Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751526AbdG0C4l (ORCPT ); Wed, 26 Jul 2017 22:56:41 -0400 Received: from mail-oi0-f50.google.com ([209.85.218.50]:33775 "EHLO mail-oi0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbdG0C4j (ORCPT ); Wed, 26 Jul 2017 22:56:39 -0400 MIME-Version: 1.0 In-Reply-To: <20170726120822.xbj3bzsoxmfgzkn4@earth> References: <20170725095931.qmxtn766wam7vufe@earth> <20170726120822.xbj3bzsoxmfgzkn4@earth> From: Baolin Wang Date: Thu, 27 Jul 2017 10:56:37 +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: 6818 Lines: 176 Hi, On 26 July 2017 at 20:08, Sebastian Reichel wrote: > Hi, > > On Wed, Jul 26, 2017 at 11:05:25AM +0800, Baolin Wang wrote: >> On 25 July 2017 at 17:59, Sebastian Reichel >> wrote: >> > 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? > > Yes, but I think the following is better, which avoids > spamming the log with probe defer messages. > > power->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0); > ret = PTR_ERR_OR_ZERO(power->usb_phy); > > switch (ret) { > case 0: > 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; > } > break; > case -EINVAL: > case -ENODEV: > /* ignore missing usb-phy, it's optional */ > power->usb_phy = NULL; > break; > default: > dev_err(&pdev->dev, "Failed to find USB phy: %d\n", ret); > /* fall-through */ > case -EPROBE_DEFER: > goto err_bat_irq; > break; > } OK. Thanks. -- Baolin.wang Best Regards