xref: /openbmc/linux/drivers/pmdomain/qcom/cpr.c (revision 0c6dfa75)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
4  * Copyright (c) 2019, Linaro Limited
5  */
6 
7 #include <linux/module.h>
8 #include <linux/err.h>
9 #include <linux/debugfs.h>
10 #include <linux/string.h>
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/bitops.h>
16 #include <linux/slab.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/pm_domain.h>
20 #include <linux/pm_opp.h>
21 #include <linux/interrupt.h>
22 #include <linux/regmap.h>
23 #include <linux/mfd/syscon.h>
24 #include <linux/regulator/consumer.h>
25 #include <linux/clk.h>
26 #include <linux/nvmem-consumer.h>
27 
28 /* Register Offsets for RB-CPR and Bit Definitions */
29 
30 /* RBCPR Version Register */
31 #define REG_RBCPR_VERSION		0
32 #define RBCPR_VER_2			0x02
33 #define FLAGS_IGNORE_1ST_IRQ_STATUS	BIT(0)
34 
35 /* RBCPR Gate Count and Target Registers */
36 #define REG_RBCPR_GCNT_TARGET(n)	(0x60 + 4 * (n))
37 
38 #define RBCPR_GCNT_TARGET_TARGET_SHIFT	0
39 #define RBCPR_GCNT_TARGET_TARGET_MASK	GENMASK(11, 0)
40 #define RBCPR_GCNT_TARGET_GCNT_SHIFT	12
41 #define RBCPR_GCNT_TARGET_GCNT_MASK	GENMASK(9, 0)
42 
43 /* RBCPR Timer Control */
44 #define REG_RBCPR_TIMER_INTERVAL	0x44
45 #define REG_RBIF_TIMER_ADJUST		0x4c
46 
47 #define RBIF_TIMER_ADJ_CONS_UP_MASK	GENMASK(3, 0)
48 #define RBIF_TIMER_ADJ_CONS_UP_SHIFT	0
49 #define RBIF_TIMER_ADJ_CONS_DOWN_MASK	GENMASK(3, 0)
50 #define RBIF_TIMER_ADJ_CONS_DOWN_SHIFT	4
51 #define RBIF_TIMER_ADJ_CLAMP_INT_MASK	GENMASK(7, 0)
52 #define RBIF_TIMER_ADJ_CLAMP_INT_SHIFT	8
53 
54 /* RBCPR Config Register */
55 #define REG_RBIF_LIMIT			0x48
56 #define RBIF_LIMIT_CEILING_MASK		GENMASK(5, 0)
57 #define RBIF_LIMIT_CEILING_SHIFT	6
58 #define RBIF_LIMIT_FLOOR_BITS		6
59 #define RBIF_LIMIT_FLOOR_MASK		GENMASK(5, 0)
60 
61 #define RBIF_LIMIT_CEILING_DEFAULT	RBIF_LIMIT_CEILING_MASK
62 #define RBIF_LIMIT_FLOOR_DEFAULT	0
63 
64 #define REG_RBIF_SW_VLEVEL		0x94
65 #define RBIF_SW_VLEVEL_DEFAULT		0x20
66 
67 #define REG_RBCPR_STEP_QUOT		0x80
68 #define RBCPR_STEP_QUOT_STEPQUOT_MASK	GENMASK(7, 0)
69 #define RBCPR_STEP_QUOT_IDLE_CLK_MASK	GENMASK(3, 0)
70 #define RBCPR_STEP_QUOT_IDLE_CLK_SHIFT	8
71 
72 /* RBCPR Control Register */
73 #define REG_RBCPR_CTL			0x90
74 
75 #define RBCPR_CTL_LOOP_EN			BIT(0)
76 #define RBCPR_CTL_TIMER_EN			BIT(3)
77 #define RBCPR_CTL_SW_AUTO_CONT_ACK_EN		BIT(5)
78 #define RBCPR_CTL_SW_AUTO_CONT_NACK_DN_EN	BIT(6)
79 #define RBCPR_CTL_COUNT_MODE			BIT(10)
80 #define RBCPR_CTL_UP_THRESHOLD_MASK	GENMASK(3, 0)
81 #define RBCPR_CTL_UP_THRESHOLD_SHIFT	24
82 #define RBCPR_CTL_DN_THRESHOLD_MASK	GENMASK(3, 0)
83 #define RBCPR_CTL_DN_THRESHOLD_SHIFT	28
84 
85 /* RBCPR Ack/Nack Response */
86 #define REG_RBIF_CONT_ACK_CMD		0x98
87 #define REG_RBIF_CONT_NACK_CMD		0x9c
88 
89 /* RBCPR Result status Register */
90 #define REG_RBCPR_RESULT_0		0xa0
91 
92 #define RBCPR_RESULT0_BUSY_SHIFT	19
93 #define RBCPR_RESULT0_BUSY_MASK		BIT(RBCPR_RESULT0_BUSY_SHIFT)
94 #define RBCPR_RESULT0_ERROR_LT0_SHIFT	18
95 #define RBCPR_RESULT0_ERROR_SHIFT	6
96 #define RBCPR_RESULT0_ERROR_MASK	GENMASK(11, 0)
97 #define RBCPR_RESULT0_ERROR_STEPS_SHIFT	2
98 #define RBCPR_RESULT0_ERROR_STEPS_MASK	GENMASK(3, 0)
99 #define RBCPR_RESULT0_STEP_UP_SHIFT	1
100 
101 /* RBCPR Interrupt Control Register */
102 #define REG_RBIF_IRQ_EN(n)		(0x100 + 4 * (n))
103 #define REG_RBIF_IRQ_CLEAR		0x110
104 #define REG_RBIF_IRQ_STATUS		0x114
105 
106 #define CPR_INT_DONE		BIT(0)
107 #define CPR_INT_MIN		BIT(1)
108 #define CPR_INT_DOWN		BIT(2)
109 #define CPR_INT_MID		BIT(3)
110 #define CPR_INT_UP		BIT(4)
111 #define CPR_INT_MAX		BIT(5)
112 #define CPR_INT_CLAMP		BIT(6)
113 #define CPR_INT_ALL	(CPR_INT_DONE | CPR_INT_MIN | CPR_INT_DOWN | \
114 			CPR_INT_MID | CPR_INT_UP | CPR_INT_MAX | CPR_INT_CLAMP)
115 #define CPR_INT_DEFAULT	(CPR_INT_UP | CPR_INT_DOWN)
116 
117 #define CPR_NUM_RING_OSC	8
118 
119 /* CPR eFuse parameters */
120 #define CPR_FUSE_TARGET_QUOT_BITS_MASK	GENMASK(11, 0)
121 
122 #define CPR_FUSE_MIN_QUOT_DIFF		50
123 
124 #define FUSE_REVISION_UNKNOWN		(-1)
125 
126 enum voltage_change_dir {
127 	NO_CHANGE,
128 	DOWN,
129 	UP,
130 };
131 
132 struct cpr_fuse {
133 	char *ring_osc;
134 	char *init_voltage;
135 	char *quotient;
136 	char *quotient_offset;
137 };
138 
139 struct fuse_corner_data {
140 	int ref_uV;
141 	int max_uV;
142 	int min_uV;
143 	int max_volt_scale;
144 	int max_quot_scale;
145 	/* fuse quot */
146 	int quot_offset;
147 	int quot_scale;
148 	int quot_adjust;
149 	/* fuse quot_offset */
150 	int quot_offset_scale;
151 	int quot_offset_adjust;
152 };
153 
154 struct cpr_fuses {
155 	int init_voltage_step;
156 	int init_voltage_width;
157 	struct fuse_corner_data *fuse_corner_data;
158 };
159 
160 struct corner_data {
161 	unsigned int fuse_corner;
162 	unsigned long freq;
163 };
164 
165 struct cpr_desc {
166 	unsigned int num_fuse_corners;
167 	int min_diff_quot;
168 	int *step_quot;
169 
170 	unsigned int		timer_delay_us;
171 	unsigned int		timer_cons_up;
172 	unsigned int		timer_cons_down;
173 	unsigned int		up_threshold;
174 	unsigned int		down_threshold;
175 	unsigned int		idle_clocks;
176 	unsigned int		gcnt_us;
177 	unsigned int		vdd_apc_step_up_limit;
178 	unsigned int		vdd_apc_step_down_limit;
179 	unsigned int		clamp_timer_interval;
180 
181 	struct cpr_fuses cpr_fuses;
182 	bool reduce_to_fuse_uV;
183 	bool reduce_to_corner_uV;
184 };
185 
186 struct acc_desc {
187 	unsigned int	enable_reg;
188 	u32		enable_mask;
189 
190 	struct reg_sequence	*config;
191 	struct reg_sequence	*settings;
192 	int			num_regs_per_fuse;
193 };
194 
195 struct cpr_acc_desc {
196 	const struct cpr_desc *cpr_desc;
197 	const struct acc_desc *acc_desc;
198 };
199 
200 struct fuse_corner {
201 	int min_uV;
202 	int max_uV;
203 	int uV;
204 	int quot;
205 	int step_quot;
206 	const struct reg_sequence *accs;
207 	int num_accs;
208 	unsigned long max_freq;
209 	u8 ring_osc_idx;
210 };
211 
212 struct corner {
213 	int min_uV;
214 	int max_uV;
215 	int uV;
216 	int last_uV;
217 	int quot_adjust;
218 	u32 save_ctl;
219 	u32 save_irq;
220 	unsigned long freq;
221 	struct fuse_corner *fuse_corner;
222 };
223 
224 struct cpr_drv {
225 	unsigned int		num_corners;
226 	unsigned int		ref_clk_khz;
227 
228 	struct generic_pm_domain pd;
229 	struct device		*dev;
230 	struct device		*attached_cpu_dev;
231 	struct mutex		lock;
232 	void __iomem		*base;
233 	struct corner		*corner;
234 	struct regulator	*vdd_apc;
235 	struct clk		*cpu_clk;
236 	struct regmap		*tcsr;
237 	bool			loop_disabled;
238 	u32			gcnt;
239 	unsigned long		flags;
240 
241 	struct fuse_corner	*fuse_corners;
242 	struct corner		*corners;
243 
244 	const struct cpr_desc *desc;
245 	const struct acc_desc *acc_desc;
246 	const struct cpr_fuse *cpr_fuses;
247 
248 	struct dentry *debugfs;
249 };
250 
251 static bool cpr_is_allowed(struct cpr_drv *drv)
252 {
253 	return !drv->loop_disabled;
