, platforms could have one regulator per port.
Regulator consumers bindings impose a <name>-supply property per 
regulator, so, what do you think about :
vbus0-supply for port#0
vbus1-supply for port#1
...
vbusN-supply for port#N

And then in probe, allocate 'struct regulator *vbus_supplies' with a 
size corresponding to 'HCS_N_PORTS(ehci->hcs_params) * sizeof(struct 
regulator *)'.
And loop to get optional regulator vbus0, vbus1,..., vbusN.
And then enable/disable the corresponding regulator in 
ehci_platform_port_power thanks to portnum.

>>   Example (Sequoia 440EPx):
>>       ehci@e0000300 {
>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>> index b065a96..05be100 100644
>> --- a/drivers/usb/host/ehci-platform.c
>> +++ b/drivers/usb/host/ehci-platform.c
>> @@ -29,6 +29,7 @@
>>   #include <linux/of.h>
>>   #include <linux/phy/phy.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>>   #include <linux/reset.h>
>>   #include <linux/usb.h>
>>   #include <linux/usb/hcd.h>
>> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
>>   	struct reset_control *rsts;
>>   	struct phy **phys;
>>   	int num_phys;
>> +	struct regulator *vbus_supply;
>>   	bool reset_on_resume;
>>   };
>>   
>> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>   	return 0;
>>   }
>>   
>> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
>> +				    bool enable)
>> +{
>> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
>> +	int ret = 0;
>> +
>> +	if (priv->vbus_supply) {
>> +		if (enable)
>> +			ret = regulator_enable(priv->vbus_supply);
>> +		else
>> +			ret = regulator_disable(priv->vbus_supply);
>> +		if (ret)
>> +			dev_err(hcd->self.controller,
>> +				"failed to %s vbus supply: %d\n",
>> +				enable ? "enable" : "disable", ret);
>> +	}
>> +	return ret;
>> +}
>> +
>>   static int ehci_platform_power_on(struct platform_device *dev)
>>   {
>>   	struct usb_hcd *hcd = platform_get_drvdata(dev);
>> @@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
>>   static const struct ehci_driver_overrides platform_overrides __initconst = {
>>   	.reset =		ehci_platform_reset,
>>   	.extra_priv_size =	sizeof(struct ehci_platform_priv),
>> +	.port_power =		ehci_platform_port_power,
>>   };
>>   
>>   static struct usb_ehci_pdata ehci_platform_defaults = {
>> @@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
>>   	if (err)
>>   		goto err_put_clks;
>>   
>> +	priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
>> +	if (IS_ERR(priv->vbus_supply)) {
>> +		err = PTR_ERR(priv->vbus_supply);
>> +		if (err == -ENODEV)
>> +			priv->vbus_supply = NULL;
>> +		else
>> +			goto err_reset;
>> +	}
>> +
>>   	if (pdata->big_endian_desc)
>>   		ehci->big_endian_desc = 1;
>>   	if (pdata->big_endian_mmio)
>>
> 

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Roger Quadros]

