xref: /dragonfly/sys/dev/netif/tl/if_tlreg.h (revision 86d7f5d3)
1 /*
2  * Copyright (c) 1997, 1998
3  *	Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by Bill Paul.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
30  * THE POSSIBILITY OF SUCH DAMAGE.
31  *
32  * $FreeBSD: src/sys/pci/if_tlreg.h,v 1.15 1999/09/19 22:39:24 wpaul Exp $
33  * $DragonFly: src/sys/dev/netif/tl/if_tlreg.h,v 1.5 2005/06/14 12:38:04 joerg Exp $
34  */
35 
36 
37 struct tl_type {
38 	u_int16_t		tl_vid;
39 	u_int16_t		tl_did;
40 	char			*tl_name;
41 };
42 
43 /*
44  * ThunderLAN TX/RX list format. The TX and RX lists are pretty much
45  * identical: the list begins with a 32-bit forward pointer which points
46  * at the next list in the chain, followed by 16 bits for the total
47  * frame size, and a 16 bit status field. This is followed by a series
48  * of 10 32-bit data count/data address pairs that point to the fragments
49  * that make up the complete frame.
50  */
51 
52 #define TL_MAXFRAGS		10
53 #define TL_RX_LIST_CNT		64
54 #define TL_TX_LIST_CNT		128
55 #define TL_MIN_FRAMELEN		64
56 
57 struct tl_frag {
58 	u_int32_t		tlist_dcnt;
59 	u_int32_t		tlist_dadr;
60 };
61 
62 struct tl_list {
63 	u_int32_t		tlist_fptr;	/* phys address of next list */
64 	u_int16_t		tlist_cstat;	/* status word */
65 	u_int16_t		tlist_frsize;	/* size of data in frame */
66 	struct tl_frag		tl_frag[TL_MAXFRAGS];
67 };
68 
69 /*
70  * This is a special case of an RX list. By setting the One_Frag
71  * bit in the NETCONFIG register, the driver can force the ThunderLAN
72  * chip to use only one fragment when DMAing RX frames.
73  */
74 
75 struct tl_list_onefrag {
76 	u_int32_t		tlist_fptr;
77 	u_int16_t		tlist_cstat;
78 	u_int16_t		tlist_frsize;
79 	struct tl_frag		tl_frag;
80 };
81 
82 struct tl_list_data {
83 	struct tl_list_onefrag	tl_rx_list[TL_RX_LIST_CNT];
84 	struct tl_list		tl_tx_list[TL_TX_LIST_CNT];
85 	unsigned char		tl_pad[TL_MIN_FRAMELEN];
86 };
87 
88 struct tl_chain {
89 	struct tl_list		*tl_ptr;
90 	struct mbuf		*tl_mbuf;
91 	struct tl_chain		*tl_next;
92 };
93 
94 struct tl_chain_onefrag {
95 	struct tl_list_onefrag	*tl_ptr;
96 	struct mbuf		*tl_mbuf;
97 	struct tl_chain_onefrag	*tl_next;
98 };
99 
100 struct tl_chain_data {
101 	struct tl_chain_onefrag	tl_rx_chain[TL_RX_LIST_CNT];
102 	struct tl_chain		tl_tx_chain[TL_TX_LIST_CNT];
103 
104 	struct tl_chain_onefrag	*tl_rx_head;
105 	struct tl_chain_onefrag	*tl_rx_tail;
106 
107 	struct tl_chain		*tl_tx_head;
108 	struct tl_chain		*tl_tx_tail;
109 	struct tl_chain		*tl_tx_free;
110 };
111 
112 struct tl_softc {
113 	struct arpcom		arpcom;		/* interface info */
114 	struct ifmedia		ifmedia;	/* media info */
115 	bus_space_handle_t	tl_bhandle;
116 	bus_space_tag_t		tl_btag;
117 	void			*tl_intrhand;
118 	struct resource		*tl_irq;
119 	struct resource		*tl_res;
120 	device_t		tl_miibus;
121 	struct tl_type		*tl_dinfo;	/* ThunderLAN adapter info */
122 	u_int8_t		tl_eeaddr;
123 	struct tl_list_data	*tl_ldata;	/* TX/RX lists and mbufs */
124 	struct tl_chain_data	tl_cdata;
125 	u_int8_t		tl_txeoc;
126 	u_int8_t		tl_bitrate;
127 	int			tl_if_flags;
128 	struct callout		tl_stat_timer;
129 };
130 
131 /*
132  * Transmit interrupt threshold.
