On 14 August 2015 at 23:27, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Aug 14, 2015 at 05:47:45PM +0800, 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.
>>
>> 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.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>> ---
>> drivers/usb/gadget/Kconfig | 7 +
>> drivers/usb/gadget/Makefile | 1 +
>> drivers/usb/gadget/charger.c | 561 +++++++++++++++++++++++++++++++++++++++
>> include/linux/usb/usb_charger.h | 145 ++++++++++
>> 4 files changed, 714 insertions(+)
>> create mode 100644 drivers/usb/gadget/charger.c
>> create mode 100644 include/linux/usb/usb_charger.h
>>
>> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
>> index bcf83c0..3d2b959 100644
>> --- a/drivers/usb/gadget/Kconfig
>> +++ b/drivers/usb/gadget/Kconfig
>> @@ -127,6 +127,13 @@ config USB_GADGET_STORAGE_NUM_BUFFERS
>> a module parameter as well.
>> If unsure, say 2.
>>
>> +config USB_CHARGER
>> + bool "USB charger support"
>> + 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/Makefile b/drivers/usb/gadget/Makefile
>> index 598a67d..1e421c1 100644
>> --- a/drivers/usb/gadget/Makefile
>> +++ b/drivers/usb/gadget/Makefile
>> @@ -10,3 +10,4 @@ libcomposite-y := usbstring.o config.o epautoconf.o
>> libcomposite-y += composite.o functions.o configfs.o u_f.o
>>
>> obj-$(CONFIG_USB_GADGET) += udc/ function/ legacy/
>> +obj-$(CONFIG_USB_CHARGER) += charger.o
>> diff --git a/drivers/usb/gadget/charger.c b/drivers/usb/gadget/charger.c
>> new file mode 100644
>> index 0000000..f24f7b7
>> --- /dev/null
>> +++ b/drivers/usb/gadget/charger.c
>> @@ -0,0 +1,561 @@
>> +/*
>> + * usb charger.c -- USB charger driver
>
> I think your company also wants a copyright line here. Not that it
> means anything at all, but some lawyers love cargo-cult text blobs.
>
Hi Greg,
Thanks for your reviewing and comments. I'll add it in next patch.
>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>
> I have to ask, do you really mean "any later version"?
>
I think I did not get your point, could you explain it detailedly?
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <linux/err.h>
>> +#include <linux/extcon.h>
>> +#include <linux/export.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include <linux/usb.h>
>> +#include <linux/usb/ch9.h>
>> +#include <linux/usb/gadget.h>
>> +#include <linux/usb/usb_charger.h>
>> +
>> +#define DEFAULT_CUR_PROTECT (50)
>> +#define DEFAULT_SDP_CUR_LIMIT (500 - DEFAULT_CUR_PROTECT)
>> +#define DEFAULT_DCP_CUR_LIMIT (1500 - DEFAULT_CUR_PROTECT)
>> +#define DEFAULT_CDP_CUR_LIMIT (1500 - DEFAULT_CUR_PROTECT)
>> +#define DEFAULT_ACA_CUR_LIMIT (1500 - DEFAULT_CUR_PROTECT)
>> +
>> +static DEFINE_IDA(usb_charger_ida);
>> +static struct bus_type usb_charger_subsys = {
>> + .name = "usb-charger",
>> + .dev_name = "usb-charger",
>> +};
>> +
>> +static struct usb_charger *dev_to_uchger(struct device *udev)
>> +{
>> + return container_of(udev, struct usb_charger, dev);
>> +}
>> +
>> +static ssize_t usb_charger_cur_show(struct device *dev,
>> + struct device_attribute *attr,
>> + char *buf)
>> +{
>> + struct usb_charger *uchger = dev_to_uchger(dev);
>> +
>> + return scnprintf(buf, PAGE_SIZE, "%d %d %d %d\n",
>> + uchger->cur_limit.sdp_cur_limit,
>> + uchger->cur_limit.dcp_cur_limit,
>> + uchger->cur_limit.cdp_cur_limit,
>> + uchger->cur_limit.aca_cur_limit);
>> +}
>> +
>> +static ssize_t usb_charger_cur_store(struct device *dev,
>> + struct device_attribute *attr,
>> + const char *buf, size_t count)
>> +{
>> + struct usb_charger *uchger = dev_to_uchger(dev);
>> + struct usb_charger_cur_limit cur;
>> + int ret;
>> +
>> + ret = sscanf(buf, "%d %d %d %d",
>> + &cur.sdp_cur_limit, &cur.dcp_cur_limit,
>> + &cur.cdp_cur_limit, &cur.aca_cur_limit);
>> + if (ret == 0)
>> + return -EINVAL;
>> +
>> + ret = usb_charger_set_cur_limit(uchger, &cur);
>> + if (ret < 0)
>> + return ret;
>> +
>> + return count;
>> +}
>> +static DEVICE_ATTR(cur_limit, 0644, usb_charger_cur_show, usb_charger_cur_store);
>
> DEVICE_ATTR_RW()?
