xircom_pgs.s

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

/*  $Id: loop.s,v 1.23 2000/03/20 09:49:06 warner Exp $
 * 
 *  Firmware for the Keyspan PDA Serial Adapter, a USB serial port based on
 *  the EzUSB microcontroller.
 * 
 *  (C) Copyright 2000 Brian Warner <[e-mail]>
 * 
 * 	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.
 * 
 *  "Keyspan PDA Serial Adapter" is probably a copyright of Keyspan, the
 *  company.
 * 
 *  This serial adapter is basically an EzUSB chip and an RS-232 line driver
 *  in a little widget that has a DB-9 on one end and a USB plug on the other.
 *  It uses the EzUSB's internal UART0 (using the pins from Port C) and timer2
 *  as a baud-rate generator. The wiring is:
 *   PC0/RxD0 <- rxd (DB9 pin 2)         PC4 <- dsr pin 6
 *   PC1/TxD0 -> txd pin 3               PC5 <- ri  pin 9
 *   PC2      -> rts pin 7               PC6 <- dcd pin 1
 *   PC3      <- cts pin 8               PC7 -> dtr pin 4
 *   PB1 -> line driver standby
 *
 *  The EzUSB register constants below come from their excellent documentation
 *  and sample code (which used to be available at www.anchorchips.com, but
 *  that has now been absorbed into Cypress' site and the CD-ROM contents
 *  don't appear to be available online anymore). If we get multiple
 *  EzUSB-based drivers into the kernel, it might be useful to pull them out
 *  into a separate .h file.
 * 
 * THEORY OF OPERATION:
 *
 *   There are two 256-byte ring buffers, one for tx, one for rx.
 *
 *   EP2out is pure tx data. When it appears, the data is copied into the tx
 *   ring and serial transmission is started if it wasn't already running. The
 *   "tx buffer empty" interrupt may kick off another character if the ring
 *   still has data. If the host is tx-blocked because the ring filled up,
 *   it will request a "tx unthrottle" interrupt. If sending a serial character
 *   empties the ring below the desired threshold, we set a bit that will send
 *   up the tx unthrottle message as soon as the rx buffer becomes free.
 *
 *   EP2in (interrupt) is used to send both rx chars and rx status messages
 *   (only "tx unthrottle" at this time) back up to the host. The first byte
 *   of the rx message indicates data (0) or status msg (1). Status messages
 *   are sent before any data.
 *
 *   Incoming serial characters are put into the rx ring by the serial
 *   interrupt, and the EP2in buffer sent if it wasn't already in transit.
 *   When the EP2in buffer returns, the interrupt prompts us to send more
 *   rx chars (or status messages) if they are pending.
 *
 *   Device control happens through "vendor specific" control messages on EP0.
 *   All messages are destined for the "Interface" (with the index always 0,
 *   so that if their two-port device might someday use similar firmware, we
 *   can use index=1 to refer to the second port). The messages defined are:
 *
 *    bRequest = 0 : set baud/bits/parity
 *               1 : unused
 *               2 : reserved for setting HW flow control (CTSRTS)
 *               3 : get/set "modem info" (pin states: DTR, RTS, DCD, RI, etc)
 *               4 : set break (on/off)
 *               5 : reserved for requesting interrupts on pin state change
 *               6 : query buffer room or chars in tx buffer
 *               7 : request tx unthrottle interrupt
 *
 *  The host-side driver is set to recognize the device ID values stashed in
 *  serial EEPROM (0x06cd, 0x0103), program this firmware into place, then
 *  start it running. This firmware will use EzUSB's "renumeration" trick by
 *  simulating a bus disconnect, then reconnect with a different device ID
 *  (encoded in the desc_device descriptor below). The host driver then
 *  recognizes the new device ID and glues it to the real serial driver code.
 *
 * USEFUL DOCS:
 *  EzUSB Technical Reference Manual: <http://www.anchorchips.com>
 *  8051 manuals: everywhere, but try www.dalsemi.com because the EzUSB is
 *   basically the Dallas enhanced 8051 code. Remember that the EzUSB IO ports
 *   use totally different registers!
 *  USB 1.1 spec: www.usb.org
 *
 * HOW TO BUILD:
 *  gcc -x assembler-with-cpp -P -E -o keyspan_pda.asm keyspan_pda.s
 *  as31 -l keyspan_pda.asm
 *  mv keyspan_pda.obj keyspan_pda.hex
 *  perl ezusb_convert.pl keyspan_pda < keyspan_pda.hex > keyspan_pda_fw.h
 * Get as31 from <http://www.pjrc.com/tech/8051/index.html>, and hack on it
 * a bit to make it build.
 *
 * THANKS:
 *  Greg Kroah-Hartman, for coordinating the whole usb-serial thing.
 *  AnchorChips, for making such an incredibly useful little microcontroller.
 *  KeySpan, for making a handy, cheap ($40) widget that was so easy to take
 *           apart and trace with an ohmmeter.
 *
 * TODO:
 *  lots. grep for TODO. Interrupt safety needs stress-testing. Better flow
 *  control. Interrupting host upon change in DCD, etc, counting transitions.
 *  Need to find a safe device id to use (the one used by the Keyspan firmware
 *  under Windows would be ideal.. can anyone figure out what it is?). Parity.
 *  More baud rates. Oh, and the string-descriptor-length silicon bug
 *  workaround should be implemented, but I'm lazy, and the consequence is
 *  that the device name strings that show up in your kernel log will have
 *  lots of trailing binary garbage in them (appears as ????). Device strings
 *  should be made more accurate.
 *
 * Questions, bugs, patches to Brian.
 *
 *  -Brian Warner <[e-mail]>
 *
 */
	
