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1/*
2 * Purna Chandra Mandal,<purna.mandal@microchip.com>
3 * Copyright (C) 2015 Microchip Technology Inc. All rights reserved.
4 *
5 * This program is free software; you can distribute it and/or modify it
6 * under the terms of the GNU General Public License (Version 2) as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
13 */
14#include <linux/clk-provider.h>
15#include <linux/delay.h>
16#include <linux/device.h>
17#include <linux/interrupt.h>
18#include <linux/iopoll.h>
19#include <asm/mach-pic32/pic32.h>
20#include <asm/traps.h>
21
22#include "clk-core.h"
23
24/* OSCCON Reg fields */
25#define OSC_CUR_MASK 0x07
26#define OSC_CUR_SHIFT 12
27#define OSC_NEW_MASK 0x07
28#define OSC_NEW_SHIFT 8
29#define OSC_SWEN BIT(0)
30
31/* SPLLCON Reg fields */
32#define PLL_RANGE_MASK 0x07
33#define PLL_RANGE_SHIFT 0
34#define PLL_ICLK_MASK 0x01
35#define PLL_ICLK_SHIFT 7
36#define PLL_IDIV_MASK 0x07
37#define PLL_IDIV_SHIFT 8
38#define PLL_ODIV_MASK 0x07
39#define PLL_ODIV_SHIFT 24
40#define PLL_MULT_MASK 0x7F
41#define PLL_MULT_SHIFT 16
42#define PLL_MULT_MAX 128
43#define PLL_ODIV_MIN 1
44#define PLL_ODIV_MAX 5
45
46/* Peripheral Bus Clock Reg Fields */
47#define PB_DIV_MASK 0x7f
48#define PB_DIV_SHIFT 0
49#define PB_DIV_READY BIT(11)
50#define PB_DIV_ENABLE BIT(15)
51#define PB_DIV_MAX 128
52#define PB_DIV_MIN 0
53
54/* Reference Oscillator Control Reg fields */
55#define REFO_SEL_MASK 0x0f
56#define REFO_SEL_SHIFT 0
57#define REFO_ACTIVE BIT(8)
58#define REFO_DIVSW_EN BIT(9)
59#define REFO_OE BIT(12)
60#define REFO_ON BIT(15)
61#define REFO_DIV_SHIFT 16
62#define REFO_DIV_MASK 0x7fff
63
64/* Reference Oscillator Trim Register Fields */
65#define REFO_TRIM_REG 0x10
66#define REFO_TRIM_MASK 0x1ff
67#define REFO_TRIM_SHIFT 23
68#define REFO_TRIM_MAX 511
69
70/* Mux Slew Control Register fields */
71#define SLEW_BUSY BIT(0)
72#define SLEW_DOWNEN BIT(1)
73#define SLEW_UPEN BIT(2)
74#define SLEW_DIV 0x07
75#define SLEW_DIV_SHIFT 8
76#define SLEW_SYSDIV 0x0f
77#define SLEW_SYSDIV_SHIFT 20
78
79/* Clock Poll Timeout */
80#define LOCK_TIMEOUT_US USEC_PER_MSEC
81
82/* SoC specific clock needed during SPLL clock rate switch */
83static struct clk_hw *pic32_sclk_hw;
84
85/* add instruction pipeline delay while CPU clock is in-transition. */
86#define cpu_nop5() \
87do { \
88 __asm__ __volatile__("nop"); \
89 __asm__ __volatile__("nop"); \
90 __asm__ __volatile__("nop"); \
91 __asm__ __volatile__("nop"); \
92 __asm__ __volatile__("nop"); \
93} while (0)
94
95/* Perpheral bus clocks */
96struct pic32_periph_clk {
97 struct clk_hw hw;
98 void __iomem *ctrl_reg;
99 struct pic32_clk_common *core;
100};
101
102#define clkhw_to_pbclk(_hw) container_of(_hw, struct pic32_periph_clk, hw)
103
104static int pbclk_is_enabled(struct clk_hw *hw)
105{
106 struct pic32_periph_clk *pb = clkhw_to_pbclk(hw);
107
108 return readl(pb->ctrl_reg) & PB_DIV_ENABLE;
109}
110
111static int pbclk_enable(struct clk_hw *hw)
112{
113 struct pic32_periph_clk *pb = clkhw_to_pbclk(hw);
114
115 writel(PB_DIV_ENABLE, PIC32_SET(pb->ctrl_reg));
116 return 0;
117}
118
119static void pbclk_disable(struct clk_hw *hw)
120{
121 struct pic32_periph_clk *pb = clkhw_to_pbclk(hw);
122
123 writel(PB_DIV_ENABLE, PIC32_CLR(pb->ctrl_reg));
124}
125
126static unsigned long calc_best_divided_rate(unsigned long rate,
127 unsigned long parent_rate,
128 u32 divider_max,
129 u32 divider_min)
130{
131 unsigned long divided_rate, divided_rate_down, best_rate;
132 unsigned long div, div_up;
133
134 /* eq. clk_rate = parent_rate / divider.