133  */
134 #define TX_THR		0x00000004
135 
136 /*
137  * General constants that are fun to know.
138  *
139  * The ThunderLAN controller is made by Texas Instruments. The
140  * manual indicates that if the EEPROM checksum fails, the PCI
141  * vendor and device ID registers will be loaded with TI-specific
142  * values.
143  */
144 #define	TI_VENDORID		0x104C
145 #define	TI_DEVICEID_THUNDERLAN	0x0500
146 
147 /*
148  * These are the PCI vendor and device IDs for Compaq ethernet
149  * adapters based on the ThunderLAN controller.
150  */
151 #define COMPAQ_VENDORID				0x0E11
152 #define COMPAQ_DEVICEID_NETEL_10_100		0xAE32
153 #define COMPAQ_DEVICEID_NETEL_UNKNOWN		0xAE33
154 #define COMPAQ_DEVICEID_NETEL_10		0xAE34
155 #define COMPAQ_DEVICEID_NETFLEX_3P_INTEGRATED	0xAE35
156 #define COMPAQ_DEVICEID_NETEL_10_100_DUAL	0xAE40
157 #define COMPAQ_DEVICEID_NETEL_10_100_PROLIANT	0xAE43
158 #define COMPAQ_DEVICEID_NETEL_10_100_EMBEDDED	0xB011
159 #define COMPAQ_DEVICEID_NETEL_10_T2_UTP_COAX	0xB012
160 #define COMPAQ_DEVICEID_NETEL_10_100_TX_UTP	0xB030
161 #define COMPAQ_DEVICEID_NETFLEX_3P		0xF130
162 #define COMPAQ_DEVICEID_NETFLEX_3P_BNC		0xF150
163 
164 /*
165  * These are the PCI vendor and device IDs for Olicom
166  * adapters based on the ThunderLAN controller.
167  */
168 #define OLICOM_VENDORID				0x108D
169 #define OLICOM_DEVICEID_OC2183			0x0013
170 #define OLICOM_DEVICEID_OC2325			0x0012
171 #define OLICOM_DEVICEID_OC2326			0x0014
172 
173 /*
174  * PCI low memory base and low I/O base
175  */
176 #define TL_PCI_LOIO		0x10
177 #define TL_PCI_LOMEM		0x14
178 
179 /*
180  * PCI latency timer (it's actually 0x0D, but we want a value
181  * that's longword aligned).
182  */
183 #define TL_PCI_LATENCY_TIMER	0x0C
184 
185 #define	TL_DIO_ADDR_INC		0x8000	/* Increment addr on each read */
186 #define TL_DIO_RAM_SEL		0x4000	/* RAM address select */
187 #define	TL_DIO_ADDR_MASK	0x3FFF	/* address bits mask */
188 
189 /*
190  * Interrupt types
191  */
192 #define TL_INTR_INVALID		0x0
193 #define TL_INTR_TXEOF		0x1
194 #define TL_INTR_STATOFLOW	0x2
195 #define TL_INTR_RXEOF		0x3
196 #define TL_INTR_DUMMY		0x4
197 #define TL_INTR_TXEOC		0x5
198 #define TL_INTR_ADCHK		0x6
199 #define TL_INTR_RXEOC		0x7
200 
201 #define TL_INT_MASK		0x001C
202 #define TL_VEC_MASK		0x1FE0
203 /*
204  * Host command register bits
205  */
206 #define TL_CMD_GO               0x80000000
207 #define TL_CMD_STOP             0x40000000
208 #define TL_CMD_ACK              0x20000000
209 #define TL_CMD_CHSEL7		0x10000000
210 #define TL_CMD_CHSEL6		0x08000000
211 #define TL_CMD_CHSEL5		0x04000000
212 #define TL_CMD_CHSEL4		0x02000000
213 #define TL_CMD_CHSEL3		0x01000000
214 #define TL_CMD_CHSEL2           0x00800000
215 #define TL_CMD_CHSEL1           0x00400000
216 #define TL_CMD_CHSEL0           0x00200000
217 #define TL_CMD_EOC              0x00100000
218 #define TL_CMD_RT               0x00080000