254 }
255 
256 static void cpr_write(struct cpr_drv *drv, u32 offset, u32 value)
257 {
258 	writel_relaxed(value, drv->base + offset);
259 }
260 
261 static u32 cpr_read(struct cpr_drv *drv, u32 offset)
262 {
263 	return readl_relaxed(drv->base + offset);
264 }
265 
266 static void
267 cpr_masked_write(struct cpr_drv *drv, u32 offset, u32 mask, u32 value)
268 {
269 	u32 val;
270 
271 	val = readl_relaxed(drv->base + offset);
272 	val &= ~mask;
273 	val |= value & mask;
274 	writel_relaxed(val, drv->base + offset);
275 }
276 
277 static void cpr_irq_clr(struct cpr_drv *drv)
278 {
279 	cpr_write(drv, REG_RBIF_IRQ_CLEAR, CPR_INT_ALL);
280 }
281 
282 static void cpr_irq_clr_nack(struct cpr_drv *drv)
283 {
284 	cpr_irq_clr(drv);
285 	cpr_write(drv, REG_RBIF_CONT_NACK_CMD, 1);
286 }
287 
288 static void cpr_irq_clr_ack(struct cpr_drv *drv)
289 {
290 	cpr_irq_clr(drv);
291 	cpr_write(drv, REG_RBIF_CONT_ACK_CMD, 1);
292 }
293 
294 static void cpr_irq_set(struct cpr_drv *drv, u32 int_bits)
295 {
296 	cpr_write(drv, REG_RBIF_IRQ_EN(0), int_bits);
297 }
298 
299 static void cpr_ctl_modify(struct cpr_drv *drv, u32 mask, u32 value)
300 {
301 	cpr_masked_write(drv, REG_RBCPR_CTL, mask, value);
302 }
303 
304 static void cpr_ctl_enable(struct cpr_drv *drv, struct corner *corner)
305 {
306 	u32 val, mask;
307 	const struct cpr_desc *desc = drv->desc;
308 
309 	/* Program Consecutive Up & Down */
310 	val = desc->timer_cons_down << RBIF_TIMER_ADJ_CONS_DOWN_SHIFT;
311 	val |= desc->timer_cons_up << RBIF_TIMER_ADJ_CONS_UP_SHIFT;
312 	mask = RBIF_TIMER_ADJ_CONS_UP_MASK | RBIF_TIMER_ADJ_CONS_DOWN_MASK;
313 	cpr_masked_write(drv, REG_RBIF_TIMER_ADJUST, mask, val);
314 	cpr_masked_write(drv, REG_RBCPR_CTL,
315 			 RBCPR_CTL_SW_AUTO_CONT_NACK_DN_EN |
316 			 RBCPR_CTL_SW_AUTO_CONT_ACK_EN,
317 			 corner->save_ctl);
318 	cpr_irq_set(drv, corner->save_irq);
319 
320 	if (cpr_is_allowed(drv) && corner->max_uV > corner->min_uV)
321 		val = RBCPR_CTL_LOOP_EN;
322 	else
323 		val = 0;
324 	cpr_ctl_modify(drv, RBCPR_CTL_LOOP_EN, val);
325 }
326 
327 static void cpr_ctl_disable(struct cpr_drv *drv)
328 {
329 	cpr_irq_set(drv, 0);
330 	cpr_ctl_modify(drv, RBCPR_CTL_SW_AUTO_CONT_NACK_DN_EN |
331 		       RBCPR_CTL_SW_AUTO_CONT_ACK_EN, 0);
332 	cpr_masked_write(drv, REG_RBIF_TIMER_ADJUST,
333 			 RBIF_TIMER_ADJ_CONS_UP_MASK |
334 			 RBIF_TIMER_ADJ_CONS_DOWN_MASK, 0);
335 	cpr_irq_clr(drv);
336 	cpr_write(drv, REG_RBIF_CONT_ACK_CMD, 1);
337 	cpr_write(drv, REG_RBIF_CONT_NACK_CMD, 1);
338 	cpr_ctl_modify(drv, RBCPR_CTL_LOOP_EN, 0);
339 }
340 
341 static bool cpr_ctl_is_enabled(struct cpr_drv *drv)
342 {
343 	u32 reg_val;
344 
345 	reg_val = cpr_read(drv, REG_RBCPR_CTL);
346 	return reg_val & RBCPR_CTL_LOOP_EN;
347 }
348 
349 static bool cpr_ctl_is_busy(struct cpr_drv *drv)
350 {
351 	u32 reg_val;
352 
353 	reg_val = cpr_read(drv, REG_RBCPR_RESULT_0);
354 	return reg_val & RBCPR_RESULT0_BUSY_MASK;
355 }
356 
357 static void cpr_corner_save(struct cpr_drv *drv, struct corner *corner)
358 {
359 	corner->save_ctl = cpr_read(drv, REG_RBCPR_CTL);
360 	corner->save_irq = cpr_read(drv, REG_RBIF_IRQ_EN(0));
361 }
362 
363 static void cpr_corner_restore(struct cpr_drv *drv, struct corner *corner)
364 {
365 	u32 gcnt, ctl, irq, ro_sel, step_quot;
366 	struct fuse_corner *fuse = corner->fuse_corner;
367 	const struct cpr_desc *desc = drv->desc;
368 	int i;
369 
370 	ro_sel = fuse->ring_osc_idx;
371 	gcnt = drv->gcnt;
372 	gcnt |= fuse->quot - corner->quot_adjust;
373 
374 	/* Program the step quotient and idle clocks */
375 	step_quot = desc->idle_clocks << RBCPR_STEP_QUOT_IDLE_CLK_SHIFT;
376 	step_quot |= fuse->step_quot & RBCPR_STEP_QUOT_STEPQUOT_MASK;
377 	cpr_write(drv, REG_RBCPR_STEP_QUOT, step_quot);
378 
379 	/* Clear the target quotient value and gate count of all ROs */
380 	for (i = 0; i < CPR_NUM_RING_OSC; i++)
381 		cpr_write(drv, REG_RBCPR_GCNT_TARGET(i), 0);
382 
383 	cpr_write(drv, REG_RBCPR_GCNT_TARGET(ro_sel), gcnt);
384 	ctl = corner->save_ctl;
385 	cpr_write(drv, REG_RBCPR_CTL, ctl);
386 	irq = corner->save_irq;
387 	cpr_irq_set(drv, irq);
388 	dev_dbg(drv->dev, "gcnt = %#08x, ctl = %#08x, irq = %#08x\n", gcnt,
389 		ctl, irq);
390 }
391 
392 static void cpr_set_acc(struct regmap *tcsr, struct fuse_corner *f,
393 			struct fuse_corner *end)
394 {
395 	if (f == end)
396 		return;
397 
398 	if (f < end) {
399 		for (f += 1; f <= end; f++)
400 			regmap_multi_reg_write(tcsr, f->accs, f->num_accs);
401 	} else {
402 		for (f -= 1; f >= end; f--)
403 			regmap_multi_reg_write(tcsr, f->accs, f->num_accs);
404 	}
405 }
406 
407 static int cpr_pre_voltage(struct cpr_drv *drv,
408 			   struct fuse_corner *fuse_corner,
409 			   enum voltage_change_dir dir)
410 {
411 	struct fuse_corner *prev_fuse_corner = drv->corner->fuse_corner;
412 
413 	if (drv->tcsr && dir == DOWN)
414 		cpr_set_acc(drv->tcsr, prev_fuse_corner, fuse_corner);
415 
416 	return 0;
417 }
418 
419 static int cpr_post_voltage(struct cpr_drv *drv,
420 			    struct fuse_corner *fuse_corner,
421 			    enum voltage_change_dir dir)
422 {
423 	struct fuse_corner *prev_fuse_corner = drv->corner->fuse_corner;
424 
425 	if (drv->tcsr && dir == UP)
426 		cpr_set_acc(drv->tcsr, prev_fuse_corner, fuse_corner);
427 
428 	return 0;
429 }
430 
431 static int cpr_scale_voltage(struct cpr_drv *drv, struct corner *corner,
432 			     int new_uV, enum voltage_change_dir dir)
433 {
434 	int ret;
435 	struct fuse_corner *fuse_corner = corner->fuse_corner;
436 
437 	ret = cpr_pre_voltage(drv, fuse_corner, dir);
438 	if (ret)
439 		return ret;
440 
441 	ret = regulator_set_voltage(drv->vdd_apc, new_uV, new_uV);
442 	if (ret) {
443 		dev_err_ratelimited(drv->dev, "failed to set apc voltage %d\n",
444 				    new_uV);
445 		return ret;
446 	}
447 
448 	ret = cpr_post_voltage(drv, fuse_corner, dir);
449 	if (ret)
450 		return ret;
451 
452 	return 0;
453 }
454 
455 static unsigned int cpr_get_cur_perf_state(struct cpr_drv *drv)
456 {
457 	return drv->corner ? drv->corner - drv->corners + 1 : 0;
458 }
459 
460 static int cpr_scale(struct cpr_drv *drv, enum voltage_change_dir dir)
461 {
462 	u32 val, error_steps, reg_mask;
463 	int last_uV, new_uV, step_uV, ret;
464 	struct corner *corner;
465 	const struct cpr_desc *desc = drv->desc;
466 
467 	if (dir != UP && dir != DOWN)
468 		return 0;
469 
470 	step_uV = regulator_get_linear_step(drv->vdd_apc);
471 	if (!step_uV)
472 		return -EINVAL;
473 
474 	corner = drv->corner;
475 
476 	val = cpr_read(drv, REG_RBCPR_RESULT_0);
477 
478 	error_steps = val >> RBCPR_RESULT0_ERROR_STEPS_SHIFT;
479 	error_steps &= RBCPR_RESULT0_ERROR_STEPS_MASK;
480 	last_uV = corner->last_uV;
481 
482 	if (dir == UP) {
483 		if (desc->clamp_timer_interval &&
484 		    error_steps < desc->up_threshold) {
485 			/*
486 			 * Handle the case where another measurement started
487 			 * after the interrupt was triggered due to a core
488 			 * exiting from power collapse.
