xref: /openbmc/u-boot/board/freescale/common/vid.c (revision 0093b3fc)
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_FSL_LSCH2
12 #include <asm/arch/immap_lsch2.h>
13 #elif defined(CONFIG_FSL_LSCH3)
14 #include <asm/arch/immap_lsch3.h>
15 #else
16 #include <asm/immap_85xx.h>
17 #endif
18 #include "vid.h"
19 
20 DECLARE_GLOBAL_DATA_PTR;
21 
22 int __weak i2c_multiplexer_select_vid_channel(u8 channel)
23 {
24 	return 0;
25 }
26 
27 /*
28  * Compensate for a board specific voltage drop between regulator and SoC
29  * return a value in mV
30  */
31 int __weak board_vdd_drop_compensation(void)
32 {
33 	return 0;
34 }
35 
36 /*
37  * Board specific settings for specific voltage value
38  */
39 int __weak board_adjust_vdd(int vdd)
40 {
41 	return 0;
42 }
43 
44 #if defined(CONFIG_VOL_MONITOR_IR36021_SET) || \
45 	defined(CONFIG_VOL_MONITOR_IR36021_READ)
46 /*
47  * Get the i2c address configuration for the IR regulator chip
48  *
49  * There are some variance in the RDB HW regarding the I2C address configuration
50  * for the IR regulator chip, which is likely a problem of external resistor
51  * accuracy. So we just check each address in a hopefully non-intrusive mode
52  * and use the first one that seems to work
53  *
54  * The IR chip can show up under the following addresses:
55  * 0x08 (Verified on T1040RDB-PA,T4240RDB-PB,X-T4240RDB-16GPA)
56  * 0x09 (Verified on T1040RDB-PA)
57  * 0x38 (Verified on T2080QDS, T2081QDS, T4240RDB)
58  */
59 static int find_ir_chip_on_i2c(void)
60 {
61 	int i2caddress;
62 	int ret;
63 	u8 byte;
64 	int i;
65 	const int ir_i2c_addr[] = {0x38, 0x08, 0x09};
66 
67 	/* Check all the address */
68 	for (i = 0; i < (sizeof(ir_i2c_addr)/sizeof(ir_i2c_addr[0])); i++) {
69 		i2caddress = ir_i2c_addr[i];
70 		ret = i2c_read(i2caddress,
71 			       IR36021_MFR_ID_OFFSET, 1, (void *)&byte,
72 			       sizeof(byte));
73 		if ((ret >= 0) && (byte == IR36021_MFR_ID))
74 			return i2caddress;
75 	}
76 	return -1;
77 }
78 #endif
79 
80 /* Maximum loop count waiting for new voltage to take effect */
81 #define MAX_LOOP_WAIT_NEW_VOL		100
82 /* Maximum loop count waiting for the voltage to be stable */
83 #define MAX_LOOP_WAIT_VOL_STABLE	100
84 /*
85  * read_voltage from sensor on I2C bus
86  * We use average of 4 readings, waiting for WAIT_FOR_ADC before
87  * another reading
88  */
89 #define NUM_READINGS    4       /* prefer to be power of 2 for efficiency */
90 
91 /* If an INA220 chip is available, we can use it to read back the voltage
92  * as it may have a higher accuracy than the IR chip for the same purpose
93  */
94 #ifdef CONFIG_VOL_MONITOR_INA220
95 #define WAIT_FOR_ADC	532	/* wait for 532 microseconds for ADC */
96 #define ADC_MIN_ACCURACY	4
97 #else
98 #define WAIT_FOR_ADC	138	/* wait for 138 microseconds for ADC */
99 #define ADC_MIN_ACCURACY	4
100 #endif
101 
102 #ifdef CONFIG_VOL_MONITOR_INA220
103 static int read_voltage_from_INA220(int i2caddress)
104 {
105 	int i, ret, voltage_read = 0;
106 	u16 vol_mon;
107 	u8 buf[2];
108 
109 	for (i = 0; i < NUM_READINGS; i++) {
110 		ret = i2c_read(I2C_VOL_MONITOR_ADDR,
111 			       I2C_VOL_MONITOR_BUS_V_OFFSET, 1,
112 			       (void *)&buf, 2);
113 		if (ret) {
114 			printf("VID: failed to read core voltage\n");
115 			return ret;
116 		}
