Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751952AbcJKEF3 (ORCPT ); Tue, 11 Oct 2016 00:05:29 -0400 Received: from mail-yw0-f172.google.com ([209.85.161.172]:35483 "EHLO mail-yw0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056AbcJKEF1 (ORCPT ); Tue, 11 Oct 2016 00:05:27 -0400 MIME-Version: 1.0 In-Reply-To: <57FC557F.6040907@linux.intel.com> References: <57FC557F.6040907@linux.intel.com> From: Baolin Wang Date: Tue, 11 Oct 2016 12:05:25 +0800 Message-ID: Subject: Re: [PATCH v17 1/4] usb: gadget: Introduce the usb charger framework To: Lu Baolu Cc: Felipe Balbi , Greg KH , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , robh@kernel.org, Jun Li , Marek Szyprowski , Ruslan Bilovol , Peter Chen , Alan Stern , r.baldyga@samsung.com, grygorii.strashko@ti.com, Yoshihiro Shimoda , Lee Jones , Mark Brown , John Stultz , Charles Keepax , patches@opensource.wolfsonmicro.com, Linux PM list , USB , device-mainlining@lists.linuxfoundation.org, LKML 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: 39624 Lines: 1144 Hi Baolu, On 11 October 2016 at 10:59, Lu Baolu wrote: > Hi Baolin, > > Some review comments below. > > On 10/10/2016 02:22 PM, Baolin Wang wrote: >> This patch introduces the usb charger driver based on usb gadget that >> makes an enhancement to a power driver. It works well in practice but >> that requires a system with suitable hardware. >> >> The basic conception of the usb charger is that, when one usb charger >> is added or removed by reporting from the usb gadget state change or >> the extcon device state change, the usb charger will report to power >> user to set the current limitation. >> >> The usb charger will register notifiees on the usb gadget or the extcon >> device to get notified the usb charger state. It also supplies the >> notification mechanism to userspace When the usb charger state is changed. >> >> Power user will register a notifiee on the usb charger to get notified >> by status changes from the usb charger. It will report to power user >> to set the current limitation when detecting the usb charger is added >> or removed from extcon device state or usb gadget state. >> >> This patch doesn't yet integrate with the gadget code, so some functions >> which rely on the 'gadget' are not completed, that will be implemented >> in the following patches. >> >> Signed-off-by: Baolin Wang >> Reviewed-by: Li Jun >> Tested-by: Li Jun >> --- >> drivers/usb/gadget/Kconfig | 8 + >> drivers/usb/gadget/udc/Makefile | 1 + >> drivers/usb/gadget/udc/charger.c | 785 ++++++++++++++++++++++++++++++++++++++ >> include/linux/usb/charger.h | 186 +++++++++ >> include/uapi/linux/usb/charger.h | 31 ++ >> 5 files changed, 1011 insertions(+) >> create mode 100644 drivers/usb/gadget/udc/charger.c >> create mode 100644 include/linux/usb/charger.h >> create mode 100644 include/uapi/linux/usb/charger.h >> >> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig >> index 2ea3fc3..7520677 100644 >> --- a/drivers/usb/gadget/Kconfig >> +++ b/drivers/usb/gadget/Kconfig >> @@ -134,6 +134,14 @@ config U_SERIAL_CONSOLE >> help >> It supports the serial gadget can be used as a console. >> >> +config USB_CHARGER >> + bool "USB charger support" >> + select EXTCON >> + help >> + The usb charger driver based on the usb gadget that makes an >> + enhancement to a power driver which can set the current limitation >> + when the usb charger is added or removed. >> + >> source "drivers/usb/gadget/udc/Kconfig" >> >> # >> diff --git a/drivers/usb/gadget/udc/Makefile b/drivers/usb/gadget/udc/Makefile >> index 98e74ed..ede2351 100644 >> --- a/drivers/usb/gadget/udc/Makefile >> +++ b/drivers/usb/gadget/udc/Makefile >> @@ -2,6 +2,7 @@ >> CFLAGS_trace.o := -I$(src) >> >> udc-core-y := core.o trace.o >> +udc-core-$(CONFIG_USB_CHARGER) += charger.o >> >> # >> # USB peripheral controller drivers >> diff --git a/drivers/usb/gadget/udc/charger.c b/drivers/usb/gadget/udc/charger.c >> new file mode 100644 >> index 0000000..16dc477 >> --- /dev/null >> +++ b/drivers/usb/gadget/udc/charger.c >> @@ -0,0 +1,785 @@ >> +/* >> + * charger.c -- USB charger driver >> + * >> + * Copyright (C) 2016 Linaro Ltd. >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +/* Default current range by charger type. */ >> +#define DEFAULT_SDP_CUR_MIN 2 >> +#define DEFAULT_SDP_CUR_MAX 500 >> +#define DEFAULT_SDP_CUR_MIN_SS 150 >> +#define DEFAULT_SDP_CUR_MAX_SS 900 >> +#define DEFAULT_DCP_CUR_MIN 500 >> +#define DEFAULT_DCP_CUR_MAX 5000 >> +#define DEFAULT_CDP_CUR_MIN 1500 >> +#define DEFAULT_CDP_CUR_MAX 5000 >> +#define DEFAULT_ACA_CUR_MIN 1500 >> +#define DEFAULT_ACA_CUR_MAX 5000 >> + >> +static DEFINE_IDA(usb_charger_ida); >> +static LIST_HEAD(charger_list); >> +static DEFINE_MUTEX(charger_lock); >> + >> +static struct usb_charger *dev_to_uchger(struct device *dev) >> +{ >> + return NULL; >> +} >> + >> +/* >> + * charger_current_show() - Show the charger current. >> + */ >> +static ssize_t charger_current_show(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct usb_charger *uchger = dev_to_uchger(dev); >> + unsigned int min, max; >> + >> + usb_charger_get_current(uchger, &min, &max); >> + return sprintf(buf, "%u-%u\n", min, max); >> +} >> +static DEVICE_ATTR_RO(charger_current); >> + >> +/* >> + * charger_type_show() - Show the charger type. >> + * >> + * It can be SDP/DCP/CDP/ACA type, else for unknown type. >> + */ >> +static ssize_t charger_type_show(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct usb_charger *uchger = dev_to_uchger(dev); >> + int cnt; >> + >> + switch (uchger->type) { >> + case SDP_TYPE: >> + cnt = sprintf(buf, "%s\n", "SDP"); >> + break; >> + case DCP_TYPE: >> + cnt = sprintf(buf, "%s\n", "DCP"); >> + break; >> + case CDP_TYPE: >> + cnt = sprintf(buf, "%s\n", "CDP"); >> + break; >> + case ACA_TYPE: >> + cnt = sprintf(buf, "%s\n", "ACA"); >> + break; >> + default: >> + cnt = sprintf(buf, "%s\n", "UNKNOWN"); >> + break; >> + } >> + >> + return cnt; >> +} >> +static DEVICE_ATTR_RO(charger_type); >> + >> +/* >> + * charger_state_show() - Show the charger state. >> + * >> + * Charger state can be present or removed. >> + */ >> +static ssize_t charger_state_show(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct usb_charger *uchger = dev_to_uchger(dev); >> + int cnt; >> + >> + switch (uchger->state) { >> + case USB_CHARGER_PRESENT: >> + cnt = sprintf(buf, "%s\n", "PRESENT"); >> + break; >> + case USB_CHARGER_REMOVE: >> + cnt = sprintf(buf, "%s\n", "REMOVE"); >> + break; >> + default: >> + cnt = sprintf(buf, "%s\n", "UNKNOWN"); >> + break; >> + } >> + >> + return cnt; >> +} >> +static DEVICE_ATTR_RO(charger_state); >> + >> +static struct attribute *usb_charger_attrs[] = { >> + &dev_attr_charger_current.attr, >> + &dev_attr_charger_type.attr, >> + &dev_attr_charger_state.attr, >> + NULL >> +}; >> + >> +static const struct attribute_group usb_charger_group = { >> + .name = "charger", >> + .attrs = usb_charger_attrs, >> +}; >> +__ATTRIBUTE_GROUPS(usb_charger); >> + >> +/* >> + * usb_charger_find_by_name() - Get the usb charger instance by name. >> + * @name - usb charger name. >> + */ >> +struct usb_charger *usb_charger_find_by_name(const char *name) >> +{ >> + struct usb_charger *uchger; >> + >> + if (WARN(!name, "can't work with NULL name")) >> + return ERR_PTR(-EINVAL); >> + >> + mutex_lock(&charger_lock); >> + list_for_each_entry(uchger, &charger_list, list) { >> + if (!strcmp(uchger->name, name)) >> + break; >> + } >> + mutex_unlock(&charger_lock); >> + >> + if (WARN(!uchger, "can't find usb charger")) >> + return ERR_PTR(-ENODEV); >> + >> + return uchger; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_find_by_name); >> + >> +/* >> + * __usb_charger_get_type() - Get the usb charger type by the callback which >> + * is implemented by users. >> + * @uchger - the usb charger instance. >> + * >> + * Note: This function is just used for getting the charger type, not for >> + * detecting charger type which might affect the DP/DM line when gadget is on >> + * enumeration state. >> + */ >> +static enum usb_charger_type __usb_charger_get_type(struct usb_charger *uchger) >> +{ >> + if (uchger->type != UNKNOWN_TYPE) >> + return uchger->type; >> + >> + if (uchger->get_charger_type) >> + uchger->type = uchger->get_charger_type(uchger); >> + else >> + uchger->type = UNKNOWN_TYPE; >> + >> + return uchger->type; >> +} >> + >> +/* >> + * usb_charger_get_type() - get the usb charger type with lock protection. >> + * @uchger - usb charger instance. >> + * >> + * Users can get the charger type by this safe API, rather than using the >> + * usb_charger