xref: /freebsd/sys/dev/aic7xxx/aic7xxx_93cx6.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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 #ifdef __linux__
68 #include "aic7xxx_osm.h"
69 #include "aic7xxx_inline.h"
70 #include "aic7xxx_93cx6.h"
71 #else
72 #include <sys/cdefs.h>
73 #include <dev/aic7xxx/aic7xxx_osm.h>
74 #include <dev/aic7xxx/aic7xxx_inline.h>
75 #include <dev/aic7xxx/aic7xxx_93cx6.h>
76 #endif
77 
78 /*
79  * Right now, we only have to read the SEEPROM.  But we make it easier to
80  * add other 93Cx6 functions.
81  */
82 struct seeprom_cmd {
83   	uint8_t len;
84  	uint8_t bits[11];
85 };
86 
87 /* Short opcodes for the c46 */
88 static struct seeprom_cmd seeprom_ewen = {9, {1, 0, 0, 1, 1, 0, 0, 0, 0}};
89 static struct seeprom_cmd seeprom_ewds = {9, {1, 0, 0, 0, 0, 0, 0, 0, 0}};
90 
91 /* Long opcodes for the C56/C66 */
92 static struct seeprom_cmd seeprom_long_ewen = {11, {1, 0, 0, 1, 1, 0, 0, 0, 0}};
93 static struct seeprom_cmd seeprom_long_ewds = {11, {1, 0, 0, 0, 0, 0, 0, 0, 0}};
94 
95 /* Common opcodes */
96 static struct seeprom_cmd seeprom_write = {3, {1, 0, 1}};
97 static struct seeprom_cmd seeprom_read  = {3, {1, 1, 0}};
98 
99 /*
100  * Wait for the SEERDY to go high; about 800 ns.
101  */
102 #define CLOCK_PULSE(sd, rdy)				\
103 	while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) {	\
104 		;  /* Do nothing */			\
105 	}						\
106 	(void)SEEPROM_INB(sd);	/* Clear clock */
107 
108 /*
109  * Send a START condition and the given command
110  */
111 static void
112 send_seeprom_cmd(struct seeprom_descriptor *sd, struct seeprom_cmd *cmd)
113 {
114 	uint8_t temp;
115 	int i = 0;
116 
117 	/* Send chip select for one clock cycle. */
118 	temp = sd->sd_MS ^ sd->sd_CS;
119 	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
120 	CLOCK_PULSE(sd, sd->sd_RDY);
121 
122 	for (i = 0; i < cmd->len; i++) {
123 		if (cmd->bits[i] != 0)
124 			temp ^= sd->sd_DO;
125 		SEEPROM_OUTB(sd, temp);
126 		CLOCK_PULSE(sd, sd->sd_RDY);
127 		SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
128 		CLOCK_PULSE(sd, sd->sd_RDY);
129 		if (cmd->bits[i] != 0)
130 			temp ^= sd->sd_DO;
131 	}
132 }
133 
134 /*
135  * Clear CS put the chip in the reset state, where it can wait for new commands.
136  */
137 static void
138 reset_seeprom(struct seeprom_descriptor *sd)
139 {
140 	uint8_t temp;
141 
142 	temp = sd->sd_MS;
143 	SEEPROM_OUTB(sd, temp);
144 	CLOCK_PULSE(sd, sd->sd_RDY);
145 	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
146 	CLOCK_PULSE(sd, sd->sd_RDY);
147 	SEEPROM_OUTB(sd, temp);
148 	CLOCK_PULSE(sd, sd->sd_RDY);
149 }
150 
151 /*
152  * Read the serial EEPROM and returns 1 if successful and 0 if
153  * not successful.
154  */
155 int
156 ahc_read_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
157 		 u_int start_addr, u_int count)
158 {
159 	int i = 0;
160 	u_int k = 0;
161 	uint16_t v;
162 	uint8_t temp;
163 
164 	/*
165 	 * Read the requested registers of the seeprom.  The loop
166 	 * will range from 0 to count-1.
167 	 */
168 	for (k = start_addr; k < count + start_addr; k++) {
169 		/*
170 		 * Now we're ready to send the read command followed by the
171 		 * address of the 16-bit register we want to read.
172 		 */
173 		send_seeprom_cmd(sd, &seeprom_read);
174 
175 		/* Send the 6 or 8 bit address (MSB first, LSB last). */
176 		temp = sd->sd_MS ^ sd->sd_CS;
177 		for (i = (sd->sd_chip - 1); i >= 0; i--) {
178 			if ((k & (1 << i)) != 0)
179 				temp ^= sd->sd_DO;
180 			SEEPROM_OUTB(sd, temp);
181 			CLOCK_PULSE(sd, sd->sd_RDY);
182 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
183 			CLOCK_PULSE(sd, sd->sd_RDY);
184 			if ((k & (1 << i)) != 0)
185 				temp ^= sd->sd_DO;
186 		}
187 
188 		/*
189 		 * Now read the 16 bit register.  An initial 0 precedes the
190 		 * register contents which begins with bit 15 (MSB) and ends
191 		 * with bit 0 (LSB).  The initial 0 will be shifted off the
192 		 * top of our word as we let the loop run from 0 to 16.