117 		vol_mon = (buf[0] << 8) | buf[1];
118 		if (vol_mon & I2C_VOL_MONITOR_BUS_V_OVF) {
119 			printf("VID: Core voltage sensor error\n");
120 			return -1;
121 		}
122 		debug("VID: bus voltage reads 0x%04x\n", vol_mon);
123 		/* LSB = 4mv */
124 		voltage_read += (vol_mon >> I2C_VOL_MONITOR_BUS_V_SHIFT) * 4;
125 		udelay(WAIT_FOR_ADC);
126 	}
127 	/* calculate the average */
128 	voltage_read /= NUM_READINGS;
129 
130 	return voltage_read;
131 }
132 #endif
133 
134 /* read voltage from IR */
135 #ifdef CONFIG_VOL_MONITOR_IR36021_READ
136 static int read_voltage_from_IR(int i2caddress)
137 {
138 	int i, ret, voltage_read = 0;
139 	u16 vol_mon;
140 	u8 buf;
141 
142 	for (i = 0; i < NUM_READINGS; i++) {
143 		ret = i2c_read(i2caddress,
144 			       IR36021_LOOP1_VOUT_OFFSET,
145 			       1, (void *)&buf, 1);
146 		if (ret) {
147 			printf("VID: failed to read vcpu\n");
148 			return ret;
149 		}
150 		vol_mon = buf;
151 		if (!vol_mon) {
152 			printf("VID: Core voltage sensor error\n");
153 			return -1;
154 		}
155 		debug("VID: bus voltage reads 0x%02x\n", vol_mon);
156 		/* Resolution is 1/128V. We scale up here to get 1/128mV
157 		 * and divide at the end
158 		 */
159 		voltage_read += vol_mon * 1000;
160 		udelay(WAIT_FOR_ADC);
161 	}
162 	/* Scale down to the real mV as IR resolution is 1/128V, rounding up */
163 	voltage_read = DIV_ROUND_UP(voltage_read, 128);
164 
165 	/* calculate the average */
166 	voltage_read /= NUM_READINGS;
167 
168 	/* Compensate for a board specific voltage drop between regulator and
169 	 * SoC before converting into an IR VID value
170 	 */
171 	voltage_read -= board_vdd_drop_compensation();
172 
173 	return voltage_read;
174 }
175 #endif
176 
177 #ifdef CONFIG_VOL_MONITOR_LTC3882_READ
178 /* read the current value of the LTC Regulator Voltage */
179 static int read_voltage_from_LTC(int i2caddress)
180 {
181 	int  ret, vcode = 0;
182 	u8 chan = PWM_CHANNEL0;
183 
184 	/* select the PAGE 0 using PMBus commands PAGE for VDD*/
185 	ret = i2c_write(I2C_VOL_MONITOR_ADDR,
186 			PMBUS_CMD_PAGE, 1, &chan, 1);
187 	if (ret) {
188 		printf("VID: failed to select VDD Page 0\n");
189 		return ret;
190 	}
191 
192 	/*read the output voltage using PMBus command READ_VOUT*/
193 	ret = i2c_read(I2C_VOL_MONITOR_ADDR,
194 		       PMBUS_CMD_READ_VOUT, 1, (void *)&vcode, 2);
195 	if (ret) {
196 		printf("VID: failed to read the volatge\n");
197 		return ret;
198 	}
199 
200 	/* Scale down to the real mV as LTC resolution is 1/4096V,rounding up */
201 	vcode = DIV_ROUND_UP(vcode * 1000, 4096);
202 
203 	return vcode;
204 }
205 #endif
206 
207 static int read_voltage(int i2caddress)
208 {
209 	int voltage_read;
210 #ifdef CONFIG_VOL_MONITOR_INA220
211 	voltage_read = read_voltage_from_INA220(i2caddress);
212 #elif defined CONFIG_VOL_MONITOR_IR36021_READ
213 	voltage_read = read_voltage_from_IR(i2caddress);
214 #elif defined CONFIG_VOL_MONITOR_LTC3882_READ
215 	voltage_read = read_voltage_from_LTC(i2caddress);
216 #else
217 	return -1;
218 #endif
219 	return voltage_read;
220 }
221 
222 #ifdef CONFIG_VOL_MONITOR_IR36021_SET
223 /*
224  * We need to calculate how long before the voltage stops to drop
225  * or increase. It returns with the loop count. Each loop takes
226  * several readings (WAIT_FOR_ADC)
227  */