On 20/02/18 16:46, Amelie DELAUNAY wrote:
> Hi,
> 
> On 02/20/2018 03:00 PM, Roger Quadros wrote:
>> Hi,
>>
>> On 20/02/18 14:58, Amelie Delaunay wrote:
>>> On some boards, especially when vbus supply requires large current,
>>> and the charge pump on the PHY isn't enough, an external vbus power switch
>>> may be used.
>>> Add support for this optional external vbus supply in ehci-platform.
>>>
>>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>>>
>>> ---
>>> Changes in v2:
>>>   * Address Roger Quadros comments: move regulator_enable/disable from
>>> ehci_platform_power_on/off to ehci_platform_port_power.
>>> ---
>>>   Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
>>>   drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
>>>   2 files changed, 32 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>> index 3efde12..fc480cd 100644
>>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>> @@ -19,6 +19,7 @@ Optional properties:
>>>    - phys : phandle + phy specifier pair
>>>    - phy-names : "usb"
>>>    - resets : phandle + reset specifier pair
>>> + - vbus-supply : phandle of regulator supplying vbus
>>>   
>>
>> Can platforms have more than one regulator e.g. one regulator per port?
>>
> 
> I imagine that yes, platforms could have one regulator per port.
> Regulator consumers bindings impose a <name>-supply property per 
> regulator, so, what do you think about :
> vbus0-supply for port#0
> vbus1-supply for port#1
> ...
> vbusN-supply for port#N
> 
> And then in probe, allocate 'struct regulator *vbus_supplies' with a 
> size corresponding to 'HCS_N_PORTS(ehci->hcs_params) * sizeof(struct 
> regulator *)'.
> And loop to get optional regulator vbus0, vbus1,..., vbusN.
> And then enable/disable the corresponding regulator in 
> ehci_platform_port_power thanks to portnum.

Looks fine to me but we need to get Alan's opinion if this is worth the effort.
If there isn't a single platform needing it we could probably do without it
but the DT binding must be scalable to add this feature in the future.

And what if it is ganged power? i.e. one regulator for more than one port.
Probably they all can point to the same regulator instance and it should work.

> 
>>>   Example (Sequoia 440EPx):
>>>       ehci@e0000300 {
>>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>>> index b065a96..05be100 100644
>>> --- a/drivers/usb/host/ehci-platform.c
>>> +++ b/drivers/usb/host/ehci-platform.c
>>> @@ -29,6 +29,7 @@
>>>   #include <linux/of.h>
>>>   #include <linux/phy/phy.h>
>>>   #include <linux/platform_device.h>
>>> +#include <linux/regulator/consumer.h>
>>>   #include <linux/reset.h>
>>>   #include <linux/usb.h>
>>>   #include <linux/usb/hcd.h>
>>> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
>>>   	struct reset_control *rsts;
>>>   	struct phy **phys;
>>>   	int num_phys;
>>> +	struct regulator *vbus_supply;
>>>   	bool reset_on_resume;
>>>   };
>>>   
>>> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>>   	return 0;
>>>   }
>>>   
>>> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
>>> +				    bool enable)
>>> +{
>>> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
>>> +	int ret = 0;
>>> +
>>> +	if (priv->vbus_supply) {
>>> +		if (enable)
>>> +			ret = regulator_enable(priv->vbus_supply);
>>> +		else
>>> +			ret = regulator_disable(priv->vbus_supply);
>>> +		if (ret)
>>> +			dev_err(hcd->self.controller,
>>> +				"failed to %s vbus supply: %d\n",
>>> +				enable ? "enable" : "disable", ret);
>>> +	}
>>> +	return ret;
>>> +}
>>> +
>>>   static int ehci_platform_power_on(struct platform_device *dev)
>>>   {
>>>   	struct usb_hcd *hcd = platform_get_drvdata(dev);
>>> @@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
>>>   static const struct ehci_driver_overrides platform_overrides __initconst = {
>>>   	.reset =		ehci_platform_reset,
>>>   	.extra_priv_size =	sizeof(struct ehci_platform_priv),
>>> +	.port_power =		ehci_platform_port_power,
>>>   };
>>>   
>>>   static struct usb_ehci_pdata ehci_platform_defaults = {
>>> @@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
>>>   	if (err)
>>>   		goto err_put_clks;
>>>   
>>> +	priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
>>> +	if (IS_ERR(priv->vbus_supply)) {
>>> +		err = PTR_ERR(priv->vbus_supply);
>>> +		if (err == -ENODEV)
>>> +			priv->vbus_supply = NULL;
>>> +		else
>>> +			goto err_reset;
>>> +	}
>>> +
>>>   	if (pdata->big_endian_desc)
>>>   		ehci->big_endian_desc = 1;
>>>   	if (pdata->big_endian_mmio)
>>>