219 #define TL_CMD_NES              0x00040000
220 #define TL_CMD_ZERO0            0x00020000
221 #define TL_CMD_ZERO1            0x00010000
222 #define TL_CMD_ADRST            0x00008000
223 #define TL_CMD_LDTMR            0x00004000
224 #define TL_CMD_LDTHR            0x00002000
225 #define TL_CMD_REQINT           0x00001000
226 #define TL_CMD_INTSOFF          0x00000800
227 #define TL_CMD_INTSON		0x00000400
228 #define TL_CMD_RSVD0		0x00000200
229 #define TL_CMD_RSVD1		0x00000100
230 #define TL_CMD_ACK7		0x00000080
231 #define TL_CMD_ACK6		0x00000040
232 #define TL_CMD_ACK5		0x00000020
233 #define TL_CMD_ACK4		0x00000010
234 #define TL_CMD_ACK3		0x00000008
235 #define TL_CMD_ACK2		0x00000004
236 #define TL_CMD_ACK1		0x00000002
237 #define TL_CMD_ACK0		0x00000001
238 
239 #define TL_CMD_CHSEL_MASK	0x01FE0000
240 #define TL_CMD_ACK_MASK		0xFF
241 
242 /*
243  * EEPROM address where station address resides.
244  */
245 #define TL_EEPROM_EADDR		0x83
246 #define TL_EEPROM_EADDR2	0x99
247 #define TL_EEPROM_EADDR3	0xAF
248 #define TL_EEPROM_EADDR_OC	0xF8	/* Olicom cards use a different
249 					   address than Compaqs. */
250 /*
251  * ThunderLAN host command register offsets.
252  * (Can be accessed either by IO ports or memory map.)
253  */
254 #define TL_HOSTCMD		0x00
255 #define TL_CH_PARM		0x04
256 #define TL_DIO_ADDR		0x08
257 #define TL_HOST_INT		0x0A
258 #define TL_DIO_DATA		0x0C
259 
260 /*
261  * ThunderLAN internal registers
262  */
263 #define TL_NETCMD		0x00
264 #define TL_NETSIO		0x01
265 #define TL_NETSTS		0x02
266 #define TL_NETMASK		0x03
267 
268 #define TL_NETCONFIG		0x04
269 #define TL_MANTEST		0x06
270 
271 #define TL_VENID_LSB		0x08
272 #define TL_VENID_MSB		0x09
273 #define TL_DEVID_LSB		0x0A
274 #define TL_DEVID_MSB		0x0B
275 
276 #define TL_REVISION		0x0C
277 #define TL_SUBCLASS		0x0D
278 #define TL_MINLAT		0x0E
279 #define TL_MAXLAT		0x0F
280 
281 #define TL_AREG0_B5		0x10
282 #define TL_AREG0_B4		0x11
283 #define TL_AREG0_B3		0x12
284 #define TL_AREG0_B2		0x13
285 
286 #define TL_AREG0_B1		0x14
287 #define TL_AREG0_B0		0x15
288 #define TL_AREG1_B5		0x16
289 #define TL_AREG1_B4		0x17
290 
291 #define TL_AREG1_B3		0x18
292 #define TL_AREG1_B2		0x19
293 #define TL_AREG1_B1		0x1A
294 #define TL_AREG1_B0		0x1B
295 
296 #define TL_AREG2_B5		0x1C
297 #define TL_AREG2_B4		0x1D
298 #define TL_AREG2_B3		0x1E
299 #define TL_AREG2_B2		0x1F
300 
301 #define TL_AREG2_B1		0x20
302 #define TL_AREG2_B0		0x21
303 #define TL_AREG3_B5		0x22
304 #define TL_AREG3_B4		0x23
305 
306 #define TL_AREG3_B3		0x24
307 #define TL_AREG3_B2		0x25
308 #define TL_AREG3_B1		0x26
309 #define TL_AREG3_B0		0x27
310 
311 #define TL_HASH1		0x28
312 #define TL_HASH2		0x2C
313 #define TL_TXGOODFRAMES		0x30
314 #define TL_TXUNDERRUN		0x33
315 #define TL_RXGOODFRAMES		0x34
316 #define TL_RXOVERRUN		0x37
317 #define TL_DEFEREDTX		0x38
318 #define TL_CRCERROR		0x3A
319 #define TL_CODEERROR		0x3B
