xref: /openbsd/sys/dev/pci/if_tlreg.h (revision 404b540a)
1 /*	$OpenBSD: if_tlreg.h,v 1.9 2005/12/17 07:31:27 miod Exp $	*/
2 
3 /*
4  * Copyright (c) 1997, 1998
5  *	Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Bill Paul.
18  * 4. Neither the name of the author nor the names of any co-contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
32  * THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * $FreeBSD: src/sys/pci/if_tlreg.h,v 1.17 2001/02/09 06:11:21 bmilekic Exp $
35  */
36 
37 
38 struct tl_type {
39 	u_int16_t		tl_vid;
40 	u_int16_t		tl_did;
41 	char			*tl_name;
42 };
43 
44 /*
45  * ThunderLAN TX/RX list format. The TX and RX lists are pretty much
46  * identical: the list begins with a 32-bit forward pointer which points
47  * at the next list in the chain, followed by 16 bits for the total
48  * frame size, and a 16 bit status field. This is followed by a series
49  * of 10 32-bit data count/data address pairs that point to the fragments
50  * that make up the complete frame.
51  */
52 
53 #define TL_MAXFRAGS		10
54 #define TL_RX_LIST_CNT		20
55 #define TL_TX_LIST_CNT		64
56 #define TL_MIN_FRAMELEN		128
57 
58 struct tl_frag {
59 	u_int32_t		tlist_dcnt;
60 	u_int32_t		tlist_dadr;
61 };
62 
63 struct tl_list {
64 	u_int32_t		tlist_fptr;	/* phys address of next list */
65 	u_int16_t		tlist_cstat;	/* status word */
66 	u_int16_t		tlist_frsize;	/* size of data in frame */
67 	struct tl_frag		tl_frag[TL_MAXFRAGS];
68 };
69 
70 /*
71  * This is a special case of an RX list. By setting the One_Frag
72  * bit in the NETCONFIG register, the driver can force the ThunderLAN
73  * chip to use only one fragment when DMAing RX frames.
74  */
75 
76 struct tl_list_onefrag {
77 	u_int32_t		tlist_fptr;
78 	u_int16_t		tlist_cstat;
79 	u_int16_t		tlist_frsize;
80 	struct tl_frag		tl_frag;
81 };
82 
83 struct tl_list_data {
84 	struct tl_list_onefrag	tl_rx_list[TL_RX_LIST_CNT];
85 	struct tl_list		tl_tx_list[TL_TX_LIST_CNT];
86 	unsigned char		tl_pad[TL_MIN_FRAMELEN];
87 };
88 
89 struct tl_chain {
90 	struct tl_list		*tl_ptr;
91 	struct mbuf		*tl_mbuf;
92 	struct tl_chain		*tl_next;
93 };
94 
95 struct tl_chain_onefrag {
96 	struct tl_list_onefrag	*tl_ptr;
97 	struct mbuf		*tl_mbuf;
98 	struct tl_chain_onefrag	*tl_next;
99 };
100 
101 struct tl_chain_data {
102 	struct tl_chain_onefrag	tl_rx_chain[TL_RX_LIST_CNT];
103 	struct tl_chain		tl_tx_chain[TL_TX_LIST_CNT];
104 
105 	struct tl_chain_onefrag	*tl_rx_head;
106 	struct tl_chain_onefrag	*tl_rx_tail;
107 
108 	struct tl_chain		*tl_tx_head;
109 	struct tl_chain		*tl_tx_tail;
110 	struct tl_chain		*tl_tx_free;
111 };
112 
113 struct tl_products {
114 	u_int16_t	tp_vend;
115 	u_int16_t	tp_prod;
116 	u_int32_t	tp_tlphymedia;
117 };
118 
119 struct tl_softc {
120 	struct device		sc_dev;		/* generic device structure */
121 	void *			sc_ih;		/* interrupt handler cookie */
122 	struct arpcom		arpcom;		/* interface info */
123 	struct ifmedia		ifmedia;	/* media info */
124 	struct timeout		tl_stats_tmo, tl_wait_tmo;
125 	bus_space_handle_t	tl_bhandle;
126 	bus_space_tag_t		tl_btag;
127 	bus_dma_tag_t		sc_dmat;
128 	struct tl_type		*tl_dinfo;	/* ThunderLAN adapter info */
129 	struct tl_type		*tl_pinfo;	/* PHY info struct */
130 	int			tl_if_flags;
131 	u_int8_t		tl_ctlr;	/* chip number */
132 	u_int8_t		tl_eeaddr;
133 	struct tl_list_data	*tl_ldata;	/* TX/RX lists and mbufs */
134 	struct tl_chain_data	tl_cdata;
135 	u_int8_t		tl_txeoc;
136 	u_int8_t		tl_bitrate;
137 	struct mii_data		sc_mii;
138 	const struct tl_products *tl_product;
139 };
140 
141 /*
142  * Transmit interrupt threshold.