-- 
cheers,
-roger

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Alan Stern]

On Tue, 20 Feb 2018, Roger Quadros wrote:

> On 20/02/18 16:46, Amelie DELAUNAY wrote:
> > Hi,
> > 
> > On 02/20/2018 03:00 PM, Roger Quadros wrote:
> >> Hi,
> >>
> >> On 20/02/18 14:58, Amelie Delaunay wrote:
> >>> On some boards, especially when vbus supply requires large current,
> >>> and the charge pump on the PHY isn't enough, an external vbus power switch
> >>> may be used.
> >>> Add support for this optional external vbus supply in ehci-platform.
> >>>
> >>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
> >>>
> >>> ---
> >>> Changes in v2:
> >>>   * Address Roger Quadros comments: move regulator_enable/disable from
> >>> ehci_platform_power_on/off to ehci_platform_port_power.
> >>> ---
> >>>   Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
> >>>   drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
> >>>   2 files changed, 32 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> >>> index 3efde12..fc480cd 100644
> >>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
> >>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> >>> @@ -19,6 +19,7 @@ Optional properties:
> >>>    - phys : phandle + phy specifier pair
> >>>    - phy-names : "usb"
> >>>    - resets : phandle + reset specifier pair
> >>> + - vbus-supply : phandle of regulator supplying vbus
> >>>   
> >>
> >> Can platforms have more than one regulator e.g. one regulator per port?
> >>
> > 
> > I imagine that yes, platforms could have one regulator per port.
> > Regulator consumers bindings impose a <name>-supply property per 
> > regulator, so, what do you think about :
> > vbus0-supply for port#0
> > vbus1-supply for port#1
> > ...
> > vbusN-supply for port#N
> > 
> > And then in probe, allocate 'struct regulator *vbus_supplies' with a 
> > size corresponding to 'HCS_N_PORTS(ehci->hcs_params) * sizeof(struct 
> > regulator *)'.
> > And loop to get optional regulator vbus0, vbus1,..., vbusN.
> > And then enable/disable the corresponding regulator in 
> > ehci_platform_port_power thanks to portnum.
> 
> Looks fine to me but we need to get Alan's opinion if this is worth the effort.
> If there isn't a single platform needing it we could probably do without it
> but the DT binding must be scalable to add this feature in the future.

I agree that for now there don't seem to be any platforms requiring 
more than one regulator, but this should be implemented in a way that 
could be expanded if necessary.

Anyway, the basic idea is reasonable.  I don't know to what extent 
people want to power-off their EHCI ports, but if they do then we ought 
to turn off external regulators at the same time.

Is there a real-life use case for this?