320 #define TL_MULTICOLTX		0x3C
321 #define TL_SINGLECOLTX		0x3E
322 #define TL_EXCESSIVECOL		0x40
323 #define TL_LATECOL		0x41
324 #define TL_CARRIERLOSS		0x42
325 #define TL_ACOMMIT		0x43
326 #define TL_LDREG		0x44
327 #define TL_BSIZEREG		0x45
328 #define TL_MAXRX		0x46
329 
330 /*
331  * ThunderLAN SIO register bits
332  */
333 #define TL_SIO_MINTEN		0x80
334 #define TL_SIO_ECLOK		0x40
335 #define TL_SIO_ETXEN		0x20
336 #define TL_SIO_EDATA		0x10
337 #define TL_SIO_NMRST		0x08
338 #define TL_SIO_MCLK		0x04
339 #define TL_SIO_MTXEN		0x02
340 #define TL_SIO_MDATA		0x01
341 
342 /*
343  * Thunderlan NETCONFIG bits
344  */
345 #define TL_CFG_RCLKTEST		0x8000
346 #define TL_CFG_TCLKTEST		0x4000
347 #define TL_CFG_BITRATE		0x2000
348 #define TL_CFG_RXCRC		0x1000
349 #define TL_CFG_PEF		0x0800
350 #define TL_CFG_ONEFRAG		0x0400
351 #define TL_CFG_ONECHAN		0x0200
352 #define TL_CFG_MTEST		0x0100
353 #define TL_CFG_PHYEN		0x0080
354 #define TL_CFG_MACSEL6		0x0040
355 #define TL_CFG_MACSEL5		0x0020
356 #define TL_CFG_MACSEL4		0x0010
357 #define TL_CFG_MACSEL3		0x0008
358 #define TL_CFG_MACSEL2		0x0004
359 #define TL_CFG_MACSEL1		0x0002
360 #define TL_CFG_MACSEL0		0x0001
361 
362 /*
363  * ThunderLAN NETSTS bits
364  */
365 #define TL_STS_MIRQ		0x80
366 #define TL_STS_HBEAT		0x40
367 #define TL_STS_TXSTOP		0x20
368 #define TL_STS_RXSTOP		0x10
369 
370 /*
371  * ThunderLAN NETCMD bits
372  */
373 #define TL_CMD_NRESET		0x80
374 #define TL_CMD_NWRAP		0x40
375 #define TL_CMD_CSF		0x20
376 #define TL_CMD_CAF		0x10
377 #define TL_CMD_NOBRX		0x08
378 #define TL_CMD_DUPLEX		0x04
379 #define TL_CMD_TRFRAM		0x02
380 #define TL_CMD_TXPACE		0x01
381 
382 /*
383  * ThunderLAN NETMASK bits
384  */
385 #define TL_MASK_MASK7		0x80
386 #define TL_MASK_MASK6		0x40
387 #define TL_MASK_MASK5		0x20
388 #define TL_MASK_MASK4		0x10
389 
390 /*
391  * MII frame format
392  */
393 #ifdef ANSI_DOESNT_ALLOW_BITFIELDS
394 struct tl_mii_frame {
395 	u_int16_t		mii_stdelim:2,
396 				mii_opcode:2,
397 				mii_phyaddr:5,
398 				mii_regaddr:5,
399 				mii_turnaround:2;
400 	u_int16_t		mii_data;
401 };
402 #else
403 struct tl_mii_frame {
404 	u_int8_t		mii_stdelim;
405 	u_int8_t		mii_opcode;
406 	u_int8_t		mii_phyaddr;
407 	u_int8_t		mii_regaddr;
408 	u_int8_t		mii_turnaround;
409 	u_int16_t		mii_data;
410 };
411 #endif
412 /*
413  * MII constants
414  */
415 #define TL_MII_STARTDELIM	0x01
416 #define TL_MII_READOP		0x02
417 #define TL_MII_WRITEOP		0x01
418 #define TL_MII_TURNAROUND	0x02
419 
420 #define TL_LAST_FRAG		0x80000000
421 #define TL_CSTAT_UNUSED		0x8000
422 #define TL_CSTAT_FRAMECMP	0x4000
423 #define TL_CSTAT_READY		0x3000
424 #define TL_CSTAT_UNUSED13	0x2000
425 #define TL_CSTAT_UNUSED12	0x1000
426 #define TL_CSTAT_EOC		0x0800
427 #define TL_CSTAT_RXERROR	0x0400
428 #define TL_CSTAT_PASSCRC	0x0200
429 #define TL_CSTAT_DPRIO		0x0100
430 
431 #define TL_FRAME_MASK		0x00FFFFFF
432 #define tl_tx_goodframes(x)	(x.tl_txstat & TL_FRAME_MASK)