489 			 */
490 			error_steps = max(desc->up_threshold,
491 					  desc->vdd_apc_step_up_limit);
492 		}
493 
494 		if (last_uV >= corner->max_uV) {
495 			cpr_irq_clr_nack(drv);
496 
497 			/* Maximize the UP threshold */
498 			reg_mask = RBCPR_CTL_UP_THRESHOLD_MASK;
499 			reg_mask <<= RBCPR_CTL_UP_THRESHOLD_SHIFT;
500 			val = reg_mask;
501 			cpr_ctl_modify(drv, reg_mask, val);
502 
503 			/* Disable UP interrupt */
504 			cpr_irq_set(drv, CPR_INT_DEFAULT & ~CPR_INT_UP);
505 
506 			return 0;
507 		}
508 
509 		if (error_steps > desc->vdd_apc_step_up_limit)
510 			error_steps = desc->vdd_apc_step_up_limit;
511 
512 		/* Calculate new voltage */
513 		new_uV = last_uV + error_steps * step_uV;
514 		new_uV = min(new_uV, corner->max_uV);
515 
516 		dev_dbg(drv->dev,
517 			"UP: -> new_uV: %d last_uV: %d perf state: %u\n",
518 			new_uV, last_uV, cpr_get_cur_perf_state(drv));
519 	} else {
520 		if (desc->clamp_timer_interval &&
521 		    error_steps < desc->down_threshold) {
522 			/*
523 			 * Handle the case where another measurement started
524 			 * after the interrupt was triggered due to a core
525 			 * exiting from power collapse.
526 			 */
527 			error_steps = max(desc->down_threshold,
528 					  desc->vdd_apc_step_down_limit);
529 		}
530 
531 		if (last_uV <= corner->min_uV) {
532 			cpr_irq_clr_nack(drv);
533 
534 			/* Enable auto nack down */
535 			reg_mask = RBCPR_CTL_SW_AUTO_CONT_NACK_DN_EN;
536 			val = RBCPR_CTL_SW_AUTO_CONT_NACK_DN_EN;
537 
538 			cpr_ctl_modify(drv, reg_mask, val);
539 
540 			/* Disable DOWN interrupt */
541 			cpr_irq_set(drv, CPR_INT_DEFAULT & ~CPR_INT_DOWN);
542 
543 			return 0;
544 		}
545 
546 		if (error_steps > desc->vdd_apc_step_down_limit)
547 			error_steps = desc->vdd_apc_step_down_limit;
548 
549 		/* Calculate new voltage */
550 		new_uV = last_uV - error_steps * step_uV;
551 		new_uV = max(new_uV, corner->min_uV);
552 
553 		dev_dbg(drv->dev,
554 			"DOWN: -> new_uV: %d last_uV: %d perf state: %u\n",
555 			new_uV, last_uV, cpr_get_cur_perf_state(drv));
556 	}
557 
558 	ret = cpr_scale_voltage(drv, corner, new_uV, dir);
559 	if (ret) {
560 		cpr_irq_clr_nack(drv);
561 		return ret;
562 	}
563 	drv->corner->last_uV = new_uV;
564 
565 	if (dir == UP) {
566 		/* Disable auto nack down */
567 		reg_mask = RBCPR_CTL_SW_AUTO_CONT_NACK_DN_EN;
568 		val = 0;
569 	} else {
570 		/* Restore default threshold for UP */
571 		reg_mask = RBCPR_CTL_UP_THRESHOLD_MASK;
572 		reg_mask <<= RBCPR_CTL_UP_THRESHOLD_SHIFT;
573 		val = desc->up_threshold;
574 		val <<= RBCPR_CTL_UP_THRESHOLD_SHIFT;
575 	}
576 
577 	cpr_ctl_modify(drv, reg_mask, val);
578 
579 	/* Re-enable default interrupts */
580 	cpr_irq_set(drv, CPR_INT_DEFAULT);
581 
582 	/* Ack */
583 	cpr_irq_clr_ack(drv);
584 
585 	return 0;
586 }
587 
588 static irqreturn_t cpr_irq_handler(int irq, void *dev)
589 {
590 	struct cpr_drv *drv = dev;
591 	const struct cpr_desc *desc = drv->desc;
592 	irqreturn_t ret = IRQ_HANDLED;
593 	u32 val;
594 
595 	mutex_lock(&drv->lock);
596 
597 	val = cpr_read(drv, REG_RBIF_IRQ_STATUS);
598 	if (drv->flags & FLAGS_IGNORE_1ST_IRQ_STATUS)
599 		val = cpr_read(drv, REG_RBIF_IRQ_STATUS);
600 
601 	dev_dbg(drv->dev, "IRQ_STATUS = %#02x\n", val);
602 
603 	if (!cpr_ctl_is_enabled(drv)) {
604 		dev_dbg(drv->dev, "CPR is disabled\n");
605 		ret = IRQ_NONE;
606 	} else if (cpr_ctl_is_busy(drv) && !desc->clamp_timer_interval) {
607 		dev_dbg(drv->dev, "CPR measurement is not ready\n");
608 	} else if (!cpr_is_allowed(drv)) {
609 		val = cpr_read(drv, REG_RBCPR_CTL);
610 		dev_err_ratelimited(drv->dev,
611 				    "Interrupt broken? RBCPR_CTL = %#02x\n",
612 				    val);
613 		ret = IRQ_NONE;
614 	} else {
615 		/*
616 		 * Following sequence of handling is as per each IRQ's
617 		 * priority
618 		 */
619 		if (val & CPR_INT_UP) {
620 			cpr_scale(drv, UP);
621 		} else if (val & CPR_INT_DOWN) {
622 			cpr_scale(drv, DOWN);
623 		} else if (val & CPR_INT_MIN) {
624 			cpr_irq_clr_nack(drv);
625 		} else if (val & CPR_INT_MAX) {
626 			cpr_irq_clr_nack(drv);
627 		} else if (val & CPR_INT_MID) {
628 			/* RBCPR_CTL_SW_AUTO_CONT_ACK_EN is enabled */
629 			dev_dbg(drv->dev, "IRQ occurred for Mid Flag\n");
630 		} else {
631 			dev_dbg(drv->dev,
632 				"IRQ occurred for unknown flag (%#08x)\n", val);
633 		}
634 
635 		/* Save register values for the corner */
636 		cpr_corner_save(drv, drv->corner);
637 	}
638 
639 	mutex_unlock(&drv->lock);
640 
641 	return ret;
642 }
643 
644 static int cpr_enable(struct cpr_drv *drv)
645 {
646 	int ret;
647 
648 	ret = regulator_enable(drv->vdd_apc);
649 	if (ret)
650 		return ret;
651 
652 	mutex_lock(&drv->lock);
653 
654 	if (cpr_is_allowed(drv) && drv->corner) {
655 		cpr_irq_clr(drv);
656 		cpr_corner_restore(drv, drv->corner);
657 		cpr_ctl_enable(drv, drv->corner);
658 	}
659 
660 	mutex_unlock(&drv->lock);
661 
662 	return 0;
663 }
664 
665 static int cpr_disable(struct cpr_drv *drv)
666 {
667 	mutex_lock(&drv->lock);
668 
669 	if (cpr_is_allowed(drv)) {
670 		cpr_ctl_disable(drv);
671 		cpr_irq_clr(drv);
672 	}
673 
674 	mutex_unlock(&drv->lock);
675 
676 	return regulator_disable(drv->vdd_apc);
677 }
678 
679 static int cpr_config(struct cpr_drv *drv)
680 {
681 	int i;
682 	u32 val, gcnt;
683 	struct corner *corner;
684 	const struct cpr_desc *desc = drv->desc;
685 
686 	/* Disable interrupt and CPR */
687 	cpr_write(drv, REG_RBIF_IRQ_EN(0), 0);
688 	cpr_write(drv, REG_RBCPR_CTL, 0);
689 
690 	/* Program the default HW ceiling, floor and vlevel */
691 	val = (RBIF_LIMIT_CEILING_DEFAULT & RBIF_LIMIT_CEILING_MASK)
692 		<< RBIF_LIMIT_CEILING_SHIFT;
693 	val |= RBIF_LIMIT_FLOOR_DEFAULT & RBIF_LIMIT_FLOOR_MASK;
694 	cpr_write(drv, REG_RBIF_LIMIT, val);
695 	cpr_write(drv, REG_RBIF_SW_VLEVEL, RBIF_SW_VLEVEL_DEFAULT);
696 
697 	/*
698 	 * Clear the target quotient value and gate count of all
699 	 * ring oscillators
700 	 */
701 	for (i = 0; i < CPR_NUM_RING_OSC; i++)
702 		cpr_write(drv, REG_RBCPR_GCNT_TARGET(i), 0);
703 
704 	/* Init and save gcnt */
705 	gcnt = (drv->ref_clk_khz * desc->gcnt_us) / 1000;
706 	gcnt = gcnt & RBCPR_GCNT_TARGET_GCNT_MASK;
707 	gcnt <<= RBCPR_GCNT_TARGET_GCNT_SHIFT;
708 	drv->gcnt = gcnt;
709 
710 	/* Program the delay count for the timer */
711 	val = (drv->ref_clk_khz * desc->timer_delay_us) / 1000;
712 	cpr_write(drv, REG_RBCPR_TIMER_INTERVAL, val);
713 	dev_dbg(drv->dev, "Timer count: %#0x (for %d us)\n", val,
714 		desc->timer_delay_us);
715 
716 	/* Program Consecutive Up & Down */
717 	val = desc->timer_cons_down << RBIF_TIMER_ADJ_CONS_DOWN_SHIFT;
718 	val |= desc->timer_cons_up << RBIF_TIMER_ADJ_CONS_UP_SHIFT;
719 	val |= desc->clamp_timer_interval << RBIF_TIMER_ADJ_CLAMP_INT_SHIFT;
720 	cpr_write(drv, REG_RBIF_TIMER_ADJUST, val);
721 
722 	/* Program the control register */
723 	val = desc->up_threshold << RBCPR_CTL_UP_THRESHOLD_SHIFT;
724 	val |= desc->down_threshold << RBCPR_CTL_DN_THRESHOLD_SHIFT;
725 	val |= RBCPR_CTL_TIMER_EN | RBCPR_CTL_COUNT_MODE;
726 	val |= RBCPR_CTL_SW_AUTO_CONT_ACK_EN;
727 	cpr_write(drv, REG_RBCPR_CTL, val);
728 
729 	for (i = 0; i < drv->num_corners; i++) {
730 		corner = &drv->corners[i];
731 		corner->save_ctl = val;
732 		corner->save_irq = CPR_INT_DEFAULT;
733 	}
734 
735 	cpr_irq_set(drv, CPR_INT_DEFAULT);
736 
737 	val = cpr_read(drv, REG_RBCPR_VERSION);
738 	if (val <= RBCPR_VER_2)
739 		drv->flags |= FLAGS_IGNORE_1ST_IRQ_STATUS;
740 
741 	return 0;
742 }
743 
744 static int cpr_set_performance_state(struct generic_pm_domain *domain,
745 				     unsigned int state)
746 {
747 	struct cpr_drv *drv = container_of(domain, struct cpr_drv, pd);
748 	struct corner *corner, *end;
749 	enum voltage_change_dir dir;
750 	int ret = 0, new_uV;
751 
752 	mutex_lock(&drv->lock);
753 
754 	dev_dbg(drv->dev, "%s: setting perf state: %u (prev state: %u)\n",
755 		__func__, state, cpr_get_cur_perf_state(drv));
756 
757 	/*
758 	 * Determine new corner we're going to.
759 	 * Remove one since lowest performance state is 1.
760 	 */
761 	corner = drv->corners + state - 1;
762 	end = &drv->corners[drv->num_corners - 1];
763 	if (corner > end || corner < drv->corners) {
764 		ret = -EINVAL;
765 		goto unlock;
766 	}
767 
768 	/* Determine direction */
769 	if (drv->corner > corner)
770 		dir = DOWN;
771 	else if (drv->corner < corner)
772 		dir = UP;
773 	else
774 		dir = NO_CHANGE;
775 
776 	if (cpr_is_allowed(drv))
777 		new_uV = corner->last_uV;
778 	else
779 		new_uV = corner->uV;
780 
781 	if (cpr_is_allowed(drv))
782 		cpr_ctl_disable(drv);
783 
784 	ret = cpr_scale_voltage(drv, corner, new_uV, dir);
785 	if (ret)
786 		goto unlock;
787 
788 	if (cpr_is_allowed(drv)) {
789 		cpr_irq_clr(drv);
790 		if (drv->corner != corner)
791 			cpr_corner_restore(drv, corner);
792 		cpr_ctl_enable(drv, corner);
793 	}
794 
795 	drv->corner = corner;
796 
797 unlock:
798 	mutex_unlock(&drv->lock);
799 
800 	return ret;
801 }
802 
803 static int
804 cpr_populate_ring_osc_idx(struct cpr_drv *drv)
805 {
806 	struct fuse_corner *fuse = drv->fuse_corners;
807 	struct fuse_corner *end = fuse + drv->desc->num_fuse_corners;
808 	const struct cpr_fuse *fuses = drv->cpr_fuses;
809 	u32 data;
810 	int ret;
811 
812 	for (; fuse < end; fuse++, fuses++) {
813 		ret = nvmem_cell_read_variable_le_u32(drv->dev, fuses->ring_osc, &data);
814 		if (ret)
815 			return ret;
816 		fuse->ring_osc_idx = data;
817 	}
818 
819 	return 0;
820 }
821 
822 static int cpr_read_fuse_uV(const struct cpr_desc *desc,
823 			    const struct fuse_corner_data *fdata,
824 			    const char *init_v_efuse,
825 			    int step_volt,
826 			    struct cpr_drv *drv)
827 {
828 	int step_size_uV, steps, uV;
829 	u32 bits = 0;
830 	int ret;
831 
832 	ret = nvmem_cell_read_variable_le_u32(drv->dev, init_v_efuse, &bits);
833 	if (ret)
834 		return ret;
835 
836 	steps = bits & ~BIT(desc->cpr_fuses.init_voltage_width - 1);
837 	/* Not two's complement.. instead highest bit is sign bit */
838 	if (bits & BIT(desc->cpr_fuses.init_voltage_width - 1))
839 		steps = -steps;
840 
841 	step_size_uV = desc->cpr_fuses.init_voltage_step;
842 
843 	uV = fdata->ref_uV + steps * step_size_uV;
844 	return DIV_ROUND_UP(uV, step_volt) * step_volt;
845 }
846 
847 static int cpr_fuse_corner_init(struct cpr_drv *drv)
848 {
849 	const struct cpr_desc *desc = drv->desc;
850 	const struct cpr_fuse *fuses = drv->cpr_fuses;
851 	const struct acc_desc *acc_desc = drv->acc_desc;
852 	int i;
853 	unsigned int step_volt;
854 	struct fuse_corner_data *fdata;
855 	struct fuse_corner *fuse, *end;
856 	int uV;
857 	const struct reg_sequence *accs;
858 	int ret;
859 
860 	accs = acc_desc->settings;
861 
862 	step_volt = regulator_get_linear_step(drv->vdd_apc);
863 	if (!step_volt)
864 		return -EINVAL;
865 
866 	/* Populate fuse_corner members */
867 	fuse = drv->fuse_corners;
868 	end = &fuse[desc->num_fuse_corners - 1];
869 	fdata = desc->cpr_fuses.fuse_corner_data;
870 
871 	for (i = 0; fuse <= end; fuse++, fuses++, i++, fdata++) {
872 		/*
873 		 * Update SoC voltages: platforms might choose a different
874 		 * regulators than the one used to characterize the algorithms
875 		 * (ie, init_voltage_step).
