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Diffstat (limited to 'keyspan_pda/xircom_pgs.S')
| -rw-r--r-- | keyspan_pda/xircom_pgs.S | 1192 |
1 files changed, 1192 insertions, 0 deletions
diff --git a/keyspan_pda/xircom_pgs.S b/keyspan_pda/xircom_pgs.S new file mode 100644 index 0000000..05d99dd --- /dev/null +++ b/keyspan_pda/xircom_pgs.S @@ -0,0 +1,1192 @@ +/* $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 <warner@lothar.com> + * + * 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 <warner@lothar.com> + * + */ + +#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 + mov dptr, #desc_strings + add a, dpl + mov dpl, a + mov a, #0 + addc a, dph + mov dph, a ; dph = desc_strings[a]. big endian! (handy) + ;; it looks like my adapter uses a revision of the EZUSB that + ;; contains "rev D errata number 8", as hinted in the EzUSB example + ;; code. I cannot find an actual errata description on the Cypress + ;; web site, but from the example code it looks like this bug causes + ;; the length of string descriptors to be read incorrectly, possibly + ;; sending back more characters than the descriptor has. The workaround + ;; is to manually send out all of the data. The consequence of not + ;; using the workaround is that the strings gathered by the kernel + ;; driver are too long and are filled with trailing garbage (including + ;; leftover strings). Writing this out by hand is a nuisance, so for + ;; now I will just live with the bug. + movx a, @dptr + mov r1, a + inc dptr + movx a, @dptr + mov r2, a + mov dptr, SUDPTRH + mov a, r1 + movx @dptr, a + mov dptr, SUDPTRL + mov a, r2 + movx @dptr, a + ;; done + ljmp setup_done_ack + +setup_Get_Descriptor_not_string: + ljmp setup_stall + +setup_breq_not_06: + cjne r2, #0x08, setup_breq_not_08 + ;; Get_Configuration. always 1. return one byte. + ;; this is reusable + mov a, #1 +setup_return_one_byte: + mov dptr, IN0BUF + movx @dptr, a + mov a, #1 + mov dptr, IN0BC + movx @dptr, a + ljmp setup_done_ack +setup_breq_not_08: + cjne r2, #0x09, setup_breq_not_09 + ;; 09: Set_Configuration. ignored. + ljmp setup_done_ack +setup_breq_not_09: + cjne r2, #0x0a, setup_breq_not_0a + ;; 0a: Get_Interface. get the current altsetting for int[wIndexL] + ;; since we only have one interface, ignore wIndexL, return a 0 + mov a, #0 + ljmp setup_return_one_byte +setup_breq_not_0a: + cjne r2, #0x0b, setup_breq_not_0b + ;; 0b: Set_Interface. set altsetting for interface[wIndexL]. ignored + ljmp setup_done_ack +setup_breq_not_0b: + ljmp setup_stall + + +setup_done_ack: + ;; now clear HSNAK + mov dptr, EP0CS + mov a, #0x02 + movx @dptr, a + sjmp setup_done +setup_stall: + ;; unhandled. STALL + ;EP0CS |= bmEPSTALL + mov dptr, EP0CS + movx a, @dptr + orl a, EP0STALLbit + movx @dptr, a + sjmp setup_done + +setup_done: + pop acc + pop dph1 + pop dpl1 + pop dph + pop dpl + pop dps + reti + +;;; ============================================================== + +set_baud: ; baud index in r3 + ;; verify a < 10 + mov a, r3 + jb ACC.7, set_baud__badbaud + clr c + subb a, #10 + jnc set_baud__badbaud + mov a, r3 + rl a ; a = index*2 + add a, #LOW(baud_table) + mov dpl, a + mov a, #HIGH(baud_table) + addc a, #0 + mov dph, a + ;; TODO: shut down xmit/receive + ;; TODO: wait for current xmit char to leave + ;; TODO: shut down timer to avoid partial-char glitch + movx a,@dptr ; BAUD_HIGH + mov RCAP2H, a + mov TH2, a + inc dptr + movx a,@dptr ; BAUD_LOW + mov RCAP2L, a + mov TL2, a + ;; TODO: restart xmit/receive + ;; TODO: reenable interrupts, resume tx if pending + clr c ; c=0: success + ret +set_baud__badbaud: + setb c ; c=1: failure + ret + +;;; ================================================== +control_pins: + cjne r1, #0x41, control_pins_in +control_pins_out: + ;TODO BKPT is DTR + mov a, r3 ; wValue[0] holds new bits: b7 is new RTS + xrl a, #0xff ; 1 means active, 0V, +12V ? + anl a, #0x80 + mov r3, a + mov dptr, OUTC + movx a, @dptr ; only change bit 7 + anl a, #0x7F ; ~0x84 + orl a, r3 + movx @dptr, a ; other pins are inputs, bits ignored + ljmp setup_done_ack +control_pins_in: + mov dptr, PINSC + movx a, @dptr + xrl a, #0xff + ljmp setup_return_one_byte + +;;; ======================================== + +ISR_Ep2in: + 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, IN07IRQ ; clear USB int + mov a,#04h + movx @dptr,a + + mov a, #0x20 ; Turn off the green LED + mov dptr,OEA + movx @dptr, a + + + ;; do stuff + lcall start_in + + mov a, #0x20 ; Turn off the green LED + mov dptr,OEA + movx @dptr, a + + + + pop acc + pop dph1 + pop dpl1 + pop dph + pop dpl + pop dps + reti + +ISR_Ep2out: + push dps + push dpl + push dph + push dpl1 + push dph1 + push acc + + mov a, #0x10 ; Turn the green LED + mov dptr,OEA + movx @dptr, a + + + + mov a,EXIF + clr acc.4 + mov EXIF,a ; clear INT2 first + mov dptr, OUT07IRQ ; clear USB int + mov a,#04h + movx @dptr,a + + ;; do stuff + + ;; copy data into buffer. for now, assume we will have enough space + mov dptr, OUT2BC ; get byte count + movx a,@dptr + mov r1, a + clr a + mov dps, a + mov dptr, OUT2BUF ; load DPTR0 with source + mov dph1, #HIGH(tx_ring) ; load DPTR1 with target + mov dpl1, tx_ring_in +OUT_loop: + movx a,@dptr ; read + inc dps ; switch to DPTR1: target + inc dpl1 ; target = tx_ring_in+1 + movx @dptr,a ; store + mov a,dpl1 + cjne a, tx_ring_out, OUT_no_overflow + sjmp OUT_overflow +OUT_no_overflow: + inc tx_ring_in ; tx_ring_in++ + inc dps ; switch to DPTR0: source + inc dptr + djnz r1, OUT_loop + sjmp OUT_done +OUT_overflow: + ;; signal overflow + ;; fall through +OUT_done: + ;; ack + mov dptr,OUT2BC + movx @dptr,a + + ;; start tx + acall maybe_start_tx + ;acall dump_stat + + mov a, #0x20 ; Turn off the green LED + mov dptr,OEA + movx @dptr, a + + pop acc + pop dph1 + pop dpl1 + pop dph + pop dpl + pop dps + reti + +dump_stat: + ;; fill in EP4in with a debugging message: + ;; tx_ring_in, tx_ring_out, rx_ring_in, rx_ring_out + ;; tx_active + ;; tx_ring[0..15] + ;; 0xfc + ;; rx_ring[0..15] + clr a + mov dps, a + + mov dptr, IN4CS + movx a, @dptr + jb acc.1, dump_stat__done; busy: cannot dump, old one still pending + mov dptr, IN4BUF + + mov a, tx_ring_in + movx @dptr, a + inc dptr + mov a, tx_ring_out + movx @dptr, a + inc dptr + + mov a, rx_ring_in + movx @dptr, a + inc dptr + mov a, rx_ring_out + movx @dptr, a + inc dptr + + clr a + jnb TX_RUNNING, dump_stat__no_tx_running + inc a +dump_stat__no_tx_running: + movx @dptr, a + inc dptr + ;; tx_ring[0..15] + inc dps + mov dptr, #tx_ring ; DPTR1: source + mov r1, #16 +dump_stat__tx_ring_loop: + movx a, @dptr + inc dptr + inc dps + movx @dptr, a + inc dptr + inc dps + djnz r1, dump_stat__tx_ring_loop + inc dps + + mov a, #0xfc + movx @dptr, a + inc dptr + + ;; rx_ring[0..15] + inc dps + mov dptr, #rx_ring ; DPTR1: source + mov r1, #16 +dump_stat__rx_ring_loop: + movx a, @dptr + inc dptr + inc dps + movx @dptr, a + inc dptr + inc dps + djnz r1, dump_stat__rx_ring_loop + + ;; now send it + clr