>
OK, I'll replace it with DEVICE_ATTR_RW().
>> +
>> +static struct attribute *uchger_attributes[] = {
>> + &dev_attr_cur_limit.attr,
>> + NULL
>> +};
>> +
>> +static const struct attribute_group uchger_attr_group = {
>> + .attrs = uchger_attributes,
>> +};
>
> ATTRIBUTE_GROUPS()?
>
OK, I'll replace it with ATTRIBUTE_GROUPS().
>> +
>> +/*
>> + * usb_charger_find_by_name - Get the usb charger device by name.
>> + * @name - usb charger device name.
>> + *
>> + * return the instance of usb charger device, the device must be
>> + * released with usb_charger_put().
>> + */
>> +struct usb_charger *usb_charger_find_by_name(const char *name)
>> +{
>> + struct device *udev;
>> +
>> + if (!name)
>> + return ERR_PTR(-EINVAL);
>> +
>> + udev = bus_find_device_by_name(&usb_charger_subsys, NULL, name);
>> + if (!udev)
>> + return ERR_PTR(-ENODEV);
>> +
>> + return dev_to_uchger(udev);
>> +}
>> +
>> +/*
>> + * usb_charger_get() - Reference a usb charger.
>> + * @uchger - usb charger
>> + */
>> +struct usb_charger *usb_charger_get(struct usb_charger *uchger)
>> +{
>> + return (uchger && get_device(&uchger->dev)) ? uchger : NULL;
>> +}
>> +
>> +/*
>> + * usb_charger_put() - Dereference a usb charger.
>> + * @uchger - charger to release
>> + */
>> +void usb_charger_put(struct usb_charger *uchger)
>> +{
>> + if (uchger)
>> + put_device(&uchger->dev);
>> +}
>> +
>> +/*
>> + * usb_charger_register_notify() - Register a notifiee to get notified by
>> + * any attach status changes from the usb charger detection.
>> + * @uchger - the usb charger device 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)
>> + return -EINVAL;
>> +
>> + mutex_lock(&uchger->lock);
>> + ret = raw_notifier_chain_register(&uchger->uchger_nh, nb);
>> +
>> + /* Generate an initial notify so users start in the right state */
>> + if (!ret) {
>> + usb_charger_detect_type(uchger);
>> + raw_notifier_call_chain(&uchger->uchger_nh,
>> + usb_charger_get_cur_limit(uchger),
>> + uchger);
>> + }
>> + mutex_unlock(&uchger->lock);
>> +
>> + return ret;
>> +}
>> +
>> +/*
>> + * usb_charger_unregister_notify() - Unregister a notifiee from the usb charger.
