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#17 $
32  *
33  * $FreeBSD$
34  */
35 
36 /*
37  *   The instruction set of the 93C66/56/46/26/06 chips are as follows:
38  *
39  *               Start  OP	    *
40  *     Function   Bit  Code  Address**  Data     Description
41  *     -------------------------------------------------------------------
42  *     READ        1    10   A5 - A0             Reads data stored in memory,
43  *                                               starting at specified address
44  *     EWEN        1    00   11XXXX              Write enable must precede
45  *                                               all programming modes
46  *     ERASE       1    11   A5 - A0             Erase register A5A4A3A2A1A0
47  *     WRITE       1    01   A5 - A0   D15 - D0  Writes register
48  *     ERAL        1    00   10XXXX              Erase all registers
49  *     WRAL        1    00   01XXXX    D15 - D0  Writes to all registers
50  *     EWDS        1    00   00XXXX              Disables all programming
51  *                                               instructions
52  *     *Note: A value of X for address is a don't care condition.
53  *    **Note: There are 8 address bits for the 93C56/66 chips unlike
54  *	      the 93C46/26/06 chips which have 6 address bits.
55  *
56  *   The 93C46 has a four wire interface: clock, chip select, data in, and
57  *   data out.  In order to perform one of the above functions, you need
58  *   to enable the chip select for a clock period (typically a minimum of
59  *   1 usec, with the clock high and low a minimum of 750 and 250 nsec
60  *   respectively).  While the chip select remains high, you can clock in
61  *   the instructions (above) starting with the start bit, followed by the
62  *   OP code, Address, and Data (if needed).  For the READ instruction, the
63  *   requested 16-bit register contents is read from the data out line but
64  *   is preceded by an initial zero (leading 0, followed by 16-bits, MSB
65  *   first).  The clock cycling from low to high initiates the next data
66  *   bit to be sent from the chip.
67  *
68  */
69 
70 #ifdef __linux__
71 #include "aic7xxx_osm.h"
72 #include "aic7xxx_inline.h"
73 #include "aic7xxx_93cx6.h"
74 #else
75 #include <dev/aic7xxx/aic7xxx_osm.h>
76 #include <dev/aic7xxx/aic7xxx_inline.h>
77 #include <dev/aic7xxx/aic7xxx_93cx6.h>
78 #endif
79 
80 /*
81  * Right now, we only have to read the SEEPROM.  But we make it easier to
82  * add other 93Cx6 functions.
83  */
84 static struct seeprom_cmd {
85   	uint8_t len;
86  	uint8_t bits[9];
87 } seeprom_read = {3, {1, 1, 0}};
88 
89 static struct seeprom_cmd seeprom_ewen = {9, {1, 0, 0, 1, 1, 0, 0, 0, 0}};
90 static struct seeprom_cmd seeprom_ewds = {9, {1, 0, 0, 0, 0, 0, 0, 0, 0}};
91 static struct seeprom_cmd seeprom_write = {3, {1, 0, 1}};
92 
93 /*
94  * Wait for the SEERDY to go high; about 800 ns.
95  */
96 #define CLOCK_PULSE(sd, rdy)				\
97 	while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) {	\
98 		;  /* Do nothing */			\
99 	}						\
100 	(void)SEEPROM_INB(sd);	/* Clear clock */
101 
102 /*
103  * Send a START condition and the given command
104  */
105 static void
106 send_seeprom_cmd(struct seeprom_descriptor *sd, struct seeprom_cmd *cmd)
107 {
108 	uint8_t temp;
109 	int i = 0;
110 
111 	/* Send chip select for one clock cycle. */
112 	temp = sd->sd_MS ^ sd->sd_CS;
113 	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
114 	CLOCK_PULSE(sd, sd->sd_RDY);
115 
116 	for (i = 0; i < cmd->len; i++) {
117 		if (cmd->bits[i] != 0)
118 			temp ^= sd->sd_DO;
119 		SEEPROM_OUTB(sd, temp);
120 		CLOCK_PULSE(sd, sd->sd_RDY);
121 		SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
122 		CLOCK_PULSE(sd, sd->sd_RDY);
123 		if (cmd->bits[i] != 0)
124 			temp ^= sd->sd_DO;
125 	}
126 }
127 
128 /*
129  * Clear CS put the chip in the reset state, where it can wait for new commands.
130  */
131 static void
132 reset_seeprom(struct seeprom_descriptor *sd)
133 {
134 	uint8_t temp;
135 
136 	temp = sd->sd_MS;
137 	SEEPROM_OUTB(sd, temp);
138 	CLOCK_PULSE(sd, sd->sd_RDY);
139 	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
140 	CLOCK_PULSE(sd, sd->sd_RDY);
141 	SEEPROM_OUTB(sd, temp);
142 	CLOCK_PULSE(sd, sd->sd_RDY);
143 }
144 
145 /*
146  * Read the serial EEPROM and returns 1 if successful and 0 if
147  * not successful.
148  */
149 int
150 ahc_read_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
151 		 u_int start_addr, u_int count)
152 {
153 	int i = 0;
154 	u_int k = 0;
155 	uint16_t v;
156 	uint8_t temp;
157 
158 	/*
159 	 * Read the requested registers of the seeprom.  The loop
160 	 * will range from 0 to count-1.
161 	 */
162 	for (k = start_addr; k < count + start_addr; k++) {
163 		/*
164 		 * Now we're ready to send the read command followed by the
165 		 * address of the 16-bit register we want to read.