#define HIGH(x) (((x) & 0xff00) / 256)
#define LOW(x) ((x) & 0xff)

#define dpl1 0x84
#define dph1 0x85
#define dps 0x86

;;; our bit assignments
#define TX_RUNNING 0
#define DO_TX_UNTHROTTLE 1
	
	;; stack from 0x60 to 0x7f: should really set SP to 0x60-1, not 0x60
#define STACK #0x60-1

#define EXIF 0x91
#define EIE 0xe8
	.flag EUSB, EIE.0
	.flag ES0, IE.4

#define EP0CS #0x7fb4
#define EP0STALLbit #0x01
#define IN0BUF #0x7f00
#define IN0BC #0x7fb5
#define OUT0BUF #0x7ec0
#define OUT0BC #0x7fc5		
#define IN2BUF #0x7e00
#define IN2BC #0x7fb9
#define IN2CS #0x7fb8
#define OUT2BC #0x7fc9
#define OUT2CS #0x7fc8
#define OUT2BUF #0x7dc0
#define IN4BUF #0x7d00
#define IN4BC #0x7fbd
#define IN4CS #0x7fbc
#define OEB #0x7f9d
#define OUTB #0x7f97
#define OEC #0x7f9e
#define OUTC #0x7f98
#define PINSC #0x7f9b
#define PORTBCFG #0x7f94
#define PORTCCFG #0x7f95
#define OEA	#0x7f9c
#define IN07IRQ #0x7fa9
#define OUT07IRQ #0x7faa
#define IN07IEN #0x7fac
#define OUT07IEN #0x7fad
#define USBIRQ #0x7fab
#define USBIEN #0x7fae
#define USBBAV #0x7faf
#define USBCS #0x7fd6
#define SUDPTRH #0x7fd4
#define SUDPTRL #0x7fd5
#define SETUPDAT #0x7fe8
		
	;; usb interrupt : enable is EIE.0 (0xe8), flag is EXIF.4 (0x91)

	.org 0
	ljmp start
	;; interrupt vectors
	.org 23H
	ljmp serial_int
	.byte 0
	
	.org 43H
	ljmp USB_Jump_Table
	.byte 0			; filled in by the USB core

;;; local variables. These are not initialized properly: do it by hand.
	.org 30H
rx_ring_in:	.byte 0
rx_ring_out:	.byte 0
tx_ring_in:	.byte 0
tx_ring_out:	.byte 0
tx_unthrottle_threshold:	.byte 0
		
	.org 0x100H		; wants to be on a page boundary
USB_Jump_Table:
	ljmp	ISR_Sudav	; Setup Data Available
	.byte 0
	ljmp	0		; Start of Frame
	.byte 0
	ljmp	0		; Setup Data Loading
	.byte 0
	ljmp	0		; Global Suspend
	.byte 	0
	ljmp	0		; USB Reset  	
	.byte	0
	ljmp	0		; Reserved
	.byte	0
	ljmp	0		; End Point 0 In
	.byte	0
	ljmp	0		; End Point 0 Out
	.byte	0
	ljmp	0		; End Point 1 In
	.byte	0
	ljmp	0		; End Point 1 Out
	.byte	0
	ljmp	ISR_Ep2in
	.byte	0
	ljmp	ISR_Ep2out
	.byte	0