228 static int wait_for_new_voltage(int vdd, int i2caddress)
229 {
230 	int timeout, vdd_current;
231 
232 	vdd_current = read_voltage(i2caddress);
233 	/* wait until voltage starts to reach the target. Voltage slew
234 	 * rates by typical regulators will always lead to stable readings
235 	 * within each fairly long ADC interval in comparison to the
236 	 * intended voltage delta change until the target voltage is
237 	 * reached. The fairly small voltage delta change to any target
238 	 * VID voltage also means that this function will always complete
239 	 * within few iterations. If the timeout was ever reached, it would
240 	 * point to a serious failure in the regulator system.
241 	 */
242 	for (timeout = 0;
243 	     abs(vdd - vdd_current) > (IR_VDD_STEP_UP + IR_VDD_STEP_DOWN) &&
244 	     timeout < MAX_LOOP_WAIT_NEW_VOL; timeout++) {
245 		vdd_current = read_voltage(i2caddress);
246 	}
247 	if (timeout >= MAX_LOOP_WAIT_NEW_VOL) {
248 		printf("VID: Voltage adjustment timeout\n");
249 		return -1;
250 	}
251 	return timeout;
252 }
253 
254 /*
255  * this function keeps reading the voltage until it is stable or until the
256  * timeout expires
257  */
258 static int wait_for_voltage_stable(int i2caddress)
259 {
260 	int timeout, vdd_current, vdd;
261 
262 	vdd = read_voltage(i2caddress);
263 	udelay(NUM_READINGS * WAIT_FOR_ADC);
264 
265 	/* wait until voltage is stable */
266 	vdd_current = read_voltage(i2caddress);
267 	/* The maximum timeout is
268 	 * MAX_LOOP_WAIT_VOL_STABLE * NUM_READINGS * WAIT_FOR_ADC
269 	 */
270 	for (timeout = MAX_LOOP_WAIT_VOL_STABLE;
271 	     abs(vdd - vdd_current) > ADC_MIN_ACCURACY &&
272 	     timeout > 0; timeout--) {
273 		vdd = vdd_current;
274 		udelay(NUM_READINGS * WAIT_FOR_ADC);
275 		vdd_current = read_voltage(i2caddress);
276 	}
277 	if (timeout == 0)
278 		return -1;
279 	return vdd_current;
280 }
281 
282 /* Set the voltage to the IR chip */
283 static int set_voltage_to_IR(int i2caddress, int vdd)
284 {
285 	int wait, vdd_last;
286 	int ret;
287 	u8 vid;
288 
289 	/* Compensate for a board specific voltage drop between regulator and
290 	 * SoC before converting into an IR VID value
291 	 */
292 	vdd += board_vdd_drop_compensation();
293 #ifdef CONFIG_FSL_LSCH2
294 	vid = DIV_ROUND_UP(vdd - 265, 5);
295 #else
296 	vid = DIV_ROUND_UP(vdd - 245, 5);
297 #endif
298 
299 	ret = i2c_write(i2caddress, IR36021_LOOP1_MANUAL_ID_OFFSET,
300 			1, (void *)&vid, sizeof(vid));
301 	if (ret) {
302 		printf("VID: failed to write VID\n");
303 		return -1;
304 	}
305 	wait = wait_for_new_voltage(vdd, i2caddress);
306 	if (wait < 0)
307 		return -1;
308 	debug("VID: Waited %d us\n", wait * NUM_READINGS * WAIT_FOR_ADC);
309 
310 	vdd_last = wait_for_voltage_stable(i2caddress);
311 	if (vdd_last < 0)
312 		return -1;
313 	debug("VID: Current voltage is %d mV\n", vdd_last);
314 	return vdd_last;
315 }
316 
317 #endif
318 
319 #ifdef CONFIG_VOL_MONITOR_LTC3882_SET
320 /* this function sets the VDD and returns the value set */
321 static int set_voltage_to_LTC(int i2caddress, int vdd)
322 {
323 	int ret, vdd_last, vdd_target = vdd;
324 
325 	/* Scale up to the LTC resolution is 1/4096V */
326 	vdd = (vdd * 4096) / 1000;
327 
328 	/* 5-byte buffer which needs to be sent following the
329 	 * PMBus command PAGE_PLUS_WRITE.