876 		 */
877 		fdata->min_uV = roundup(fdata->min_uV, step_volt);
878 		fdata->max_uV = roundup(fdata->max_uV, step_volt);
879 
880 		/* Populate uV */
881 		uV = cpr_read_fuse_uV(desc, fdata, fuses->init_voltage,
882 				      step_volt, drv);
883 		if (uV < 0)
884 			return uV;
885 
886 		fuse->min_uV = fdata->min_uV;
887 		fuse->max_uV = fdata->max_uV;
888 		fuse->uV = clamp(uV, fuse->min_uV, fuse->max_uV);
889 
890 		if (fuse == end) {
891 			/*
892 			 * Allow the highest fuse corner's PVS voltage to
893 			 * define the ceiling voltage for that corner in order
894 			 * to support SoC's in which variable ceiling values
895 			 * are required.
896 			 */
897 			end->max_uV = max(end->max_uV, end->uV);
898 		}
899 
900 		/* Populate target quotient by scaling */
901 		ret = nvmem_cell_read_variable_le_u32(drv->dev, fuses->quotient, &fuse->quot);
902 		if (ret)
903 			return ret;
904 
905 		fuse->quot *= fdata->quot_scale;
906 		fuse->quot += fdata->quot_offset;
907 		fuse->quot += fdata->quot_adjust;
908 		fuse->step_quot = desc->step_quot[fuse->ring_osc_idx];
909 
910 		/* Populate acc settings */
911 		fuse->accs = accs;
912 		fuse->num_accs = acc_desc->num_regs_per_fuse;
913 		accs += acc_desc->num_regs_per_fuse;
914 	}
915 
916 	/*
917 	 * Restrict all fuse corner PVS voltages based upon per corner
918 	 * ceiling and floor voltages.
919 	 */
920 	for (fuse = drv->fuse_corners, i = 0; fuse <= end; fuse++, i++) {
921 		if (fuse->uV > fuse->max_uV)
922 			fuse->uV = fuse->max_uV;
923 		else if (fuse->uV < fuse->min_uV)
924 			fuse->uV = fuse->min_uV;
925 
926 		ret = regulator_is_supported_voltage(drv->vdd_apc,
927 						     fuse->min_uV,
928 						     fuse->min_uV);
929 		if (!ret) {
930 			dev_err(drv->dev,
931 				"min uV: %d (fuse corner: %d) not supported by regulator\n",
932 				fuse->min_uV, i);
933 			return -EINVAL;
934 		}
935 
936 		ret = regulator_is_supported_voltage(drv->vdd_apc,
937 						     fuse->max_uV,
938 						     fuse->max_uV);
939 		if (!ret) {
940 			dev_err(drv->dev,
941 				"max uV: %d (fuse corner: %d) not supported by regulator\n",
942 				fuse->max_uV, i);
943 			return -EINVAL;
944 		}
945 
946 		dev_dbg(drv->dev,
947 			"fuse corner %d: [%d %d %d] RO%hhu quot %d squot %d\n",
948 			i, fuse->min_uV, fuse->uV, fuse->max_uV,
949 			fuse->ring_osc_idx, fuse->quot, fuse->step_quot);
950 	}
951 
952 	return 0;
953 }
954 
955 static int cpr_calculate_scaling(const char *quot_offset,
956 				 struct cpr_drv *drv,
957 				 const struct fuse_corner_data *fdata,
958 				 const struct corner *corner)
959 {
960 	u32 quot_diff = 0;
961 	unsigned long freq_diff;
962 	int scaling;
963 	const struct fuse_corner *fuse, *prev_fuse;
964 	int ret;
965 
966 	fuse = corner->fuse_corner;
967 	prev_fuse = fuse - 1;
968 
969 	if (quot_offset) {
970 		ret = nvmem_cell_read_variable_le_u32(drv->dev, quot_offset, &quot_diff);
971 		if (ret)
972 			return ret;
973 
974 		quot_diff *= fdata->quot_offset_scale;
975 		quot_diff += fdata->quot_offset_adjust;
976 	} else {
977 		quot_diff = fuse->quot - prev_fuse->quot;
978 	}
979 
980 	freq_diff = fuse->max_freq - prev_fuse->max_freq;
981 	freq_diff /= 1000000; /* Convert to MHz */
982 	scaling = 1000 * quot_diff / freq_diff;
983 	return min(scaling, fdata->max_quot_scale);
984 }
985 
986 static int cpr_interpolate(const struct corner *corner, int step_volt,
987 			   const struct fuse_corner_data *fdata)
988 {
989 	unsigned long f_high, f_low, f_diff;
990 	int uV_high, uV_low, uV;
991 	u64 temp, temp_limit;
992 	const struct fuse_corner *fuse, *prev_fuse;
993 
994 	fuse = corner->fuse_corner;
995 	prev_fuse = fuse - 1;
996 
997 	f_high = fuse->max_freq;
998 	f_low = prev_fuse->max_freq;
999 	uV_high = fuse->uV;
1000 	uV_low = prev_fuse->uV;
1001 	f_diff = fuse->max_freq - corner->freq;
1002 
1003 	/*
1004 	 * Don't interpolate in the wrong direction. This could happen
1005 	 * if the adjusted fuse voltage overlaps with the previous fuse's
1006 	 * adjusted voltage.
1007 	 */
1008 	if (f_high <= f_low || uV_high <= uV_low || f_high <= corner->freq)
1009 		return corner->uV;
1010 
1011 	temp = f_diff * (uV_high - uV_low);
1012 	temp = div64_ul(temp, f_high - f_low);
1013 
1014 	/*
1015 	 * max_volt_scale has units of uV/MHz while freq values
1016 	 * have units of Hz.  Divide by 1000000 to convert to.
1017 	 */
1018 	temp_limit = f_diff * fdata->max_volt_scale;
1019 	do_div(temp_limit, 1000000);
1020 
1021 	uV = uV_high - min(temp, temp_limit);
1022 	return roundup(uV, step_volt);
1023 }
1024 
1025 static unsigned int cpr_get_fuse_corner(struct dev_pm_opp *opp)
1026 {
1027 	struct device_node *np;
1028 	unsigned int fuse_corner = 0;
1029 
1030 	np = dev_pm_opp_get_of_node(opp);
1031 	if (of_property_read_u32(np, "qcom,opp-fuse-level", &fuse_corner))
1032 		pr_err("%s: missing 'qcom,opp-fuse-level' property\n",
1033 		       __func__);
1034 
1035 	of_node_put(np);
1036 
1037 	return fuse_corner;
1038 }
1039 
1040 static unsigned long cpr_get_opp_hz_for_req(struct dev_pm_opp *ref,
1041 					    struct device *cpu_dev)
1042 {
1043 	u64 rate = 0;
1044 	struct device_node *ref_np;
1045 	struct device_node *desc_np;
1046 	struct device_node *child_np = NULL;
1047 	struct device_node *child_req_np = NULL;
1048 
1049 	desc_np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
1050 	if (!desc_np)
1051 		return 0;
1052 
1053 	ref_np = dev_pm_opp_get_of_node(ref);
1054 	if (!ref_np)
1055 		goto out_ref;
1056 
1057 	do {
1058 		of_node_put(child_req_np);
1059 		child_np = of_get_next_available_child(desc_np, child_np);
1060 		child_req_np = of_parse_phandle(child_np, "required-opps", 0);
1061 	} while (child_np && child_req_np != ref_np);
1062 
1063 	if (child_np && child_req_np == ref_np)
1064 		of_property_read_u64(child_np, "opp-hz", &rate);
1065 
1066 	of_node_put(child_req_np);
1067 	of_node_put(child_np);
1068 	of_node_put(ref_np);
1069 out_ref:
1070 	of_node_put(desc_np);
1071 
1072 	return (unsigned long) rate;
1073 }
1074 
1075 static int cpr_corner_init(struct cpr_drv *drv)
1076 {
1077 	const struct cpr_desc *desc = drv->desc;
1078 	const struct cpr_fuse *fuses = drv->cpr_fuses;
1079 	int i, level, scaling = 0;
1080 	unsigned int fnum, fc;
1081 	const char *quot_offset;
1082 	struct fuse_corner *fuse, *prev_fuse;
1083 	struct corner *corner, *end;
1084 	struct corner_data *cdata;
1085 	const struct fuse_corner_data *fdata;
1086 	bool apply_scaling;
1087 	unsigned long freq_diff, freq_diff_mhz;
1088 	unsigned long freq;
1089 	int step_volt = regulator_get_linear_step(drv->vdd_apc);
1090 	struct dev_pm_opp *opp;
1091 
1092 	if (!step_volt)
1093 		return -EINVAL;
1094 
1095 	corner = drv->corners;
1096 	end = &corner[drv->num_corners - 1];
1097 
1098 	cdata = devm_kcalloc(drv->dev, drv->num_corners,
1099 			     sizeof(struct corner_data),
1100 			     GFP_KERNEL);
1101 	if (!cdata)
1102 		return -ENOMEM;
1103 
1104 	/*
1105 	 * Store maximum frequency for each fuse corner based on the frequency
1106 	 * plan
1107 	 */
1108 	for (level = 1; level <= drv->num_corners; level++) {
1109 		opp = dev_pm_opp_find_level_exact(&drv->pd.dev, level);