Alan Stern

> And what if it is ganged power? i.e. one regulator for more than one port.
> Probably they all can point to the same regulator instance and it should work.
> 
> > 
> >>>   Example (Sequoia 440EPx):
> >>>       ehci@e0000300 {
> >>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> >>> index b065a96..05be100 100644
> >>> --- a/drivers/usb/host/ehci-platform.c
> >>> +++ b/drivers/usb/host/ehci-platform.c
> >>> @@ -29,6 +29,7 @@
> >>>   #include <linux/of.h>
> >>>   #include <linux/phy/phy.h>
> >>>   #include <linux/platform_device.h>
> >>> +#include <linux/regulator/consumer.h>
> >>>   #include <linux/reset.h>
> >>>   #include <linux/usb.h>
> >>>   #include <linux/usb/hcd.h>
> >>> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
> >>>   	struct reset_control *rsts;
> >>>   	struct phy **phys;
> >>>   	int num_phys;
> >>> +	struct regulator *vbus_supply;
> >>>   	bool reset_on_resume;
> >>>   };
> >>>   
> >>> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
> >>>   	return 0;
> >>>   }
> >>>   
> >>> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
> >>> +				    bool enable)
> >>> +{
> >>> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
> >>> +	int ret = 0;
> >>> +
> >>> +	if (priv->vbus_supply) {
> >>> +		if (enable)
> >>> +			ret = regulator_enable(priv->vbus_supply);
> >>> +		else
> >>> +			ret = regulator_disable(priv->vbus_supply);
> >>> +		if (ret)
> >>> +			dev_err(hcd->self.controller,
> >>> +				"failed to %s vbus supply: %d\n",
> >>> +				enable ? "enable" : "disable", ret);
> >>> +	}
> >>> +	return ret;
> >>> +}
> >>> +
> >>>   static int ehci_platform_power_on(struct platform_device *dev)
> >>>   {
> >>>   	struct usb_hcd *hcd = platform_get_drvdata(dev);
> >>> @@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
> >>>   static const struct ehci_driver_overrides platform_overrides __initconst = {
> >>>   	.reset =		ehci_platform_reset,
> >>>   	.extra_priv_size =	sizeof(struct ehci_platform_priv),
> >>> +	.port_power =		ehci_platform_port_power,
> >>>   };
> >>>   
> >>>   static struct usb_ehci_pdata ehci_platform_defaults = {
> >>> @@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
> >>>   	if (err)
> >>>   		goto err_put_clks;
> >>>   
> >>> +	priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
> >>> +	if (IS_ERR(priv->vbus_supply)) {
> >>> +		err = PTR_ERR(priv->vbus_supply);
> >>> +		if (err == -ENODEV)
> >>> +			priv->vbus_supply = NULL;
> >>> +		else
> >>> +			goto err_reset;
> >>> +	}
> >>> +
> >>>   	if (pdata->big_endian_desc)
> >>>   		ehci->big_endian_desc = 1;
> >>>   	if (pdata->big_endian_mmio)
> >>>
> 
> 

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Amelie DELAUNAY]

Hi,

On 02/20/2018 07:10 PM, Alan Stern wrote:
> On Tue, 20 Feb 2018, Roger Quadros wrote:
> 
>> On 20/02/18 16:46, Amelie DELAUNAY wrote:
>>> Hi,
>>>
>>> On 02/20/2018 03:00 PM, Roger Quadros wrote:
>>>> Hi,
>>>>
>>>> On 20/02/18 14:58, Amelie Delaunay wrote:
>>>>> On some boards, especially when vbus supply requires large current,
>>>>> and the charge pump on the PHY isn't enough, an external vbus power switch
>>>>> may be used.
>>>>> Add support for this optional external vbus supply in ehci-platform.
>>>>>
>>>>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>>>>>
>>>>> ---
>>>>> Changes in v2:
>>>>>    * Address Roger Quadros comments: move regulator_enable/disable from
>>>>> ehci_platform_power_on/off to ehci_platform_port_power.
>>>>> ---
>>>>>    Documentation/devicetree/bindings/usb/usb-ehci.txt |  1 +
>>>>>    drivers/usb/host/ehci-platform.c                   | 31 ++++++++++++++++++++++
>>>>>    2 files changed, 32 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>>>> index 3efde12..fc480cd 100644
>>>>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>>>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>>>> @@ -19,6 +19,7 @@ Optional properties:
>>>>>     - phys : phandle + phy specifier pair
>>>>>     - phy-names : "usb"
>>>>>     - resets : phandle + reset specifier pair
>>>>> + - vbus-supply : phandle of regulator supplying vbus
>>>>>    
>>>>
>>>> Can platforms have more than one regulator e.g. one regulator per port?
>>>>
>>>
>>> I imagine that yes, platforms could have one regulator per port.
>>> Regulator consumers bindings impose a <name>-supply property per
>>> regulator, so, what do you think about :
>>> vbus0-supply for port#0
>>> vbus1-supply for port#1
>>> ...
>>> vbusN-supply for port#N
>>>
>>> And then in probe, allocate 'struct regulator *vbus_supplies' with a
>>> size corresponding to 'HCS_N_PORTS(ehci->hcs_params) * sizeof(struct
>>> regulator *)'.
>>> And loop to get optional regulator vbus0, vbus1,..., vbusN.
>>> And then enable/disable the corresponding regulator in
>>> ehci_platform_port_power thanks to portnum.
>>
>> Looks fine to me but we need to get Alan's opinion if this is worth the effort.
>> If there isn't a single platform needing it we could probably do without it
>> but the DT binding must be scalable to add this feature in the future.
> 
> I agree that for now there don't seem to be any platforms requiring
> more than one regulator, but this should be implemented in a way that
> could be expanded if necessary.
> 
> Anyway, the basic idea is reasonable.  I don't know to what extent
> people want to power-off their EHCI ports, but if they do then we ought
> to turn off external regulators at the same time.
> 
> Is there a real-life use case for this?
> 
> Alan Stern
> 