a + mov dps, a + mov dptr, IN4BC + mov a, #38 + movx @dptr, a +dump_stat__done: + ret + +;;; ============================================================ + +maybe_start_tx: + ;; make sure the tx process is running. + jb TX_RUNNING, start_tx_done +start_tx: + ;; is there work to be done? + mov a, tx_ring_in + cjne a,tx_ring_out, start_tx__work + ret ; no work +start_tx__work: + ;; tx was not running. send the first character, setup the TI int + inc tx_ring_out ; [++tx_ring_out] + mov dph, #HIGH(tx_ring) + mov dpl, tx_ring_out + movx a, @dptr + mov sbuf, a + setb TX_RUNNING +start_tx_done: + ;; can we unthrottle the host tx process? + ;; step 1: do we care? + mov a, #0 + cjne a, tx_unthrottle_threshold, start_tx__maybe_unthrottle_tx + ;; nope +start_tx_really_done: + ret +start_tx__maybe_unthrottle_tx: + ;; step 2: is there now room? + mov a, tx_ring_out + setb c + subb a, tx_ring_in + ;; a is now write_room. If thresh >= a, we can unthrottle + clr c + subb a, tx_unthrottle_threshold + jc start_tx_really_done ; nope + ;; yes, we can unthrottle. remove the threshold and mark a request + mov tx_unthrottle_threshold, #0 + setb DO_TX_UNTHROTTLE + ;; prod rx, which will actually send the message when in2 becomes free + ljmp start_in + + +serial_int: + push dps + push dpl + push dph + push dpl1 + push dph1 + push acc + jnb TI, serial_int__not_tx + ;; tx finished. send another character if we have one + clr TI ; clear int + clr TX_RUNNING + lcall start_tx +serial_int__not_tx: + jnb RI, serial_int__not_rx + lcall get_rx_char + clr RI ; clear int +serial_int__not_rx: + ;; return + pop acc + pop dph1 + pop dpl1 + pop dph + pop dpl + pop dps + reti + +get_rx_char: + mov dph, #HIGH(rx_ring) + mov dpl, rx_ring_in + inc dpl ; target = rx_ring_in+1 + mov a, sbuf + movx @dptr, a + ;; check for overflow before incrementing rx_ring_in + mov a, dpl + cjne a, rx_ring_out, get_rx_char__no_overflow + ;; signal overflow + ret +get_rx_char__no_overflow: + inc rx_ring_in + ;; kick off USB INpipe + acall start_in + ret + +start_in: + ;; check if the inpipe is already running. + mov a,#0x10 + mov dptr, OEA + movx @dptr,a + + mov dptr, IN2CS + movx a, @dptr + jb acc.1, start_in__done; int will handle it + jb DO_TX_UNTHROTTLE, start_in__do_tx_unthrottle + ;; see if there is any work to do. a serial interrupt might occur + ;; during this sequence? + mov a, rx_ring_in + cjne a, rx_ring_out, start_in__have_work + ret ; nope +start_in__have_work: + ;; now copy as much data as possible into the pipe. 63 bytes max. + clr a + mov dps, a + mov dph, #HIGH(rx_ring) ; load DPTR0 with source + inc dps + mov dptr, IN2BUF ; load DPTR1 with target + movx @dptr, a ; in[0] signals that rest of IN is rx data + inc dptr + inc dps + ;; loop until we run out of data, or we have copied 64 bytes + mov r1, #1 ; INbuf size counter +start_in__loop: + mov a, rx_ring_in + cjne a, rx_ring_out, start_inlocal_irq_enablell_copying + sjmp start_in__kick +start_inlocal_irq_enablell_copying: + inc rx_ring_out + mov dpl, rx_ring_out + movx a, @dptr + inc dps + movx @dptr, a ; write into IN buffer + inc dptr + inc dps + inc r1 + cjne r1, #64, start_in__loop; loop +start_in__kick: + ;; either we ran out of data, or we copied 64 bytes. r1 has byte count + ;; kick off IN + mov a, #0x10 ; Turn the green LED + mov dptr,OEA + movx @dptr, a + mov dptr, IN2BC + mov a, r1 + jz start_in__done + movx @dptr, a + ;; done +start_in__done: + ;acall dump_stat + ret +start_in__do_tx_unthrottle: + ;; special sequence: send a tx unthrottle message + clr DO_TX_UNTHROTTLE + clr a + mov dps, a + mov dptr, IN2BUF + mov a, #1 + movx @dptr, a + inc dptr + mov a, #2 + movx @dptr, a + mov dptr, IN2BC + movx @dptr, a + ret + +putchar: + clr TI + mov SBUF, a +putchar_wait: + jnb TI, putchar_wait + clr TI + ret + + +baud_table: ; baud_high, then baud_low + ;; baud[0]: 110 + .byte BAUD_HIGH(110) + .byte BAUD_LOW(110) + ;; baud[1]: 300 + .byte BAUD_HIGH(300) + .byte BAUD_LOW(300) + ;; baud[2]: 1200 + .byte BAUD_HIGH(1200) + .byte BAUD_LOW(1200) + ;; baud[3]: 2400 + .byte BAUD_HIGH(2400) + .byte BAUD_LOW(2400) + ;; baud[4]: 4800 + .byte BAUD_HIGH(4800) + .byte BAUD_LOW(4800) + ;; baud[5]: 9600 + .byte BAUD_HIGH(9600) + .byte BAUD_LOW(9600) + ;; baud[6]: 19200 + .byte BAUD_HIGH(19200) + .byte BAUD_LOW(19200) + ;; baud[7]: 38400 + .byte BAUD_HIGH(38400) + .byte BAUD_LOW(38400) + ;; baud[8]: 57600 + .byte BAUD_HIGH(57600) + .byte BAUD_LOW(57600) + ;; baud[9]: 115200 + .byte BAUD_HIGH(115200) + .byte BAUD_LOW(115200) + +desc_device: + .byte 0x12, 0x01, 0x00, 0x01, 0xff, 0xff, 0xff, 0x40 + .byte 0xcd, 0x06, 0x04, 0x01, 0x89, 0xab, 1, 2, 3, 0x01 +;;; The "real" device id, which must match the host driver, is that +;;; "0xcd 0x06 0x04 0x01" sequence, which is 0x06cd, 0x0104 + +desc_config1: + .byte 0x09, 0x02, 0x20, 0x00, 0x01, 0x01, 0x00, 0x80, 0x32 + .byte 0x09, 0x04, 0x00, 0x00, 0x02, 0xff, 0xff, 0xff, 0x00 + .byte 0x07, 0x05, 0x82, 0x03, 0x40, 0x00, 0x01 + .byte 0x07, 0x05, 0x02, 0x02, 0x40, 0x00, 0x00 + +desc_strings: + .word string_langids, string_mfg, string_product, string_serial +desc_strings_end: + +string_langids: .byte string_langids_end-string_langids + .byte 3 + .word 0 +string_langids_end: + + ;; sigh. These strings are Unicode, meaning UTF16? 2 bytes each. Now + ;; *that* is a pain in the ass to encode. And they are little-endian + ;; too. Use this perl snippet to get the bytecodes: + /* while (<>) { + @c = split(//); + foreach $c (@c) { + printf("0x%02x, 0x00, ", ord($c)); + } + } + */ + +string_mfg: .byte string_mfg_end-string_mfg + .byte 3 +; .byte "ACME usb widgets" + .byte 0x41, 0x00, 0x43, 0x00, 0x4d, 0x00, 0x45, 0x00, 0x20, 0x00, 0x75, 0x00, 0x73, 0x00, 0x62, 0x00, 0x20, 0x00, 0x77, 0x00, 0x69, 0x00, 0x64, 0x00, 0x67, 0x00, 0x65, 0x00, 0x74, 0x00, 0x73, 0x00 +string_mfg_end: + +string_product: .byte string_product_end-string_product + .byte 3 +; .byte "ACME USB serial widget" + .byte 0x41, 0x00, 0x43, 0x00, 0x4d, 0x00, 0x45, 0x00, 0x20, 0x00, 0x55, 0x00, 0x53, 0x00, 0x42, 0x00, 0x20, 0x00, 0x73, 0x00, 0x65, 0x00, 0x72, 0x00, 0x69, 0x00, 0x61, 0x00, 0x6c, 0x00, 0x20, 0x00, 0x77, 0x00, 0x69, 0x00, 0x64, 0x00, 0x67, 0x00, 0x65, 0x00, 0x74, 0x00 +string_product_end: + +string_serial: .byte string_serial_end-string_serial + .byte 3 +; .byte "47" + .byte 0x34, 0x00, 0x37, 0x00 +string_serial_end: + +;;; ring buffer memory + ;; tx_ring_in+1 is where the next input byte will go + ;; [tx_ring_out] has been sent + ;; if tx_ring_in == tx_ring_out, theres no work to do + ;; there are (tx_ring_in - tx_ring_out) chars to be written + ;; dont let _in lap _out + ;; cannot inc if tx_ring_in+1 == tx_ring_out + ;; write [tx_ring_in+1] then tx_ring_in++ + ;; if (tx_ring_in+1 == tx_ring_out), overflow + ;; else tx_ring_in++ + ;; read/send [tx_ring_out+1], then tx_ring_out++ + + ;; rx_ring_in works the same way + + .org 0x1000 +tx_ring: + .skip 0x100 ; 256 bytes +rx_ring: + .skip 0x100 ; 256 bytes + + + .END + |