xref: /freebsd/sys/dev/aic7xxx/aic7xxx_93cx6.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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 __FBSDID("$FreeBSD$");
74 #include <dev/aic7xxx/aic7xxx_osm.h>
75 #include <dev/aic7xxx/aic7xxx_inline.h>
76 #include <dev/aic7xxx/aic7xxx_93cx6.h>
77 #endif
78 
79 /*
80  * Right now, we only have to read the SEEPROM.  But we make it easier to
81  * add other 93Cx6 functions.
82  */
83 struct seeprom_cmd {
84   	uint8_t len;
85  	uint8_t bits[11];
86 };
87 
88 /* Short opcodes for the c46 */
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 
92 /* Long opcodes for the C56/C66 */
93 static struct seeprom_cmd seeprom_long_ewen = {11, {1, 0, 0, 1, 1, 0, 0, 0, 0}};
94 static struct seeprom_cmd seeprom_long_ewds = {11, {1, 0, 0, 0, 0, 0, 0, 0, 0}};
95 
96 /* Common opcodes */
97 static struct seeprom_cmd seeprom_write = {3, {1, 0, 1}};
98 static struct seeprom_cmd seeprom_read  = {3, {1, 1, 0}};
99 
100 /*
101  * Wait for the SEERDY to go high; about 800 ns.
102  */
103 #define CLOCK_PULSE(sd, rdy)				\
104 	while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) {	\
105 		;  /* Do nothing */			\
106 	}						\
107 	(void)SEEPROM_INB(sd);	/* Clear clock */
108 
109 /*
110  * Send a START condition and the given command
111  */
112 static void
113 send_seeprom_cmd(struct seeprom_descriptor *sd, struct seeprom_cmd *cmd)
114 {
115 	uint8_t temp;
116 	int i = 0;
117 
118 	/* Send chip select for one clock cycle. */
119 	temp = sd->sd_MS ^ sd->sd_CS;
120 	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
121 	CLOCK_PULSE(sd, sd->sd_RDY);
122 
123 	for (i = 0; i < cmd->len; i++) {
124 		if (cmd->bits[i] != 0)
125 			temp ^= sd->sd_DO;
126 		SEEPROM_OUTB(sd, temp);
127 		CLOCK_PULSE(sd, sd->sd_RDY);
128 		SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
129 		CLOCK_PULSE(sd, sd->sd_RDY);
130 		if (cmd->bits[i] != 0)
131 			temp ^= sd->sd_DO;
132 	}
133 }
134 
135 /*
136  * Clear CS put the chip in the reset state, where it can wait for new commands.
137  */
138 static void
139 reset_seeprom(struct seeprom_descriptor *sd)
140 {
141 	uint8_t temp;
142 
143 	temp = sd->sd_MS;
144 	SEEPROM_OUTB(sd, temp);
145 	CLOCK_PULSE(sd, sd->sd_RDY);
146 	SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
147 	CLOCK_PULSE(sd, sd->sd_RDY);
148 	SEEPROM_OUTB(sd, temp);
149 	CLOCK_PULSE(sd, sd->sd_RDY);
150 }
151 
152 /*
153  * Read the serial EEPROM and returns 1 if successful and 0 if
154  * not successful.
155  */
156 int
157 ahc_read_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
158 		 u_int start_addr, u_int count)
159 {
160 	int i = 0;
161 	u_int k = 0;
162 	uint16_t v;
163 	uint8_t temp;
164 
165 	/*
166 	 * Read the requested registers of the seeprom.  The loop
167 	 * will range from 0 to count-1.
168 	 */
169 	for (k = start_addr; k < count + start_addr; k++) {
170 		/*
171 		 * Now we're ready to send the read command followed by the
172 		 * address of the 16-bit register we want to read.
173 		 */
174 		send_seeprom_cmd(sd, &seeprom_read);
175 
176 		/* Send the 6 or 8 bit address (MSB first, LSB last). */
177 		temp = sd->sd_MS ^ sd->sd_CS;
178 		for (i = (sd->sd_chip - 1); i >= 0; i--) {
179 			if ((k & (1 << i)) != 0)
180 				temp ^= sd->sd_DO;
181 			SEEPROM_OUTB(sd, temp);
182 			CLOCK_PULSE(sd, sd->sd_RDY);
183 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
184 			CLOCK_PULSE(sd, sd->sd_RDY);
185 			if ((k & (1 << i)) != 0)
186 				temp ^= sd->sd_DO;
187 		}
188 
189 		/*
190 		 * Now read the 16 bit register.  An initial 0 precedes the
191 		 * register contents which begins with bit 15 (MSB) and ends
192 		 * with bit 0 (LSB).  The initial 0 will be shifted off the
193 		 * top of our word as we let the loop run from 0 to 16.