1110 		if (IS_ERR(opp))
1111 			return -EINVAL;
1112 		fc = cpr_get_fuse_corner(opp);
1113 		if (!fc) {
1114 			dev_pm_opp_put(opp);
1115 			return -EINVAL;
1116 		}
1117 		fnum = fc - 1;
1118 		freq = cpr_get_opp_hz_for_req(opp, drv->attached_cpu_dev);
1119 		if (!freq) {
1120 			dev_pm_opp_put(opp);
1121 			return -EINVAL;
1122 		}
1123 		cdata[level - 1].fuse_corner = fnum;
1124 		cdata[level - 1].freq = freq;
1125 
1126 		fuse = &drv->fuse_corners[fnum];
1127 		dev_dbg(drv->dev, "freq: %lu level: %u fuse level: %u\n",
1128 			freq, dev_pm_opp_get_level(opp) - 1, fnum);
1129 		if (freq > fuse->max_freq)
1130 			fuse->max_freq = freq;
1131 		dev_pm_opp_put(opp);
1132 	}
1133 
1134 	/*
1135 	 * Get the quotient adjustment scaling factor, according to:
1136 	 *
1137 	 * scaling = min(1000 * (QUOT(corner_N) - QUOT(corner_N-1))
1138 	 *		/ (freq(corner_N) - freq(corner_N-1)), max_factor)
1139 	 *
1140 	 * QUOT(corner_N):	quotient read from fuse for fuse corner N
1141 	 * QUOT(corner_N-1):	quotient read from fuse for fuse corner (N - 1)
1142 	 * freq(corner_N):	max frequency in MHz supported by fuse corner N
1143 	 * freq(corner_N-1):	max frequency in MHz supported by fuse corner
1144 	 *			 (N - 1)
1145 	 *
1146 	 * Then walk through the corners mapped to each fuse corner
1147 	 * and calculate the quotient adjustment for each one using the
1148 	 * following formula:
1149 	 *
1150 	 * quot_adjust = (freq_max - freq_corner) * scaling / 1000
1151 	 *
1152 	 * freq_max: max frequency in MHz supported by the fuse corner
1153 	 * freq_corner: frequency in MHz corresponding to the corner
1154 	 * scaling: calculated from above equation
1155 	 *
1156 	 *
1157 	 *     +                           +
1158 	 *     |                         v |
1159 	 *   q |           f c           o |           f c
1160 	 *   u |         c               l |         c
1161 	 *   o |       f                 t |       f
1162 	 *   t |     c                   a |     c
1163 	 *     | c f                     g | c f
1164 	 *     |                         e |
1165 	 *     +---------------            +----------------
1166 	 *       0 1 2 3 4 5 6               0 1 2 3 4 5 6
1167 	 *          corner                      corner
1168 	 *
1169 	 *    c = corner
1170 	 *    f = fuse corner
1171 	 *
1172 	 */
1173 	for (apply_scaling = false, i = 0; corner <= end; corner++, i++) {
1174 		fnum = cdata[i].fuse_corner;
1175 		fdata = &desc->cpr_fuses.fuse_corner_data[fnum];
1176 		quot_offset = fuses[fnum].quotient_offset;
1177 		fuse = &drv->fuse_corners[fnum];
1178 		if (fnum)
1179 			prev_fuse = &drv->fuse_corners[fnum - 1];
1180 		else
1181 			prev_fuse = NULL;
1182 
1183 		corner->fuse_corner = fuse;
1184 		corner->freq = cdata[i].freq;
1185 		corner->uV = fuse->uV;
1186 
1187 		if (prev_fuse && cdata[i - 1].freq == prev_fuse->max_freq) {
1188 			scaling = cpr_calculate_scaling(quot_offset, drv,
1189 							fdata, corner);
1190 			if (scaling < 0)
1191 				return scaling;
1192 
1193 			apply_scaling = true;
1194 		} else if (corner->freq == fuse->max_freq) {
1195 			/* This is a fuse corner; don't scale anything */
1196 			apply_scaling = false;
1197 		}
1198 
1199 		if (apply_scaling) {
1200 			freq_diff = fuse->max_freq - corner->freq;
1201 			freq_diff_mhz = freq_diff / 1000000;
1202 			corner->quot_adjust = scaling * freq_diff_mhz / 1000;
1203 
1204 			corner->uV = cpr_interpolate(corner, step_volt, fdata);
1205 		}
1206 
1207 		corner->max_uV = fuse->max_uV;
1208 		corner->min_uV = fuse->min_uV;
1209 		corner->uV = clamp(corner->uV, corner->min_uV, corner->max_uV);
1210 		corner->last_uV = corner->uV;
1211 
1212 		/* Reduce the ceiling voltage if needed */
1213 		if (desc->reduce_to_corner_uV && corner->uV < corner->max_uV)
1214 			corner->max_uV = corner->uV;
1215 		else if (desc->reduce_to_fuse_uV && fuse->uV < corner->max_uV)
1216 			corner->max_uV = max(corner->min_uV, fuse->uV);
1217 
1218 		dev_dbg(drv->dev, "corner %d: [%d %d %d] quot %d\n", i,
1219 			corner->min_uV, corner->uV, corner->max_uV,
1220 			fuse->quot - corner->quot_adjust);
1221 	}
1222 
1223 	return 0;
1224 }
1225 
1226 static const struct cpr_fuse *cpr_get_fuses(struct cpr_drv *drv)
1227 {
1228 	const struct cpr_desc *desc = drv->desc;
1229 	struct cpr_fuse *fuses;
1230 	int i;
1231 
1232 	fuses = devm_kcalloc(drv->dev, desc->num_fuse_corners,
1233 			     sizeof(struct cpr_fuse),
1234 			     GFP_KERNEL);
1235 	if (!fuses)
1236 		return ERR_PTR(-ENOMEM);
1237 
1238 	for (i = 0; i < desc->num_fuse_corners; i++) {
1239 		char tbuf[32];
1240 
1241 		snprintf(tbuf, 32, "cpr_ring_osc%d", i + 1);
1242 		fuses[i].ring_osc = devm_kstrdup(drv->dev, tbuf, GFP_KERNEL);
1243 		if (!fuses[i].ring_osc)
1244 			return ERR_PTR(-ENOMEM);
1245 
1246 		snprintf(tbuf, 32, "cpr_init_voltage%d", i + 1);
1247 		fuses[i].init_voltage = devm_kstrdup(drv->dev, tbuf,
1248 						     GFP_KERNEL);
1249 		if (!fuses[i].init_voltage)
1250 			return ERR_PTR(-ENOMEM);
1251 
1252 		snprintf(tbuf, 32, "cpr_quotient%d", i + 1);
1253 		fuses[i].quotient = devm_kstrdup(drv->dev, tbuf, GFP_KERNEL);
1254 		if (!fuses[i].quotient)
1255 			return ERR_PTR(-ENOMEM);
1256 
1257 		snprintf(tbuf, 32, "cpr_quotient_offset%d", i + 1);
1258 		fuses[i].quotient_offset = devm_kstrdup(drv->dev, tbuf,
1259 							GFP_KERNEL);
1260 		if (!fuses[i].quotient_offset)
1261 			return ERR_PTR(-ENOMEM);
1262 	}
1263 
1264 	return fuses;
1265 }
1266 
1267 static void cpr_set_loop_allowed(struct cpr_drv *drv)
1268 {
1269 	drv->loop_disabled = false;
1270 }
1271 
1272 static int cpr_init_parameters(struct cpr_drv *drv)
1273 {
1274 	const struct cpr_desc *desc = drv->desc;
1275 	struct clk *clk;
1276 
1277 	clk = clk_get(drv->dev, "ref");
1278 	if (IS_ERR(clk))
1279 		return PTR_ERR(clk);
1280 
1281 	drv->ref_clk_khz = clk_get_rate(clk) / 1000;
1282 	clk_put(clk);
1283 
1284 	if (desc->timer_cons_up > RBIF_TIMER_ADJ_CONS_UP_MASK ||
1285 	    desc->timer_cons_down > RBIF_TIMER_ADJ_CONS_DOWN_MASK ||
1286 	    desc->up_threshold > RBCPR_CTL_UP_THRESHOLD_MASK ||
1287 	    desc->down_threshold > RBCPR_CTL_DN_THRESHOLD_MASK ||
1288 	    desc->idle_clocks > RBCPR_STEP_QUOT_IDLE_CLK_MASK ||
1289 	    desc->clamp_timer_interval > RBIF_TIMER_ADJ_CLAMP_INT_MASK)
1290 		return -EINVAL;
1291 
1292 	dev_dbg(drv->dev, "up threshold = %u, down threshold = %u\n",
1293 		desc->up_threshold, desc->down_threshold);
1294 
1295 	return 0;
1296 }
1297 
1298 static int cpr_find_initial_corner(struct cpr_drv *drv)
1299 {
1300 	unsigned long rate;
1301 	const struct corner *end;
1302 	struct corner *iter;
1303 	unsigned int i = 0;
1304 
1305 	if (!drv->cpu_clk) {
1306 		dev_err(drv->dev, "cannot get rate from NULL clk\n");
1307 		return -EINVAL;
1308 	}
1309 
1310 	end = &drv->corners[drv->num_corners - 1];
1311 	rate = clk_get_rate(drv->cpu_clk);
1312 
1313 	/*
1314 	 * Some bootloaders set a CPU clock frequency that is not defined
1315 	 * in the OPP table. When running at an unlisted frequency,
1316 	 * cpufreq_online() will change to the OPP which has the lowest
1317 	 * frequency, at or above the unlisted frequency.