143  */
144 #define TX_THR		0x00000004
145 
146 /*
147  * General constants that are fun to know.
148  *
149  * The ThunderLAN controller is made by Texas Instruments. The
150  * manual indicates that if the EEPROM checksum fails, the PCI
151  * vendor and device ID registers will be loaded with TI-specific
152  * values.
153  */
154 #define	TI_VENDORID		0x104C
155 #define	TI_DEVICEID_THUNDERLAN	0x0500
156 
157 /*
158  * These are the PCI vendor and device IDs for Compaq ethernet
159  * adapters based on the ThunderLAN controller.
160  */
161 #define COMPAQ_VENDORID				0x0E11
162 #define COMPAQ_DEVICEID_NETEL_10_100		0xAE32
163 #define COMPAQ_DEVICEID_NETEL_UNKNOWN		0xAE33
164 #define COMPAQ_DEVICEID_NETEL_10		0xAE34
165 #define COMPAQ_DEVICEID_NETFLEX_3P_INTEGRATED	0xAE35
166 #define COMPAQ_DEVICEID_NETEL_10_100_DUAL	0xAE40
167 #define COMPAQ_DEVICEID_NETEL_10_100_PROLIANT	0xAE43
168 #define COMPAQ_DEVICEID_NETEL_10_100_EMBEDDED	0xB011
169 #define COMPAQ_DEVICEID_NETEL_10_T2_UTP_COAX	0xB012
170 #define COMPAQ_DEVICEID_NETEL_10_100_TX_UTP	0xB030
171 #define COMPAQ_DEVICEID_NETFLEX_3P		0xF130
172 #define COMPAQ_DEVICEID_NETFLEX_3P_BNC		0xF150
173 
174 /*
175  * These are the PCI vendor and device IDs for Olicom
176  * adapters based on the ThunderLAN controller.
177  */
178 #define OLICOM_VENDORID				0x108D
179 #define OLICOM_DEVICEID_OC2183			0x0013
180 #define OLICOM_DEVICEID_OC2325			0x0012
181 #define OLICOM_DEVICEID_OC2326			0x0014
182 
183 /*
184  * PCI low memory base and low I/O base
185  */
186 #define TL_PCI_LOIO		0x10
187 #define TL_PCI_LOMEM		0x14
188 
189 /*
190  * PCI latency timer (it's actually 0x0D, but we want a value
191  * that's longword aligned).
192  */
193 #define TL_PCI_LATENCY_TIMER	0x0C
194 
195 #define	TL_DIO_ADDR_INC		0x8000	/* Increment addr on each read */
196 #define TL_DIO_RAM_SEL		0x4000	/* RAM address select */
197 #define	TL_DIO_ADDR_MASK	0x3FFF	/* address bits mask */
198 
199 /*
200  * Interrupt types
201  */
202 #define TL_INTR_INVALID		0x0
203 #define TL_INTR_TXEOF		0x1
204 #define TL_INTR_STATOFLOW	0x2
205 #define TL_INTR_RXEOF		0x3
206 #define TL_INTR_DUMMY		0x4
207 #define TL_INTR_TXEOC		0x5
208 #define TL_INTR_ADCHK		0x6
209 #define TL_INTR_RXEOC		0x7
210 
211 #define TL_INT_MASK		0x001C
212 #define TL_VEC_MASK		0x1FE0
213 /*
214  * Host command register bits
215  */
216 #define TL_CMD_GO               0x80000000
217 #define TL_CMD_STOP             0x40000000
218 #define TL_CMD_ACK              0x20000000
219 #define TL_CMD_CHSEL7		0x10000000
220 #define TL_CMD_CHSEL6		0x08000000
221 #define TL_CMD_CHSEL5		0x04000000
222 #define TL_CMD_CHSEL4		0x02000000
223 #define TL_CMD_CHSEL3		0x01000000
224 #define TL_CMD_CHSEL2           0x00800000
225 #define TL_CMD_CHSEL1           0x00400000
226 #define TL_CMD_CHSEL0           0x00200000
227 #define TL_CMD_EOC              0x00100000
228 #define TL_CMD_RT               0x00080000