330 	 */
331 	u8 buff[5] = {0x04, PWM_CHANNEL0, PMBUS_CMD_VOUT_COMMAND,
332 			vdd & 0xFF, (vdd & 0xFF00) >> 8};
333 
334 	/* Write the desired voltage code to the regulator */
335 	ret = i2c_write(I2C_VOL_MONITOR_ADDR,
336 			PMBUS_CMD_PAGE_PLUS_WRITE, 1, (void *)&buff, 5);
337 	if (ret) {
338 		printf("VID: I2C failed to write to the volatge regulator\n");
339 		return -1;
340 	}
341 
342 	/* Wait for the volatge to get to the desired value */
343 	do {
344 		vdd_last = read_voltage_from_LTC(i2caddress);
345 		if (vdd_last < 0) {
346 			printf("VID: Couldn't read sensor abort VID adjust\n");
347 			return -1;
348 		}
349 	} while (vdd_last != vdd_target);
350 
351 	return vdd_last;
352 }
353 #endif
354 
355 static int set_voltage(int i2caddress, int vdd)
356 {
357 	int vdd_last = -1;
358 
359 #ifdef CONFIG_VOL_MONITOR_IR36021_SET
360 	vdd_last = set_voltage_to_IR(i2caddress, vdd);
361 #elif defined CONFIG_VOL_MONITOR_LTC3882_SET
362 	vdd_last = set_voltage_to_LTC(i2caddress, vdd);
363 #else
364 	#error Specific voltage monitor must be defined
365 #endif
366 	return vdd_last;
367 }
368 
369 #ifdef CONFIG_FSL_LSCH3
370 int adjust_vdd(ulong vdd_override)
371 {
372 	int re_enable = disable_interrupts();
373 	struct ccsr_gur *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
374 	u32 fusesr;
375 #if defined(CONFIG_VOL_MONITOR_IR36021_SET) || \
376 	defined(CONFIG_VOL_MONITOR_IR36021_READ)
377 	u8 vid, buf;
378 #else
379 	u8 vid;
380 #endif
381 	int vdd_target, vdd_current, vdd_last;
382 	int ret, i2caddress;
383 	unsigned long vdd_string_override;
384 	char *vdd_string;
385 #ifdef CONFIG_ARCH_LS1088A
386 	static const uint16_t vdd[32] = {
387 		10250,
388 		9875,
389 		9750,
390 		0,      /* reserved */
391 		0,      /* reserved */
392 		0,      /* reserved */
393 		0,      /* reserved */
394 		0,      /* reserved */
395 		9000,
396 		0,      /* reserved */
397 		0,      /* reserved */
398 		0,      /* reserved */
399 		0,      /* reserved */
400 		0,      /* reserved */
401 		0,      /* reserved */
402 		0,      /* reserved */
403 		10000,  /* 1.0000V */
404 		10125,
405 		10250,
406 		0,      /* reserved */
407 		0,      /* reserved */
408 		0,      /* reserved */
409 		0,      /* reserved */
410 		0,      /* reserved */
411 		0,      /* reserved */
412 		0,      /* reserved */
413 		0,      /* reserved */
414 		0,      /* reserved */
415 		0,      /* reserved */
416 		0,      /* reserved */
417 		0,      /* reserved */
418 		0,      /* reserved */
419 	};
420 
421 #else
422 	static const uint16_t vdd[32] = {
423 		10500,
424 		0,      /* reserved */
425 		9750,
426 		0,      /* reserved */
427 		9500,
428 		0,      /* reserved */
429 		0,      /* reserved */
430 		0,      /* reserved */
431 		0,      /* reserved */
432 		0,      /* reserved */
433 		0,      /* reserved */
434 		0,      /* reserved */
435 		0,      /* reserved */
436 		0,      /* reserved */
437 		0,      /* reserved */
438 		0,      /* reserved */
