ch341.h

#ifndef _CH341_H
#define _CH341_H

/*
 * Baud rate and default timeout
 */
#define DEFAULT_BAUD_RATE 9600
#define DEFAULT_TIMEOUT	  2000

/*
 * CMSPAR, some architectures can't have space and mark parity.
 */
#ifndef CMSPAR
#define CMSPAR 0
#endif

/*
 * Major and minor numbers.
 */
#define CH341_TTY_MAJOR	 169
#define CH341_TTY_MINORS 256

/*
 * Requests.
 */
#define USB_RT_CH341 (USB_TYPE_CLASS | USB_RECIP_INTERFACE)

#define CMD_R  0x95
#define CMD_W  0x9A
#define CMD_C1 0xA1
#define CMD_C2 0xA4
#define CMD_C3 0x5F

#define CH341_CTO_O   0x10
#define CH341_CTO_D   0x20
#define CH341_CTO_R   0x40
#define CH341_CTI_C   0x01
#define CH341_CTI_DS  0x02
#define CH341_CTRL_RI 0x04
#define CH341_CTI_DC  0x08
#define CH341_CTI_ST  0x0f

#define CH341_CTT_M BIT(3)
#define CH341_CTT_F (BIT(2) | BIT(6))
#define CH341_CTT_P BIT(2)
#define CH341_CTT_O BIT(1)

#define CH341_L_ER 0x80
#define CH341_L_ET 0x40
#define CH341_L_PS 0x38
#define CH341_L_PM 0x28
#define CH341_L_PE 0x18
#define CH341_L_PO 0x08
#define CH341_L_SB 0x04
#define CH341_L_D8 0x03
#define CH341_L_D7 0x02
#define CH341_L_D6 0x01
#define CH341_L_D5 0x00

#define CH341_RB 0x05
#define CH341_RL 0x18
#define CH341_NB 0x01

#define CH341_NW 2
#define CH341_NR 2

struct ch341_wb {
	unsigned char *buf;
	dma_addr_t dmah;
	int len;
	int use;
	struct urb *urb;
	struct ch341 *instance;
};

struct ch341_rb {
	int size;
	unsigned char *base;
	dma_addr_t dma;
	int index;
	struct ch341 *instance;
};

struct usb_ch341_line_coding {
	__le32 dwDTERate;
	__u8 bCharFormat;
#define USB_CH341_1_STOP_BITS	0
#define USB_CH341_1_5_STOP_BITS 1
#define USB_CH341_2_STOP_BITS	2

	__u8 bParityType;
#define USB_CH341_NO_PARITY    0
#define USB_CH341_ODD_PARITY   1
#define USB_CH341_EVEN_PARITY  2
#define USB_CH341_MARK_PARITY  3
#define USB_CH341_SPACE_PARITY 4

	__u8 bDataBits;
} __attribute__((packed));

struct ch341 {
	struct usb_device *dev;	    /* the corresponding usb device */
	struct usb_interface *data; /* data interface */
	struct tty_port port;	    /* our tty port data */
	struct urb *ctrlurb;	    /* urbs */
	u8 *ctrl_buffer;	    /* buffers of urbs */
	dma_addr_t ctrl_dma;	    /* dma handles of buffers */
	struct ch341_wb wb[CH341_NW];
	unsigned long read_urbs_free;
	struct urb *read_urbs[CH341_NR];
	struct ch341_rb read_buffers[CH341_NR];
	int rx_buflimit;
	int rx_endpoint;
	spinlock_t read_lock;
	int write_used; /* number of non-empty write buffers */
	int transmitting;
	spinlock_t write_lock;
	struct mutex mutex;
	bool disconnected;
	struct usb_ch341_line_coding line; /* bits, stop, parity */
	struct work_struct work;	   /* work queue entry for line discipline waking up */
	unsigned int ctrlin;		   /* input control lines (DCD, DSR, RI, break, overruns) */
	unsigned int ctrlout;		   /* output control lines (DTR, RTS) */
	struct async_icount iocount;	   /* counters for control line changes */
	struct async_icount oldcount;	   /* for comparison of counter */
	wait_queue_head_t wioctl;	   /* for ioctl */
	unsigned int writesize;		   /* max packet size for the output bulk endpoint */
	unsigned int readsize, ctrlsize;   /* buffer sizes for freeing */
	unsigned int minor;		   /* ch341 minor number */
	unsigned char clocal;		   /* termios CLOCAL */
	unsigned int susp_count;	   /* number of suspended interfaces */
	u8 bInterval;
	struct usb_anchor delayed; /* writes queued for a device about to be woken */
	unsigned long quirks;
	bool hardflow;
};

/* constants describing various quirks and errors */
#define NO_UNION_NORMAL		 BIT(0)
#define SINGLE_RX_URB		 BIT(1)
#define NO_CAP_LINE		 BIT(2)
#define NO_DATA_INTERFACE	 BIT(4)
#define IGNORE_DEVICE		 BIT(5)
#define QUIRK_CONTROL_LINE_STATE BIT(6)
#define CLEAR_HALT_CONDITIONS	 BIT(7)
#endif