On my setup I have the following:

                  regulator_____vbus
  _________________             \
| EHCI controller |-port0-----[USB connector]
|_________________|-port1-----X

So, I have one regulator only for port0. But I could I have one more if 
port1 was connected. My current regulator could also supplies port1.

To allocate a vbus_supplies array depending on N_PORTS, I have to move 
this initialization from probe to ehci_platform_reset, after ehci_setup 
is done.
Then, I have to define each regulator id depending on the port number.
This imposes a binding like
- portN_vbus-supply : phandle of regulator supplying vbus for port N
But I don't know if we can describe it like this in dt-bindings ?

&ehci {
	...
	port0_vbus-supply = <&vbus_reg>;
	port1_vbus-supply = <&vbus_reg>; //Could be another regulator, or not 
specified if port is not connected.
	...
};

Is it ok to move vbus_supplies initialization in ehci_platform_reset ?

Regards,
Amelie

>> And what if it is ganged power? i.e. one regulator for more than one port.
>> Probably they all can point to the same regulator instance and it should work.
>>
>>>
>>>>>    Example (Sequoia 440EPx):
>>>>>        ehci@e0000300 {
>>>>> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
>>>>> index b065a96..05be100 100644
>>>>> --- a/drivers/usb/host/ehci-platform.c
>>>>> +++ b/drivers/usb/host/ehci-platform.c
>>>>> @@ -29,6 +29,7 @@
>>>>>    #include <linux/of.h>
>>>>>    #include <linux/phy/phy.h>
>>>>>    #include <linux/platform_device.h>
>>>>> +#include <linux/regulator/consumer.h>
>>>>>    #include <linux/reset.h>
>>>>>    #include <linux/usb.h>
>>>>>    #include <linux/usb/hcd.h>
>>>>> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
>>>>>    	struct reset_control *rsts;
>>>>>    	struct phy **phys;
>>>>>    	int num_phys;
>>>>> +	struct regulator *vbus_supply;
>>>>>    	bool reset_on_resume;
>>>>>    };
>>>>>    
>>>>> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
>>>>>    	return 0;
>>>>>    }
>>>>>    
>>>>> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
>>>>> +				    bool enable)
>>>>> +{
>>>>> +	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
>>>>> +	int ret = 0;
>>>>> +
>>>>> +	if (priv->vbus_supply) {
>>>>> +		if (enable)
>>>>> +			ret = regulator_enable(priv->vbus_supply);
>>>>> +		else
>>>>> +			ret = regulator_disable(priv->vbus_supply);
>>>>> +		if (ret)
>>>>> +			dev_err(hcd->self.controller,
>>>>> +				"failed to %s vbus supply: %d\n",
>>>>> +				enable ? "enable" : "disable", ret);
>>>>> +	}
>>>>> +	return ret;
>>>>> +}
>>>>> +
>>>>>    static int ehci_platform_power_on(struct platform_device *dev)
>>>>>    {
>>>>>    	struct usb_hcd *hcd = platform_get_drvdata(dev);
>>>>> @@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
>>>>>    static const struct ehci_driver_overrides platform_overrides __initconst = {
>>>>>    	.reset =		ehci_platform_reset,
>>>>>    	.extra_priv_size =	sizeof(struct ehci_platform_priv),
>>>>> +	.port_power =		ehci_platform_port_power,
>>>>>    };
>>>>>    
>>>>>    static struct usb_ehci_pdata ehci_platform_defaults = {
>>>>> @@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
>>>>>    	if (err)
>>>>>    		goto err_put_clks;
>>>>>    
>>>>> +	priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
>>>>> +	if (IS_ERR(priv->vbus_supply)) {
>>>>> +		err = PTR_ERR(priv->vbus_supply);
>>>>> +		if (err == -ENODEV)
>>>>> +			priv->vbus_supply = NULL;
>>>>> +		else
>>>>> +			goto err_reset;
>>>>> +	}
>>>>> +
>>>>>    	if (pdata->big_endian_desc)
>>>>>    		ehci->big_endian_desc = 1;
>>>>>    	if (pdata->big_endian_mmio)
>>>>>
>>
>>
> 
> 
> 