structure directly. >> + */ >> +enum usb_charger_type usb_charger_get_type(struct usb_charger *uchger) >> +{ >> + enum usb_charger_type type; >> + >> + mutex_lock(&uchger->lock); >> + type = __usb_charger_get_type(uchger); >> + mutex_unlock(&uchger->lock); >> + >> + return type; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_get_type); >> + >> +/* >> + * usb_charger_get_state() - Get the charger state with lock protection. >> + * @uchger - the usb charger instance. >> + * >> + * Users should get the charger state by this safe API. >> + */ >> +enum usb_charger_state usb_charger_get_state(struct usb_charger *uchger) >> +{ >> + enum usb_charger_state state; >> + >> + mutex_lock(&uchger->lock); >> + state = uchger->state; >> + mutex_unlock(&uchger->lock); >> + >> + return state; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_get_state); >> + >> +/* >> + * usb_charger_detect_type() - detect the charger type manually. >> + * @uchger - usb charger instance. >> + * >> + * Note: You should ensure you need to detect the charger type manually on your >> + * platform. >> + * You should call it at the right gadget state to avoid affecting gadget >> + * enumeration. >> + */ >> +int usb_charger_detect_type(struct usb_charger *uchger) >> +{ >> + enum usb_charger_type type; >> + >> + if (!uchger->charger_detect) >> + return -EINVAL; >> + >> + type = uchger->charger_detect(uchger); >> + >> + mutex_lock(&uchger->lock); >> + uchger->type = type; >> + mutex_unlock(&uchger->lock); >> + >> + return 0; >> +} > > Are there any duplicated code in this function and __usb_charger_get_type()? No. This API is for software detection for charger type. Since we can detect the charger type by software or hardware. > >> +EXPORT_SYMBOL_GPL(usb_charger_detect_type); >> + >> +/* >> + * usb_charger_notify_work() - Notify users the current has changed by work. >> + * @work - the work instance. >> + * >> + * Note: When users receive the charger present event, they should check the >> + * charger current by usb_charger_get_current() API. >> + */ >> +static void usb_charger_notify_work(struct work_struct *work) >> +{ >> + struct usb_charger *uchger = work_to_charger(work); >> + >> + mutex_lock(&uchger->lock); >> + if (uchger->state == USB_CHARGER_PRESENT) { >> + raw_notifier_call_chain(&uchger->uchger_nh, >> + USB_CHARGER_PRESENT, >> + uchger); >> + } >> + mutex_unlock(&uchger->lock); >> +} >> + >> +/* >> + * __usb_charger_set_cur_limit_by_type() - Set the current limitation >> + * by charger type. >> + * @uchger - the usb charger instance. >> + * @type - the usb charger type. >> + * @cur_limit - the current limitation. >> + */ >> +static int __usb_charger_set_cur_limit_by_type(struct usb_charger *uchger, >> + enum usb_charger_type type, >> + unsigned int cur_limit) >> +{ >> + switch (type) { >> + case SDP_TYPE: >> + uchger->cur.sdp_max = (cur_limit > DEFAULT_SDP_CUR_MAX) ? >> + DEFAULT_SDP_CUR_MAX : cur_limit; >> + uchger->sdp_default_cur_change = 1; >> + break; >> + case DCP_TYPE: >> + uchger->cur.dcp_max = (cur_limit > DEFAULT_DCP_CUR_MAX) ? >> + DEFAULT_DCP_CUR_MAX : cur_limit; >> + break; >> + case CDP_TYPE: >> + uchger->cur.cdp_max = (cur_limit > DEFAULT_CDP_CUR_MAX) ? >> + DEFAULT_CDP_CUR_MAX : cur_limit; >> + break; >> + case ACA_TYPE: >> + uchger->cur.aca_max = (cur_limit > DEFAULT_ACA_CUR_MAX) ? >> + DEFAULT_ACA_CUR_MAX : cur_limit; >> + break; >> + default: >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> + >> +/* >> + * usb_charger_set_cur_limit_by_gadget() - Set the current limitation from >> + * gadget layer. >> + * @gadget - the usb gadget device. >> + * @cur_limit - the current limitation. >> + * >> + * Note: This function is used in atomic contexts without mutex lock. >> + */ >> +int usb_charger_set_cur_limit_by_gadget(struct usb_gadget *gadget, >> + unsigned int cur_limit) >> +{ >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_set_cur_limit_by_gadget); >> + >> +/* >> + * usb_charger_set_cur_limit_by_type() - Set the current limitation >> + * by charger type with lock protection. >> + * @uchger - the usb charger instance. >> + * @type - the usb charger type. >> + * @cur_limit - the current limitation. >> + * >> + * Users should set the current limitation by this lock protection API. >> + */ >> +int