xref: /openbmc/u-boot/drivers/misc/ds4510.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2008 Extreme Engineering Solutions, Inc.
4  */
5 
6 /*
7  * Driver for DS4510, a CPU supervisor with integrated EEPROM, SRAM,
8  * and 4 programmable non-volatile GPIO pins.
9  */
10 
11 #include <common.h>
12 #include <i2c.h>
13 #include <command.h>
14 #include "ds4510.h"
15 
16 enum {
17 	DS4510_CMD_INFO,
18 	DS4510_CMD_DEVICE,
19 	DS4510_CMD_NV,
20 	DS4510_CMD_RSTDELAY,
21 	DS4510_CMD_OUTPUT,
22 	DS4510_CMD_INPUT,
23 	DS4510_CMD_PULLUP,
24 	DS4510_CMD_EEPROM,
25 	DS4510_CMD_SEEPROM,
26 	DS4510_CMD_SRAM,
27 };
28 
29 /*
30  * Write to DS4510, taking page boundaries into account
31  */
32 static int ds4510_mem_write(uint8_t chip, int offset, uint8_t *buf, int count)
33 {
34 	int wrlen;
35 	int i = 0;
36 
37 	do {
38 		wrlen = DS4510_EEPROM_PAGE_SIZE -
39 			DS4510_EEPROM_PAGE_OFFSET(offset);
40 		if (count < wrlen)
41 			wrlen = count;
42 		if (i2c_write(chip, offset, 1, &buf[i], wrlen))
43 			return -1;
44 
45 		/*
46 		 * This delay isn't needed for SRAM writes but shouldn't delay
47 		 * things too much, so do it unconditionally for simplicity
48 		 */
49 		udelay(DS4510_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
50 		count -= wrlen;
51 		offset += wrlen;
52 		i += wrlen;
53 	} while (count > 0);
54 
55 	return 0;
56 }
57 
58 /*
59  * General read from DS4510
60  */
61 static int ds4510_mem_read(uint8_t chip, int offset, uint8_t *buf, int count)
62 {
63 	return i2c_read(chip, offset, 1, buf, count);
64 }
65 
66 /*
67  * Write SEE bit in config register.
68  * nv = 0 - Writes to SEEPROM registers behave like EEPROM
69  * nv = 1 - Writes to SEEPROM registers behave like SRAM
70  */
71 static int ds4510_see_write(uint8_t chip, uint8_t nv)
72 {
73 	uint8_t data;
74 
75 	if (i2c_read(chip, DS4510_CFG, 1, &data, 1))
76 		return -1;
77 
78 	if (nv)	/* Treat SEEPROM bits as EEPROM */
79 		data &= ~DS4510_CFG_SEE;
80 	else	/* Treat SEEPROM bits as SRAM */
81 		data |= DS4510_CFG_SEE;
82 
83 	return ds4510_mem_write(chip, DS4510_CFG, &data, 1);
84 }
85 
86 /*
87  * Write de-assertion of reset signal delay
88  */
89 static int ds4510_rstdelay_write(uint8_t chip, uint8_t delay)
90 {
91 	uint8_t data;
92 
93 	if (i2c_read(chip, DS4510_RSTDELAY, 1, &data, 1))
94 		return -1;
95 
96 	data &= ~DS4510_RSTDELAY_MASK;
97 	data |= delay & DS4510_RSTDELAY_MASK;
98 
99 	return ds4510_mem_write(chip, DS4510_RSTDELAY, &data, 1);
100 }
101 
102 /*
103  * Write pullup characteristics of IO pins
104  */
105 static int ds4510_pullup_write(uint8_t chip, uint8_t val)
106 {
107 	val &= DS4510_IO_MASK;
108 
109 	return ds4510_mem_write(chip, DS4510_PULLUP, (uint8_t *)&val, 1);
110 }
111 
112 /*
113  * Read pullup characteristics of IO pins
114  */
115 static int ds4510_pullup_read(uint8_t chip)
116 {
117 	uint8_t val;
118 
119 	if (i2c_read(chip, DS4510_PULLUP, 1, &val, 1))
120 		return -1;
121 
122 	return val & DS4510_IO_MASK;
123 }
124 
125 /*
126  * Write drive level of IO pins
127  */
128 static int ds4510_gpio_write(uint8_t chip, uint8_t val)
129 {
130 	uint8_t data;
131 	int i;
132 
133 	for (i = 0; i < DS4510_NUM_IO; i++) {
134 		if (i2c_read(chip, DS4510_IO0 - i, 1, &data, 1))
135 			return -1;
136 
137 		if (val & (0x1 << i))
138 			data |= 0x1;
139 		else
140 			data &= ~0x1;
141 
142 		if (ds4510_mem_write(chip, DS4510_IO0 - i, &data, 1))
143 			return -1;
144 	}
