em28xx_read_reg_req
dev->em28xx_read_reg_req = em28xx_read_reg_req;
return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req))
int (*em28xx_read_reg_req)(struct em28xx *dev, u8 req, u16 reg);
int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg);