xref: /openbmc/u-boot/board/freescale/common/vid.c (revision 9ecb0c41)
1 /*
2  * Copyright 2014 Freescale Semiconductor, Inc.
3  *
4  * SPDX-License-Identifier:     GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <command.h>
9 #include <i2c.h>
10 #include <asm/io.h>
11 #ifdef CONFIG_LS1043A
12 #include <asm/arch/immap_lsch2.h>
13 #else
14 #include <asm/immap_85xx.h>
15 #endif
16 #include "vid.h"
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 int __weak i2c_multiplexer_select_vid_channel(u8 channel)
21 {
22 	return 0;
23 }
24 
25 /*
26  * Compensate for a board specific voltage drop between regulator and SoC
27  * return a value in mV
28  */
29 int __weak board_vdd_drop_compensation(void)
30 {
31 	return 0;
32 }
33 
34 /*
35  * Get the i2c address configuration for the IR regulator chip
36  *
37  * There are some variance in the RDB HW regarding the I2C address configuration
38  * for the IR regulator chip, which is likely a problem of external resistor
39  * accuracy. So we just check each address in a hopefully non-intrusive mode
40  * and use the first one that seems to work
41  *
42  * The IR chip can show up under the following addresses:
43  * 0x08 (Verified on T1040RDB-PA,T4240RDB-PB,X-T4240RDB-16GPA)
44  * 0x09 (Verified on T1040RDB-PA)
45  * 0x38 (Verified on T2080QDS, T2081QDS, T4240RDB)
46  */
47 static int find_ir_chip_on_i2c(void)
48 {
49 	int i2caddress;
50 	int ret;
51 	u8 byte;
52 	int i;
53 	const int ir_i2c_addr[] = {0x38, 0x08, 0x09};
54 
55 	/* Check all the address */
56 	for (i = 0; i < (sizeof(ir_i2c_addr)/sizeof(ir_i2c_addr[0])); i++) {
57 		i2caddress = ir_i2c_addr[i];
58 		ret = i2c_read(i2caddress,
59 			       IR36021_MFR_ID_OFFSET, 1, (void *)&byte,
60 			       sizeof(byte));
61 		if ((ret >= 0) && (byte == IR36021_MFR_ID))
62 			return i2caddress;
63 	}
64 	return -1;
65 }
66 
67 /* Maximum loop count waiting for new voltage to take effect */
68 #define MAX_LOOP_WAIT_NEW_VOL		100
69 /* Maximum loop count waiting for the voltage to be stable */
70 #define MAX_LOOP_WAIT_VOL_STABLE	100
71 /*
72  * read_voltage from sensor on I2C bus
73  * We use average of 4 readings, waiting for WAIT_FOR_ADC before
74  * another reading
75  */
76 #define NUM_READINGS    4       /* prefer to be power of 2 for efficiency */
77 
78 /* If an INA220 chip is available, we can use it to read back the voltage
79  * as it may have a higher accuracy than the IR chip for the same purpose
80  */
81 #ifdef CONFIG_VOL_MONITOR_INA220
82 #define WAIT_FOR_ADC	532	/* wait for 532 microseconds for ADC */
83 #define ADC_MIN_ACCURACY	4
84 #else
85 #define WAIT_FOR_ADC	138	/* wait for 138 microseconds for ADC */
86 #define ADC_MIN_ACCURACY	4
87 #endif
88 
89 #ifdef CONFIG_VOL_MONITOR_INA220
90 static int read_voltage_from_INA220(int i2caddress)
91 {
92 	int i, ret, voltage_read = 0;
93 	u16 vol_mon;
94 	u8 buf[2];
95 
96 	for (i = 0; i < NUM_READINGS; i++) {
97 		ret = i2c_read(I2C_VOL_MONITOR_ADDR,
98 			       I2C_VOL_MONITOR_BUS_V_OFFSET, 1,
99 			       (void *)&buf, 2);
100 		if (ret) {
101 			printf("VID: failed to read core voltage\n");
102 			return ret;
103 		}
104 		vol_mon = (buf[0] << 8) | buf[1];
105 		if (vol_mon & I2C_VOL_MONITOR_BUS_V_OVF) {
106 			printf("VID: Core voltage sensor error\n");
107 			return -1;
108 		}
109 		debug("VID: bus voltage reads 0x%04x\n", vol_mon);
110 		/* LSB = 4mv */
111 		voltage_read += (vol_mon >> I2C_VOL_MONITOR_BUS_V_SHIFT) * 4;
112 		udelay(WAIT_FOR_ADC);
113 	}
114 	/* calculate the average */
115 	voltage_read /= NUM_READINGS;
116 
117 	return voltage_read;
118 }
119 #endif
120 
121 /* read voltage from IR */
122 #ifdef CONFIG_VOL_MONITOR_IR36021_READ
123 static int read_voltage_from_IR(int i2caddress)
124 {
125 	int i, ret, voltage_read = 0;
126 	u16 vol_mon;
127 	u8 buf;
128 
129 	for (i = 0; i < NUM_READINGS; i++) {
130 		ret = i2c_read(i2caddress,
131 			       IR36021_LOOP1_VOUT_OFFSET,
132 			       1, (void *)&buf, 1);
133 		if (ret) {
134 			printf("VID: failed to read vcpu\n");
135 			return ret;
136 		}
137 		vol_mon = buf;
138 		if (!vol_mon) {
139 			printf("VID: Core voltage sensor error\n");
140 			return -1;
141 		}
142 		debug("VID: bus voltage reads 0x%02x\n", vol_mon);
143 		/* Resolution is 1/128V. We scale up here to get 1/128mV
144 		 * and divide at the end
145 		 */
146 		voltage_read += vol_mon * 1000;
147 		udelay(WAIT_FOR_ADC);
148 	}
149 	/* Scale down to the real mV as IR resolution is 1/128V, rounding up */
150 	voltage_read = DIV_ROUND_UP(voltage_read, 128);
151 
152 	/* calculate the average */
153 	voltage_read /= NUM_READINGS;
154 
155 	/* Compensate for a board specific voltage drop between regulator and
156 	 * SoC before converting into an IR VID value
157 	 */
158 	voltage_read -= board_vdd_drop_compensation();
159 
160 	return voltage_read;
161 }
162 #endif
163 
164 static int read_voltage(int i2caddress)
165 {
166 	int voltage_read;
167 #ifdef CONFIG_VOL_MONITOR_INA220
168 	voltage_read = read_voltage_from_INA220(i2caddress);
169 #elif defined CONFIG_VOL_MONITOR_IR36021_READ
170 	voltage_read = read_voltage_from_IR(i2caddress);
171 #else
172 	return -1;
173 #endif
174 	return voltage_read;
175 }
176 
177 /*
178  * We need to calculate how long before the voltage stops to drop
179  * or increase. It returns with the loop count. Each loop takes
180  * several readings (WAIT_FOR_ADC)
181  */
182 static int wait_for_new_voltage(int vdd, int i2caddress)
183 {
184 	int timeout, vdd_current;
185 
186 	vdd_current = read_voltage(i2caddress);
187 	/* wait until voltage starts to reach the target. Voltage slew
188 	 * rates by typical regulators will always lead to stable readings
189 	 * within each fairly long ADC interval in comparison to the
190 	 * intended voltage delta change until the target voltage is
191 	 * reached. The fairly small voltage delta change to any target
192 	 * VID voltage also means that this function will always complete
193 	 * within few iterations. If the timeout was ever reached, it would
194 	 * point to a serious failure in the regulator system.
195 	 */
196 	for (timeout = 0;
197 	     abs(vdd - vdd_current) > (IR_VDD_STEP_UP + IR_VDD_STEP_DOWN) &&
198 	     timeout < MAX_LOOP_WAIT_NEW_VOL; timeout++) {
199 		vdd_current = read_voltage(i2caddress);
200 	}
201 	if (timeout >= MAX_LOOP_WAIT_NEW_VOL) {
202 		printf("VID: Voltage adjustment timeout\n");
203 		return -1;
204 	}
205 	return timeout;
206 }
207 
208 /*
209  * this function keeps reading the voltage until it is stable or until the
210  * timeout expires
211  */
212 static int wait_for_voltage_stable(int i2caddress)
213 {
214 	int timeout, vdd_current, vdd;
215 
216 	vdd = read_voltage(i2caddress);
217 	udelay(NUM_READINGS * WAIT_FOR_ADC);
218 
219 	/* wait until voltage is stable */
220 	vdd_current = read_voltage(i2caddress);
221 	/* The maximum timeout is
222 	 * MAX_LOOP_WAIT_VOL_STABLE * NUM_READINGS * WAIT_FOR_ADC
223 	 */
224 	for (timeout = MAX_LOOP_WAIT_VOL_STABLE;
225 	     abs(vdd - vdd_current) > ADC_MIN_ACCURACY &&
226 	     timeout > 0; timeout--) {
227 		vdd = vdd_current;
228 		udelay(NUM_READINGS * WAIT_FOR_ADC);
229 		vdd_current = read_voltage(i2caddress);
230 	}
231 	if (timeout == 0)
232 		return -1;
233 	return vdd_current;
234 }
235 
236 #ifdef CONFIG_VOL_MONITOR_IR36021_SET
237 /* Set the voltage to the IR chip */
238 static int set_voltage_to_IR(int i2caddress, int vdd)
239 {
240 	int wait, vdd_last;
241 	int ret;
242 	u8 vid;
243 
244 	/* Compensate for a board specific voltage drop between regulator and
245 	 * SoC before converting into an IR VID value
246 	 */
247 	vdd += board_vdd_drop_compensation();
248 #ifdef CONFIG_LS1043A
249 	vid = DIV_ROUND_UP(vdd - 265, 5);
250 #else
251 	vid = DIV_ROUND_UP(vdd - 245, 5);
252 #endif
253 
254 	ret = i2c_write(i2caddress, IR36021_LOOP1_MANUAL_ID_OFFSET,
255 			1, (void *)&vid, sizeof(vid));
256 	if (ret) {
257 		printf("VID: failed to write VID\n");
258 		return -1;
259 	}
260 	wait = wait_for_new_voltage(vdd, i2caddress);
261 	if (wait < 0)
262 		return -1;
263 	debug("VID: Waited %d us\n", wait * NUM_READINGS * WAIT_FOR_ADC);
264 
265 	vdd_last = wait_for_voltage_stable(i2caddress);
266 	if (vdd_last < 0)
267 		return -1;
268 	debug("VID: Current voltage is %d mV\n", vdd_last);
269 	return vdd_last;
270 }
271 #endif
272 
273 static int set_voltage(int i2caddress, int vdd)
274 {
275 	int vdd_last = -1;
276 
277 #ifdef CONFIG_VOL_MONITOR_IR36021_SET
278 	vdd_last = set_voltage_to_IR(i2caddress, vdd);
279 #else
280 	#error Specific voltage monitor must be defined
281 #endif
282 	return vdd_last;
283 }
284 
285 int adjust_vdd(ulong vdd_override)
286 {
287 	int re_enable = disable_interrupts();
288 #ifdef CONFIG_LS1043A
289 	struct ccsr_gur *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
290 #else
291 	ccsr_gur_t __iomem *gur =
292 		(void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
293 #endif
294 	u32 fusesr;
295 	u8 vid, buf;
296 	int vdd_target, vdd_current, vdd_last;
297 	int ret, i2caddress;
298 	unsigned long vdd_string_override;
299 	char *vdd_string;
300 	static const uint16_t vdd[32] = {
301 		0,      /* unused */
302 		9875,   /* 0.9875V */
303 		9750,
304 		9625,
305 		9500,
306 		9375,
307 		9250,
308 		9125,
309 		9000,
310 		8875,
311 		8750,
312 		8625,
313 		8500,
314 		8375,
315 		8250,
316 		8125,
317 		10000,  /* 1.0000V */
318 		10125,
319 		10250,
320 		10375,
321 		10500,
322 		10625,
323 		10750,
324 		10875,
325 		11000,
326 		0,      /* reserved */
327 	};
328 	struct vdd_drive {
329 		u8 vid;
330 		unsigned voltage;
331 	};
332 
333 	ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
334 	if (ret) {
335 		debug("VID: I2C failed to switch channel\n");
336 		ret = -1;
337 		goto exit;
338 	}
339 	ret = find_ir_chip_on_i2c();
340 	if (ret < 0) {
341 		printf("VID: Could not find voltage regulator on I2C.\n");
342 		ret = -1;
343 		goto exit;
344 	} else {
345 		i2caddress = ret;
346 		debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
347 	}
348 
349 	/* check IR chip work on Intel mode*/
350 	ret = i2c_read(i2caddress,
351 		       IR36021_INTEL_MODE_OOFSET,
352 		       1, (void *)&buf, 1);
353 	if (ret) {
354 		printf("VID: failed to read IR chip mode.\n");
355 		ret = -1;
356 		goto exit;
357 	}
358 	if ((buf & IR36021_MODE_MASK) != IR36021_INTEL_MODE) {
359 		printf("VID: IR Chip is not used in Intel mode.\n");
360 		ret = -1;
361 		goto exit;
362 	}
363 
364 	/* get the voltage ID from fuse status register */
365 	fusesr = in_be32(&gur->dcfg_fusesr);
366 	/*
367 	 * VID is used according to the table below
368 	 *                ---------------------------------------
369 	 *                |                DA_V                 |
370 	 *                |-------------------------------------|
371 	 *                | 5b00000 | 5b00001-5b11110 | 5b11111 |
372 	 * ---------------+---------+-----------------+---------|
373 	 * | D | 5b00000  | NO VID  | VID = DA_V      | NO VID  |
374 	 * | A |----------+---------+-----------------+---------|
375 	 * | _ | 5b00001  |VID =    | VID =           |VID =    |
376 	 * | V |   ~      | DA_V_ALT|   DA_V_ALT      | DA_A_VLT|
377 	 * | _ | 5b11110  |         |                 |         |
378 	 * | A |----------+---------+-----------------+---------|
379 	 * | L | 5b11111  | No VID  | VID = DA_V      | NO VID  |
380 	 * | T |          |         |                 |         |
381 	 * ------------------------------------------------------
382 	 */
383 #ifdef CONFIG_LS1043A
384 	vid = (fusesr >> FSL_CHASSIS2_DCFG_FUSESR_ALTVID_SHIFT) &
385 		FSL_CHASSIS2_DCFG_FUSESR_ALTVID_MASK;
386 	if ((vid == 0) || (vid == FSL_CHASSIS2_DCFG_FUSESR_ALTVID_MASK)) {
387 		vid = (fusesr >> FSL_CHASSIS2_DCFG_FUSESR_VID_SHIFT) &
388 			FSL_CHASSIS2_DCFG_FUSESR_VID_MASK;
389 	}
390 #else
391 	vid = (fusesr >> FSL_CORENET_DCFG_FUSESR_ALTVID_SHIFT) &
392 		FSL_CORENET_DCFG_FUSESR_ALTVID_MASK;
393 	if ((vid == 0) || (vid == FSL_CORENET_DCFG_FUSESR_ALTVID_MASK)) {
394 		vid = (fusesr >> FSL_CORENET_DCFG_FUSESR_VID_SHIFT) &
395 			FSL_CORENET_DCFG_FUSESR_VID_MASK;
396 	}
397 #endif
398 	vdd_target = vdd[vid];
399 
400 	/* check override variable for overriding VDD */
401 	vdd_string = getenv(CONFIG_VID_FLS_ENV);
402 	if (vdd_override == 0 && vdd_string &&
403 	    !strict_strtoul(vdd_string, 10, &vdd_string_override))
404 		vdd_override = vdd_string_override;
405 	if (vdd_override >= VDD_MV_MIN && vdd_override <= VDD_MV_MAX) {
406 		vdd_target = vdd_override * 10; /* convert to 1/10 mV */
407 		debug("VDD override is %lu\n", vdd_override);
408 	} else if (vdd_override != 0) {
409 		printf("Invalid value.\n");
410 	}
411 	if (vdd_target == 0) {
412 		debug("VID: VID not used\n");
413 		ret = 0;
414 		goto exit;
415 	} else {
416 		/* divide and round up by 10 to get a value in mV */
417 		vdd_target = DIV_ROUND_UP(vdd_target, 10);
418 		debug("VID: vid = %d mV\n", vdd_target);
419 	}
420 
421 	/*
422 	 * Read voltage monitor to check real voltage.