193 		 */
194 		v = 0;
195 		for (i = 16; i >= 0; i--) {
196 			SEEPROM_OUTB(sd, temp);
197 			CLOCK_PULSE(sd, sd->sd_RDY);
198 			v <<= 1;
199 			if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
200 				v |= 1;
201 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
202 			CLOCK_PULSE(sd, sd->sd_RDY);
203 		}
204 
205 		buf[k - start_addr] = v;
206 
207 		/* Reset the chip select for the next command cycle. */
208 		reset_seeprom(sd);
209 	}
210 #ifdef AHC_DUMP_EEPROM
211 	printf("\nSerial EEPROM:\n\t");
212 	for (k = 0; k < count; k = k + 1) {
213 		if (((k % 8) == 0) && (k != 0)) {
214 			printf ("\n\t");
215 		}
216 		printf (" 0x%x", buf[k]);
217 	}
218 	printf ("\n");
219 #endif
220 	return (1);
221 }
222 
223 /*
224  * Write the serial EEPROM and return 1 if successful and 0 if
225  * not successful.
226  */
227 int
228 ahc_write_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
229 		  u_int start_addr, u_int count)
230 {
231 	struct seeprom_cmd *ewen, *ewds;
232 	uint16_t v;
233 	uint8_t temp;
234 	int i, k;
235 
236 	/* Place the chip into write-enable mode */
237 	if (sd->sd_chip == C46) {
238 		ewen = &seeprom_ewen;
239 		ewds = &seeprom_ewds;
240 	} else if (sd->sd_chip == C56_66) {
241 		ewen = &seeprom_long_ewen;
242 		ewds = &seeprom_long_ewds;
243 	} else {
244 		printf("ahc_write_seeprom: unsupported seeprom type %d\n",
245 		       sd->sd_chip);
246 		return (0);
247 	}
248 
249 	send_seeprom_cmd(sd, ewen);
250 	reset_seeprom(sd);
251 
252 	/* Write all requested data out to the seeprom. */
253 	temp = sd->sd_MS ^ sd->sd_CS;
254 	for (k = start_addr; k < count + start_addr; k++) {
255 		/* Send the write command */
256 		send_seeprom_cmd(sd, &seeprom_write);
257 
258 		/* Send the 6 or 8 bit address (MSB first). */
259 		for (i = (sd->sd_chip - 1); i >= 0; i--) {
260 			if ((k & (1 << i)) != 0)
261 				temp ^= sd->sd_DO;
262 			SEEPROM_OUTB(sd, temp);
263 			CLOCK_PULSE(sd, sd->sd_RDY);
264 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
265 			CLOCK_PULSE(sd, sd->sd_RDY);
266 			if ((k & (1 << i)) != 0)
267 				temp ^= sd->sd_DO;
268 		}
269 
270 		/* Write the 16 bit value, MSB first */
271 		v = buf[k - start_addr];
272 		for (i = 15; i >= 0; i--) {
273 			if ((v & (1 << i)) != 0)
274 				temp ^= sd->sd_DO;
275 			SEEPROM_OUTB(sd, temp);
276 			CLOCK_PULSE(sd, sd->sd_RDY);
277 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
278 			CLOCK_PULSE(sd, sd->sd_RDY);
279 			if ((v & (1 << i)) != 0)
280 				temp ^= sd->sd_DO;
281 		}
282 
283 		/* Wait for the chip to complete the write */
284 		temp = sd->sd_MS;
285 		SEEPROM_OUTB(sd, temp);
286 		CLOCK_PULSE(sd, sd->sd_RDY);
287 		temp = sd->sd_MS ^ sd->sd_CS;
288 		do {
289 			SEEPROM_OUTB(sd, temp);
290 			CLOCK_PULSE(sd, sd->sd_RDY);
291 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
292 			CLOCK_PULSE(sd, sd->sd_RDY);
293 		} while ((SEEPROM_DATA_INB(sd) & sd->sd_DI) == 0);
294 
295 		reset_seeprom(sd);
296 	}
297 
298 	/* Put the chip back into write-protect mode */
299 	send_seeprom_cmd(sd, ewds);
300 	reset_seeprom(sd);
301 
302 	return (1);
303 }
304 
305 int
306 ahc_verify_cksum(struct seeprom_config *sc)
307 {
308 	int i;
309 	int maxaddr;
310 	uint32_t checksum;
311 	uint16_t *scarray;
312 
313 	maxaddr = (sizeof(*sc)/2) - 1;
314 	checksum = 0;
315 	scarray = (uint16_t *)sc;
316 
317 	for (i = 0; i < maxaddr; i++)
318 		checksum = checksum + scarray[i];
319 	if (checksum == 0
320 	 || (checksum & 0xFFFF) != sc->checksum) {
321 		return (0);
322 	} else {
323 		return(1);
324 	}
325 }
326