	.org 0x200
		
start:	mov SP,STACK-1 ; set stack
	;; clear local variables
	clr a
	mov tx_ring_in, a
	mov tx_ring_out, a
	mov rx_ring_in, a
	mov rx_ring_out, a
	mov tx_unthrottle_threshold, a
	clr TX_RUNNING
	clr DO_TX_UNTHROTTLE
	
	;; clear fifo with "fe"
	mov r1, 0
	mov a, #0xfe
	mov dptr, #tx_ring
clear_tx_ring_loop:
	movx @dptr, a
	inc dptr
	djnz r1, clear_tx_ring_loop

	mov a, #0xfd
	mov dptr, #rx_ring
clear_rx_ring_loop:
	movx @dptr, a
	inc dptr
	djnz r1, clear_rx_ring_loop

;;; turn on the RS-232 driver chip (bring the STANDBY pin low)
;;; on Xircom the STANDBY is wired to PB6 and PC4 
	mov dptr, PORTBCFG
        mov a, #0xBf
        movx @dptr, a
	mov dptr, PORTCCFG
        mov a, #0xef
        movx @dptr, a
	
	;; set OEC.4
        mov a, #0x10
        mov dptr,OEC
        movx @dptr,a

        ;; clear PC4
        mov a, #0x00
        mov dptr,OUTC
        movx @dptr,a

	;; set OEB.6
	mov a, #0x40
	mov dptr,OEB
	movx @dptr,a

	;; clear PB6
	mov a, #0x00
	mov dptr,OUTB
	movx @dptr,a

	;; set OEC.[17]
	mov a, #0x82
	mov dptr,OEC
	movx @dptr,a


	;; set PORTCCFG.[01] to route TxD0,RxD0 to serial port
	mov dptr, PORTCCFG
	mov a, #0x03
	movx @dptr, a
	
	;; set up interrupts, autovectoring
	;; set BKPT
	mov dptr, USBBAV
	movx a,@dptr
	setb acc.0		; AVEN bit to 0
	movx @dptr, a

	mov a,#0x01		; enable SUDAV:	setup data available (for ep0)
	mov dptr, USBIRQ
	movx @dptr, a		; clear SUDAVI
	mov dptr, USBIEN
	movx @dptr, a
	
	mov dptr, IN07IEN
	mov a,#0x04		; enable IN2 int
	movx @dptr, a
	
	mov dptr, OUT07IEN
	mov a,#0x04		; enable OUT2 int
	movx @dptr, a
	mov dptr, OUT2BC
	movx @dptr, a		; arm OUT2

;;	mov a, #0x84		; turn on RTS, DTR
;;	mov dptr,OUTC
;;	movx @dptr, a

	mov a, #0x7             ; turn on  DTR
        mov dptr,USBBAV
        movx @dptr, a

	mov a, #0x20             ; turn on the RED led 
        mov dptr,OEA
        movx @dptr, a

	mov a, #0x80            ; turn on  RTS
        mov dptr,OUTC
        movx @dptr, a

	;; setup the serial port. 9600 8N1.
	mov a,#0x53		; mode 1, enable rx, clear int
	mov SCON, a
	;;  using timer2, in 16-bit baud-rate-generator mode
	;;   (xtal 12MHz, internal fosc 24MHz)
	;;  RCAP2H,RCAP2L = 65536 - fosc/(32*baud)
	;;  57600: 0xFFF2.F, say 0xFFF3
	;;   9600: 0xFFB1.E, say 0xFFB2
	;;    300: 0xF63C
#define BAUD 9600
#define BAUD_TIMEOUT(rate) (65536 - (24 * 1000 * 1000) / (32 * rate))
#define BAUD_HIGH(rate) HIGH(BAUD_TIMEOUT(rate))
#define BAUD_LOW(rate) LOW(BAUD_TIMEOUT(rate))
		
	mov T2CON, #030h	; rclk=1,tclk=1,cp=0,tr2=0(enable later)
	mov r3, #5
	acall set_baud
	setb TR2
	mov SCON, #050h
	
#if 0
	mov r1, #0x40
	mov a, #0x41
send:	
	mov SBUF, a
	inc a
	anl a, #0x3F
	orl a, #0x40
;	xrl a, #0x02
wait1:	
	jnb TI, wait1
	clr TI
	djnz r1, send
;done:	sjmp done