>> + * @uchger - the usb charger device 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)
>> + return -EINVAL;
>> +
>> + mutex_lock(&uchger->lock);
>> + ret = raw_notifier_chain_unregister(&uchger->uchger_nh, nb);
>> + mutex_unlock(&uchger->lock);
>> +
>> + return ret;
>> +}
>> +
>> +/*
>> + * usb_charger_detect_type() - Get the usb charger type by the callback
>> + * which is implemented by gadget operations.
>> + * @uchger - the usb charger device.
>> + *
>> + * return the usb charger type.
>> + */
>> +enum usb_charger_type
>> +usb_charger_detect_type(struct usb_charger *uchger)
>> +{
>> + if (uchger->gadget && uchger->gadget->ops
>> + && uchger->gadget->ops->get_charger_type)
>> + uchger->type =
>> + uchger->gadget->ops->get_charger_type(uchger->gadget);
>> + else
>> + uchger->type = UNKNOWN_TYPE;
>> +
>> + return uchger->type;
>> +}
>> +
>> +/*
>> + * usb_charger_set_cur_limit() - Set the current limitation.
>> + * @uchger - the usb charger device.
>> + * @cur_limit_set - the current limitation.
>> + */
>> +int usb_charger_set_cur_limit(struct usb_charger *uchger,
>> + struct usb_charger_cur_limit *cur_limit_set)
>> +{
>> + if (!uchger || !cur_limit_set)
>> + return -EINVAL;
>> +
>> + uchger->cur_limit.sdp_cur_limit = cur_limit_set->sdp_cur_limit;
>> + uchger->cur_limit.dcp_cur_limit = cur_limit_set->dcp_cur_limit;
>> + uchger->cur_limit.cdp_cur_limit = cur_limit_set->cdp_cur_limit;
>> + uchger->cur_limit.aca_cur_limit = cur_limit_set->aca_cur_limit;
>> + return 0;
>> +}
>> +
>> +/*
>> + * usb_charger_get_cur_limit() - Get the current limitation by
>> + * different usb charger type.
>> + * @uchger - the usb charger device.
>> + *
>> + * return the current limitation to set.
>> + */
>> +unsigned int
>> +usb_charger_get_cur_limit(struct usb_charger *uchger)
>> +{
>> + enum usb_charger_type uchger_type = uchger->type;
>> + unsigned int cur_limit;
>> +
>> + switch (uchger_type) {
>> + case SDP_TYPE:
>> + cur_limit = uchger->cur_limit.sdp_cur_limit;
>> + break;
>> + case DCP_TYPE:
>> + cur_limit = uchger->cur_limit.dcp_cur_limit;
>> + break;
>> + case CDP_TYPE:
>> + cur_limit = uchger->cur_limit.cdp_cur_limit;
>> + break;
>> + case ACA_TYPE:
>> + cur_limit = uchger->cur_limit.aca_cur_limit;
>> + break;
>> + default:
>> + return 0;
>> + }
>> +
>> + return cur_limit;
>> +}
>> +
>> +/*
>> + * usb_charger_notifier_others() - It will notify other device registered
>> + * on usb charger when the usb charger state is changed.
>> + * @uchger - the usb charger device.
>> + * @state - the state of the usb charger.
>> + */
>> +static void
>> +usb_charger_notify_others(struct usb_charger *uchger,
>> + enum usb_charger_state state)
>> +{
>> + mutex_lock(&uchger->lock);
>> + uchger->state = state;
>> +
>> + switch (state) {
>> + case USB_CHARGER_PRESENT:
>> + usb_charger_detect_type(uchger);
>> + raw_notifier_call_chain(&uchger->uchger_nh,
>> + usb_charger_get_cur_limit(uchger),
>> + uchger);
>> + break;
>> + case USB_CHARGER_REMOVE:
>> + uchger->type = UNKNOWN_TYPE;
>> + raw_notifier_call_chain(&uchger->uchger_nh, 0, uchger);
>> + break;
>> + default:
>> + dev_warn(&uchger->dev, "Unknown USB charger state: %d\n",
>> + state);
>> + break;
>> + }
>> + mutex_unlock(&uchger->lock);
>> +}
>> +
>> +/*
>> + * 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 (!uchger)
>> + return NOTIFY_BAD;
>> +
>> + /* Report event to power 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_others(uchger, uchger_state);
>> +
>> + return NOTIFY_OK;
>> +}
>> +
>> +/*
>> + * usb_charger_plug_by_gadget() - Set the usb charger current limitation
>> + * according to the usb gadget device state.
