[U-Boot] [PATCH v5 04/11] usb: host: xhci-rockchip: use fixed regulator to control vbus

[Marek Vasut]

On 06/19/2017 11:50 AM, rock-chips(daniel.meng) wrote:
> 
> 
> On 2017/6/18 13:11, Marek Vasut wrote:
>> On 06/18/2017 12:10 AM, Simon Glass wrote:
>>> Hi Marek,
>>>
>>> On 17 June 2017 at 13:33, Marek Vasut <marex at denx.de> wrote:
>>>> On 06/17/2017 07:28 PM, Simon Glass wrote:
>>>>> Hi Marek,
>>>>>
>>>>> On 17 June 2017 at 00:22, Marek Vasut <marex at denx.de> wrote:
>>>>>> On 06/17/2017 05:41 AM, Simon Glass wrote:
>>>>>>> Hi Marek,
>>>>>>>
>>>>>>> On 15 June 2017 at 10:53, Marek Vasut <marex at denx.de> wrote:
>>>>>>>> On 06/15/2017 05:51 AM, rock-chips(daniel.meng) wrote:
>>>>>>>>>
>>>>>>>>> On 2017/6/13 17:11, Marek Vasut wrote:
>>>>>>>>>> On 06/12/2017 11:19 AM, Meng Dongyang wrote:
>>>>>>>>>>> Use fixed regulator to control the voltage of vbus and turn off
>>>>>>>>>>> vbus when usb stop.
>>>>>>>>>>>
>>>>>>>>>>> Signed-off-by: Meng Dongyang <daniel.meng at rock-chips.com>
>>>>>>>>>>> ---
>>>>>>>>>>>
>>>>>>>>>>> Changes in v5:
>>>>>>>>>>> - Propagate return value and print error message when failed
>>>>>>>>>>>
>>>>>>>>>>> Changes in v4:
>>>>>>>>>>> - Splited from patch [Uboot,v3,04/10]
>>>>>>>>>>> - Define set vbus as empty function if the macros aren't set
>>>>>>>>>>>
>>>>>>>>>>> Changes in v3: None
>>>>>>>>>>> Changes in v2:
>>>>>>>>>>> - Use fixed regulator to control vbus instead of gpio
>>>>>>>>>>>
>>>>>>>>>>>    drivers/usb/host/xhci-rockchip.c | 55
>>>>>>>>>>> ++++++++++++++++++++++++++++++----------
>>>>>>>>>>>    1 file changed, 42 insertions(+), 13 deletions(-)
>>>>>>>>>>>
>>>>>>>>>>> diff --git a/drivers/usb/host/xhci-rockchip.c
>>>>>>>>>>> b/drivers/usb/host/xhci-rockchip.c
>>>>>>>>>>> index f559830..15df6ef 100644
>>>>>>>>>>> --- a/drivers/usb/host/xhci-rockchip.c
>>>>>>>>>>> +++ b/drivers/usb/host/xhci-rockchip.c
>>>>>>>>>>> @@ -11,10 +11,10 @@
>>>>>>>>>>>    #include <malloc.h>
>>>>>>>>>>>    #include <usb.h>
>>>>>>>>>>>    #include <watchdog.h>
>>>>>>>>>>> -#include <asm/gpio.h>
>>>>>>>>>>>    #include <linux/errno.h>
>>>>>>>>>>>    #include <linux/compat.h>
>>>>>>>>>>>    #include <linux/usb/dwc3.h>
>>>>>>>>>>> +#include <power/regulator.h>
>>>>>>>>>>>      #include "xhci.h"
>>>>>>>>>>>    @@ -23,7 +23,7 @@ DECLARE_GLOBAL_DATA_PTR;
>>>>>>>>>>>    struct rockchip_xhci_platdata {
>>>>>>>>>>>        fdt_addr_t hcd_base;
>>>>>>>>>>>        fdt_addr_t phy_base;
>>>>>>>>>>> -    struct gpio_desc vbus_gpio;
>>>>>>>>>>> +    struct udevice *vbus_supply;
>>>>>>>>>>>    };
>>>>>>>>>>>      /*
>>>>>>>>>>> @@ -48,7 +48,7 @@ static int xhci_usb_ofdata_to_platdata(struct
>>>>>>>>>>> udevice *dev)
>>>>>>>>>>>         */
>>>>>>>>>>>        plat->hcd_base = dev_get_addr(dev);
>>>>>>>>>>>        if (plat->hcd_base == FDT_ADDR_T_NONE) {
>>>>>>>>>>> -        debug("Can't get the XHCI register base address\n");
>>>>>>>>>>> +        error("Can't get the XHCI register base address\n");
>>>>>>>>>>>            return -ENXIO;
>>>>>>>>>>>        }