229 #define TL_CMD_NES              0x00040000
230 #define TL_CMD_ZERO0            0x00020000
231 #define TL_CMD_ZERO1            0x00010000
232 #define TL_CMD_ADRST            0x00008000
233 #define TL_CMD_LDTMR            0x00004000
234 #define TL_CMD_LDTHR            0x00002000
235 #define TL_CMD_REQINT           0x00001000
236 #define TL_CMD_INTSOFF          0x00000800
237 #define TL_CMD_INTSON		0x00000400
238 #define TL_CMD_RSVD0		0x00000200
239 #define TL_CMD_RSVD1		0x00000100
240 #define TL_CMD_ACK7		0x00000080
241 #define TL_CMD_ACK6		0x00000040
242 #define TL_CMD_ACK5		0x00000020
243 #define TL_CMD_ACK4		0x00000010
244 #define TL_CMD_ACK3		0x00000008
245 #define TL_CMD_ACK2		0x00000004
246 #define TL_CMD_ACK1		0x00000002
247 #define TL_CMD_ACK0		0x00000001
248 
249 #define TL_CMD_CHSEL_MASK	0x01FE0000
250 #define TL_CMD_ACK_MASK		0xFF
251 
252 /*
253  * EEPROM address where station address resides.
254  */
255 #define TL_EEPROM_EADDR		0x83
256 #define TL_EEPROM_EADDR2	0x99
257 #define TL_EEPROM_EADDR3	0xAF
258 #define TL_EEPROM_EADDR_OC	0xF8	/* Olicom cards use a different
259 					   address than Compaqs. */
260 /*
261  * ThunderLAN host command register offsets.
262  * (Can be accessed either by IO ports or memory map.)
263  */
264 #define TL_HOSTCMD		0x00
265 #define TL_CH_PARM		0x04
266 #define TL_DIO_ADDR		0x08
267 #define TL_HOST_INT		0x0A
268 #define TL_DIO_DATA		0x0C
269 
270 /*
271  * ThunderLAN internal registers
272  */
273 #define TL_NETCMD		0x00
274 #define TL_NETSIO		0x01
275 #define TL_NETSTS		0x02
276 #define TL_NETMASK		0x03
277 
278 #define TL_NETCONFIG		0x04
279 #define TL_MANTEST		0x06
280 
281 #define TL_VENID_LSB		0x08
282 #define TL_VENID_MSB		0x09
283 #define TL_DEVID_LSB		0x0A
284 #define TL_DEVID_MSB		0x0B
285 
286 #define TL_REVISION		0x0C
287 #define TL_SUBCLASS		0x0D
288 #define TL_MINLAT		0x0E
289 #define TL_MAXLAT		0x0F
290 
291 #define TL_AREG0_B5		0x10
292 #define TL_AREG0_B4		0x11
293 #define TL_AREG0_B3		0x12
294 #define TL_AREG0_B2		0x13
295 
296 #define TL_AREG0_B1		0x14
297 #define TL_AREG0_B0		0x15
298 #define TL_AREG1_B5		0x16
299 #define TL_AREG1_B4		0x17
300 
301 #define TL_AREG1_B3		0x18
302 #define TL_AREG1_B2		0x19
303 #define TL_AREG1_B1		0x1A
304 #define TL_AREG1_B0		0x1B
305 
306 #define TL_AREG2_B5		0x1C
307 #define TL_AREG2_B4		0x1D
308 #define TL_AREG2_B3		0x1E
309 #define TL_AREG2_B2		0x1F
310 
311 #define TL_AREG2_B1		0x20
312 #define TL_AREG2_B0		0x21
313 #define TL_AREG3_B5		0x22
314 #define TL_AREG3_B4		0x23
315 
316 #define TL_AREG3_B3		0x24
317 #define TL_AREG3_B2		0x25
318 #define TL_AREG3_B1		0x26
319 #define TL_AREG3_B0		0x27
320 
321 #define TL_HASH1		0x28
322 #define TL_HASH2		0x2C
323 #define TL_TXGOODFRAMES		0x30
324 #define TL_TXUNDERRUN		0x33
325 #define TL_RXGOODFRAMES		0x34
326 #define TL_RXOVERRUN		0x37
327 #define TL_DEFEREDTX		0x38
328 #define TL_CRCERROR		0x3A
329 #define TL_CODEERROR		0x3B
