Re: [PATCH v4 5/5] power: wm831x_power: Support USB charger current limit management

[Baolin Wang]

On 19 August 2015 at 17:56, Lee Jones <lee.jones@xxxxxxxxxx> wrote:
> On Wed, 19 Aug 2015, Baolin Wang wrote:
>
>> Integrate with the newly added USB charger interface to limit the current
>> we draw from the USB input based on the input device configuration
>> identified by the USB stack, allowing us to charge more quickly from high
>> current inputs without drawing more current than specified from others.
>>
>> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>> ---
>>  drivers/power/wm831x_power.c     |   69 ++++++++++++++++++++++++++++++++++++++
>>  include/linux/mfd/wm831x/pdata.h |    3 ++
>
> I'm not going to keep reviewing this.  You should carry forward any
> Acks received onto subsequent submissions yourself.
>

OK, thanks.

>>  2 files changed, 72 insertions(+)
>>
>> diff --git a/drivers/power/wm831x_power.c b/drivers/power/wm831x_power.c
>> index db11ae6..72c661f 100644
>> --- a/drivers/power/wm831x_power.c
>> +++ b/drivers/power/wm831x_power.c
>> @@ -13,6 +13,7 @@
>>  #include <linux/platform_device.h>
>>  #include <linux/power_supply.h>
>>  #include <linux/slab.h>
>> +#include <linux/usb/usb_charger.h>
>>
>>  #include <linux/mfd/wm831x/core.h>
>>  #include <linux/mfd/wm831x/auxadc.h>
>> @@ -31,6 +32,8 @@ struct wm831x_power {
>>       char usb_name[20];
>>       char battery_name[20];
>>       bool have_battery;
>> +     struct usb_charger *usb_charger;
>> +     struct notifier_block usb_notify;
>>  };
>>
>>  static int wm831x_power_check_online(struct wm831x *wm831x, int supply,
>> @@ -125,6 +128,43 @@ static enum power_supply_property wm831x_usb_props[] = {
>>       POWER_SUPPLY_PROP_VOLTAGE_NOW,
>>  };
>>
>> +/* In miliamps */
>> +static unsigned int wm831x_usb_limits[] = {
>> +     0,
>> +     2,
>> +     100,
>> +     500,
>> +     900,
>> +     1500,
>> +     1800,
>> +     550,
>> +};
>> +
>> +static int wm831x_usb_limit_change(struct notifier_block *nb,
>> +                                unsigned long limit, void *data)
>> +{
>> +     struct wm831x_power *wm831x_power = container_of(nb,
>> +                                                      struct wm831x_power,
>> +                                                      usb_notify);
>> +     int i, best;
>> +
>> +     /* Find the highest supported limit */
>> +     best = 0;
>> +     for (i = 0; i < ARRAY_SIZE(wm831x_usb_limits); i++) {
>> +             if (limit < wm831x_usb_limits[i] &&
>> +                 wm831x_usb_limits[best] < wm831x_usb_limits[i])
>> +                     best = i;
>> +     }
>> +
>> +     dev_dbg(wm831x_power->wm831x->dev,
>> +             "Limiting USB current to %dmA", wm831x_usb_limits[best]);
>> +
>> +     wm831x_set_bits(wm831x_power->wm831x, WM831X_POWER_STATE,
>> +                     WM831X_USB_ILIM_MASK, best);
>> +
>> +     return 0;
>> +}
>> +
>>  /*********************************************************************
>>   *           Battery properties
>>   *********************************************************************/
>> @@ -606,8 +646,31 @@ static int wm831x_power_probe(struct platform_device *pdev)
>>               }
>>       }
>>
>> +     if (wm831x_pdata && wm831x_pdata->usb_gadget) {
>> +             power->usb_charger =
>> +                     usb_charger_find_by_name(wm831x_pdata->usb_gadget);
>> +             if (IS_ERR(power->usb_charger)) {
>> +                     ret = PTR_ERR(power->usb_charger);
>> +                     dev_err(&pdev->dev,
>> +                             "Failed to find USB gadget: %d\n", ret);
>> +                     goto err_bat_irq;
>> +             }
>> +
>> +             power->usb_notify.notifier_call = wm831x_usb_limit_change;
>> +
>> +             ret = usb_charger_register_notify(power->usb_charger,
>> +                                               &power->usb_notify);
>> +             if (ret != 0) {
>> +                     dev_err(&pdev->dev,
>> +                             "Failed to register notifier: %d\n", ret);
>> +                     goto err_usb_charger;
>> +             }
>> +     }
>> +
>>       return ret;
>>
>> +err_usb_charger:
>> +     usb_charger_put(power->usb_charger);
>>  err_bat_irq:
>>       --i;
>>       for (; i >= 0; i--) {
>> @@ -637,6 +700,12 @@ static int wm831x_power_remove(struct platform_device *pdev)
>>       struct wm831x *wm831x = wm831x_power->wm831x;
>>       int irq, i;
>>
>> +     if (wm831x_power->usb_charger) {
>> +             usb_charger_unregister_notify(wm831x_power->usb_charger,
>> +                                           &wm831x_power->usb_notify);
>> +             usb_charger_put(wm831x_power->usb_charger);
>> +     }
>> +
>>       for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) {
>>               irq = wm831x_irq(wm831x,
>>                                platform_get_irq_byname(pdev,
>> diff --git a/include/linux/mfd/wm831x/pdata.h b/include/linux/mfd/wm831x/pdata.h
>> index dcc9631..5af8399 100644
>> --- a/include/linux/mfd/wm831x/pdata.h
>> +++ b/include/linux/mfd/wm831x/pdata.h
>> @@ -126,6 +126,9 @@ struct wm831x_pdata {
>>       /** The driver should initiate a power off sequence during shutdown */
>>       bool soft_shutdown;
>>
>> +     /** dev_name of USB charger gadget to integrate with */
>> +     const char *usb_gadget;
>> +
>>       int irq_base;
>>       int gpio_base;
>>       int gpio_defaults[WM831X_GPIO_NUM];
>
> --
> Lee Jones
> Linaro STMicroelectronics Landing Team Lead
> Linaro.org â Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog



-- 
Baolin.wang
Best Regards
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