>> + * @nb - the notifier block that notified by usb gadget device.
>> + * @state - the usb gadget state.
>> + * @data - here specify a usb gadget device.
>> + */
>> +static int
>> +usb_charger_plug_by_gadget(struct notifier_block *nb,
>> + unsigned long state, void *data)
>> +{
>> + struct usb_gadget *gadget = (struct usb_gadget *)data;
>> + struct usb_charger *uchger = gadget->uchger;
>> + enum usb_charger_state uchger_state;
>> +
>> + if (!uchger)
>> + return NOTIFY_BAD;
>> +
>> + /* Report event to power to setting the current limitation
>> + * for this usb charger when one usb charger state is changed
>> + * with detecting by usb gadget state.
>> + */
>> + if (uchger->old_gadget_state != state) {
>> + uchger->old_gadget_state = state;
>> +
>> + if (state >= USB_STATE_ATTACHED)
>> + uchger_state = USB_CHARGER_PRESENT;
>> + else if (state == USB_STATE_NOTATTACHED)
>> + uchger_state = USB_CHARGER_REMOVE;
>> + else
>> + uchger_state = USB_CHARGER_DEFAULT;
>> +
>> + usb_charger_notify_others(uchger, uchger_state);
>> + }
>> +
>> + return NOTIFY_OK;
>> +}
>> +
>> +static int devm_uchger_dev_match(struct device *dev, void *res, void *data)
>> +{
>> + struct usb_charger **r = res;
>> +
>> + if (WARN_ON(!r || !*r))
>> + return 0;
>> +
>> + return *r == data;
>> +}
>> +
>> +static void usb_charger_release(struct device *dev)
>> +{
>> + struct usb_charger *uchger = dev_get_drvdata(dev);
>> +
>> + kfree(uchger->name);
>> + kfree(uchger);
>> +}
>> +
>> +/*
>> + * usb_charger_unregister() - Unregister a usb charger device.
>> + * @uchger - the usb charger to be unregistered.
>> + */
>> +static int usb_charger_unregister(struct usb_charger *uchger)
>> +{
>> + if (!uchger)
>> + return -EINVAL;
>> +
>> + sysfs_remove_group(&uchger->dev.kobj, &uchger_attr_group);
>> + device_unregister(&uchger->dev);
>> +
>> + return 0;
>> +}
>> +
>> +static void devm_uchger_dev_unreg(struct device *dev, void *res)
>> +{
>> + usb_charger_unregister(*(struct usb_charger **)res);
>> +}
>> +
>> +void devm_usb_charger_unregister(struct device *dev,
>> + struct usb_charger *uchger)
>> +{
>> + devres_release(dev, devm_uchger_dev_unreg,
>> + devm_uchger_dev_match, uchger);
>> +}
>> +
>> +/*
>> + * usb_charger_register() - Register a new usb charger device
>> + * which is created by the usb charger framework.
>> + * @uchger - the new usb charger device.
>> + */
>> +static int usb_charger_register(struct device *dev, struct usb_charger *uchger)
>> +{
>> + int ret;
>> +
>> + if (!uchger) {
>> + dev_err(dev, "no device provided for charger\n");
>> + return -EINVAL;
>> + }
>> +
>> + uchger->dev.parent = dev;
>> + uchger->dev.release = usb_charger_release;
>> + uchger->dev.bus = &usb_charger_subsys;
>> +
>> + ret = ida_simple_get(&usb_charger_ida, 0, 0, GFP_KERNEL);
>> + if (ret < 0) {
>> + dev_err(dev, "get usb charger id failed\n");
>> + return ret;
>> + }
>> +
>> + uchger->id = ret;
>> + dev_set_name(&uchger->dev, "usb-charger.%d", uchger->id);
>> + dev_set_drvdata(&uchger->dev, uchger);
>> +
>> + ret = device_register(&uchger->dev);
>> + if (ret)
>> + goto fail_register;
>> +
>> + ret = sysfs_create_group(&uchger->dev.kobj, &uchger_attr_group);
>
> And you just raced with userspace, and lost :(
>
> Assign the group to the device _before_ you tell userspace about it.
