xref: /openbmc/u-boot/drivers/misc/ds4510.c (revision 85ab0452)
1 /*
2  * Copyright 2008 Extreme Engineering Solutions, Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0
5  */
6 
7 /*
8  * Driver for DS4510, a CPU supervisor with integrated EEPROM, SRAM,
9  * and 4 programmable non-volatile GPIO pins.
10  */
11 
12 #include <common.h>
13 #include <i2c.h>
14 #include <command.h>
15 #include "ds4510.h"
16 
17 enum {
18 	DS4510_CMD_INFO,
19 	DS4510_CMD_DEVICE,
20 	DS4510_CMD_NV,
21 	DS4510_CMD_RSTDELAY,
22 	DS4510_CMD_OUTPUT,
23 	DS4510_CMD_INPUT,
24 	DS4510_CMD_PULLUP,
25 	DS4510_CMD_EEPROM,
26 	DS4510_CMD_SEEPROM,
27 	DS4510_CMD_SRAM,
28 };
29 
30 /*
31  * Write to DS4510, taking page boundaries into account
32  */
33 static int ds4510_mem_write(uint8_t chip, int offset, uint8_t *buf, int count)
34 {
35 	int wrlen;
36 	int i = 0;
37 
38 	do {
39 		wrlen = DS4510_EEPROM_PAGE_SIZE -
40 			DS4510_EEPROM_PAGE_OFFSET(offset);
41 		if (count < wrlen)
42 			wrlen = count;
43 		if (i2c_write(chip, offset, 1, &buf[i], wrlen))
44 			return -1;
45 
46 		/*
47 		 * This delay isn't needed for SRAM writes but shouldn't delay
48 		 * things too much, so do it unconditionally for simplicity
49 		 */
50 		udelay(DS4510_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
51 		count -= wrlen;
52 		offset += wrlen;
53 		i += wrlen;
54 	} while (count > 0);
55 
56 	return 0;
57 }
58 
59 /*
60  * General read from DS4510
61  */
62 static int ds4510_mem_read(uint8_t chip, int offset, uint8_t *buf, int count)
63 {
64 	return i2c_read(chip, offset, 1, buf, count);
65 }
66 
67 /*
68  * Write SEE bit in config register.
69  * nv = 0 - Writes to SEEPROM registers behave like EEPROM
70  * nv = 1 - Writes to SEEPROM registers behave like SRAM
71  */
72 static int ds4510_see_write(uint8_t chip, uint8_t nv)
73 {
74 	uint8_t data;
75 
76 	if (i2c_read(chip, DS4510_CFG, 1, &data, 1))
77 		return -1;
78 
79 	if (nv)	/* Treat SEEPROM bits as EEPROM */
80 		data &= ~DS4510_CFG_SEE;
81 	else	/* Treat SEEPROM bits as SRAM */
82 		data |= DS4510_CFG_SEE;
83 
84 	return ds4510_mem_write(chip, DS4510_CFG, &data, 1);
85 }
86 
87 /*
88  * Write de-assertion of reset signal delay
89  */
90 static int ds4510_rstdelay_write(uint8_t chip, uint8_t delay)
91 {
92 	uint8_t data;
93 
94 	if (i2c_read(chip, DS4510_RSTDELAY, 1, &data, 1))
95 		return -1;
96 
97 	data &= ~DS4510_RSTDELAY_MASK;
98 	data |= delay & DS4510_RSTDELAY_MASK;
99 
100 	return ds4510_mem_write(chip, DS4510_RSTDELAY, &data, 1);
101 }
102 
103 /*
104  * Write pullup characteristics of IO pins
105  */
106 static int ds4510_pullup_write(uint8_t chip, uint8_t val)
107 {
108 	val &= DS4510_IO_MASK;
109 
110 	return ds4510_mem_write(chip, DS4510_PULLUP, (uint8_t *)&val, 1);
111 }
112 
113 /*
114  * Read pullup characteristics of IO pins
115  */
116 static int ds4510_pullup_read(uint8_t chip)
117 {
118 	uint8_t val;
119 
120 	if (i2c_read(chip, DS4510_PULLUP, 1, &val, 1))
121 		return -1;
122 
123 	return val & DS4510_IO_MASK;
124 }
125 
126 /*
127  * Write drive level of IO pins
128  */
129 static int ds4510_gpio_write(uint8_t chip, uint8_t val)
130 {
131 	uint8_t data;
132 	int i;
133 
134 	for (i = 0; i < DS4510_NUM_IO; i++) {
135 		if (i2c_read(chip, DS4510_IO0 - i, 1, &data, 1))
136 			return -1;
137 
138 		if (val & (0x1 << i))
139 			data |= 0x1;
140 		else
141 			data &= ~0x1;
142 
143 		if (ds4510_mem_write(chip, DS4510_IO0 - i, &data, 1))