194 		 */
195 		v = 0;
196 		for (i = 16; i >= 0; i--) {
197 			SEEPROM_OUTB(sd, temp);
198 			CLOCK_PULSE(sd, sd->sd_RDY);
199 			v <<= 1;
200 			if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
201 				v |= 1;
202 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
203 			CLOCK_PULSE(sd, sd->sd_RDY);
204 		}
205 
206 		buf[k - start_addr] = v;
207 
208 		/* Reset the chip select for the next command cycle. */
209 		reset_seeprom(sd);
210 	}
211 #ifdef AHC_DUMP_EEPROM
212 	printf("\nSerial EEPROM:\n\t");
213 	for (k = 0; k < count; k = k + 1) {
214 		if (((k % 8) == 0) && (k != 0)) {
215 			printf ("\n\t");
216 		}
217 		printf (" 0x%x", buf[k]);
218 	}
219 	printf ("\n");
220 #endif
221 	return (1);
222 }
223 
224 /*
225  * Write the serial EEPROM and return 1 if successful and 0 if
226  * not successful.
227  */
228 int
229 ahc_write_seeprom(struct seeprom_descriptor *sd, uint16_t *buf,
230 		  u_int start_addr, u_int count)
231 {
232 	struct seeprom_cmd *ewen, *ewds;
233 	uint16_t v;
234 	uint8_t temp;
235 	int i, k;
236 
237 	/* Place the chip into write-enable mode */
238 	if (sd->sd_chip == C46) {
239 		ewen = &seeprom_ewen;
240 		ewds = &seeprom_ewds;
241 	} else if (sd->sd_chip == C56_66) {
242 		ewen = &seeprom_long_ewen;
243 		ewds = &seeprom_long_ewds;
244 	} else {
245 		printf("ahc_write_seeprom: unsupported seeprom type %d\n",
246 		       sd->sd_chip);
247 		return (0);
248 	}
249 
250 	send_seeprom_cmd(sd, ewen);
251 	reset_seeprom(sd);
252 
253 	/* Write all requested data out to the seeprom. */
254 	temp = sd->sd_MS ^ sd->sd_CS;
255 	for (k = start_addr; k < count + start_addr; k++) {
256 		/* Send the write command */
257 		send_seeprom_cmd(sd, &seeprom_write);
258 
259 		/* Send the 6 or 8 bit address (MSB first). */
260 		for (i = (sd->sd_chip - 1); i >= 0; i--) {
261 			if ((k & (1 << i)) != 0)
262 				temp ^= sd->sd_DO;
263 			SEEPROM_OUTB(sd, temp);
264 			CLOCK_PULSE(sd, sd->sd_RDY);
265 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
266 			CLOCK_PULSE(sd, sd->sd_RDY);
267 			if ((k & (1 << i)) != 0)
268 				temp ^= sd->sd_DO;
269 		}
270 
271 		/* Write the 16 bit value, MSB first */
272 		v = buf[k - start_addr];
273 		for (i = 15; i >= 0; i--) {
274 			if ((v & (1 << i)) != 0)
275 				temp ^= sd->sd_DO;
276 			SEEPROM_OUTB(sd, temp);
277 			CLOCK_PULSE(sd, sd->sd_RDY);
278 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
279 			CLOCK_PULSE(sd, sd->sd_RDY);
280 			if ((v & (1 << i)) != 0)
281 				temp ^= sd->sd_DO;
282 		}
283 
284 		/* Wait for the chip to complete the write */
285 		temp = sd->sd_MS;
286 		SEEPROM_OUTB(sd, temp);
287 		CLOCK_PULSE(sd, sd->sd_RDY);
288 		temp = sd->sd_MS ^ sd->sd_CS;
289 		do {
290 			SEEPROM_OUTB(sd, temp);
291 			CLOCK_PULSE(sd, sd->sd_RDY);
292 			SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
293 			CLOCK_PULSE(sd, sd->sd_RDY);
294 		} while ((SEEPROM_DATA_INB(sd) & sd->sd_DI) == 0);
295 
296 		reset_seeprom(sd);
297 	}
298 
299 	/* Put the chip back into write-protect mode */
300 	send_seeprom_cmd(sd, ewds);
301 	reset_seeprom(sd);
302 
303 	return (1);
304 }
305 
306 int
307 ahc_verify_cksum(struct seeprom_config *sc)
308 {
309 	int i;
310 	int maxaddr;
311 	uint32_t checksum;
312 	uint16_t *scarray;
313 
314 	maxaddr = (sizeof(*sc)/2) - 1;
315 	checksum = 0;
316 	scarray = (uint16_t *)sc;
317 
318 	for (i = 0; i < maxaddr; i++)
319 		checksum = checksum + scarray[i];
320 	if (checksum == 0
321 	 || (checksum & 0xFFFF) != sc->checksum) {
322 		return (0);
323 	} else {
324 		return(1);
325 	}
326 }
327