Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751849AbdGZDF3 (ORCPT ); Tue, 25 Jul 2017 23:05:29 -0400 Received: from mail-oi0-f41.google.com ([209.85.218.41]:36129 "EHLO mail-oi0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbdGZDF1 (ORCPT ); Tue, 25 Jul 2017 23:05:27 -0400 MIME-Version: 1.0 In-Reply-To: <20170725095931.qmxtn766wam7vufe@earth> References: <20170725095931.qmxtn766wam7vufe@earth> From: Baolin Wang Date: Wed, 26 Jul 2017 11:05:25 +0800 Message-ID: Subject: Re: [PATCH v3 3/3] power: wm831x_power: Support USB charger current limit management To: Sebastian Reichel Cc: Felipe Balbi , Greg KH , Lee Jones , Rob Herring , Mark Rutland , Jun Li , Peter Chen , Mark Brown , John Stultz , NeilBrown , patches@opensource.wolfsonmicro.com, Linux PM list , USB , device-mainlining@lists.linuxfoundation.org, LKML , devicetree@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6030 Lines: 164 Hi, On 25 July 2017 at 17:59, Sebastian Reichel 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 >> Signed-off-by: Baolin Wang >> --- >> 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 >> #include >> #include >> +#include >> >> #include >> #include >> @@ -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