path: root/drivers/usb/gadget/configfs.c

#include <linux/configfs.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/nls.h>
#include <linux/usb/composite.h>
#include <linux/usb/gadget_configfs.h>
#include "configfs.h"
#include "u_f.h"
#include "u_os_desc.h"

int check_user_usb_string(const char *name,
		struct usb_gadget_strings *stringtab_dev)
{
	unsigned primary_lang;
	unsigned sub_lang;
	u16 num;
	int ret;

	ret = kstrtou16(name, 0, &num);
	if (ret)
		return ret;

	primary_lang = num & 0x3ff;
	sub_lang = num >> 10;

	/* simple sanity check for valid langid */
	switch (primary_lang) {
	case 0:
	case 0x62 ... 0xfe:
	case 0x100 ... 0x3ff:
		return -EINVAL;
	}
	if (!sub_lang)
		return -EINVAL;

	stringtab_dev->language = num;
	return 0;
}

#define MAX_NAME_LEN	40
#define MAX_USB_STRING_LANGS 2

static const struct usb_descriptor_header *otg_desc[2];

struct gadget_info {
	struct config_group group;
	struct config_group functions_group;
	struct config_group configs_group;
	struct config_group strings_group;
	struct config_group os_desc_group;

	struct mutex lock;
	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
	struct list_head string_list;
	struct list_head available_func;

	struct usb_composite_driver composite;
	struct usb_composite_dev cdev;
	bool use_os_desc;
	char b_vendor_code;
	char qw_sign[OS_STRING_QW_SIGN_LEN];
};

static inline struct gadget_info *to_gadget_info(struct config_item *item)
{
	 return container_of(to_config_group(item), struct gadget_info, group);
}

struct config_usb_cfg {
	struct config_group group;
	struct config_group strings_group;
	struct list_head string_list;
	struct usb_configuration c;
	struct list_head func_list;
	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
};

static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
{
	return container_of(to_config_group(item), struct config_usb_cfg,
			group);
}

struct gadget_strings {
	struct usb_gadget_strings stringtab_dev;
	struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
	char *manufacturer;
	char *product;
	char *serialnumber;

	struct config_group group;
	struct list_head list;
};

struct os_desc {
	struct config_group group;
};

struct gadget_config_name {
	struct usb_gadget_strings stringtab_dev;
	struct usb_string strings;
	char *configuration;

	struct config_group group;
	struct list_head list;
};

static int usb_string_copy(const char *s, char **s_copy)
{
	int ret;
	char *str;
	char *copy = *s_copy;
	ret = strlen(s);
	if (ret > 126)
		return -EOVERFLOW;

	str = kstrdup(s, GFP_KERNEL);
	if (!str)
		return -ENOMEM;
	if (str[ret - 1] == '\n')
		str[ret - 1] = '\0';
	kfree(copy);
	*s_copy = str;
	return 0;
}

#define GI_DEVICE_DESC_SIMPLE_R_u8(__name)	\
static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
			char *page)	\
{	\
	return sprintf(page, "0x%02x\n", \
		to_gadget_info(item)->cdev.desc.__name); \
}

#define GI_DEVICE_DESC_SIMPLE_R_u16(__name)	\
static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
			char *page)	\
{	\
	return sprintf(page, "0x%04x\n", \
		le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
}


#define GI_DEVICE_DESC_SIMPLE_W_u8(_name)		\
static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
		const char *page, size_t len)		\
{							\
	u8 val;						\
	int ret;					\
	ret = kstrtou8(page, 0, &val);			\
	if (ret)					\
		return ret;				\
	to_gadget_info(item)->cdev.desc._name = val;	\
	return len;					\
}

#define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
		const char *page, size_t len)		\
{							\
	u16 val;					\
	int ret;					\
	ret = kstrtou16(page, 0, &val);			\
	if (ret)					\
		return ret;				\
	to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);	\
	return len;					\
}

#define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)	\
	GI_DEVICE_DESC_SIMPLE_R_##_type(_name)	\
	GI_DEVICE_DESC_SIMPLE_W_##_type(_name)

GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);

static ssize_t is_valid_bcd(u16 bcd_val)
{
	if ((bcd_val & 0xf) > 9)
		return -EINVAL;
	if (((bcd_val >> 4) & 0xf) > 9)
		return -EINVAL;
	if (((bcd_val >> 8) & 0xf) > 9)
		return -EINVAL;
	if (((bcd_val >> 12) & 0xf) > 9)
		return -EINVAL;
	return 0;
}

static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
		const char *page, size_t len)
{
	u16 bcdDevice;
	int ret;

	ret = kstrtou16(page, 0, &bcdDevice);
	if (ret)
		return ret;
	ret = is_valid_bcd(bcdDevice);
	if (ret)
		return ret;

	to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
	return len;
}

static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
		const char *page, size_t len)
{
	u16 bcdUSB;
	int ret;

	ret = kstrtou16(page, 0, &bcdUSB);
	if (ret)
		return ret;
	ret = is_valid_bcd(bcdUSB);
	if (ret)
		return ret;

	to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
	return len;
}

static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
{
	char *udc_name = to_gadget_info(item)->composite.gadget_driver.udc_name;

	return sprintf(page, "%s\n", udc_name ?: "");
}

static int unregister_gadget(struct gadget_info *gi)
{
	int ret;

	if (!gi->composite.gadget_driver.udc_name)
		return -ENODEV;

	ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
	if (ret)
		return ret;
	kfree(gi->composite.gadget_driver.udc_name);
	gi->composite.gadget_driver.udc_name = NULL;
	return 0;
}

static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
		const char *page, size_t len)
{
	struct gadget_info *gi = to_gadget_info(item);
	char *name;
	int ret;

	name = kstrdup(page, GFP_KERNEL);
	if (!name)
		return -ENOMEM;
	if (name[len - 1] == '\n')
		name[len - 1] = '\0';

	mutex_lock(&gi->lock);

	if (!strlen(name)) {
		ret = unregister_gadget(gi);
		if (ret)
			goto err;
	} else {
		if (gi->composite.gadget_driver.udc_name) {
			ret = -EBUSY;
			goto err;
		}
		gi->composite.gadget_driver.udc_name = name;
		ret = usb_gadget_probe_driver(&gi->composite.gadget_driver);
		if (ret) {
			gi->composite.gadget_driver.udc_name = NULL;
			goto err;
		}
	}
	mutex_unlock(&gi->lock);
	return len;
err:
	kfree(name);
	mutex_unlock(&gi->lock);
	return ret;
}

CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
CONFIGFS_ATTR(gadget_dev_desc_, UDC);

static struct configfs_attribute *gadget_root_attrs[] = {
	&gadget_dev_desc_attr_bDeviceClass,
	&gadget_dev_desc_attr_bDeviceSubClass,
	&gadget_dev_desc_attr_bDeviceProtocol,
	&gadget_dev_desc_attr_bMaxPacketSize0,
	&gadget_dev_desc_attr_idVendor,
	&gadget_dev_desc_attr_idProduct,
	&gadget_dev_desc_attr_bcdDevice,
	&gadget_dev_desc_attr_bcdUSB,
	&gadget_dev_desc_attr_UDC,
	NULL,
};

static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
{
	 return container_of(to_config_group(item), struct gadget_strings,
			 group);
}

static inline struct gadget_config_name *to_gadget_config_name(
		struct config_item *item)
{
	 return container_of(to_config_group(item), struct gadget_config_name,
			 group);
}

static inline struct usb_function_instance *to_usb_function_instance(
		struc