166 		 */
167 		send_seeprom_cmd(sd, &seeprom_read);
168 
169 		/* Send the 6 or 8 bit address (MSB first, LSB last). */
170 		temp = sd->sd_MS ^ sd->sd_CS;
171 		for (i = (sd->sd_chip - 1); i >= 0; i--) {
172 			if ((k & (1 << i)) != 0)
173 				temp ^= sd->sd_DO;
174 			SEEPROM_OUTB(sd, temp);
175 			CLOCK_PULSE(sd, sd->sd_RDY);
176 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
177 			CLOCK_PULSE(sd, sd->sd_RDY);
178 			if ((k & (1 << i)) != 0)
179 				temp ^= sd->sd_DO;
180 		}
181 
182 		/*
183 		 * Now read the 16 bit register.  An initial 0 precedes the
184 		 * register contents which begins with bit 15 (MSB) and ends
185 		 * with bit 0 (LSB).  The initial 0 will be shifted off the
186 		 * top of our word as we let the loop run from 0 to 16.
187 		 */
188 		v = 0;
189 		for (i = 16; i >= 0; i--) {
190 			SEEPROM_OUTB(sd, temp);
191 			CLOCK_PULSE(sd, sd->sd_RDY);
192 			v <<= 1;
193 			if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
194 				v |= 1;
195 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
196 			CLOCK_PULSE(sd, sd->sd_RDY);
197 		}
198 
199 		buf[k - start_addr] = v;
200 
201 		/* Reset the chip select for the next command cycle. */
202 		reset_seeprom(sd);
203 	}
204 #ifdef AHC_DUMP_EEPROM
205 	printf("\nSerial EEPROM:\n\t");
206 	for (k = 0; k < count; k = k + 1) {
207 		if (((k % 8) == 0) && (k != 0)) {
208 			printf ("\n\t");
209 		}
210 		printf (" 0x%x", buf[k]);
211 	}
212 	printf ("\n");
213 #endif
214 	return (1);
215 }
216 
217 /*
218  * Write the serial EEPROM and return 1 if successful and 0 if
219  * not successful.
220  */
221 int
222 ahc_write_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
223 		  u_int start_addr, u_int count)
224 {
225 	uint16_t v;
226 	uint8_t temp;
227 	int i, k;
228 
229 	/* Place the chip into write-enable mode */
230 	send_seeprom_cmd(sd, &seeprom_ewen);
231 	reset_seeprom(sd);
232 
233 	/* Write all requested data out to the seeprom. */
234 	temp = sd->sd_MS ^ sd->sd_CS;
235 	for (k = start_addr; k < count + start_addr; k++) {
236 		/* Send the write command */
237 		send_seeprom_cmd(sd, &seeprom_write);
238 
239 		/* Send the 6 or 8 bit address (MSB first). */
240 		for (i = (sd->sd_chip - 1); i >= 0; i--) {
241 			if ((k & (1 << i)) != 0)
242 				temp ^= sd->sd_DO;
243 			SEEPROM_OUTB(sd, temp);
244 			CLOCK_PULSE(sd, sd->sd_RDY);
245 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
246 			CLOCK_PULSE(sd, sd->sd_RDY);
247 			if ((k & (1 << i)) != 0)
248 				temp ^= sd->sd_DO;
249 		}
250 
251 		/* Write the 16 bit value, MSB first */
252 		v = buf[k - start_addr];
253 		for (i = 15; i >= 0; i--) {
254 			if ((v & (1 << i)) != 0)
255 				temp ^= sd->sd_DO;
256 			SEEPROM_OUTB(sd, temp);
257 			CLOCK_PULSE(sd, sd->sd_RDY);
258 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
259 			CLOCK_PULSE(sd, sd->sd_RDY);
260 			if ((v & (1 << i)) != 0)
261 				temp ^= sd->sd_DO;
262 		}
263 
264 		/* Wait for the chip to complete the write */
265 		temp = sd->sd_MS;
266 		SEEPROM_OUTB(sd, temp);
267 		CLOCK_PULSE(sd, sd->sd_RDY);
268 		temp = sd->sd_MS ^ sd->sd_CS;
269 		do {
270 			SEEPROM_OUTB(sd, temp);
271 			CLOCK_PULSE(sd, sd->sd_RDY);
272 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
273 			CLOCK_PULSE(sd, sd->sd_RDY);
274 		} while ((SEEPROM_DATA_INB(sd) & sd->sd_DI) == 0);
275 
276 		reset_seeprom(sd);
277 	}
278 
279 	/* Put the chip back into write-protect mode */
280 	send_seeprom_cmd(sd, &seeprom_ewds);
281 	reset_seeprom(sd);
282 
283 	return (1);
284 }
285 
286 int
287 ahc_verify_cksum(struct seeprom_config *sc)
288 {
289 	int i;
290 	int maxaddr;
291 	uint32_t checksum;
292 	uint16_t *scarray;
293 
294 	maxaddr = (sizeof(*sc)/2) - 1;
295 	checksum = 0;
296 	scarray = (uint16_t *)sc;
297 
298 	for (i = 0; i < maxaddr; i++)
299 		checksum = checksum + scarray[i];
300 	if (checksum == 0
301 	 || (checksum & 0xFFFF) != sc->checksum) {
302 		return (0);
303 	} else {
304 		return(1);
305 	}
306 }
307