1/*-
2 * Interface for the 93C66/56/46/26/06 serial eeprom parts.
3 *
4 * Copyright (c) 1995, 1996 Daniel M. Eischen
5 * 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 *    without modification.
13 * 2. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * Alternatively, this software may be distributed under the terms of the
17 * GNU General Public License ("GPL").
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $Id: //depot/aic7xxx/aic7xxx/aic7xxx_93cx6.c#19 $
32 */
33
34/*
35 *   The instruction set of the 93C66/56/46/26/06 chips are as follows:
36 *
37 *               Start  OP	    *
38 *     Function   Bit  Code  Address**  Data     Description
39 *     -------------------------------------------------------------------
40 *     READ        1    10   A5 - A0             Reads data stored in memory,
41 *                                               starting at specified address
42 *     EWEN        1    00   11XXXX              Write enable must precede
43 *                                               all programming modes
44 *     ERASE       1    11   A5 - A0             Erase register A5A4A3A2A1A0
45 *     WRITE       1    01   A5 - A0   D15 - D0  Writes register
46 *     ERAL        1    00   10XXXX              Erase all registers
47 *     WRAL        1    00   01XXXX    D15 - D0  Writes to all registers
48 *     EWDS        1    00   00XXXX              Disables all programming
49 *                                               instructions
50 *     *Note: A value of X for address is a don't care condition.
51 *    **Note: There are 8 address bits for the 93C56/66 chips unlike
52 *	      the 93C46/26/06 chips which have 6 address bits.
53 *
54 *   The 93C46 has a four wire interface: clock, chip select, data in, and
55 *   data out.  In order to perform one of the above functions, you need
56 *   to enable the chip select for a clock period (typically a minimum of
57 *   1 usec, with the clock high and low a minimum of 750 and 250 nsec
58 *   respectively).  While the chip select remains high, you can clock in
59 *   the instructions (above) starting with the start bit, followed by the
60 *   OP code, Address, and Data (if needed).  For the READ instruction, the
61 *   requested 16-bit register contents is read from the data out line but
62 *   is preceded by an initial zero (leading 0, followed by 16-bits, MSB
63 *   first).  The clock cycling from low to high initiates the next data
64 *   bit to be sent from the chip.
65 */
66
67#include <dev/aic7xxx/aic7xxx_osm.h>
68#include <dev/aic7xxx/aic7xxx_inline.h>
69#include <dev/aic7xxx/aic7xxx_93cx6.h>
70
71/*
72 * Right now, we only have to read the SEEPROM.  But we make it easier to
73 * add other 93Cx6 functions.
74 */
75struct seeprom_cmd {
76  	uint8_t len;
77 	uint8_t bits[11];
78};
79
80/* Short opcodes for the c46 */
81static struct seeprom_cmd seeprom_ewen = {9, {1, 0, 0, 1, 1, 0, 0, 0, 0}};
82static struct seeprom_cmd seeprom_ewds = {9, {1, 0, 0, 0, 0, 0, 0, 0, 0}};
83
84/* Long opcodes for the C56/C66 */
85static struct seeprom_cmd seeprom_long_ewen = {11, {1, 0, 0, 1, 1, 0, 0, 0, 0}};
86static struct seeprom_cmd seeprom_long_ewds = {11, {1, 0, 0, 0, 0, 0, 0, 0, 0}};
87
88/* Common opcodes */
89static struct seeprom_cmd seeprom_write = {3, {1, 0, 1}};
90static struct seeprom_cmd seeprom_read  = {3, {1, 1, 0}};
91
92/*
93 * Wait for the SEERDY to go high; about 800 ns.
94 */
95#define CLOCK_PULSE(sd, rdy)				\
96	while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) {	\
97		;  /* Do nothing */			\
98	}						\
99	(void)SEEPROM_INB(sd);	/* Clear clock */
100
101/*
102 * Send a START condition and the given command
103 */
104static void
105send_seeprom_cmd(struct seeprom_descriptor *sd, struct seeprom_cmd *cmd)
106{
107	uint8_t temp;
108	int i = 0;
109
110	/* Send chip select for one clock cycle. */
111	temp = sd->sd_MS ^ sd->sd_CS;
112	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
113	CLOCK_PULSE(sd, sd->sd_RDY);
114
115	for (i = 0; i < cmd->len; i++) {
116		if (cmd->bits[i] != 0)
117			temp ^= sd->sd_DO;
118		SEEPROM_OUTB(sd, temp);
119		CLOCK_PULSE(sd, sd->sd_RDY);
120		SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
121		CLOCK_PULSE(sd, sd->sd_RDY);
122		if (cmd->bits[i] != 0)
123			temp ^= sd->sd_DO;
124	}
125}
126
127/*
128 * Clear CS put the chip in the reset state, where it can wait for new commands.
129 */
130static void
131reset_seeprom(struct seeprom_descriptor *sd)
132{
133	uint8_t temp;
134
135	temp = sd->sd_MS;
136	SEEPROM_OUTB(sd, temp);
137	CLOCK_PULSE(sd, sd->sd_RDY);
138	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
139	CLOCK_PULSE(sd, sd->sd_RDY);
140	SEEPROM_OUTB(sd, temp);
141	CLOCK_PULSE(sd, sd->sd_RDY);
142}
143
144/*
145 * Read the serial EEPROM and returns 1 if successful and 0 if
146 * not successful.
147 */
148int
149ahc_read_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
150		 u_int start_addr, u_int count)
151{
152	int i = 0;
153	u_int k = 0;
154	uint16_t v;
155	uint8_t temp;
156
157	/*
158	 * Read the requested registers of the seeprom.  The loop
159	 * will range from 0 to count-1.