330 #define TL_MULTICOLTX		0x3C
331 #define TL_SINGLECOLTX		0x3E
332 #define TL_EXCESSIVECOL		0x40
333 #define TL_LATECOL		0x41
334 #define TL_CARRIERLOSS		0x42
335 #define TL_ACOMMIT		0x43
336 #define TL_LDREG		0x44
337 #define TL_BSIZEREG		0x45
338 #define TL_MAXRX		0x46
339 
340 /*
341  * ThunderLAN SIO register bits
342  */
343 #define TL_SIO_MINTEN		0x80
344 #define TL_SIO_ECLOK		0x40
345 #define TL_SIO_ETXEN		0x20
346 #define TL_SIO_EDATA		0x10
347 #define TL_SIO_NMRST		0x08
348 #define TL_SIO_MCLK		0x04
349 #define TL_SIO_MTXEN		0x02
350 #define TL_SIO_MDATA		0x01
351 
352 /*
353  * Thunderlan NETCONFIG bits
354  */
355 #define TL_CFG_RCLKTEST		0x8000
356 #define TL_CFG_TCLKTEST		0x4000
357 #define TL_CFG_BITRATE		0x2000
358 #define TL_CFG_RXCRC		0x1000
359 #define TL_CFG_PEF		0x0800
360 #define TL_CFG_ONEFRAG		0x0400
361 #define TL_CFG_ONECHAN		0x0200
362 #define TL_CFG_MTEST		0x0100
363 #define TL_CFG_PHYEN		0x0080
364 #define TL_CFG_MACSEL6		0x0040
365 #define TL_CFG_MACSEL5		0x0020
366 #define TL_CFG_MACSEL4		0x0010
367 #define TL_CFG_MACSEL3		0x0008
368 #define TL_CFG_MACSEL2		0x0004
369 #define TL_CFG_MACSEL1		0x0002
370 #define TL_CFG_MACSEL0		0x0001
371 
372 /*
373  * ThunderLAN NETSTS bits
374  */
375 #define TL_STS_MIRQ		0x80
376 #define TL_STS_HBEAT		0x40
377 #define TL_STS_TXSTOP		0x20
378 #define TL_STS_RXSTOP		0x10
379 
380 /*
381  * ThunderLAN NETCMD bits
382  */
383 #define TL_CMD_NRESET		0x80
384 #define TL_CMD_NWRAP		0x40
385 #define TL_CMD_CSF		0x20
386 #define TL_CMD_CAF		0x10
387 #define TL_CMD_NOBRX		0x08
388 #define TL_CMD_DUPLEX		0x04
389 #define TL_CMD_TRFRAM		0x02
390 #define TL_CMD_TXPACE		0x01
391 
392 /*
393  * ThunderLAN NETMASK bits
394  */
395 #define TL_MASK_MASK7		0x80
396 #define TL_MASK_MASK6		0x40
397 #define TL_MASK_MASK5		0x20
398 #define TL_MASK_MASK4		0x10
399 
400 /*
401  * MII frame format
402  */
403 #ifdef ANSI_DOESNT_ALLOW_BITFIELDS
404 struct tl_mii_frame {
405 	u_int16_t		mii_stdelim:2,
406 				mii_opcode:2,
407 				mii_phyaddr:5,
408 				mii_regaddr:5,
409 				mii_turnaround:2;
410 	u_int16_t		mii_data;
411 };
412 #else
413 struct tl_mii_frame {
414 	u_int8_t		mii_stdelim;
415 	u_int8_t		mii_opcode;
416 	u_int8_t		mii_phyaddr;
417 	u_int8_t		mii_regaddr;
418 	u_int8_t		mii_turnaround;
419 	u_int16_t		mii_data;
420 };
421 #endif
422 /*
423  * MII constants
424  */
425 #define TL_MII_STARTDELIM	0x01
426 #define TL_MII_READOP		0x02
427 #define TL_MII_WRITEOP		0x01
428 #define TL_MII_TURNAROUND	0x02
429 
430 #define TL_LAST_FRAG		0x80000000
431 #define TL_CSTAT_UNUSED		0x8000
432 #define TL_CSTAT_FRAMECMP	0x4000
433 #define TL_CSTAT_READY		0x3000
434 #define TL_CSTAT_UNUSED13	0x2000
435 #define TL_CSTAT_UNUSED12	0x1000
436 #define TL_CSTAT_EOC		0x0800
437 #define TL_CSTAT_RXERROR	0x0400
438 #define TL_CSTAT_PASSCRC	0x0200
439 #define TL_CSTAT_DPRIO		0x0100
440 
441 #define TL_FRAME_MASK		0x00FFFFFF