144 			return -1;
145 	}
146 
147 	return 0;
148 }
149 
150 /*
151  * Read drive level of IO pins
152  */
153 static int ds4510_gpio_read(uint8_t chip)
154 {
155 	uint8_t data;
156 	int val = 0;
157 	int i;
158 
159 	for (i = 0; i < DS4510_NUM_IO; i++) {
160 		if (i2c_read(chip, DS4510_IO0 - i, 1, &data, 1))
161 			return -1;
162 
163 		if (data & 1)
164 			val |= (1 << i);
165 	}
166 
167 	return val;
168 }
169 
170 /*
171  * Read physical level of IO pins
172  */
173 static int ds4510_gpio_read_val(uint8_t chip)
174 {
175 	uint8_t val;
176 
177 	if (i2c_read(chip, DS4510_IO_STATUS, 1, &val, 1))
178 		return -1;
179 
180 	return val & DS4510_IO_MASK;
181 }
182 
183 /*
184  * Display DS4510 information
185  */
186 static int ds4510_info(uint8_t chip)
187 {
188 	int i;
189 	int tmp;
190 	uint8_t data;
191 
192 	printf("DS4510 @ 0x%x:\n\n", chip);
193 
194 	if (i2c_read(chip, DS4510_RSTDELAY, 1, &data, 1))
195 		return -1;
196 	printf("rstdelay = 0x%x\n\n", data & DS4510_RSTDELAY_MASK);
197 
198 	if (i2c_read(chip, DS4510_CFG, 1, &data, 1))
199 		return -1;
200 	printf("config   = 0x%x\n", data);
201 	printf(" /ready  = %d\n", data & DS4510_CFG_READY ? 1 : 0);
202 	printf(" trip pt = %d\n", data & DS4510_CFG_TRIP_POINT ? 1 : 0);
203 	printf(" rst sts = %d\n", data & DS4510_CFG_RESET ? 1 : 0);
204 	printf(" /see    = %d\n", data & DS4510_CFG_SEE ? 1 : 0);
205 	printf(" swrst   = %d\n\n", data & DS4510_CFG_SWRST ? 1 : 0);
206 
207 	printf("gpio pins: 3210\n");
208 	printf("---------------\n");
209 	printf("pullup     ");
210 
211 	tmp = ds4510_pullup_read(chip);
212 	if (tmp == -1)
213 		return tmp;
214 	for (i = DS4510_NUM_IO - 1; i >= 0; i--)
215 		printf("%d", (tmp & (1 << i)) ? 1 : 0);
216 	printf("\n");
217 
218 	printf("driven     ");
219 	tmp = ds4510_gpio_read(chip);
220 	if (tmp == -1)
221 		return -1;
222 	for (i = DS4510_NUM_IO - 1; i >= 0; i--)
223 		printf("%d", (tmp & (1 << i)) ? 1 : 0);
224 	printf("\n");
225 
226 	printf("read       ");
227 	tmp = ds4510_gpio_read_val(chip);
228 	if (tmp == -1)
229 		return -1;
230 	for (i = DS4510_NUM_IO - 1; i >= 0; i--)
231 		printf("%d", (tmp & (1 << i)) ? 1 : 0);
232 	printf("\n");
233 
234 	return 0;
235 }
236 
237 cmd_tbl_t cmd_ds4510[] = {
238 	U_BOOT_CMD_MKENT(device, 3, 0, (void *)DS4510_CMD_DEVICE, "", ""),
239 	U_BOOT_CMD_MKENT(nv, 3, 0, (void *)DS4510_CMD_NV, "", ""),
240 	U_BOOT_CMD_MKENT(output, 4, 0, (void *)DS4510_CMD_OUTPUT, "", ""),
241 	U_BOOT_CMD_MKENT(input, 3, 0, (void *)DS4510_CMD_INPUT, "", ""),
242 	U_BOOT_CMD_MKENT(pullup, 4, 0, (void *)DS4510_CMD_PULLUP, "", ""),
243 	U_BOOT_CMD_MKENT(info, 2, 0, (void *)DS4510_CMD_INFO, "", ""),
244 	U_BOOT_CMD_MKENT(rstdelay, 3, 0, (void *)DS4510_CMD_RSTDELAY, "", ""),
245 	U_BOOT_CMD_MKENT(eeprom, 6, 0, (void *)DS4510_CMD_EEPROM, "", ""),
246 	U_BOOT_CMD_MKENT(seeprom, 6, 0, (void *)DS4510_CMD_SEEPROM, "", ""),
247 	U_BOOT_CMD_MKENT(sram, 6, 0, (void *)DS4510_CMD_SRAM, "", ""),
248 };
249 
250 int do_ds4510(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
251 {
252 	static uint8_t chip = 0x51;
253 	cmd_tbl_t *c;
254 	ulong ul_arg2 = 0;
255 	ulong ul_arg3 = 0;
256 	int tmp;
257 	ulong addr;
258 	ulong off;
259 	ulong cnt;
260 	int end;
261 	int (*rw_func)(uint8_t, int, uint8_t *, int);
262 
263 	c = find_cmd_tbl(argv[1], cmd_ds4510, ARRAY_SIZE(cmd_ds4510));
264 
265 	/* All commands but "device" require 'maxargs' arguments */
266 	if (!c || !((argc == (c->maxargs)) ||
