Hi,
On 02/20/2018 10:27 AM, Roger Quadros wrote:
> Hi,
>
> On 20/02/18 11:11, 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.
>
> Isn't this generic enough to be done for all *hci-platform drivers?
>
I can only test ehci-platform on my setup.
> And if this is a VBUS supply to the port, the root hub driver should be controlling it
> based on port power on/off commands to the port right?
>
You're right.
This means to overload platform_overrides with
.port_power = ehci_platform_port_power,
and manage vbus_supply enable/disable in this function instead of
ehci_platform_power_on/off.
>>
>> Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxx>
>> ---
>> Documentation/devicetree/bindings/usb/usb-ehci.txt | 1 +
>> drivers/usb/host/ehci-platform.c | 23 ++++++++++++++++++++++
>> 2 files changed, 24 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..76cc781 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;
>> };
>>
>> @@ -99,6 +101,15 @@ static int ehci_platform_power_on(struct platform_device *dev)
>> }
>> }
>>
>> + if (priv->vbus_supply) {
>> + ret = regulator_enable(priv->vbus_supply);
>> + if (ret) {
>> + dev_err(&dev->dev,
>> + "failed to enable vbus supply: %d\n", ret);
>> + goto err_exit_phy;
>> + }
>> + }
>> +
>> return 0;
>>
>> err_exit_phy:
>> @@ -119,6 +130,9 @@ static void ehci_platform_power_off(struct platform_device *dev)
>> struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
>> int clk, phy_num;
>>
>> + if (priv->vbus_supply)
>> + regulator_disable(priv->vbus_supply);
>> +
>
> If we disable the VBUS here, which is being called during ehci_platform_suspend(),
> how can we expect remote wakeup to work?
> This is unconditionally powering down the port.
>
Sure. With .port_power, it will be OK.
Thanks for review,
Amelie
>> for (phy_num = 0; phy_num < priv->num_phys; phy_num++) {
>> phy_power_off(priv->phys[phy_num]);
>> phy_exit(priv->phys[phy_num]);
>> @@ -247,6 +261,15 @@ 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)
>>
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