442 #define tl_tx_goodframes(x)	(x.tl_txstat & TL_FRAME_MASK)
443 #define tl_tx_underrun(x)	((x.tl_txstat & ~TL_FRAME_MASK) >> 24)
444 #define tl_rx_goodframes(x)	(x.tl_rxstat & TL_FRAME_MASK)
445 #define tl_rx_overrun(x)	((x.tl_rxstat & ~TL_FRAME_MASK) >> 24)
446 
447 struct tl_stats {
448 	u_int32_t		tl_txstat;
449 	u_int32_t		tl_rxstat;
450 	u_int16_t		tl_deferred;
451 	u_int8_t		tl_crc_errors;
452 	u_int8_t		tl_code_errors;
453 	u_int16_t		tl_tx_multi_collision;
454 	u_int16_t		tl_tx_single_collision;
455 	u_int8_t		tl_excessive_collision;
456 	u_int8_t		tl_late_collision;
457 	u_int8_t		tl_carrier_loss;
458 	u_int8_t		acommit;
459 };
460 
461 /*
462  * ACOMMIT register bits. These are used only when a bitrate
463  * PHY is selected ('bitrate' bit in netconfig register is set).
464  */
465 #define TL_AC_MTXER		0x01	/* reserved */
466 #define TL_AC_MTXD1		0x02	/* 0 == 10baseT 1 == AUI */
467 #define TL_AC_MTXD2		0x04	/* loopback disable */
468 #define TL_AC_MTXD3		0x08	/* full duplex disable */
469 
470 #define TL_AC_TXTHRESH		0xF0
471 #define TL_AC_TXTHRESH_16LONG	0x00
472 #define TL_AC_TXTHRESH_32LONG	0x10
473 #define TL_AC_TXTHRESH_64LONG	0x20
474 #define TL_AC_TXTHRESH_128LONG	0x30
475 #define TL_AC_TXTHRESH_256LONG	0x40
476 #define TL_AC_TXTHRESH_WHOLEPKT	0x50
477 
478 /*
479  * PCI burst size register (TL_BSIZEREG).
480  */
481 #define TL_RXBURST		0x0F
482 #define TL_TXBURST		0xF0
483 
484 #define TL_RXBURST_4LONG	0x00
485 #define TL_RXBURST_8LONG	0x01
486 #define TL_RXBURST_16LONG	0x02
487 #define TL_RXBURST_32LONG	0x03
488 #define TL_RXBURST_64LONG	0x04
489 #define TL_RXBURST_128LONG	0x05
490 
491 #define TL_TXBURST_4LONG	0x00
492 #define TL_TXBURST_8LONG	0x10
493 #define TL_TXBURST_16LONG	0x20
494 #define TL_TXBURST_32LONG	0x30
495 #define TL_TXBURST_64LONG	0x40
496 #define TL_TXBURST_128LONG	0x50
497 
498 /*
499  * register space access macros
500  */
501 #define CSR_WRITE_4(sc, reg, val) \
502 	bus_space_write_4(sc->tl_btag, sc->tl_bhandle, reg, val)
503 #define CSR_WRITE_2(sc, reg, val) \
504 	bus_space_write_2(sc->tl_btag, sc->tl_bhandle, reg, val)
505 #define CSR_WRITE_1(sc, reg, val) \
506 	bus_space_write_1(sc->tl_btag, sc->tl_bhandle, reg, val)
507 
508 #define CSR_READ_4(sc, reg) \
509 	bus_space_read_4(sc->tl_btag, sc->tl_bhandle, reg)
510 #define CSR_READ_2(sc, reg) \
511 	bus_space_read_2(sc->tl_btag, sc->tl_bhandle, reg)
512 #define CSR_READ_1(sc, reg) \
513 	bus_space_read_1(sc->tl_btag, sc->tl_bhandle, reg)
514 
515 #define CMD_PUT(sc, x) CSR_WRITE_4(sc, TL_HOSTCMD, x)
516 #define CMD_SET(sc, x)	\
517 	CSR_WRITE_4(sc, TL_HOSTCMD, CSR_READ_4(sc, TL_HOSTCMD) | (x))
518 #define CMD_CLR(sc, x)	\
519 	CSR_WRITE_4(sc, TL_HOSTCMD, CSR_READ_4(sc, TL_HOSTCMD) & ~(x))
520 
521 /*
522  * ThunderLAN adapters typically have a serial EEPROM containing
523  * configuration information. The main reason we're interested in
524  * it is because it also contains the adapters's station address.