#endif
	
	setb EUSB
	setb EA
	setb ES0
	;acall dump_stat

	;; hey, what say we RENUMERATE! (TRM p.62)
	mov a, #0
	mov dps, a
	mov dptr, USBCS
	mov a, #0x02		; DISCON=0, DISCOE=0, RENUM=1
	movx @dptr, a
	;; now presence pin is floating, simulating disconnect. wait 0.5s
	mov r1, #46
renum_wait1:
	mov r2, #0
renum_wait2:
	mov r3, #0
renum_wait3:
	djnz r3, renum_wait3
	djnz r2, renum_wait2
	djnz r1, renum_wait1	; wait about n*(256^2) 6MHz clocks
	mov a, #0x06		; DISCON=0, DISCOE=1, RENUM=1
	movx @dptr, a
	;; we are back online. the host device will now re-query us
	
	
main:	sjmp main

	

ISR_Sudav:
	push dps
	push dpl
	push dph
	push dpl1
	push dph1
	push acc
	mov a,EXIF
	clr acc.4
	mov EXIF,a		; clear INT2 first
	mov dptr, USBIRQ	; clear USB int
	mov a,#01h
	movx @dptr,a

	;; get request type
	mov dptr, SETUPDAT
	movx a, @dptr
	mov r1, a		; r1 = bmRequestType
	inc dptr
	movx a, @dptr
	mov r2, a		; r2 = bRequest
	inc dptr
	movx a, @dptr
	mov r3, a		; r3 = wValueL
	inc dptr
	movx a, @dptr
	mov r4, a		; r4 = wValueH

	;; main switch on bmRequest.type: standard or vendor
	mov a, r1
	anl a, #0x60
	cjne a, #0x00, setup_bmreq_type_not_standard
	;; standard request: now main switch is on bRequest
	ljmp setup_bmreq_is_standard
	
setup_bmreq_type_not_standard:	
	;; a still has bmreq&0x60
	cjne a, #0x40, setup_bmreq_type_not_vendor
	;; Anchor reserves bRequest 0xa0-0xaf, we use small ones
	;; switch on bRequest. bmRequest will always be 0x41 or 0xc1
	cjne r2, #0x00, setup_ctrl_not_00
	;; 00 is set baud, wValue[0] has baud rate index
	lcall set_baud		; index in r3, carry set if error
	jc setup_bmreq_type_not_standard__do_stall
	ljmp setup_done_ack
setup_bmreq_type_not_standard__do_stall:
	ljmp setup_stall
setup_ctrl_not_00:
	cjne r2, #0x01, setup_ctrl_not_01
	;; 01 is reserved for set bits (parity). TODO
	ljmp setup_stall
setup_ctrl_not_01:
	cjne r2, #0x02, setup_ctrl_not_02
	;; 02 is set HW flow control. TODO
	ljmp setup_stall
setup_ctrl_not_02:
	cjne r2, #0x03, setup_ctrl_not_03
	;; 03 is control pins (RTS, DTR).
	ljmp control_pins	; will jump to setup_done_ack,
				;  or setup_return_one_byte
setup_ctrl_not_03:
	cjne r2, #0x04, setup_ctrl_not_04
	;; 04 is send break (really "turn break on/off"). TODO
	cjne r3, #0x00, setup_ctrl_do_break_on
	;; do break off: restore PORTCCFG.1 to reconnect TxD0 to serial port
	mov dptr, PORTCCFG
	movx a, @dptr
	orl a, #0x02
	movx @dptr, a
	ljmp setup_done_ack
setup_ctrl_do_break_on:
	;; do break on: clear PORTCCFG.0, set TxD high(?) (b1 low)
	mov dptr, OUTC
	movx a, @dptr
	anl a, #0xfd		; ~0x02
	movx @dptr, a
	mov dptr, PORTCCFG
	movx a, @dptr
	anl a, #0xfd		; ~0x02
	movx @dptr, a
	ljmp setup_done_ack
setup_ctrl_not_04:
	cjne r2, #0x05, setup_ctrl_not_05
	;; 05 is set desired interrupt bitmap. TODO
	ljmp setup_stall
setup_ctrl_not_05:
	cjne r2, #0x06, setup_ctrl_not_06
	;; 06 is query room
	cjne r3, #0x00, setup_ctrl_06_not_00
	;; 06, wValue[0]=0 is query write_room
	mov a, tx_ring_out
	setb c
	subb a, tx_ring_in	; out-1-in = 255 - (in-out)
	ljmp setup_return_one_byte
setup_ctrl_06_not_00:
	cjne r3, #0x01, setup_ctrl_06_not_01
	;; 06, wValue[0]=1 is query chars_in_buffer
	mov a, tx_ring_in
	clr c
	subb a, tx_ring_out	; in-out
	ljmp setup_return_one_byte
setup_ctrl_06_not_01:	
	ljmp setup_stall
setup_ctrl_not_06:
	cjne r2, #0x07, setup_ctrl_not_07
	;; 07 is request tx unthrottle interrupt
	mov tx_unthrottle_threshold, r3; wValue[0] is threshold value
	ljmp setup_done_ack
setup_ctrl_not_07:
	ljmp setup_stall
	