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Alan Stern]

On Thu, 22 Feb 2018, Amelie DELAUNAY wrote:

> >>>>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
> >>>>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> >>>>> @@ -19,6 +19,7 @@ Optional properties:
> >>>>>     - phys : phandle + phy specifier pair
> >>>>>     - phy-names : "usb"
> >>>>>     - resets : phandle + reset specifier pair
> >>>>> + - vbus-supply : phandle of regulator supplying vbus
> >>>>>    
> >>>>
> >>>> Can platforms have more than one regulator e.g. one regulator per port?
> >>>>
> >>>
> >>> I imagine that yes, platforms could have one regulator per port.
> >>> Regulator consumers bindings impose a <name>-supply property per
> >>> regulator, so, what do you think about :
> >>> vbus0-supply for port#0
> >>> vbus1-supply for port#1
> >>> ...
> >>> vbusN-supply for port#N
> >>>
> >>> And then in probe, allocate 'struct regulator *vbus_supplies' with a
> >>> size corresponding to 'HCS_N_PORTS(ehci->hcs_params) * sizeof(struct
> >>> regulator *)'.
> >>> And loop to get optional regulator vbus0, vbus1,..., vbusN.
> >>> And then enable/disable the corresponding regulator in
> >>> ehci_platform_port_power thanks to portnum.
> >>
> >> Looks fine to me but we need to get Alan's opinion if this is worth the effort.
> >> If there isn't a single platform needing it we could probably do without it
> >> but the DT binding must be scalable to add this feature in the future.
> > 
> > I agree that for now there don't seem to be any platforms requiring
> > more than one regulator, but this should be implemented in a way that
> > could be expanded if necessary.
> > 
> > Anyway, the basic idea is reasonable.  I don't know to what extent
> > people want to power-off their EHCI ports, but if they do then we ought
> > to turn off external regulators at the same time.
> > 
> > Is there a real-life use case for this?
> > 
> > Alan Stern
> > 
> 
> On my setup I have the following:
> 
>                   regulator_____vbus
>   _________________             \
> | EHCI controller |-port0-----[USB connector]
> |_________________|-port1-----X
> 
> So, I have one regulator only for port0. But I could I have one more if 
> port1 was connected. My current regulator could also supplies port1.
> 
> To allocate a vbus_supplies array depending on N_PORTS, I have to move 
> this initialization from probe to ehci_platform_reset, after ehci_setup 
> is done.
> Then, I have to define each regulator id depending on the port number.
> This imposes a binding like
> - portN_vbus-supply : phandle of regulator supplying vbus for port N
> But I don't know if we can describe it like this in dt-bindings ?
> 
> &ehci {
> 	...
> 	port0_vbus-supply = <&vbus_reg>;
> 	port1_vbus-supply = <&vbus_reg>; //Could be another regulator, or not 
> specified if port is not connected.
> 	...
> };
> 
> Is it ok to move vbus_supplies initialization in ehci_platform_reset ?