>
> The big hint here that is wrong is that you have to call a sysfs_*
> function for a struct device. There is no device_create_group() call
> for a reason.
>
I think your suggestion is device_add_groups() and not
device_create_group() which is not found in mainline. Is it right?
>
>
>> + if (ret)
>> + goto fail_create_files;
>> +
>> + return 0;
>> +
>> +fail_create_files:
>> + device_unregister(&uchger->dev);
>> +fail_register:
>> + put_device(&uchger->dev);
>> + ida_simple_remove(&usb_charger_ida, uchger->id);
>> + uchger->id = -1;
>> + dev_err(dev, "Failed to register usb charger (%s)\n",
>> + uchger->name);
>> + return ret;
>> +}
>> +
>> +int devm_usb_charger_register(struct device *dev,
>> + struct usb_charger *uchger)
>> +{
>> + struct usb_charger **ptr;
>> + int ret;
>> +
>> + ptr = devres_alloc(devm_uchger_dev_unreg, sizeof(*ptr), GFP_KERNEL);
>> + if (!ptr)
>> + return -ENOMEM;
>> +
>> + ret = usb_charger_register(dev, uchger);
>> + if (ret) {
>> + devres_free(ptr);
>> + return ret;
>> + }
>> +
>> + *ptr = uchger;
>> + devres_add(dev, ptr);
>> +
>> + return 0;
>> +}
>> +
>> +int usb_charger_init(struct usb_gadget *ugadget)
>> +{
>> + struct usb_charger *uchger;
>> + struct extcon_dev *edev;
>> + char buf[100];
>
> That's a lot of stack, why?
>
Consider storing a new usb charger name firstly with buf[], but now
will remove the 'name' memeber in struct usb_charger.
>> + char *str;
>> + int ret;
>> +
>> + if (!ugadget)
>> + return -EINVAL;
>> +
>> + uchger = devm_kzalloc(&ugadget->dev, sizeof(struct usb_charger),
>> + GFP_KERNEL);
>
> No, you are creating a new struct device, you can't assign its resources
> to another struct device, that breaks all of the lifetime rules.
> kzalloc() only please.
>
Make sense of it.
>> + if (!uchger)
>> + return -ENOMEM;
>> +
>> + sprintf(buf, "usb-charger.%s", ugadget->name);
>> + str = devm_kzalloc(&ugadget->dev, sizeof(char) * (strlen(buf) + 1),
>> + GFP_KERNEL);
>
> Why have a string when you already have a name for the device, in the
> device itself? What is this all for?
>
Consider expanding to other uses with member 'name' in future, but I
think it is reasonable to remove these with your suggestion.