439 		10000,  /* 1.0000V */
440 		0,      /* reserved */
441 		10250,
442 		0,      /* reserved */
443 		10500,
444 		0,      /* reserved */
445 		0,      /* reserved */
446 		0,      /* reserved */
447 		0,      /* reserved */
448 		0,      /* reserved */
449 		0,      /* reserved */
450 		0,      /* reserved */
451 		0,      /* reserved */
452 		0,      /* reserved */
453 		0,      /* reserved */
454 		0,      /* reserved */
455 	};
456 #endif
457 	struct vdd_drive {
458 		u8 vid;
459 		unsigned voltage;
460 	};
461 
462 	ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
463 	if (ret) {
464 		debug("VID: I2C failed to switch channel\n");
465 		ret = -1;
466 		goto exit;
467 	}
468 #if defined(CONFIG_VOL_MONITOR_IR36021_SET) || \
469 	defined(CONFIG_VOL_MONITOR_IR36021_READ)
470 	ret = find_ir_chip_on_i2c();
471 	if (ret < 0) {
472 		printf("VID: Could not find voltage regulator on I2C.\n");
473 		ret = -1;
474 		goto exit;
475 	} else {
476 		i2caddress = ret;
477 		debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
478 	}
479 
480 	/* check IR chip work on Intel mode*/
481 	ret = i2c_read(i2caddress,
482 		       IR36021_INTEL_MODE_OOFSET,
483 		       1, (void *)&buf, 1);
484 	if (ret) {
485 		printf("VID: failed to read IR chip mode.\n");
486 		ret = -1;
487 		goto exit;
488 	}
489 	if ((buf & IR36021_MODE_MASK) != IR36021_INTEL_MODE) {
490 		printf("VID: IR Chip is not used in Intel mode.\n");
491 		ret = -1;
492 		goto exit;
493 	}
494 #endif
495 
496 	/* get the voltage ID from fuse status register */
497 	fusesr = in_le32(&gur->dcfg_fusesr);
498 	vid = (fusesr >> FSL_CHASSIS3_DCFG_FUSESR_ALTVID_SHIFT) &
499 		FSL_CHASSIS3_DCFG_FUSESR_ALTVID_MASK;
500 	if ((vid == 0) || (vid == FSL_CHASSIS3_DCFG_FUSESR_ALTVID_MASK)) {
501 		vid = (fusesr >> FSL_CHASSIS3_DCFG_FUSESR_VID_SHIFT) &
502 			FSL_CHASSIS3_DCFG_FUSESR_VID_MASK;
503 	}
504 	vdd_target = vdd[vid];
505 
506 	/* check override variable for overriding VDD */
507 	vdd_string = env_get(CONFIG_VID_FLS_ENV);
508 	if (vdd_override == 0 && vdd_string &&
509 	    !strict_strtoul(vdd_string, 10, &vdd_string_override))
510 		vdd_override = vdd_string_override;
511 
512 	if (vdd_override >= VDD_MV_MIN && vdd_override <= VDD_MV_MAX) {
513 		vdd_target = vdd_override * 10; /* convert to 1/10 mV */
514 		debug("VDD override is %lu\n", vdd_override);
515 	} else if (vdd_override != 0) {
516 		printf("Invalid value.\n");
517 	}
518 
519 	/* divide and round up by 10 to get a value in mV */
520 	vdd_target = DIV_ROUND_UP(vdd_target, 10);
521 	if (vdd_target == 0) {
522 		debug("VID: VID not used\n");
523 		ret = 0;
524 		goto exit;
525 	} else if (vdd_target < VDD_MV_MIN || vdd_target > VDD_MV_MAX) {
526 		/* Check vdd_target is in valid range */
527 		printf("VID: Target VID %d mV is not in range.\n",
528 		       vdd_target);
529 		ret = -1;
530 		goto exit;
531 	} else {
532 		debug("VID: vid = %d mV\n", vdd_target);
533 	}
534 
535 	/*
536 	 * Read voltage monitor to check real voltage.
