Hi, On 25 July 2017 at 17:59, Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx> wrote: > Hi, > > On Tue, Jul 25, 2017 at 04:00:01PM +0800, 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> >> --- >> Documentation/devicetree/bindings/mfd/wm831x.txt | 1 + >> drivers/power/supply/wm831x_power.c | 58 ++++++++++++++++++++++ >> 2 files changed, 59 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/mfd/wm831x.txt b/Documentation/devicetree/bindings/mfd/wm831x.txt >> index 9f8b743..4e3bc07 100644 >> --- a/Documentation/devicetree/bindings/mfd/wm831x.txt >> +++ b/Documentation/devicetree/bindings/mfd/wm831x.txt >> @@ -31,6 +31,7 @@ Required properties: >> ../interrupt-controller/interrupts.txt >> >> Optional sub-nodes: >> + - usb-phy : Contains a phandle to the USB PHY. >> - regulators : Contains sub-nodes for each of the regulators supplied by >> the device. The regulators are bound using their names listed below: >> >> diff --git a/drivers/power/supply/wm831x_power.c b/drivers/power/supply/wm831x_power.c >> index 7082301..d3948ab 100644 >> --- a/drivers/power/supply/wm831x_power.c >> +++ b/drivers/power/supply/wm831x_power.c >> @@ -13,6 +13,7 @@ >> #include <linux/platform_device.h> >> #include <linux/power_supply.h> >> #include <linux/slab.h> >> +#include <linux/usb/phy.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_phy *usb_phy; >> + struct notifier_block usb_notify; >> }; >> >> static int wm831x_power_check_online(struct wm831x *wm831x, int supply, >> @@ -125,6 +128,43 @@ static int wm831x_usb_get_prop(struct power_supply *psy, >> POWER_SUPPLY_PROP_VOLTAGE_NOW, >> }; >> >> +/* In milliamps */ >> +static const 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); >> + unsigned 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 %umA", wm831x_usb_limits[best]); >> + >> + wm831x_set_bits(wm831x_power->wm831x, WM831X_POWER_STATE, >> + WM831X_USB_ILIM_MASK, best); >> + >> + return 0; >> +} >> + >> /********************************************************************* >> * Battery properties >> *********************************************************************/ >> @@ -607,6 +647,19 @@ static int wm831x_power_probe(struct platform_device *pdev) >> } >> } >> >> + power->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, >> + "usb-phy", 0); >> + if (!IS_ERR(power->usb_phy)) { >> + power->usb_notify.notifier_call = wm831x_usb_limit_change; >> + ret = usb_register_notifier(power->usb_phy, >> + &power->usb_notify); >> + if (ret) { >> + dev_err(&pdev->dev, "Failed to register notifier: %d\n", >> + ret); >> + goto err_bat_irq; >> + } >> + } > > No error handling for power->usb_phy? I think you should bail out > for all errors except for "not defined in DT". Especially I would > expect probe defer handling in case the power supply driver is > loaded before the phy driver. Make sense. So I think I need to change like below: power->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0); if (!IS_ERR(power->usb_phy)) { power->usb_notify.notifier_call = wm831x_usb_limit_change; ret = usb_register_notifier(power->usb_phy, &power->usb_notify); if (ret) { dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret); goto err_bat_irq; } } else if (PTR_ERR(power->usb_phy) != -ENODEV && PTR_ERR(power->usb_phy) != -EINVAL) { ret = PTR_ERR(power->usb_phy); dev_err(&pdev->dev, "Failed to find USB phy: %d\n", ret); goto err_bat_irq; } The return value -EINVAL means the platform device does not have a device node and -ENODEV means we did not set the 'usb-phy' phandle, other errors we should bail out including -PROBE_DEFER. Is it OK for you? > >> return ret; >> >> err_bat_irq: >> @@ -637,6 +690,11 @@ static int wm831x_power_remove(struct platform_device *pdev) >> struct wm831x *wm831x = wm831x_power->wm831x; >> int irq, i; >> >> + if (!IS_ERR(wm831x_power->usb_phy)) { >> + usb_unregister_notifier(wm831x_power->usb_phy, >> + &wm831x_power->usb_notify); >> + } >> + >> for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) { >> irq = wm831x_irq(wm831x, >> platform_get_irq_byname(pdev, > > -- Sebastian -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html