>
>> + if (!str)
>> + return -ENOMEM;
>> +
>> + strcpy(str, buf);
>> + uchger->name = str;
>> + uchger->type = UNKNOWN_TYPE;
>> + uchger->state = USB_CHARGER_DEFAULT;
>> + uchger->id = -1;
>> + uchger->cur_limit.sdp_cur_limit = DEFAULT_SDP_CUR_LIMIT;
>> + uchger->cur_limit.dcp_cur_limit = DEFAULT_DCP_CUR_LIMIT;
>> + uchger->cur_limit.cdp_cur_limit = DEFAULT_CDP_CUR_LIMIT;
>> + uchger->cur_limit.aca_cur_limit = DEFAULT_ACA_CUR_LIMIT;
>> +
>> + mutex_init(&uchger->lock);
>> + INIT_LIST_HEAD(&uchger->entry);
>> + RAW_INIT_NOTIFIER_HEAD(&uchger->uchger_nh);
>> +
>> + /* 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;
>> + extcon_register_notifier(edev, EXTCON_USB, &uchger->extcon_nb.nb);
>> + }
>> +
>> + /* register a notifier on a usb gadget device */
>> + uchger->gadget = ugadget;
>> + ugadget->uchger = uchger;
>> + uchger->old_gadget_state = ugadget->state;
>> + uchger->gadget_nb.notifier_call = usb_charger_plug_by_gadget;
>> + usb_gadget_register_notify(ugadget, &uchger->gadget_nb);
>> +
>> + /* register a new usb charger */
>> + ret = usb_charger_register(&ugadget->dev, uchger);
>> + if (ret)
>> + goto fail;
>> +
>> + return 0;
>> +
>> +fail:
>> + if (uchger->extcon_dev)
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_USB, &uchger->extcon_nb.nb);
>> +
>> + usb_gadget_unregister_notify(uchger->gadget, &uchger->gadget_nb);
>> + return ret;
>> +}
>> +
>> +int usb_charger_exit(struct usb_gadget *ugadget)
>> +{
>> + struct usb_charger *uchger = ugadget->uchger;
>> +
>> + if (!uchger)
>> + return -EINVAL;
>> +
>> + if (uchger->extcon_dev)
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_USB, &uchger->extcon_nb.nb);
>> +
>> + usb_gadget_unregister_notify(uchger->gadget, &uchger->gadget_nb);
>> + ida_simple_remove(&usb_charger_ida, uchger->id);
>> +
>> + return usb_charger_unregister(uchger);
>> +}
>> +
>> +static int __init usb_charger_sysfs_init(void)
>> +{
>> + return subsys_system_register(&usb_charger_subsys, NULL);
>> +}
>> +core_initcall(usb_charger_sysfs_init);
>> +
>> +MODULE_AUTHOR("Baolin Wang <baolin.wang@xxxxxxxxxx>");
>> +MODULE_DESCRIPTION("USB charger driver");
>> +MODULE_LICENSE("GPL");
>> diff --git a/include/linux/usb/usb_charger.h b/include/linux/usb/usb_charger.h
>> new file mode 100644
>> index 0000000..8cbfaae
>> --- /dev/null
>> +++ b/include/linux/usb/usb_charger.h
>> @@ -0,0 +1,145 @@
>> +#ifndef __LINUX_USB_CHARGER_H__
>> +#define __LINUX_USB_CHARGER_H__
>> +
>> +#include <linux/device.h>
>> +#include <linux/notifier.h>
>> +#include <linux/sysfs.h>
>> +#include <linux/usb/ch9.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,
>> +};
>> +
>> +/* Current limitation by charger type */
>> +struct usb_charger_cur_limit {
>> + unsigned int sdp_cur_limit;
>> + unsigned int dcp_cur_limit;
>> + unsigned int cdp_cur_limit;
>> + unsigned int aca_cur_limit;
>> +};
>> +
>> +struct usb_charger_nb {
>> + struct notifier_block nb;
>> + struct usb_charger *uchger;
>> +};
>> +
>> +struct usb_charger {
>> + /* Internal data. Please do not set. */
>
> Heh, as if people read comments :(
>
OK, remove it.
>> + const char *name;
>
> This isn't needed, use the one in your struct device.
>
OK, remove it.
>> + struct device dev;
>> + struct raw_notifier_head uchger_nh;
>> + struct list_head entry;
>
> Why do you need another list? The device already is on a list.
>
Sorry, I did not remember to remove the 'entry' member in the structure
>> + struct mutex lock;
>
> What is this protecting, document it.
>
OK, I'll add some comments for the lock.
> thanks,
>
> greg k-h
--
Baolin.wang
Best Regards
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