145 
146 	return 0;
147 }
148 
149 /*
150  * Read drive level of IO pins
151  */
152 static int ds4510_gpio_read(uint8_t chip)
153 {
154 	uint8_t data;
155 	int val = 0;
156 	int i;
157 
158 	for (i = 0; i < DS4510_NUM_IO; i++) {
159 		if (i2c_read(chip, DS4510_IO0 - i, 1, &data, 1))
160 			return -1;
161 
162 		if (data & 1)
163 			val |= (1 << i);
164 	}
165 
166 	return val;
167 }
168 
169 /*
170  * Read physical level of IO pins
171  */
172 static int ds4510_gpio_read_val(uint8_t chip)
173 {
174 	uint8_t val;
175 
176 	if (i2c_read(chip, DS4510_IO_STATUS, 1, &val, 1))
177 		return -1;
178 
179 	return val & DS4510_IO_MASK;
180 }
181 
182 /*
183  * Display DS4510 information
184  */
185 static int ds4510_info(uint8_t chip)
186 {
187 	int i;
188 	int tmp;
189 	uint8_t data;
190 
191 	printf("DS4510 @ 0x%x:\n\n", chip);
192 
193 	if (i2c_read(chip, DS4510_RSTDELAY, 1, &data, 1))
194 		return -1;
195 	printf("rstdelay = 0x%x\n\n", data & DS4510_RSTDELAY_MASK);
196 
197 	if (i2c_read(chip, DS4510_CFG, 1, &data, 1))
198 		return -1;
199 	printf("config   = 0x%x\n", data);
200 	printf(" /ready  = %d\n", data & DS4510_CFG_READY ? 1 : 0);
201 	printf(" trip pt = %d\n", data & DS4510_CFG_TRIP_POINT ? 1 : 0);
202 	printf(" rst sts = %d\n", data & DS4510_CFG_RESET ? 1 : 0);
203 	printf(" /see    = %d\n", data & DS4510_CFG_SEE ? 1 : 0);
204 	printf(" swrst   = %d\n\n", data & DS4510_CFG_SWRST ? 1 : 0);
205 
206 	printf("gpio pins: 3210\n");
207 	printf("---------------\n");
208 	printf("pullup     ");
209 
210 	tmp = ds4510_pullup_read(chip);
211 	if (tmp == -1)
212 		return tmp;
213 	for (i = DS4510_NUM_IO - 1; i >= 0; i--)
214 		printf("%d", (tmp & (1 << i)) ? 1 : 0);
215 	printf("\n");
216 
217 	printf("driven     ");
218 	tmp = ds4510_gpio_read(chip);
219 	if (tmp == -1)
220 		return -1;
221 	for (i = DS4510_NUM_IO - 1; i >= 0; i--)
222 		printf("%d", (tmp & (1 << i)) ? 1 : 0);
223 	printf("\n");
224 
225 	printf("read       ");
226 	tmp = ds4510_gpio_read_val(chip);
227 	if (tmp == -1)
228 		return -1;
229 	for (i = DS4510_NUM_IO - 1; i >= 0; i--)
230 		printf("%d", (tmp & (1 << i)) ? 1 : 0);
231 	printf("\n");
232 
233 	return 0;
234 }
235 
236 cmd_tbl_t cmd_ds4510[] = {
237 	U_BOOT_CMD_MKENT(device, 3, 0, (void *)DS4510_CMD_DEVICE, "", ""),
238 	U_BOOT_CMD_MKENT(nv, 3, 0, (void *)DS4510_CMD_NV, "", ""),
239 	U_BOOT_CMD_MKENT(output, 4, 0, (void *)DS4510_CMD_OUTPUT, "", ""),
240 	U_BOOT_CMD_MKENT(input, 3, 0, (void *)DS4510_CMD_INPUT, "", ""),
241 	U_BOOT_CMD_MKENT(pullup, 4, 0, (void *)DS4510_CMD_PULLUP, "", ""),
242 	U_BOOT_CMD_MKENT(info, 2, 0, (void *)DS4510_CMD_INFO, "", ""),
243 	U_BOOT_CMD_MKENT(rstdelay, 3, 0, (void *)DS4510_CMD_RSTDELAY, "", ""),
244 	U_BOOT_CMD_MKENT(eeprom, 6, 0, (void *)DS4510_CMD_EEPROM, "", ""),
245 	U_BOOT_CMD_MKENT(seeprom, 6, 0, (void *)DS4510_CMD_SEEPROM, "", ""),
246 	U_BOOT_CMD_MKENT(sram, 6, 0, (void *)DS4510_CMD_SRAM, "", ""),
247 };
248 
249 int do_ds4510(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
250 {
251 	static uint8_t chip = 0x51;
252 	cmd_tbl_t *c;
253 	ulong ul_arg2 = 0;
254 	ulong ul_arg3 = 0;
255 	int tmp;
256 	ulong addr;
257 	ulong off;
258 	ulong cnt;
259 	int end;
260 	int (*rw_func)(uint8_t, int, uint8_t *, int);
261 
262 	c = find_cmd_tbl(argv[1], cmd_ds4510, ARRAY_SIZE(cmd_ds4510));
263 
264 	/* All commands but "device" require 'maxargs' arguments */
265 	if (!c || !((argc == (c->maxargs)) ||