433 #define tl_tx_underrun(x)	((x.tl_txstat & ~TL_FRAME_MASK) >> 24)
434 #define tl_rx_goodframes(x)	(x.tl_rxstat & TL_FRAME_MASK)
435 #define tl_rx_overrun(x)	((x.tl_rxstat & ~TL_FRAME_MASK) >> 24)
436 
437 struct tl_stats {
438 	u_int32_t		tl_txstat;
439 	u_int32_t		tl_rxstat;
440 	u_int16_t		tl_deferred;
441 	u_int8_t		tl_crc_errors;
442 	u_int8_t		tl_code_errors;
443 	u_int16_t		tl_tx_multi_collision;
444 	u_int16_t		tl_tx_single_collision;
445 	u_int8_t		tl_excessive_collision;
446 	u_int8_t		tl_late_collision;
447 	u_int8_t		tl_carrier_loss;
448 	u_int8_t		acommit;
449 };
450 
451 /*
452  * ACOMMIT register bits. These are used only when a bitrate
453  * PHY is selected ('bitrate' bit in netconfig register is set).
454  */
455 #define TL_AC_MTXER		0x01	/* reserved */
456 #define TL_AC_MTXD1		0x02	/* 0 == 10baseT 1 == AUI */
457 #define TL_AC_MTXD2		0x04	/* loopback disable */
458 #define TL_AC_MTXD3		0x08	/* full duplex disable */
459 
460 #define TL_AC_TXTHRESH		0xF0
461 #define TL_AC_TXTHRESH_16LONG	0x00
462 #define TL_AC_TXTHRESH_32LONG	0x10
463 #define TL_AC_TXTHRESH_64LONG	0x20
464 #define TL_AC_TXTHRESH_128LONG	0x30
465 #define TL_AC_TXTHRESH_256LONG	0x40
466 #define TL_AC_TXTHRESH_WHOLEPKT	0x50
467 
468 /*
469  * PCI burst size register (TL_BSIZEREG).
470  */
471 #define TL_RXBURST		0x0F
472 #define TL_TXBURST		0xF0
473 
474 #define TL_RXBURST_4LONG	0x00
475 #define TL_RXBURST_8LONG	0x01
476 #define TL_RXBURST_16LONG	0x02
477 #define TL_RXBURST_32LONG	0x03
478 #define TL_RXBURST_64LONG	0x04
479 #define TL_RXBURST_128LONG	0x05
480 
481 #define TL_TXBURST_4LONG	0x00
482 #define TL_TXBURST_8LONG	0x10
483 #define TL_TXBURST_16LONG	0x20
484 #define TL_TXBURST_32LONG	0x30
485 #define TL_TXBURST_64LONG	0x40
486 #define TL_TXBURST_128LONG	0x50
487 
488 /*
489  * register space access macros
490  */
491 #define CSR_WRITE_4(sc, reg, val)	\
492 	bus_space_write_4(sc->tl_btag, sc->tl_bhandle, reg, val)
493 #define CSR_WRITE_2(sc, reg, val)	\
494 	bus_space_write_2(sc->tl_btag, sc->tl_bhandle, reg, val)
495 #define CSR_WRITE_1(sc, reg, val)	\
496 	bus_space_write_1(sc->tl_btag, sc->tl_bhandle, reg, val)
497 
498 #define CSR_READ_4(sc, reg)		\
499 	bus_space_read_4(sc->tl_btag, sc->tl_bhandle, reg)
500 #define CSR_READ_2(sc, reg)		\
501 	bus_space_read_2(sc->tl_btag, sc->tl_bhandle, reg)
502 #define CSR_READ_1(sc, reg)		\
503 	bus_space_read_1(sc->tl_btag, sc->tl_bhandle, reg)
504 
505 #define CMD_PUT(sc, x) CSR_WRITE_4(sc, TL_HOSTCMD, x)
506 #define CMD_SET(sc, x)	\
507 	CSR_WRITE_4(sc, TL_HOSTCMD, CSR_READ_4(sc, TL_HOSTCMD) | (x))
508 #define CMD_CLR(sc, x)	\
509 	CSR_WRITE_4(sc, TL_HOSTCMD, CSR_READ_4(sc, TL_HOSTCMD) & ~(x))
510 
511 /*
512  * ThunderLAN adapters typically have a serial EEPROM containing
513  * configuration information. The main reason we're interested in
514  * it is because it also contains the adapters's station address.
