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/usb/composite.h>
#include <linux/usb/gadget_configfs.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

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 *default_groups[4];

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

	const char *udc_name;
#ifdef CONFIG_USB_OTG
	struct usb_otg_descriptor otg;
#endif
	struct usb_composite_driver composite;
	struct usb_composite_dev cdev;
};

struct config_usb_cfg {
	struct config_group group;
	struct config_group strings_group;
	struct config_group *default_groups[2];
	struct list_head string_list;
	struct usb_configuration c;
	struct list_head func_list;
	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
};

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 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;
}

CONFIGFS_ATTR_STRUCT(gadget_info);
CONFIGFS_ATTR_STRUCT(config_usb_cfg);

#define GI_DEVICE_DESC_ITEM_ATTR(name)	\
	static struct gadget_info_attribute gadget_cdev_desc_##name = \
		__CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,		\
				gadget_dev_desc_##name##_show,		\
				gadget_dev_desc_##name##_store)

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

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


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

#define GI_DEVICE_DESC_SIMPLE_W_u16(_name)	\
	static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
		const char *page, size_t len)		\
{							\
	u16 val;					\
	int ret;					\
	ret = kstrtou16(page, 0, &val);			\
	if (ret)					\
		return ret;				\
	gi->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