usb_charger_set_cur_limit_by_type(struct usb_charger *uchger, >> + enum usb_charger_type type, >> + unsigned int cur_limit) >> +{ >> + int ret; >> + >> + if (!uchger) >> + return -EINVAL; >> + >> + mutex_lock(&uchger->lock); >> + ret = __usb_charger_set_cur_limit_by_type(uchger, type, cur_limit); >> + mutex_unlock(&uchger->lock); >> + >> + schedule_work(&uchger->work); >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_set_cur_limit_by_type); >> + >> +/* >> + * usb_charger_set_current() - Set the usb charger current. >> + * @uchger - the usb charger instance. >> + * @values - the current setting values. >> + */ >> +int usb_charger_set_current(struct usb_charger *uchger, >> + struct usb_charger_current *values) >> +{ >> + if (!uchger || !values) >> + return -EINVAL; >> + >> + mutex_lock(&uchger->lock); >> + uchger->cur.sdp_min = values->sdp_min; >> + uchger->cur.sdp_max = (values->sdp_max > DEFAULT_SDP_CUR_MAX) ? >> + DEFAULT_SDP_CUR_MAX : values->sdp_max; >> + uchger->cur.dcp_min = values->dcp_min; >> + uchger->cur.dcp_max = (values->dcp_max > DEFAULT_DCP_CUR_MAX) ? >> + DEFAULT_DCP_CUR_MAX : values->dcp_max; >> + uchger->cur.cdp_min = values->cdp_min; >> + uchger->cur.cdp_max = (values->cdp_max > DEFAULT_CDP_CUR_MAX) ? >> + DEFAULT_CDP_CUR_MAX : values->cdp_max; >> + uchger->cur.aca_min = values->aca_min; >> + uchger->cur.aca_max = (values->aca_max > DEFAULT_ACA_CUR_MAX) ? >> + DEFAULT_ACA_CUR_MAX : values->aca_max; >> + uchger->sdp_default_cur_change = 2; >> + mutex_unlock(&uchger->lock); >> + >> + schedule_work(&uchger->work); >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_set_current); >> + >> +/* >> + * usb_charger_get_current() - Get the charger current with lock protection. >> + * @uchger - the usb charger instance. >> + * @min - return the minimum current. >> + * @max - return the maximum current. >> + * >> + * Users should get the charger current by this safe API. >> + */ >> +int usb_charger_get_current(struct usb_charger *uchger, >> + unsigned int *min, >> + unsigned int *max) >> +{ >> + enum usb_charger_type type; >> + >> + if (!uchger) >> + return -EINVAL; >> + >> + mutex_lock(&uchger->lock); >> + type = __usb_charger_get_type(uchger); >> + >> + switch (type) { >> + case SDP_TYPE: >> + /* >> + * For super speed gadget, the default charger maximum current >> + * should be 900 mA and the default minimum current should be >> + * 150mA. >> + */ >> + if (uchger->sdp_default_cur_change != 2 && uchger->gadget && >> + uchger->gadget->speed >= USB_SPEED_SUPER) { >> + if (!uchger->sdp_default_cur_change) >> + uchger->cur.sdp_max = DEFAULT_SDP_CUR_MAX_SS; >> + uchger->cur.sdp_min = DEFAULT_SDP_CUR_MIN_SS; >> + uchger->sdp_default_cur_change = 2; >> + } >> + >> + *min = uchger->cur.sdp_min; >> + *max = uchger->cur.sdp_max; >> + break; >> + case DCP_TYPE: >> + *min = uchger->cur.dcp_min; >> + *max = uchger->cur.dcp_max; >> + break; >> + case CDP_TYPE: >> + *min = uchger->cur.cdp_min; >> + *max = uchger->cur.cdp_max; >> + break; >> + case ACA_TYPE: >> + *min = uchger->cur.aca_min; >> + *max = uchger->cur.aca_max; >> + break; >> + default: >> + *min = 0; >> + *max = 0; >> + break; >> + } >> + mutex_unlock(&uchger->lock); >> + >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_get_current); >> + >> +/* >> + * usb_charger_register_notify() - Register a notifiee to get notified by >> + * any attach status changes from the usb charger detection. >> + * @uchger - the usb charger instance which is monitored. >> + * @nb - a notifier block to be registered. >> + */ >> +int usb_charger_register_notify(struct usb_charger *uchger, >> + struct notifier_block *nb) >> +{ >> + int ret; >> + >> + if (!uchger || !nb) { >> + pr_err("Charger or nb can not be NULL.\n"); >> + return -EINVAL; >> + } >> + >> + mutex_lock(&uchger->lock); >> + ret = raw_notifier_chain_register(&uchger->uchger_nh, nb); >> + mutex_unlock(&uchger->lock); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_register_notify); >> + >> +/* >> + * usb_charger_unregister_notify() - Unregister a notifiee from the usb charger. >> + * @uchger - the usb charger instance which is monitored. >> + * @nb - a notifier block to be unregistered. >> + */ >> +int usb_charger_unregister_notify(struct usb_charger *uchger, >> + struct notifier_block *nb) >> +{ >> + int ret; >> + >> + if (!uchger || !nb) { >> + pr_err("Charger or nb can not be NULL.\n"); >> + return -EINVAL; >> + } >> + >> + mutex_lock(&uchger->lock); >> + ret = raw_notifier_chain_unregister(&uchger->uchger_nh, nb); >> + mutex_unlock(&uchger->lock); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_unregister_notify); >> + >> +/* >> + * usb_charger_notify_state() - It will notify other device registered >> + * on usb charger when the usb charger state is changed. >> + * @uchger - the usb charger instance. >> + * @state - the state of the usb charger. >> + * >> + * Note: When notify the charger present state to power driver, the power driver >> + * should get the current by usb_charger_get_current() API to set current. >> + */ >> +static void usb_charger_notify_state(struct usb_charger *uchger, >> + enum usb_charger_state state) >> +{ >> + char uchger_state[50] = { 0 }; >> + char *envp[] = { uchger_state, NULL }; >> + >> + mutex_lock(&uchger->lock); >> + if (uchger->state == state) { >> + mutex_unlock(&uchger->lock); >> + return; >> + } >> + >> + uchger->state = state; >> + >> + switch (state) { >> + case USB_CHARGER_PRESENT: >> + __usb_charger_get_type(uchger); >> + raw_notifier_call_chain(&uchger->uchger_nh, >> + USB_CHARGER_PRESENT, >> + uchger); >> + snprintf(uchger_state, ARRAY_SIZE(uchger_state), >> + "USB_CHARGER_STATE=%s", "USB_CHARGER_PRESENT"); >> + break; >> + case USB_CHARGER_REMOVE: >> + uchger->type = UNKNOWN_TYPE; >> + raw_notifier_call_chain(&uchger->uchger_nh, >> + USB_CHARGER_REMOVE, >> + uchger); >> + snprintf(uchger_state, ARRAY_SIZE(uchger_state), >> + "USB_CHARGER_STATE=%s", "USB_CHARGER_REMOVE"); >> + break; >> + default: >> + pr_warn("Unknown USB charger state: %d\n", state); >> + mutex_unlock(&uchger->lock); >> + return; >> + } >> + >> + kobject_uevent_env(&uchger->gadget->dev.kobj, KOBJ_CHANGE, envp); >> + mutex_unlock(&uchger->lock); >> +} >> + >> +/* >> + * usb_charger_type_by_extcon() - The notifier call function which is registered >> + * on the extcon device. >> + * @nb - the notifier block that notified by extcon device. >> + * @state - the extcon device state. >> + * @data - here specify a extcon device. >> + * >> + * return the notify flag. >> + */ >> +static int usb_charger_type_by_extcon(struct notifier_block *nb, >> + unsigned long state, void *data) >> +{ >> + struct usb_charger_nb *extcon_nb = >> + container_of(nb, struct usb_charger_nb, nb); >> + struct usb_charger *uchger = extcon_nb->uchger; >> + enum usb_charger_state uchger_state; >> + enum usb_charger_type type; >> + >> + if (WARN(!uchger, "charger can not be NULL")) >> + return NOTIFY_BAD; >> + >> + /* Determine charger type */ >> + if (extcon_get_cable_state_(uchger->extcon_dev, >> + EXTCON_CHG_USB_SDP) > 0) { >> + type = SDP_TYPE; >> + uchger_state = USB_CHARGER_PRESENT; >> + } else if (extcon_get_cable_state_(uchger->extcon_dev, >> + EXTCON_CHG_USB_CDP) > 0) { >> + type = CDP_TYPE; >> + uchger_state = USB_CHARGER_PRESENT; >> + } else if (extcon_get_cable_state_(uchger->extcon_dev, >> + EXTCON_CHG_USB_DCP) > 0) { >> + type = DCP_TYPE; >> + uchger_state = USB_CHARGER_PRESENT; >> + } else if (extcon_get_cable_state_(uchger->extcon_dev, >> + EXTCON_CHG_USB_ACA) > 0) { >> + type = ACA_TYPE; >> + uchger_state = USB_CHARGER_PRESENT; >> + } else { >> + type = UNKNOWN_TYPE; >> + uchger_state = USB_CHARGER_REMOVE; >> + } >> + >> + mutex_lock(&uchger->lock); >> + uchger->type = type; >> + mutex_unlock(&uchger->lock); >> + >> + usb_charger_notify_state(uchger, uchger_state); >> + >> + return NOTIFY_OK; >> +} >> + >> +/* >> + * usb_charger_plug_by_extcon() - The notifier call function which is registered >> + * on the extcon device. >> + * @nb - the notifier block that notified by extcon device. >> + * @state - the extcon device state. >> + * @data - here specify a extcon device. >> + * >> + * return the notify flag. >> + */ >> +static int usb_charger_plug_by_extcon(struct notifier_block *nb, >> + unsigned long state, void *data) >> +{ >> + struct usb_charger_nb *extcon_nb = >> + container_of(nb, struct usb_charger_nb, nb); >> + struct usb_charger *uchger = extcon_nb->uchger; >> + enum usb_charger_state uchger_state; >> + >> + if (WARN(!uchger, "charger can not be NULL")) >> + return NOTIFY_BAD; >> + >> + /* >> + * Report event to power users