1318 	 * Since cpufreq_online() always "rounds up" in the case of an
1319 	 * unlisted frequency, this function always "rounds down" in case
1320 	 * of an unlisted frequency. That way, when cpufreq_online()
1321 	 * triggers the first ever call to cpr_set_performance_state(),
1322 	 * it will correctly determine the direction as UP.
1323 	 */
1324 	for (iter = drv->corners; iter <= end; iter++) {
1325 		if (iter->freq > rate)
1326 			break;
1327 		i++;
1328 		if (iter->freq == rate) {
1329 			drv->corner = iter;
1330 			break;
1331 		}
1332 		if (iter->freq < rate)
1333 			drv->corner = iter;
1334 	}
1335 
1336 	if (!drv->corner) {
1337 		dev_err(drv->dev, "boot up corner not found\n");
1338 		return -EINVAL;
1339 	}
1340 
1341 	dev_dbg(drv->dev, "boot up perf state: %u\n", i);
1342 
1343 	return 0;
1344 }
1345 
1346 static const struct cpr_desc qcs404_cpr_desc = {
1347 	.num_fuse_corners = 3,
1348 	.min_diff_quot = CPR_FUSE_MIN_QUOT_DIFF,
1349 	.step_quot = (int []){ 25, 25, 25, },
1350 	.timer_delay_us = 5000,
1351 	.timer_cons_up = 0,
1352 	.timer_cons_down = 2,
1353 	.up_threshold = 1,
1354 	.down_threshold = 3,
1355 	.idle_clocks = 15,
1356 	.gcnt_us = 1,
1357 	.vdd_apc_step_up_limit = 1,
1358 	.vdd_apc_step_down_limit = 1,
1359 	.cpr_fuses = {
1360 		.init_voltage_step = 8000,
1361 		.init_voltage_width = 6,
1362 		.fuse_corner_data = (struct fuse_corner_data[]){
1363 			/* fuse corner 0 */
1364 			{
1365 				.ref_uV = 1224000,
1366 				.max_uV = 1224000,
1367 				.min_uV = 1048000,
1368 				.max_volt_scale = 0,
1369 				.max_quot_scale = 0,
1370 				.quot_offset = 0,
1371 				.quot_scale = 1,
1372 				.quot_adjust = 0,
1373 				.quot_offset_scale = 5,
1374 				.quot_offset_adjust = 0,
1375 			},
1376 			/* fuse corner 1 */
1377 			{
1378 				.ref_uV = 1288000,
1379 				.max_uV = 1288000,
1380 				.min_uV = 1048000,
1381 				.max_volt_scale = 2000,
1382 				.max_quot_scale = 1400,
1383 				.quot_offset = 0,
1384 				.quot_scale = 1,
1385 				.quot_adjust = -20,
1386 				.quot_offset_scale = 5,
1387 				.quot_offset_adjust = 0,
1388 			},
1389 			/* fuse corner 2 */
1390 			{
1391 				.ref_uV = 1352000,
1392 				.max_uV = 1384000,
1393 				.min_uV = 1088000,
1394 				.max_volt_scale = 2000,
1395 				.max_quot_scale = 1400,
1396 				.quot_offset = 0,
1397 				.quot_scale = 1,
1398 				.quot_adjust = 0,
1399 				.quot_offset_scale = 5,
1400 				.quot_offset_adjust = 0,
1401 			},
1402 		},
1403 	},
1404 };
1405 
1406 static const struct acc_desc qcs404_acc_desc = {
1407 	.settings = (struct reg_sequence[]){
1408 		{ 0xb120, 0x1041040 },
1409 		{ 0xb124, 0x41 },
1410 		{ 0xb120, 0x0 },
1411 		{ 0xb124, 0x0 },
1412 		{ 0xb120, 0x0 },
1413 		{ 0xb124, 0x0 },
1414 	},
1415 	.config = (struct reg_sequence[]){
1416 		{ 0xb138, 0xff },
1417 		{ 0xb130, 0x5555 },
1418 	},
1419 	.num_regs_per_fuse = 2,
1420 };
1421 
1422 static const struct cpr_acc_desc qcs404_cpr_acc_desc = {
1423 	.cpr_desc = &qcs404_cpr_desc,
1424 	.acc_desc = &qcs404_acc_desc,
1425 };
1426 
1427 static unsigned int cpr_get_performance_state(struct generic_pm_domain *genpd,
1428 					      struct dev_pm_opp *opp)
1429 {
1430 	return dev_pm_opp_get_level(opp);
1431 }
1432 
1433 static int cpr_power_off(struct generic_pm_domain *domain)
1434 {
1435 	struct cpr_drv *drv = container_of(domain, struct cpr_drv, pd);
1436 
1437 	return cpr_disable(drv);
1438 }
1439 
1440 static int cpr_power_on(struct generic_pm_domain *domain)
1441 {
1442 	struct cpr_drv *drv = container_of(domain, struct cpr_drv, pd);
1443 
1444 	return cpr_enable(drv);
1445 }
1446 
1447 static int cpr_pd_attach_dev(struct generic_pm_domain *domain,
1448 			     struct device *dev)
1449 {
1450 	struct cpr_drv *drv = container_of(domain, struct cpr_drv, pd);
1451 	const struct acc_desc *acc_desc = drv->acc_desc;
1452 	int ret = 0;
1453 
1454 	mutex_lock(&drv->lock);
1455 
1456 	dev_dbg(drv->dev, "attach callback for: %s\n", dev_name(dev));
1457 
1458 	/*
1459 	 * This driver only supports scaling voltage for a CPU cluster
1460 	 * where all CPUs in the cluster share a single regulator.
1461 	 * Therefore, save the struct device pointer only for the first
1462 	 * CPU device that gets attached. There is no need to do any
1463 	 * additional initialization when further CPUs get attached.
1464 	 */
1465 	if (drv->attached_cpu_dev)
1466 		goto unlock;
1467 
1468 	/*
1469 	 * cpr_scale_voltage() requires the direction (if we are changing
1470 	 * to a higher or lower OPP). The first time
1471 	 * cpr_set_performance_state() is called, there is no previous
1472 	 * performance state defined. Therefore, we call
1473 	 * cpr_find_initial_corner() that gets the CPU clock frequency
1474 	 * set by the bootloader, so that we can determine the direction
1475 	 * the first time cpr_set_performance_state() is called.
1476 	 */
1477 	drv->cpu_clk = devm_clk_get(dev, NULL);
1478 	if (IS_ERR(drv->cpu_clk)) {
1479 		ret = PTR_ERR(drv->cpu_clk);
1480 		if (ret != -EPROBE_DEFER)
1481 			dev_err(drv->dev, "could not get cpu clk: %d\n", ret);
1482 		goto unlock;
1483 	}
1484 	drv->attached_cpu_dev = dev;
1485 
1486 	dev_dbg(drv->dev, "using cpu clk from: %s\n",
1487 		dev_name(drv->attached_cpu_dev));
1488 
1489 	/*
1490 	 * Everything related to (virtual) corners has to be initialized
1491 	 * here, when attaching to the power domain, since we need to know
1492 	 * the maximum frequency for each fuse corner, and this is only
1493 	 * available after the cpufreq driver has attached to us.
1494 	 * The reason for this is that we need to know the highest
1495 	 * frequency associated with each fuse corner.