525  *
526  * Access to the EEPROM is a bit goofy since it is a serial device:
527  * you have to do reads and writes one bit at a time. The state of
528  * the DATA bit can only change while the CLOCK line is held low.
529  * Transactions work basically like this:
530  *
531  * 1) Send the EEPROM_START sequence to prepare the EEPROM for
532  *    accepting commands. This pulls the clock high, sets
533  *    the data bit to 0, enables transmission to the EEPROM,
534  *    pulls the data bit up to 1, then pulls the clock low.
535  *    The idea is to do a 0 to 1 transition of the data bit
536  *    while the clock pin is held high.
537  *
538  * 2) To write a bit to the EEPROM, set the TXENABLE bit, then
539  *    set the EDATA bit to send a 1 or clear it to send a 0.
540  *    Finally, set and then clear ECLOK. Strobing the clock
541  *    transmits the bit. After 8 bits have been written, the
542  *    EEPROM should respond with an ACK, which should be read.
543  *
544  * 3) To read a bit from the EEPROM, clear the TXENABLE bit,
545  *    then set ECLOK. The bit can then be read by reading EDATA.
546  *    ECLOCK should then be cleared again. This can be repeated
547  *    8 times to read a whole byte, after which the
548  *
549  * 4) We need to send the address byte to the EEPROM. For this
550  *    we have to send the write control byte to the EEPROM to
551  *    tell it to accept data. The byte is 0xA0. The EEPROM should
552  *    ack this. The address byte can be send after that.
553  *
554  * 5) Now we have to tell the EEPROM to send us data. For that we
555  *    have to transmit the read control byte, which is 0xA1. This
556  *    byte should also be acked. We can then read the data bits
557  *    from the EEPROM.
558  *
559  * 6) When we're all finished, send the EEPROM_STOP sequence.
560  *
561  * Note that we use the ThunderLAN's NetSio register to access the
562  * EEPROM, however there is an alternate method. There is a PCI NVRAM
563  * register at PCI offset 0xB4 which can also be used with minor changes.
564  * The difference is that access to PCI registers via pci_conf_read()
565  * and pci_conf_write() is done using programmed I/O, which we want to
566  * avoid.
567  */
568 
569 /*
570  * Note that EEPROM_START leaves transmission enabled.
571  */
572 #define EEPROM_START							\
573 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock pin high */\
574 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Set DATA bit to 1 */	\
575 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Enable xmit to write bit */\
576 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Pull DATA bit to 0 again */\
577 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock low again */
578 
579 /*
580  * EEPROM_STOP ends access to the EEPROM and clears the ETXEN bit so
581  * that no further data can be written to the EEPROM I/O pin.
582  */
583 #define EEPROM_STOP							\
584 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Disable xmit */	\
585 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Pull DATA to 0 */	\
586 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock high */	\
587 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Enable xmit */	\
588 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Toggle DATA to 1 */	\
589 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Disable xmit. */	\
590 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock low again */
591 
592 /*
593  * Microchip Technology 24Cxx EEPROM control bytes
594  */
595 #define EEPROM_CTL_READ			0xA1	/* 0101 0001 */
596 #define EEPROM_CTL_WRITE		0xA0	/* 0101 0000 */
597 
598 #ifdef __alpha__
599 #undef vtophys
600 #define vtophys(va)		alpha_XXX_dmamap((vaddr_t)va)
601 #endif
602