515  *
516  * Access to the EEPROM is a bit goofy since it is a serial device:
517  * you have to do reads and writes one bit at a time. The state of
518  * the DATA bit can only change while the CLOCK line is held low.
519  * Transactions work basically like this:
520  *
521  * 1) Send the EEPROM_START sequence to prepare the EEPROM for
522  *    accepting commands. This pulls the clock high, sets
523  *    the data bit to 0, enables transmission to the EEPROM,
524  *    pulls the data bit up to 1, then pulls the clock low.
525  *    The idea is to do a 0 to 1 transition of the data bit
526  *    while the clock pin is held high.
527  *
528  * 2) To write a bit to the EEPROM, set the TXENABLE bit, then
529  *    set the EDATA bit to send a 1 or clear it to send a 0.
530  *    Finally, set and then clear ECLOK. Strobing the clock
531  *    transmits the bit. After 8 bits have been written, the
532  *    EEPROM should respond with an ACK, which should be read.
533  *
534  * 3) To read a bit from the EEPROM, clear the TXENABLE bit,
535  *    then set ECLOK. The bit can then be read by reading EDATA.
536  *    ECLOCK should then be cleared again. This can be repeated
537  *    8 times to read a whole byte, after which the
538  *
539  * 4) We need to send the address byte to the EEPROM. For this
540  *    we have to send the write control byte to the EEPROM to
541  *    tell it to accept data. The byte is 0xA0. The EEPROM should
542  *    ack this. The address byte can be send after that.
543  *
544  * 5) Now we have to tell the EEPROM to send us data. For that we
545  *    have to transmit the read control byte, which is 0xA1. This
546  *    byte should also be acked. We can then read the data bits
547  *    from the EEPROM.
548  *
549  * 6) When we're all finished, send the EEPROM_STOP sequence.
550  *
551  * Note that we use the ThunderLAN's NetSio register to access the
552  * EEPROM, however there is an alternate method. There is a PCI NVRAM
553  * register at PCI offset 0xB4 which can also be used with minor changes.
554  * The difference is that access to PCI registers via pci_conf_read()
555  * and pci_conf_write() is done using programmed I/O, which we want to
556  * avoid.
557  */
558 
559 /*
560  * Note that EEPROM_START leaves transmission enabled.
561  */
562 #define EEPROM_START							\
563 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock pin high */\
564 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Set DATA bit to 1 */	\
565 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Enable xmit to write bit */\
566 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Pull DATA bit to 0 again */\
567 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock low again */
568 
569 /*
570  * EEPROM_STOP ends access to the EEPROM and clears the ETXEN bit so
571  * that no further data can be written to the EEPROM I/O pin.
572  */
573 #define EEPROM_STOP							\
574 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Disable xmit */	\
575 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Pull DATA to 0 */	\
576 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock high */	\
577 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Enable xmit */	\
578 	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Toggle DATA to 1 */	\
579 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Disable xmit. */	\
580 	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock low again */
581 
582 
583 /*
584  * Microchip Technology 24Cxx EEPROM control bytes
585  */
586 #define EEPROM_CTL_READ			0xA1	/* 0101 0001 */
587 #define EEPROM_CTL_WRITE		0xA0	/* 0101 0000 */
588