1496 	 */
1497 	ret = dev_pm_opp_get_opp_count(&drv->pd.dev);
1498 	if (ret < 0) {
1499 		dev_err(drv->dev, "could not get OPP count\n");
1500 		goto unlock;
1501 	}
1502 	drv->num_corners = ret;
1503 
1504 	if (drv->num_corners < 2) {
1505 		dev_err(drv->dev, "need at least 2 OPPs to use CPR\n");
1506 		ret = -EINVAL;
1507 		goto unlock;
1508 	}
1509 
1510 	drv->corners = devm_kcalloc(drv->dev, drv->num_corners,
1511 				    sizeof(*drv->corners),
1512 				    GFP_KERNEL);
1513 	if (!drv->corners) {
1514 		ret = -ENOMEM;
1515 		goto unlock;
1516 	}
1517 
1518 	ret = cpr_corner_init(drv);
1519 	if (ret)
1520 		goto unlock;
1521 
1522 	cpr_set_loop_allowed(drv);
1523 
1524 	ret = cpr_init_parameters(drv);
1525 	if (ret)
1526 		goto unlock;
1527 
1528 	/* Configure CPR HW but keep it disabled */
1529 	ret = cpr_config(drv);
1530 	if (ret)
1531 		goto unlock;
1532 
1533 	ret = cpr_find_initial_corner(drv);
1534 	if (ret)
1535 		goto unlock;
1536 
1537 	if (acc_desc->config)
1538 		regmap_multi_reg_write(drv->tcsr, acc_desc->config,
1539 				       acc_desc->num_regs_per_fuse);
1540 
1541 	/* Enable ACC if required */
1542 	if (acc_desc->enable_mask)
1543 		regmap_update_bits(drv->tcsr, acc_desc->enable_reg,
1544 				   acc_desc->enable_mask,
1545 				   acc_desc->enable_mask);
1546 
1547 	dev_info(drv->dev, "driver initialized with %u OPPs\n",
1548 		 drv->num_corners);
1549 
1550 unlock:
1551 	mutex_unlock(&drv->lock);
1552 
1553 	return ret;
1554 }
1555 
1556 static int cpr_debug_info_show(struct seq_file *s, void *unused)
1557 {
1558 	u32 gcnt, ro_sel, ctl, irq_status, reg, error_steps;
1559 	u32 step_dn, step_up, error, error_lt0, busy;
1560 	struct cpr_drv *drv = s->private;
1561 	struct fuse_corner *fuse_corner;
1562 	struct corner *corner;
1563 
1564 	corner = drv->corner;
1565 	fuse_corner = corner->fuse_corner;
1566 
1567 	seq_printf(s, "corner, current_volt = %d uV\n",
1568 		       corner->last_uV);
1569 
1570 	ro_sel = fuse_corner->ring_osc_idx;
1571 	gcnt = cpr_read(drv, REG_RBCPR_GCNT_TARGET(ro_sel));
1572 	seq_printf(s, "rbcpr_gcnt_target (%u) = %#02X\n", ro_sel, gcnt);
1573 
1574 	ctl = cpr_read(drv, REG_RBCPR_CTL);
1575 	seq_printf(s, "rbcpr_ctl = %#02X\n", ctl);
1576 
1577 	irq_status = cpr_read(drv, REG_RBIF_IRQ_STATUS);
1578 	seq_printf(s, "rbcpr_irq_status = %#02X\n", irq_status);
1579 
1580 	reg = cpr_read(drv, REG_RBCPR_RESULT_0);
1581 	seq_printf(s, "rbcpr_result_0 = %#02X\n", reg);
1582 
1583 	step_dn = reg & 0x01;
1584 	step_up = (reg >> RBCPR_RESULT0_STEP_UP_SHIFT) & 0x01;
1585 	seq_printf(s, "  [step_dn = %u", step_dn);
1586 
1587 	seq_printf(s, ", step_up = %u", step_up);
1588 
1589 	error_steps = (reg >> RBCPR_RESULT0_ERROR_STEPS_SHIFT)
1590 				& RBCPR_RESULT0_ERROR_STEPS_MASK;
1591 	seq_printf(s, ", error_steps = %u", error_steps);
1592 
1593 	error = (reg >> RBCPR_RESULT0_ERROR_SHIFT) & RBCPR_RESULT0_ERROR_MASK;
1594 	seq_printf(s, ", error = %u", error);
1595 
1596 	error_lt0 = (reg >> RBCPR_RESULT0_ERROR_LT0_SHIFT) & 0x01;
1597 	seq_printf(s, ", error_lt_0 = %u", error_lt0);
1598 
1599 	busy = (reg >> RBCPR_RESULT0_BUSY_SHIFT) & 0x01;
1600 	seq_printf(s, ", busy = %u]\n", busy);
1601 
1602 	return 0;
1603 }
1604 DEFINE_SHOW_ATTRIBUTE(cpr_debug_info);
1605 
1606 static void cpr_debugfs_init(struct cpr_drv *drv)
1607 {
1608 	drv->debugfs = debugfs_create_dir("qcom_cpr", NULL);
1609 
1610 	debugfs_create_file("debug_info", 0444, drv->debugfs,
1611 			    drv, &cpr_debug_info_fops);
1612 }
1613 
1614 static int cpr_probe(struct platform_device *pdev)
1615 {
1616 	struct device *dev = &pdev->dev;
1617 	struct cpr_drv *drv;
1618 	int irq, ret;
1619 	const struct cpr_acc_desc *data;
1620 	struct device_node *np;
1621 	u32 cpr_rev = FUSE_REVISION_UNKNOWN;
1622 
1623 	data = of_device_get_match_data(dev);
1624 	if (!data || !data->cpr_desc || !data->acc_desc)
1625 		return -EINVAL;
1626 
1627 	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
1628 	if (!drv)
1629 		return -ENOMEM;
1630 	drv->dev = dev;
1631 	drv->desc = data->cpr_desc;
1632 	drv->acc_desc = data->acc_desc;
1633 
1634 	drv->fuse_corners = devm_kcalloc(dev, drv->desc->num_fuse_corners,
1635 					 sizeof(*drv->fuse_corners),
1636 					 GFP_KERNEL);
1637 	if (!drv->fuse_corners)
1638 		return -ENOMEM;
1639 
1640 	np = of_parse_phandle(dev->of_node, "acc-syscon", 0);
1641 	if (!np)
1642 		return -ENODEV;
1643 
1644 	drv->tcsr = syscon_node_to_regmap(np);
1645 	of_node_put(np);
1646 	if (IS_ERR(drv->tcsr))
1647 		return PTR_ERR(drv->tcsr);
1648 
1649 	drv->base = devm_platform_ioremap_resource(pdev, 0);
1650 	if (IS_ERR(drv->base))
1651 		return PTR_ERR(drv->base);
1652 
1653 	irq = platform_get_irq(pdev, 0);
1654 	if (irq < 0)
1655 		return -EINVAL;
1656 
1657 	drv->vdd_apc = devm_regulator_get(dev, "vdd-apc");
1658 	if (IS_ERR(drv->vdd_apc))
1659 		return PTR_ERR(drv->vdd_apc);
1660 
1661 	/*
1662 	 * Initialize fuse corners, since it simply depends
1663 	 * on data in efuses.
1664 	 * Everything related to (virtual) corners has to be
1665 	 * initialized after attaching to the power domain,
1666 	 * since it depends on the CPU's OPP table.
1667 	 */
1668 	ret = nvmem_cell_read_variable_le_u32(dev, "cpr_fuse_revision", &cpr_rev);
1669 	if (ret)
1670 		return ret;
1671 
1672 	drv->cpr_fuses = cpr_get_fuses(drv);
1673 	if (IS_ERR(drv->cpr_fuses))
1674 		return PTR_ERR(drv->cpr_fuses);
1675 
1676 	ret = cpr_populate_ring_osc_idx(drv);
1677 	if (ret)
1678 		return ret;
1679 
1680 	ret = cpr_fuse_corner_init(drv);
1681 	if (ret)
1682 		return ret;
1683 
1684 	mutex_init(&drv->lock);
1685 
1686 	ret = devm_request_threaded_irq(dev, irq, NULL,
1687 					cpr_irq_handler,
1688 					IRQF_ONESHOT | IRQF_TRIGGER_RISING,
1689 					"cpr", drv);
1690 	if (ret)
1691 		return ret;
1692 
1693 	drv->pd.name = devm_kstrdup_const(dev, dev->of_node->full_name,
1694 					  GFP_KERNEL);
1695 	if (!drv->pd.name)
1696 		return -EINVAL;
1697 
1698 	drv->pd.power_off = cpr_power_off;
1699 	drv->pd.power_on = cpr_power_on;
1700 	drv->pd.set_performance_state = cpr_set_performance_state;
1701 	drv->pd.opp_to_performance_state = cpr_get_performance_state;
1702 	drv->pd.attach_dev = cpr_pd_attach_dev;
1703 
1704 	ret = pm_genpd_init(&drv->pd, NULL, true);
1705 	if (ret)
1706 		return ret;
1707 
1708 	ret = of_genpd_add_provider_simple(dev->of_node, &drv->pd);
1709 	if (ret)
1710 		goto err_remove_genpd;
1711 
1712 	platform_set_drvdata(pdev, drv);
1713 	cpr_debugfs_init(drv);
1714 
1715 	return 0;
1716 
1717 err_remove_genpd:
1718 	pm_genpd_remove(&drv->pd);
1719 	return ret;
1720 }
1721 
1722 static int cpr_remove(struct platform_device *pdev)
1723 {
1724 	struct cpr_drv *drv = platform_get_drvdata(pdev);
1725 
1726 	if (cpr_is_allowed(drv)) {
1727 		cpr_ctl_disable(drv);
1728 		cpr_irq_set(drv, 0);
1729 	}
1730 
1731 	of_genpd_del_provider(pdev->dev.of_node);
1732 	pm_genpd_remove(&drv->pd);
1733 
1734 	debugfs_remove_recursive(drv->debugfs);
1735 
1736 	return 0;
1737 }
1738 
1739 static const struct of_device_id cpr_match_table[] = {
1740 	{ .compatible = "qcom,qcs404-cpr", .data = &qcs404_cpr_acc_desc },
1741 	{ }
1742 };
1743 MODULE_DEVICE_TABLE(of, cpr_match_table);
1744 
1745 static struct platform_driver cpr_driver = {
1746 	.probe		= cpr_probe,
1747 	.remove		= cpr_remove,
1748 	.driver		= {
1749 		.name	= "qcom-cpr",
1750 		.of_match_table = cpr_match_table,
1751 	},
1752 };
1753 module_platform_driver(cpr_driver);
1754 
1755 MODULE_DESCRIPTION("Core Power Reduction (CPR) driver");
1756 MODULE_LICENSE("GPL v2");
1757