266 		(((int)c->cmd == DS4510_CMD_DEVICE) &&
267 		 (argc == (c->maxargs - 1))))) {
268 		return cmd_usage(cmdtp);
269 	}
270 
271 	/* arg2 used as chip addr and pin number */
272 	if (argc > 2)
273 		ul_arg2 = simple_strtoul(argv[2], NULL, 16);
274 
275 	/* arg3 used as output/pullup value */
276 	if (argc > 3)
277 		ul_arg3 = simple_strtoul(argv[3], NULL, 16);
278 
279 	switch ((int)c->cmd) {
280 	case DS4510_CMD_DEVICE:
281 		if (argc == 3)
282 			chip = ul_arg2;
283 		printf("Current device address: 0x%x\n", chip);
284 		return 0;
285 	case DS4510_CMD_NV:
286 		return ds4510_see_write(chip, ul_arg2);
287 	case DS4510_CMD_OUTPUT:
288 		tmp = ds4510_gpio_read(chip);
289 		if (tmp == -1)
290 			return -1;
291 		if (ul_arg3)
292 			tmp |= (1 << ul_arg2);
293 		else
294 			tmp &= ~(1 << ul_arg2);
295 		return ds4510_gpio_write(chip, tmp);
296 	case DS4510_CMD_INPUT:
297 		tmp = ds4510_gpio_read_val(chip);
298 		if (tmp == -1)
299 			return -1;
300 		return (tmp & (1 << ul_arg2)) != 0;
301 	case DS4510_CMD_PULLUP:
302 		tmp = ds4510_pullup_read(chip);
303 		if (tmp == -1)
304 			return -1;
305 		if (ul_arg3)
306 			tmp |= (1 << ul_arg2);
307 		else
308 			tmp &= ~(1 << ul_arg2);
309 		return ds4510_pullup_write(chip, tmp);
310 	case DS4510_CMD_INFO:
311 		return ds4510_info(chip);
312 	case DS4510_CMD_RSTDELAY:
313 		return ds4510_rstdelay_write(chip, ul_arg2);
314 	case DS4510_CMD_EEPROM:
315 		end = DS4510_EEPROM + DS4510_EEPROM_SIZE;
316 		off = DS4510_EEPROM;
317 		break;
318 	case DS4510_CMD_SEEPROM:
319 		end = DS4510_SEEPROM + DS4510_SEEPROM_SIZE;
320 		off = DS4510_SEEPROM;
321 		break;
322 	case DS4510_CMD_SRAM:
323 		end = DS4510_SRAM + DS4510_SRAM_SIZE;
324 		off = DS4510_SRAM;
325 		break;
326 	default:
327 		/* We should never get here... */
328 		return 1;
329 	}
330 
331 	/* Only eeprom, seeprom, and sram commands should make it here */
332 	if (strcmp(argv[2], "read") == 0)
333 		rw_func = ds4510_mem_read;
334 	else if (strcmp(argv[2], "write") == 0)
335 		rw_func = ds4510_mem_write;
336 	else
337 		return cmd_usage(cmdtp);
338 
339 	addr = simple_strtoul(argv[3], NULL, 16);
340 	off += simple_strtoul(argv[4], NULL, 16);
341 	cnt = simple_strtoul(argv[5], NULL, 16);
342 
343 	if ((off + cnt) > end) {
344 		printf("ERROR: invalid len\n");
345 		return -1;
346 	}
347 
348 	return rw_func(chip, off, (uint8_t *)addr, cnt);
349 }
350 
351 U_BOOT_CMD(
352 	ds4510,	6,	1,	do_ds4510,
353 	"ds4510 eeprom/seeprom/sram/gpio access",
354 	"device [dev]\n"
355 	"	- show or set current device address\n"
356 	"ds4510 info\n"
357 	"	- display ds4510 info\n"
358 	"ds4510 output pin 0|1\n"
359 	"	- set pin low or high-Z\n"
360 	"ds4510 input pin\n"
361 	"	- read value of pin\n"
362 	"ds4510 pullup pin 0|1\n"
363 	"	- disable/enable pullup on specified pin\n"
364 	"ds4510 nv 0|1\n"
365 	"	- make gpio and seeprom writes volatile/non-volatile"
366 	"\n"
367 	"ds4510 rstdelay 0-3\n"
368 	"	- set reset output delay"
369 	"\n"
370 	"ds4510 eeprom read addr off cnt\n"
371 	"ds4510 eeprom write addr off cnt\n"
372 	"	- read/write 'cnt' bytes at EEPROM offset 'off'\n"
373 	"ds4510 seeprom read addr off cnt\n"
374 	"ds4510 seeprom write addr off cnt\n"
375 	"	- read/write 'cnt' bytes at SRAM-shadowed EEPROM offset 'off'\n"
376 	"ds4510 sram read addr off cnt\n"
377 	"ds4510 sram write addr off cnt\n"
378 	"	- read/write 'cnt' bytes at SRAM offset 'off'"
379 );
380