160	 */
161	for (k = start_addr; k < count + start_addr; k++) {
162		/*
163		 * Now we're ready to send the read command followed by the
164		 * address of the 16-bit register we want to read.
165		 */
166		send_seeprom_cmd(sd, &seeprom_read);
167
168		/* Send the 6 or 8 bit address (MSB first, LSB last). */
169		temp = sd->sd_MS ^ sd->sd_CS;
170		for (i = (sd->sd_chip - 1); i >= 0; i--) {
171			if ((k & (1 << i)) != 0)
172				temp ^= sd->sd_DO;
173			SEEPROM_OUTB(sd, temp);
174			CLOCK_PULSE(sd, sd->sd_RDY);
175			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
176			CLOCK_PULSE(sd, sd->sd_RDY);
177			if ((k & (1 << i)) != 0)
178				temp ^= sd->sd_DO;
179		}
180
181		/*
182		 * Now read the 16 bit register.  An initial 0 precedes the
183		 * register contents which begins with bit 15 (MSB) and ends
184		 * with bit 0 (LSB).  The initial 0 will be shifted off the
185		 * top of our word as we let the loop run from 0 to 16.
186		 */
187		v = 0;
188		for (i = 16; i >= 0; i--) {
189			SEEPROM_OUTB(sd, temp);
190			CLOCK_PULSE(sd, sd->sd_RDY);
191			v <<= 1;
192			if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
193				v |= 1;
194			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
195			CLOCK_PULSE(sd, sd->sd_RDY);
196		}
197
198		buf[k - start_addr] = v;
199
200		/* Reset the chip select for the next command cycle. */
201		reset_seeprom(sd);
202	}
203#ifdef AHC_DUMP_EEPROM
204	printf("\nSerial EEPROM:\n\t");
205	for (k = 0; k < count; k = k + 1) {
206		if (((k % 8) == 0) && (k != 0)) {
207			printf ("\n\t");
208		}
209		printf (" 0x%x", buf[k]);
210	}
211	printf ("\n");
212#endif
213	return (1);
214}
215
216/*
217 * Write the serial EEPROM and return 1 if successful and 0 if
218 * not successful.
219 */
220int
221ahc_write_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
222		  u_int start_addr, u_int count)
223{
224	struct seeprom_cmd *ewen, *ewds;
225	uint16_t v;
226	uint8_t temp;
227	int i, k;
228
229	/* Place the chip into write-enable mode */
230	if (sd->sd_chip == C46) {
231		ewen = &seeprom_ewen;
232		ewds = &seeprom_ewds;
233	} else if (sd->sd_chip == C56_66) {
234		ewen = &seeprom_long_ewen;
235		ewds = &seeprom_long_ewds;
236	} else {
237		printf("ahc_write_seeprom: unsupported seeprom type %d\n",
238		       sd->sd_chip);
239		return (0);
240	}
241
242	send_seeprom_cmd(sd, ewen);
243	reset_seeprom(sd);
244
245	/* Write all requested data out to the seeprom. */
246	temp = sd->sd_MS ^ sd->sd_CS;
247	for (k = start_addr; k < count + start_addr; k++) {
248		/* Send the write command */
249		send_seeprom_cmd(sd, &seeprom_write);
250
251		/* Send the 6 or 8 bit address (MSB first). */
252		for (i = (sd->sd_chip - 1); i >= 0; i--) {
253			if ((k & (1 << i)) != 0)
254				temp ^= sd->sd_DO;
255			SEEPROM_OUTB(sd, temp);
256			CLOCK_PULSE(sd, sd->sd_RDY);
257			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
258			CLOCK_PULSE(sd, sd->sd_RDY);
259			if ((k & (1 << i)) != 0)
260				temp ^= sd->sd_DO;
261		}
262
263		/* Write the 16 bit value, MSB first */
264		v = buf[k - start_addr];
265		for (i = 15; i >= 0; i--) {
266			if ((v & (1 << i)) != 0)
267				temp ^= sd->sd_DO;
268			SEEPROM_OUTB(sd, temp);
269			CLOCK_PULSE(sd, sd->sd_RDY);
270			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
271			CLOCK_PULSE(sd, sd->sd_RDY);
272			if ((v & (1 << i)) != 0)
273				temp ^= sd->sd_DO;
274		}
275
276		/* Wait for the chip to complete the write */
277		temp = sd->sd_MS;
278		SEEPROM_OUTB(sd, temp);
279		CLOCK_PULSE(sd, sd->sd_RDY);
280		temp = sd->sd_MS ^ sd->sd_CS;
281		do {
282			SEEPROM_OUTB(sd, temp);
283			CLOCK_PULSE(sd, sd->sd_RDY);
284			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
285			CLOCK_PULSE(sd, sd->sd_RDY);
286		} while ((SEEPROM_DATA_INB(sd) & sd->sd_DI) == 0);
287
288		reset_seeprom(sd);
289	}
290
291	/* Put the chip back into write-protect mode */
292	send_seeprom_cmd(sd, ewds);
293	reset_seeprom(sd);
294
295	return (1);
296}
297
298int
299ahc_verify_cksum(struct seeprom_config *sc)
300{
301	int i;
302	int maxaddr;
303	uint32_t checksum;
304	uint16_t *scarray;
305
306	maxaddr = (sizeof(*sc)/2) - 1;
307	checksum = 0;
308	scarray = (uint16_t *)sc;
309
310	for (i = 0; i < maxaddr; i++)
311		checksum = checksum + scarray[i];
312	if (checksum == 0
313	 || (checksum & 0xFFFF) != sc->checksum) {
314		return (0);
315	} else {
316		return(1);
317	}
318}
319