537 	 */
538 	vdd_last = read_voltage(i2caddress);
539 	if (vdd_last < 0) {
540 		printf("VID: Couldn't read sensor abort VID adjustment\n");
541 		ret = -1;
542 		goto exit;
543 	}
544 	vdd_current = vdd_last;
545 	debug("VID: Core voltage is currently at %d mV\n", vdd_last);
546 
547 #ifdef CONFIG_VOL_MONITOR_LTC3882_SET
548 	/* Set the target voltage */
549 	vdd_last = vdd_current = set_voltage(i2caddress, vdd_target);
550 #else
551 	/*
552 	  * Adjust voltage to at or one step above target.
553 	  * As measurements are less precise than setting the values
554 	  * we may run through dummy steps that cancel each other
555 	  * when stepping up and then down.
556 	  */
557 	while (vdd_last > 0 &&
558 	       vdd_last < vdd_target) {
559 		vdd_current += IR_VDD_STEP_UP;
560 		vdd_last = set_voltage(i2caddress, vdd_current);
561 	}
562 	while (vdd_last > 0 &&
563 	       vdd_last > vdd_target + (IR_VDD_STEP_DOWN - 1)) {
564 		vdd_current -= IR_VDD_STEP_DOWN;
565 		vdd_last = set_voltage(i2caddress, vdd_current);
566 	}
567 
568 #endif
569 	if (board_adjust_vdd(vdd_target) < 0) {
570 		ret = -1;
571 		goto exit;
572 	}
573 
574 	if (vdd_last > 0)
575 		printf("VID: Core voltage after adjustment is at %d mV\n",
576 		       vdd_last);
577 	else
578 		ret = -1;
579 exit:
580 	if (re_enable)
581 		enable_interrupts();
582 	i2c_multiplexer_select_vid_channel(I2C_MUX_CH_DEFAULT);
583 	return ret;
584 }
585 #else /* !CONFIG_FSL_LSCH3 */
586 int adjust_vdd(ulong vdd_override)
587 {
588 	int re_enable = disable_interrupts();
589 #if defined(CONFIG_FSL_LSCH2)
590 	struct ccsr_gur *gur = (void *)(CONFIG_SYS_FSL_GUTS_ADDR);
591 #else
592 	ccsr_gur_t __iomem *gur =
593 		(void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
594 #endif
595 	u32 fusesr;
596 	u8 vid, buf;
597 	int vdd_target, vdd_current, vdd_last;
598 	int ret, i2caddress;
599 	unsigned long vdd_string_override;
600 	char *vdd_string;
601 	static const uint16_t vdd[32] = {
602 		0,      /* unused */
603 		9875,   /* 0.9875V */
604 		9750,
605 		9625,
606 		9500,
607 		9375,
608 		9250,
609 		9125,
610 		9000,
611 		8875,
612 		8750,
613 		8625,
614 		8500,
615 		8375,
616 		8250,
617 		8125,
618 		10000,  /* 1.0000V */
619 		10125,
620 		10250,
621 		10375,
622 		10500,
623 		10625,
624 		10750,
625 		10875,
626 		11000,
627 		0,      /* reserved */
628 	};
629 	struct vdd_drive {
630 		u8 vid;
631 		unsigned voltage;
632 	};
633 
634 	ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
635 	if (ret) {
636 		debug("VID: I2C failed to switch channel\n");
637 		ret = -1;
638 		goto exit;
639 	}
640 #if defined(CONFIG_VOL_MONITOR_IR36021_SET) || \
641 	defined(CONFIG_VOL_MONITOR_IR36021_READ)
642 	ret = find_ir_chip_on_i2c();
643 	if (ret < 0) {
644 		printf("VID: Could not find voltage regulator on I2C.\n");
645 		ret = -1;
646 		goto exit;
647 	} else {
648 		i2caddress = ret;
649 		debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
650 	}
651 
652 	/* check IR chip work on Intel mode*/
653 	ret = i2c_read(i2caddress,
654 		       IR36021_INTEL_MODE_OOFSET,
655 		       1, (void *)&buf, 1);
656 	if (ret) {
657 		printf("VID: failed to read IR chip mode.\n");
658 		ret = -1;
659 		goto exit;
660 	}
661 	if ((buf & IR36021_MODE_MASK) != IR36021_INTEL_MODE) {
662 		printf("VID: IR Chip is not used in Intel mode.\n");
663 		ret = -1;
664 		goto exit;
665 	}
666 #endif
667 
668 	/* get the voltage ID from fuse status register */
669 	fusesr = in_be32(&gur->dcfg_fusesr);
670 	/*
671 	 * VID is used according to the table below
672 	 *                ---------------------------------------
673 	 *                |                DA_V                 |
674 	 *                |-------------------------------------|
675 	 *                | 5b00000 | 5b00001-5b11110 | 5b11111 |
676 	 * ---------------+---------+-----------------+---------|
677 	 * | D | 5b00000  | NO VID  | VID = DA_V      | NO VID  |
678 	 * | A |----------+---------+-----------------+---------|
679 	 * | _ | 5b00001  |VID =    | VID =           |VID =    |
680 	 * | V |   ~      | DA_V_ALT|   DA_V_ALT      | DA_A_VLT|
681 	 * | _ | 5b11110  |         |                 |         |
682 	 * | A |----------+---------+-----------------+---------|
683 	 * | L | 5b11111  | No VID  | VID = DA_V      | NO VID  |
684 	 * | T |          |         |                 |         |
685 	 * ------------------------------------------------------
686 	 */
687 #ifdef CONFIG_FSL_LSCH2
688 	vid = (fusesr >> FSL_CHASSIS2_DCFG_FUSESR_ALTVID_SHIFT) &
689 		FSL_CHASSIS2_DCFG_FUSESR_ALTVID_MASK;
690 	if ((vid == 0) || (vid == FSL_CHASSIS2_DCFG_FUSESR_ALTVID_MASK)) {
691 		vid = (fusesr >> FSL_CHASSIS2_DCFG_FUSESR_VID_SHIFT) &
692 			FSL_CHASSIS2_DCFG_FUSESR_VID_MASK;
693 	}
694 #else
695 	vid = (fusesr >> FSL_CORENET_DCFG_FUSESR_ALTVID_SHIFT) &
696 		FSL_CORENET_DCFG_FUSESR_ALTVID_MASK;
697 	if ((vid == 0) || (vid == FSL_CORENET_DCFG_FUSESR_ALTVID_MASK)) {
698 		vid = (fusesr >> FSL_CORENET_DCFG_FUSESR_VID_SHIFT) &
699 			FSL_CORENET_DCFG_FUSESR_VID_MASK;
700 	}
701 #endif
702 	vdd_target = vdd[vid];
703 
704 	/* check override variable for overriding VDD */
705 	vdd_string = env_get(CONFIG_VID_FLS_ENV);
706 	if (vdd_override == 0 && vdd_string &&
707 	    !strict_strtoul(vdd_string, 10, &vdd_string_override))
708 		vdd_override = vdd_string_override;
709 	if (vdd_override >= VDD_MV_MIN && vdd_override <= VDD_MV_MAX) {
710 		vdd_target = vdd_override * 10; /* convert to 1/10 mV */
711 		debug("VDD override is %lu\n", vdd_override);
712 	} else if (vdd_override != 0) {
713 		printf("Invalid value.\n");
714 	}
715 	if (vdd_target == 0) {
716 		debug("VID: VID not used\n");
717 		ret = 0;
718 		goto exit;
719 	} else {
720 		/* divide and round up by 10 to get a value in mV */
721 		vdd_target = DIV_ROUND_UP(vdd_target, 10);
722 		debug("VID: vid = %d mV\n", vdd_target);
723 	}
724 
725 	/*
726 	 * Read voltage monitor to check real voltage.