setup_bmreq_type_not_vendor:
	ljmp setup_stall


setup_bmreq_is_standard:	
	cjne r2, #0x00, setup_breq_not_00
	;; 00:	Get_Status (sub-switch on bmRequestType: device, ep, int)
	cjne r1, #0x80, setup_Get_Status_not_device
	;; Get_Status(device)
	;;  are we self-powered? no. can we do remote wakeup? no
	;;   so return two zero bytes. This is reusable
setup_return_two_zero_bytes:
	mov dptr, IN0BUF
	clr a
	movx @dptr, a
	inc dptr
	movx @dptr, a
	mov dptr, IN0BC
	mov a, #2
	movx @dptr, a
	ljmp setup_done_ack
setup_Get_Status_not_device:
	cjne r1, #0x82, setup_Get_Status_not_endpoint
	;; Get_Status(endpoint)
	;;  must get stall bit for ep[wIndexL], return two bytes, bit in lsb 0
	;; for now: cheat. TODO
	sjmp setup_return_two_zero_bytes
setup_Get_Status_not_endpoint:
	cjne r1, #0x81, setup_Get_Status_not_interface
	;; Get_Status(interface): return two zeros
	sjmp setup_return_two_zero_bytes
setup_Get_Status_not_interface:	
	ljmp setup_stall
	
setup_breq_not_00:
	cjne r2, #0x01, setup_breq_not_01
	;; 01:	Clear_Feature (sub-switch on wValueL: stall, remote wakeup)
	cjne r3, #0x00, setup_Clear_Feature_not_stall
	;; Clear_Feature(stall). should clear a stall bit. TODO
	ljmp setup_stall
setup_Clear_Feature_not_stall:
	cjne r3, #0x01, setup_Clear_Feature_not_rwake
	;; Clear_Feature(remote wakeup). ignored.
	ljmp setup_done_ack
setup_Clear_Feature_not_rwake:
	ljmp setup_stall
	
setup_breq_not_01:
	cjne r2, #0x03, setup_breq_not_03
	;; 03:	Set_Feature (sub-switch on wValueL: stall, remote wakeup)
	cjne r3, #0x00, setup_Set_Feature_not_stall
	;; Set_Feature(stall). Should set a stall bit. TODO
	ljmp setup_stall
setup_Set_Feature_not_stall:
	cjne r3, #0x01, setup_Set_Feature_not_rwake
	;; Set_Feature(remote wakeup). ignored.
	ljmp setup_done_ack
setup_Set_Feature_not_rwake:
	ljmp setup_stall
	
setup_breq_not_03:	
	cjne r2, #0x06, setup_breq_not_06
	;; 06:	Get_Descriptor (s-switch on wValueH: dev, config[n], string[n])
	cjne r4, #0x01, setup_Get_Descriptor_not_device
	;; Get_Descriptor(device)
	mov dptr, SUDPTRH
	mov a, #HIGH(desc_device)
	movx @dptr, a
	mov dptr, SUDPTRL
	mov a, #LOW(desc_device)
	movx @dptr, a
	ljmp setup_done_ack
setup_Get_Descriptor_not_device:
	cjne r4, #0x02, setup_Get_Descriptor_not_config
	;; Get_Descriptor(config[n])
	cjne r3, #0x00, setup_stall; only handle n==0
	;; Get_Descriptor(config[0])
	mov dptr, SUDPTRH
	mov a, #HIGH(desc_config1)
	movx @dptr, a
	mov dptr, SUDPTRL
	mov a, #LOW(desc_config1)
	movx @dptr, a
	ljmp setup_done_ack
setup_Get_Descriptor_not_config:
	cjne r4, #0x03, setup_Get_Descriptor_not_string
	;; Get_Descriptor(string[wValueL])
	;;  if (wValueL >= maxstrings) stall
	mov a, #((desc_strings_end-desc_strings)/2)
	clr c
	subb a,r3		; a=4, r3 = 0..3 . if a<=0 then stall
	jc  setup_stall
	jz  setup_stall
	mov a, r3
	add a, r3		; a = 2*wValueL