to setting the current limitation >> + * for this usb charger when one usb charger is added or removed >> + * with detecting by extcon device. >> + */ >> + if (state) >> + uchger_state = USB_CHARGER_PRESENT; >> + else >> + uchger_state = USB_CHARGER_REMOVE; >> + >> + usb_charger_notify_state(uchger, uchger_state); >> + >> + return NOTIFY_OK; >> +} >> + >> +/* >> + * usb_charger_plug_by_gadget() - Set the usb charger current limitation >> + * according to the usb gadget device state. >> + * @gadget - the usb gadget device. >> + * @state - the usb gadget state. >> + */ >> +int usb_charger_plug_by_gadget(struct usb_gadget *gadget, >> + unsigned long state) >> +{ >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(usb_charger_plug_by_gadget); >> + >> +/* >> + * usb_charger_register() - Register a new usb charger. >> + * @uchger - the new usb charger instance. >> + */ > > Where is usb_charger_unregister()? Please see patch 3. > >> +static int usb_charger_register(struct usb_charger *uchger) >> +{ >> + int ret; >> + >> + ret = ida_simple_get(&usb_charger_ida, 0, 0, GFP_KERNEL); >> + if (ret < 0) { >> + pr_err("Failed to register usb charger: %d\n", ret); >> + return ret; >> + } >> + >> + uchger->id = ret; >> + scnprintf(uchger->name, CHARGER_NAME_MAX, "usb-charger.%d", uchger->id); >> + >> + ret = sysfs_create_groups(&uchger->gadget->dev.kobj, >> + usb_charger_groups); >> + if (ret) { >> + pr_err("Failed to create usb charger attributes: %d\n", ret); >> + goto fail; >> + } >> + >> + mutex_lock(&charger_lock); >> + list_add_tail(&uchger->list, &charger_list); >> + mutex_unlock(&charger_lock); >> + >> + return 0; >> + >> +fail: >> + ida_simple_remove(&usb_charger_ida, uchger->id); >> + uchger->id = -1; >> + return ret; > > You only have one point to goto here. Why not just move this code block > to above goto place? Sure. > >> +} >> + >> +int usb_charger_init(struct usb_gadget *ugadget) >> +{ >> + struct usb_charger *uchger; >> + struct extcon_dev *edev; >> + int ret; >> + >> + uchger = kzalloc(sizeof(struct usb_charger), GFP_KERNEL); > > Memory leak. I didn't find kfree() in usb_charger_exit(). Please see patch 3. > >> + if (!uchger) >> + return -ENOMEM; >> + >> + uchger->type = UNKNOWN_TYPE; >> + uchger->state = USB_CHARGER_DEFAULT; >> + uchger->id = -1; >> + uchger->sdp_default_cur_change = 0; >> + >> + uchger->cur.sdp_min = DEFAULT_SDP_CUR_MIN; >> + uchger->cur.sdp_max = DEFAULT_SDP_CUR_MAX; >> + uchger->cur.dcp_min = DEFAULT_DCP_CUR_MIN; >> + uchger->cur.dcp_max = DEFAULT_DCP_CUR_MAX; >> + uchger->cur.cdp_min = DEFAULT_CDP_CUR_MIN; >> + uchger->cur.cdp_max = DEFAULT_CDP_CUR_MAX; >> + uchger->cur.aca_min = DEFAULT_ACA_CUR_MIN; >> + uchger->cur.aca_max = DEFAULT_ACA_CUR_MAX; >> + >> + mutex_init(&uchger->lock); >> + RAW_INIT_NOTIFIER_HEAD(&uchger->uchger_nh); >> + INIT_WORK(&uchger->work, usb_charger_notify_work); >> + >> + /* Register a notifier on a extcon device if it is exsited */ >> + edev = extcon_get_edev_by_phandle(ugadget->dev.parent, 0); >> + if (!IS_ERR_OR_NULL(edev)) { >> + uchger->extcon_dev = edev; >> + uchger->extcon_nb.nb.notifier_call = usb_charger_plug_by_extcon; >> + uchger->extcon_nb.uchger = uchger; >> + ret = extcon_register_notifier(edev, EXTCON_USB, >> + &uchger->extcon_nb.nb); >> + if (ret) { >> + pr_err("Failed to register extcon USB notifier.\n"); >> + goto fail_extcon; >> + } >> + >> + uchger->extcon_type_nb.nb.notifier_call = >> + usb_charger_type_by_extcon; >> + uchger->extcon_type_nb.uchger = uchger; >> + >> + ret = extcon_register_notifier(edev, EXTCON_CHG_USB_SDP, >> + &uchger->extcon_type_nb.nb); >> + if (ret) { >> + pr_err("Failed to register extcon USB SDP notifier.\n"); >> + goto fail_extcon_sdp; >> + } >> + >> + ret = extcon_register_notifier(edev, EXTCON_CHG_USB_CDP, >> + &uchger->extcon_type_nb.nb); >> + if (ret) { >> + pr_err("Failed to register extcon USB CDP notifier.\n"); >> + goto fail_extcon_cdp; >> + } >> + >> + ret = extcon_register_notifier(edev, EXTCON_CHG_USB_DCP, >> + &uchger->extcon_type_nb.nb); >> + if (ret) { >> + pr_err("Failed to register extcon USB DCP notifier.\n"); >> + goto fail_extcon_dcp; >> + } >> + >> + ret = extcon_register_notifier(edev, EXTCON_CHG_USB_ACA, >> + &uchger->extcon_type_nb.nb); >> + if (ret) { >> + pr_err("Failed to register extcon USB ACA notifier.