267 		(((int)c->cmd == DS4510_CMD_DEVICE) &&
268 		 (argc == (c->maxargs - 1))))) {
269 		return cmd_usage(cmdtp);
270 	}
271 
272 	/* arg2 used as chip addr and pin number */
273 	if (argc > 2)
274 		ul_arg2 = simple_strtoul(argv[2], NULL, 16);
275 
276 	/* arg3 used as output/pullup value */
277 	if (argc > 3)
278 		ul_arg3 = simple_strtoul(argv[3], NULL, 16);
279 
280 	switch ((int)c->cmd) {
281 	case DS4510_CMD_DEVICE:
282 		if (argc == 3)
283 			chip = ul_arg2;
284 		printf("Current device address: 0x%x\n", chip);
285 		return 0;
286 	case DS4510_CMD_NV:
287 		return ds4510_see_write(chip, ul_arg2);
288 	case DS4510_CMD_OUTPUT:
289 		tmp = ds4510_gpio_read(chip);
290 		if (tmp == -1)
291 			return -1;
292 		if (ul_arg3)
293 			tmp |= (1 << ul_arg2);
294 		else
295 			tmp &= ~(1 << ul_arg2);
296 		return ds4510_gpio_write(chip, tmp);
297 	case DS4510_CMD_INPUT:
298 		tmp = ds4510_gpio_read_val(chip);
299 		if (tmp == -1)
300 			return -1;
301 		return (tmp & (1 << ul_arg2)) != 0;
302 	case DS4510_CMD_PULLUP:
303 		tmp = ds4510_pullup_read(chip);
304 		if (tmp == -1)
305 			return -1;
306 		if (ul_arg3)
307 			tmp |= (1 << ul_arg2);
308 		else
309 			tmp &= ~(1 << ul_arg2);
310 		return ds4510_pullup_write(chip, tmp);
311 	case DS4510_CMD_INFO:
312 		return ds4510_info(chip);
313 	case DS4510_CMD_RSTDELAY:
314 		return ds4510_rstdelay_write(chip, ul_arg2);
315 	case DS4510_CMD_EEPROM:
316 		end = DS4510_EEPROM + DS4510_EEPROM_SIZE;
317 		off = DS4510_EEPROM;
318 		break;
319 	case DS4510_CMD_SEEPROM:
320 		end = DS4510_SEEPROM + DS4510_SEEPROM_SIZE;
321 		off = DS4510_SEEPROM;
322 		break;
323 	case DS4510_CMD_SRAM:
324 		end = DS4510_SRAM + DS4510_SRAM_SIZE;
325 		off = DS4510_SRAM;
326 		break;
327 	default:
328 		/* We should never get here... */
329 		return 1;
330 	}
331 
332 	/* Only eeprom, seeprom, and sram commands should make it here */
333 	if (strcmp(argv[2], "read") == 0)
334 		rw_func = ds4510_mem_read;
335 	else if (strcmp(argv[2], "write") == 0)
336 		rw_func = ds4510_mem_write;
337 	else
338 		return cmd_usage(cmdtp);
339 
340 	addr = simple_strtoul(argv[3], NULL, 16);
341 	off += simple_strtoul(argv[4], NULL, 16);
342 	cnt = simple_strtoul(argv[5], NULL, 16);
343 
344 	if ((off + cnt) > end) {
345 		printf("ERROR: invalid len\n");
346 		return -1;
347 	}
348 
349 	return rw_func(chip, off, (uint8_t *)addr, cnt);
350 }
351 
352 U_BOOT_CMD(
353 	ds4510,	6,	1,	do_ds4510,
354 	"ds4510 eeprom/seeprom/sram/gpio access",
355 	"device [dev]\n"
356 	"	- show or set current device address\n"
357 	"ds4510 info\n"
358 	"	- display ds4510 info\n"
359 	"ds4510 output pin 0|1\n"
360 	"	- set pin low or high-Z\n"
361 	"ds4510 input pin\n"
362 	"	- read value of pin\n"
363 	"ds4510 pullup pin 0|1\n"
364 	"	- disable/enable pullup on specified pin\n"
365 	"ds4510 nv 0|1\n"
366 	"	- make gpio and seeprom writes volatile/non-volatile"
367 	"\n"
368 	"ds4510 rstdelay 0-3\n"
369 	"	- set reset output delay"
370 	"\n"
371 	"ds4510 eeprom read addr off cnt\n"
372 	"ds4510 eeprom write addr off cnt\n"
373 	"	- read/write 'cnt' bytes at EEPROM offset 'off'\n"
374 	"ds4510 seeprom read addr off cnt\n"
375 	"ds4510 seeprom write addr off cnt\n"
376 	"	- read/write 'cnt' bytes at SRAM-shadowed EEPROM offset 'off'\n"
377 	"ds4510 sram read addr off cnt\n"
378 	"ds4510 sram write addr off cnt\n"
379 	"	- read/write 'cnt' bytes at SRAM offset 'off'"
380 );
381