>>>>>>>>>>>    @@ -62,19 +62,39 @@ static int
>>>>>>>>>>> xhci_usb_ofdata_to_platdata(struct
>>>>>>>>>>> udevice *dev)
>>>>>>>>>>>        }
>>>>>>>>>>>          if (plat->phy_base == FDT_ADDR_T_NONE) {
>>>>>>>>>>> -        debug("Can't get the usbphy register address\n");
>>>>>>>>>>> +        error("Can't get the usbphy register address\n");
>>>>>>>>>>>            return -ENXIO;
>>>>>>>>>>>        }
>>>>>>>>>>>    -    /* Vbus gpio */
>>>>>>>>>>> -    ret = gpio_request_by_name(dev, "rockchip,vbus-gpio", 0,
>>>>>>>>>>> -                   &plat->vbus_gpio, GPIOD_IS_OUT);
>>>>>>>>>>> +#if defined(CONFIG_DM_USB) && defined(CONFIG_DM_REGULATOR)
>>>>>>>>>> I don't think you need the CONFIG_DM_USB , the driver depends
>>>>>>>>>> on it (or
>>>>>>>>>> should) already anyway.
>>>>>>>>> Yes, I will remove it in v6.
>>>>>>>>>>> +    /* Vbus regulator */
>>>>>>>>>>> +    ret = device_get_supply_regulator(dev, "vbus-supply",
>>>>>>>>>>> +                      &plat->vbus_supply);
>>>>>>>>>> So I was curious, does this expand to empty function or is
>>>>>>>>>> this not
>>>>>>>>>> defined if CONFIG_DM_REGULATOR is not defined ?
>>>>>>>>> This is not defined if CONFIG_DM_REGULATOR is not defined.
>>>>>>>> Simon, can you comment on this ?
>>>>>>> It looks OK to me.
>>>>>> Shouldn't you have empty stub functions instead to avoid
>>>>>> proliferation
>>>>>> of adhoc #ifdef CONFIG_FOO throughout the codebase ?
>>>>> You could, but this is just a temporary state while apparently some
>>>>> rockchip boards don't use DM_USB and DM_REGULATOR. I'm not sure what
>>>>> those bad boards are, actually.
>>>> Temporary state ? What's the final state then ?
>>> Well I wasn't aware that any rockchip boards didn't use regulators.
>>> Presumably this #ifdef is because of a board that does not.
>> This is IMO unrelated to rockchip.
>>
>>>> Anyway, what if you just disable regulator support (because you don't
>>>> need it for whatever reason), but want to keep USB ? Wouldn't it make
>>>> more sense to have empty stub functions instead of swamping the drivers
>>>> with ifdefs ?
>>> USB would not work without VBUS, which is handled with regulators
>> The VBUS can be directly tied to 5V rail without power switching.
>>
>>> , so
>>> there is something I don't understand here. Anyway I don't see any
>>> point in adding stub functions here.
>> Not here, into the regulator framework, so you don't have to pollute
>> drivers which use the regulators with ifdefs if the regulator framework
>> is not enabled in the config.
>>
>>> Meng can you please explain why the #ifdef is needed?
> 
> Because the function "device_get_supply_regulator" is undefined if
> undefined
> CONFIG_DM_REGULATOR and this will result in a compile error. Maybe the
> regulator
> framework can be optimized and make it compiled successful whether define
> CONFIG_DM_REGULATOR.
> So is this #ifdef still needed here?

Thus my discussion with Simon. Linux does keep the ifdefs in framework
header files , so I think we should do the same.

-- 
Best regards,
Marek Vasut