\n"); >> + goto fail_extcon_aca; >> + } >> + } >> + >> + uchger->gadget = ugadget; >> + uchger->old_gadget_state = USB_STATE_NOTATTACHED; >> + >> + /* Register a new usb charger */ >> + ret = usb_charger_register(uchger); >> + if (ret) >> + goto fail_register; >> + >> + return 0; >> + >> +fail_register: >> + extcon_unregister_notifier(uchger->extcon_dev, >> + EXTCON_CHG_USB_ACA, >> + &uchger->extcon_type_nb.nb); >> +fail_extcon_aca: >> + extcon_unregister_notifier(uchger->extcon_dev, >> + EXTCON_CHG_USB_DCP, >> + &uchger->extcon_type_nb.nb); >> +fail_extcon_dcp: >> + extcon_unregister_notifier(uchger->extcon_dev, >> + EXTCON_CHG_USB_CDP, >> + &uchger->extcon_type_nb.nb); >> +fail_extcon_cdp: >> + extcon_unregister_notifier(uchger->extcon_dev, >> + EXTCON_CHG_USB_SDP, >> + &uchger->extcon_type_nb.nb); >> +fail_extcon_sdp: >> + extcon_unregister_notifier(uchger->extcon_dev, >> + EXTCON_USB, >> + &uchger->extcon_nb.nb); >> +fail_extcon: >> + kfree(uchger); >> + >> + return ret; >> +} >> + >> +int usb_charger_exit(struct usb_gadget *ugadget) >> +{ >> + return 0; >> +} >> + >> +MODULE_AUTHOR("Baolin Wang "); >> +MODULE_DESCRIPTION("USB charger driver"); >> +MODULE_LICENSE("GPL v2"); >> diff --git a/include/linux/usb/charger.h b/include/linux/usb/charger.h >> new file mode 100644 >> index 0000000..7819eac >> --- /dev/null >> +++ b/include/linux/usb/charger.h >> @@ -0,0 +1,186 @@ >> +#ifndef __LINUX_USB_CHARGER_H__ >> +#define __LINUX_USB_CHARGER_H__ >> + >> +#include >> +#include >> + >> +#define CHARGER_NAME_MAX 30 >> +#define work_to_charger(w) (container_of((w), struct usb_charger, work)) >> + >> +/* Current range by charger type */ >> +struct usb_charger_current { >> + unsigned int sdp_min; >> + unsigned int sdp_max; >> + unsigned int dcp_min; >> + unsigned int dcp_max; >> + unsigned int cdp_min; >> + unsigned int cdp_max; >> + unsigned int aca_min; >> + unsigned int aca_max; >> +}; >> + >> +struct usb_charger_nb { >> + struct notifier_block nb; >> + struct usb_charger *uchger; >> +}; >> + >> +/** >> + * struct usb_charger - describe one usb charger >> + * @name: Charger name. >> + * @list: For linking usb charger instances into one global list. >> + * @uchger_nh: Notifier head for users to register. >> + * @lock: Protect the notifier head and charger. >> + * @id: The charger id. >> + * @type: The charger type, it can be SDP_TYPE, DCP_TYPE, CDP_TYPE or >> + * ACA_TYPE. >> + * @state: Indicate the charger state. >> + * @cur: Describe the current range by charger type. >> + * @work: Workqueue to be used for reporting users current has changed. >> + * @extcon_dev: For supporting extcon usb gpio device to detect usb cable >> + * event (plugin or not). >> + * @extcon_nb: Report the events to charger from extcon device. >> + * @extcon_type_nb: Report the charger type from extcon device. >> + * @gadget: One usb charger is always tied to one usb gadget. >> + * @old_gadget_state: Record the previous state of one usb gadget to check if >> + * the gadget state is changed. If gadget state is changed, then notify the >> + * event to charger. >> + * @sdp_default_cur_change: Check if it is needed to change the SDP charger >> + * default maximum current. >> + * @get_charger_type: User can get charger type by implementing this callback. >> + * @charger_detect: Charger detection method can be implemented if you need to >> + * manually detect the charger type. >> + * >> + * Users can set 'get_charger_type' and 'charger_detect' callbacks directly >> + * according to their own requirements. Beyond that, users can not touch >> + * anything else directly in this structure. >> + */ >> +struct usb_charger { >> + char name[CHARGER_NAME_MAX]; >> + struct list_head list; >> + struct raw_notifier_head uchger_nh; >> + struct mutex lock; > > Needs comments for lock. I think the above kernel doc has explained this. > >> + int id; >> + enum usb_charger_type type; >> + enum usb_charger_state state; >> + struct usb_charger_current cur; >> + struct work_struct work; >> + >> + struct extcon_dev *extcon_dev; >> + struct usb_charger_nb extcon_nb; >> + struct usb_charger_nb extcon_type_nb; >> + >> + struct usb_gadget *gadget; >> + enum usb_device_state old_gadget_state; >> + unsigned int sdp_default_cur_change; >> + >> + enum usb_charger_type (*get_charger_type)(struct usb_charger *); >> + enum usb_charger_type (*charger_detect)(struct usb_charger *); >> +}; >> + >> +#ifdef CONFIG_USB_CHARGER >> +extern struct usb_charger *usb_charger_find_by_name(const char *name); >> + >> +extern int usb_charger_register_notify(struct usb_charger *uchger, >> + struct notifier_block *nb); >> +extern int usb_charger_unregister_notify(struct usb_charger *uchger, >> + struct notifier_block *nb); >> + >> +extern int usb_charger_set_current(struct usb_charger *uchger, >> + struct usb_charger_current *values); >> +extern int usb_charger_get_current(struct usb_charger *uchger, >> + unsigned int *min, unsigned int *max); >> + >> +extern int usb_charger_set_cur_limit_by_type(struct usb_charger *uchger, >> + enum usb_charger_type type, >> + unsigned int cur_limit); >> +extern int usb_charger_set_cur_limit_by_gadget(struct usb_gadget *gadget, >> + unsigned int cur_limit); >> + >> +extern int usb_charger_plug_by_gadget(struct usb_gadget *gadget, >> + unsigned long state); >> +extern enum usb_charger_type usb_charger_get_type(struct usb_charger *uchger); >> +extern int usb_charger_detect_type(struct usb_charger *uchger); >> +extern enum usb_charger_state usb_charger_get_state(struct usb_charger *uchger); >> + >> +extern int usb_charger_init(struct usb_gadget *ugadget); >> +extern int usb_charger_exit(struct usb_gadget *ugadget); > > You don't need to put "extern" here. > > Please use "scripts/checkpatch.pl --strict" to check this. Sure. Thanks. > >> +#else >> +static inline struct usb_charger *usb_charger_find_by_name(const char *name) >> +{ >> + return ERR_PTR(-ENODEV); >> +} >> + >> +static inline int usb_charger_register_notify(struct usb_charger *uchger, >> + struct notifier_block *nb) >> +{ >> + return 0; >> +} >> + >> +static inline int usb_charger_unregister_notify(struct usb_charger *uchger, >> + struct notifier_block *nb) >> +{ >> + return 0; >> +} >> + >> +static inline int usb_charger_set_current(struct usb_charger *uchger, >> + struct usb_charger_current *values) >> +{ >> + return 0; >> +} >> + >> +static inline int usb_charger_get_current(struct usb_charger *uchger, >> + unsigned int *min, unsigned int *max) >> +{ >> + return 0; >> +} >> + >> +static inline int >> +usb_charger_set_cur_limit_by_type(struct usb_charger *uchger, >> + enum usb_charger_type type, >> + unsigned int cur_limit) >> +{ >> + return 0; >> +} >> + >> +static inline int >> +usb_charger_set_cur_limit_by_gadget(struct usb_gadget *gadget, >> + unsigned int cur_limit) >> +{ >> + return 0; >> +} >> + >> +static inline enum usb_charger_type >> +usb_charger_get_type(struct usb_charger *uchger) >> +{ >> + return UNKNOWN_TYPE; >> +} >> + >> +static inline enum usb_charger_state >> +usb_charger_get_state(struct usb_charger *uchger) >> +{ >> + return USB_CHARGER_REMOVE; >> +} >> + >> +static inline int usb_charger_detect_type(struct usb_charger *uchger) >> +{ >> + return 0; >> +} >> + >> +static inline int usb_charger_plug_by_gadget(struct usb_gadget *gadget, >> + unsigned long state) >> +{ >> + return 0; >> +} >> + >> +static inline int usb_charger_init(struct usb_gadget *ugadget) >> +{ >> + return 0; >> +} >> + >> +static inline int usb_charger_exit(struct usb_gadget *ugadget) >> +{ >> + return 0; >> +} >> +#endif >> + >> +#endif /* __LINUX_USB_CHARGER_H__ */ >> diff --git a/include/uapi/linux/usb/charger.h b/include/uapi/linux/usb/charger.h >> new file mode 100644 >> index 0000000..3c56ec4 >> --- /dev/null >> +++ b/include/uapi/linux/usb/charger.h >> @@ -0,0 +1,31 @@ >> +/* >> + * This file defines the USB charger type and state that are needed for >> + * USB device APIs. >> + */ >> + >> +#ifndef _UAPI__LINUX_USB_CHARGER_H >> +#define _UAPI__LINUX_USB_CHARGER_H >> + >> +/* >> + * USB charger type: >> + * SDP (Standard Downstream Port) >> + * DCP (Dedicated Charging Port) >> + * CDP (Charging Downstream Port) >> + * ACA (Accessory Charger Adapters) >> + */ >> +enum usb_charger_type { >> + UNKNOWN_TYPE, >> + SDP_TYPE, >> + DCP_TYPE, >> + CDP_TYPE, >> + ACA_TYPE, >> +}; >> + >> +/* USB charger state */ >> +enum usb_charger_state { >> + USB_CHARGER_DEFAULT, >> + USB_CHARGER_PRESENT, >> + USB_CHARGER_REMOVE, >> +}; >> + >> +#endif /* _UAPI__LINUX_USB_CHARGER_H */ > > Best regards, > Lu Baolu -- Baolin.wang Best Regards