727 	 */
728 	vdd_last = read_voltage(i2caddress);
729 	if (vdd_last < 0) {
730 		printf("VID: Couldn't read sensor abort VID adjustment\n");
731 		ret = -1;
732 		goto exit;
733 	}
734 	vdd_current = vdd_last;
735 	debug("VID: Core voltage is currently at %d mV\n", vdd_last);
736 	/*
737 	  * Adjust voltage to at or one step above target.
738 	  * As measurements are less precise than setting the values
739 	  * we may run through dummy steps that cancel each other
740 	  * when stepping up and then down.
741 	  */
742 	while (vdd_last > 0 &&
743 	       vdd_last < vdd_target) {
744 		vdd_current += IR_VDD_STEP_UP;
745 		vdd_last = set_voltage(i2caddress, vdd_current);
746 	}
747 	while (vdd_last > 0 &&
748 	       vdd_last > vdd_target + (IR_VDD_STEP_DOWN - 1)) {
749 		vdd_current -= IR_VDD_STEP_DOWN;
750 		vdd_last = set_voltage(i2caddress, vdd_current);
751 	}
752 
753 	if (vdd_last > 0)
754 		printf("VID: Core voltage after adjustment is at %d mV\n",
755 		       vdd_last);
756 	else
757 		ret = -1;
758 exit:
759 	if (re_enable)
760 		enable_interrupts();
761 
762 	i2c_multiplexer_select_vid_channel(I2C_MUX_CH_DEFAULT);
763 
764 	return ret;
765 }
766 #endif
767 
768 static int print_vdd(void)
769 {
770 	int vdd_last, ret, i2caddress;
771 
772 	ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
773 	if (ret) {
774 		debug("VID : I2c failed to switch channel\n");
775 		return -1;
776 	}
777 #if defined(CONFIG_VOL_MONITOR_IR36021_SET) || \
778 	defined(CONFIG_VOL_MONITOR_IR36021_READ)
779 	ret = find_ir_chip_on_i2c();
780 	if (ret < 0) {
781 		printf("VID: Could not find voltage regulator on I2C.\n");
782 		goto exit;
783 	} else {
784 		i2caddress = ret;
785 		debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
786 	}
787 #endif
788 
789 	/*
790 	 * Read voltage monitor to check real voltage.
791 	 */
792 	vdd_last = read_voltage(i2caddress);
793 	if (vdd_last < 0) {
794 		printf("VID: Couldn't read sensor abort VID adjustment\n");
795 		goto exit;
796 	}
797 	printf("VID: Core voltage is at %d mV\n", vdd_last);
798 exit:
799 	i2c_multiplexer_select_vid_channel(I2C_MUX_CH_DEFAULT);
800 
801 	return ret < 0 ? -1 : 0;
802 
803 }
804 
805 static int do_vdd_override(cmd_tbl_t *cmdtp,
806 			   int flag, int argc,
807 			   char * const argv[])
808 {
809 	ulong override;
810 
811 	if (argc < 2)
812 		return CMD_RET_USAGE;
813 
814 	if (!strict_strtoul(argv[1], 10, &override))
815 		adjust_vdd(override);   /* the value is checked by callee */
816 	else
817 		return CMD_RET_USAGE;
818 	return 0;
819 }
820 
821 static int do_vdd_read(cmd_tbl_t *cmdtp,
822 			 int flag, int argc,
823 			 char * const argv[])
824 {
825 	if (argc < 1)
826 		return CMD_RET_USAGE;
827 	print_vdd();
828 
829 	return 0;
830 }
831 
832 U_BOOT_CMD(
833 	vdd_override, 2, 0, do_vdd_override,
834 	"override VDD",
835 	" - override with the voltage specified in mV, eg. 1050"
836 );
837 
838 U_BOOT_CMD(
839 	vdd_read, 1, 0, do_vdd_read,
840 	"read VDD",
841 	" - Read the voltage specified in mV"
842 )
843