Yes, it's okay to move the code if you need to.

However, I can not speak on the DT implications.  Someone who knows
more about it should chime in.

Alan Stern

Re: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply

[Amelie DELAUNAY]

On 02/22/2018 07:27 PM, Alan Stern wrote:
> On Thu, 22 Feb 2018, Amelie DELAUNAY wrote:
> 
>>>>>>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>>>>>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>>>>>>> @@ -19,6 +19,7 @@ Optional properties:
>>>>>>>      - phys : phandle + phy specifier pair
>>>>>>>      - phy-names : "usb"
>>>>>>>      - resets : phandle + reset specifier pair
>>>>>>> + - vbus-supply : phandle of regulator supplying vbus
>>>>>>>     
>>>>>>
>>>>>> Can platforms have more than one regulator e.g. one regulator per port?
>>>>>>
>>>>>
>>>>> I imagine that yes, platforms could have one regulator per port.
>>>>> Regulator consumers bindings impose a <name>-supply property per
>>>>> regulator, so, what do you think about :
>>>>> vbus0-supply for port#0
>>>>> vbus1-supply for port#1
>>>>> ...
>>>>> vbusN-supply for port#N
>>>>>
>>>>> And then in probe, allocate 'struct regulator *vbus_supplies' with a
>>>>> size corresponding to 'HCS_N_PORTS(ehci->hcs_params) * sizeof(struct
>>>>> regulator *)'.
>>>>> And loop to get optional regulator vbus0, vbus1,..., vbusN.
>>>>> And then enable/disable the corresponding regulator in
>>>>> ehci_platform_port_power thanks to portnum.
>>>>
>>>> Looks fine to me but we need to get Alan's opinion if this is worth the effort.
>>>> If there isn't a single platform needing it we could probably do without it
>>>> but the DT binding must be scalable to add this feature in the future.
>>>
>>> I agree that for now there don't seem to be any platforms requiring
>>> more than one regulator, but this should be implemented in a way that
>>> could be expanded if necessary.
>>>
>>> Anyway, the basic idea is reasonable.  I don't know to what extent
>>> people want to power-off their EHCI ports, but if they do then we ought
>>> to turn off external regulators at the same time.
>>>
>>> Is there a real-life use case for this?
>>>
>>> Alan Stern
>>>
>>
>> On my setup I have the following:
>>
>>                    regulator_____vbus
>>    _________________             \
>> | EHCI controller |-port0-----[USB connector]
>> |_________________|-port1-----X
>>
>> So, I have one regulator only for port0. But I could I have one more if
>> port1 was connected. My current regulator could also supplies port1.
>>
>> To allocate a vbus_supplies array depending on N_PORTS, I have to move
>> this initialization from probe to ehci_platform_reset, after ehci_setup
>> is done.
>> Then, I have to define each regulator id depending on the port number.
>> This imposes a binding like
>> - portN_vbus-supply : phandle of regulator supplying vbus for port N
>> But I don't know if we can describe it like this in dt-bindings ?
>>
>> &ehci {
>> 	...
>> 	port0_vbus-supply = <&vbus_reg>;
>> 	port1_vbus-supply = <&vbus_reg>; //Could be another regulator, or not
>> specified if port is not connected.
>> 	...
>> };
>>
>> Is it ok to move vbus_supplies initialization in ehci_platform_reset ?
> 
> Yes, it's okay to move the code if you need to.
> 
> However, I can not speak on the DT implications.  Someone who knows
> more about it should chime in.
> 
> Alan Stern
> 

Thanks Alan,

I'm going to send a v3 including all these changes to ease review.

Regards,
Amelie