423 	 */
424 	vdd_last = read_voltage(i2caddress);
425 	if (vdd_last < 0) {
426 		printf("VID: Couldn't read sensor abort VID adjustment\n");
427 		ret = -1;
428 		goto exit;
429 	}
430 	vdd_current = vdd_last;
431 	debug("VID: Core voltage is currently at %d mV\n", vdd_last);
432 	/*
433 	  * Adjust voltage to at or one step above target.
434 	  * As measurements are less precise than setting the values
435 	  * we may run through dummy steps that cancel each other
436 	  * when stepping up and then down.
437 	  */
438 	while (vdd_last > 0 &&
439 	       vdd_last < vdd_target) {
440 		vdd_current += IR_VDD_STEP_UP;
441 		vdd_last = set_voltage(i2caddress, vdd_current);
442 	}
443 	while (vdd_last > 0 &&
444 	       vdd_last > vdd_target + (IR_VDD_STEP_DOWN - 1)) {
445 		vdd_current -= IR_VDD_STEP_DOWN;
446 		vdd_last = set_voltage(i2caddress, vdd_current);
447 	}
448 
449 	if (vdd_last > 0)
450 		printf("VID: Core voltage after adjustment is at %d mV\n",
451 		       vdd_last);
452 	else
453 		ret = -1;
454 exit:
455 	if (re_enable)
456 		enable_interrupts();
457 
458 	i2c_multiplexer_select_vid_channel(I2C_MUX_CH_DEFAULT);
459 
460 	return ret;
461 }
462 
463 static int print_vdd(void)
464 {
465 	int vdd_last, ret, i2caddress;
466 
467 	ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
468 	if (ret) {
469 		debug("VID : I2c failed to switch channel\n");
470 		return -1;
471 	}
472 	ret = find_ir_chip_on_i2c();
473 	if (ret < 0) {
474 		printf("VID: Could not find voltage regulator on I2C.\n");
475 		goto exit;
476 	} else {
477 		i2caddress = ret;
478 		debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
479 	}
480 
481 	/*
482 	 * Read voltage monitor to check real voltage.
483 	 */
484 	vdd_last = read_voltage(i2caddress);
485 	if (vdd_last < 0) {
486 		printf("VID: Couldn't read sensor abort VID adjustment\n");
487 		goto exit;
488 	}
489 	printf("VID: Core voltage is at %d mV\n", vdd_last);
490 exit:
491 	i2c_multiplexer_select_vid_channel(I2C_MUX_CH_DEFAULT);
492 
493 	return ret < 0 ? -1 : 0;
494 
495 }
496 
497 static int do_vdd_override(cmd_tbl_t *cmdtp,
498 			   int flag, int argc,
499 			   char * const argv[])
500 {
501 	ulong override;
502 
503 	if (argc < 2)
504 		return CMD_RET_USAGE;
505 
506 	if (!strict_strtoul(argv[1], 10, &override))
507 		adjust_vdd(override);   /* the value is checked by callee */
508 	else
509 		return CMD_RET_USAGE;
510 	return 0;
511 }
512 
513 static int do_vdd_read(cmd_tbl_t *cmdtp,
514 			 int flag, int argc,
515 			 char * const argv[])
516 {
517 	if (argc < 1)
518 		return CMD_RET_USAGE;
519 	print_vdd();
520 
521 	return 0;
522 }
523 
524 U_BOOT_CMD(
525 	vdd_override, 2, 0, do_vdd_override,
526 	"override VDD",
527 	" - override with the voltage specified in mV, eg. 1050"
528 );
529 
530 U_BOOT_CMD(
531 	vdd_read, 1, 0, do_vdd_read,
532 	"read VDD",
533 	" - Read the voltage specified in mV"
534 )
535