135 *
136 * Find best divider to produce closest of target divided rate.
137 */
138 div = parent_rate / rate;
139 div = clamp_val(div, divider_min, divider_max);
140 div_up = clamp_val(div + 1, divider_min, divider_max);
141
142 divided_rate = parent_rate / div;
143 divided_rate_down = parent_rate / div_up;
144 if (abs(rate - divided_rate_down) < abs(rate - divided_rate))
145 best_rate = divided_rate_down;
146 else
147 best_rate = divided_rate;
148
149 return best_rate;
150}
151
152static inline u32 pbclk_read_pbdiv(struct pic32_periph_clk *pb)
153{
154 return ((readl(pb->ctrl_reg) >> PB_DIV_SHIFT) & PB_DIV_MASK) + 1;
155}
156
157static unsigned long pbclk_recalc_rate(struct clk_hw *hw,
158 unsigned long parent_rate)
159{
160 struct pic32_periph_clk *pb = clkhw_to_pbclk(hw);
161
162 return parent_rate / pbclk_read_pbdiv(pb);
163}
164
165static long pbclk_round_rate(struct clk_hw *hw, unsigned long rate,
166 unsigned long *parent_rate)
167{
168 return calc_best_divided_rate(rate, *parent_rate,
169 PB_DIV_MAX, PB_DIV_MIN);
170}
171
172static int pbclk_set_rate(struct clk_hw *hw, unsigned long rate,
173 unsigned long parent_rate)
174{
175 struct pic32_periph_clk *pb = clkhw_to_pbclk(hw);
176 unsigned long flags;
177 u32 v, div;
178 int err;
179
180 /* check & wait for DIV_READY */
181 err = readl_poll_timeout(pb->ctrl_reg, v, v & PB_DIV_READY,
182 1, LOCK_TIMEOUT_US);
183 if (err)
184 return err;
185
186 /* calculate clkdiv and best rate */
187 div = DIV_ROUND_CLOSEST(parent_rate, rate);
188
189 spin_lock_irqsave(&pb->core->reg_lock, flags);
190
191 /* apply new div */
192 v = readl(pb->ctrl_reg);
193 v &= ~PB_DIV_MASK;
194 v |= (div - 1);
195
196 pic32_syskey_unlock();
197
198 writel(v, pb->ctrl_reg);
199
200 spin_unlock_irqrestore(&pb->core->reg_lock, flags);
201
202 /* wait again for DIV_READY */
203 err = readl_poll_timeout(pb->ctrl_reg, v, v & PB_DIV_READY,
204 1, LOCK_TIMEOUT_US);
205 if (err)
206 return err;
207
208 /* confirm that new div is applied correctly */
209 return (pbclk_read_pbdiv(pb) == div) ? 0 : -EBUSY;
210}
211
212const struct clk_ops pic32_pbclk_ops = {
213 .enable = pbclk_enable,
214 .disable = pbclk_disable,
215 .is_enabled = pbclk_is_enabled,
216 .recalc_rate = pbclk_recalc_rate,
217 .round_rate = pbclk_round_rate,
218 .set_rate = pbclk_set_rate,
219};
220
221struct clk *pic32_periph_clk_register(const struct pic32_periph_clk_data *desc,
222 struct pic32_clk_common *core)
223{
224 struct pic32_periph_clk *pbclk;
225 struct clk *clk;
226
227 pbclk = devm_kzalloc(core->dev, sizeof(*pbclk), GFP_KERNEL);
228 if (!pbclk)
229 return ERR_PTR(-ENOMEM);
230
231 pbclk->hw.init = &desc->init_data;
232 pbclk->core = core;
233 pbclk->ctrl_reg = desc->ctrl_reg + core->iobase;
234
235 clk = devm_clk_register(core->dev, &pbclk->hw);
236 if (IS_ERR(clk)) {
237 dev_err(core->dev, "%s: clk_register() failed\n", __func__);
238 devm_kfree(core->dev, pbclk);
239 }
240
241 return clk;
242}
243
244/* Reference oscillator operations */
245struct pic32_ref_osc {
246 struct clk_hw hw;
247 void __iomem *ctrl_reg;
248 const u32 *parent_map;
249 struct pic32_clk_common *core;
250};
251
252#define clkhw_to_refosc(_hw) container_of(_hw, struct pic32_ref_osc, hw)
253
254static int roclk_is_enabled(struct clk_hw *hw)
255{
256 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
257
258 return readl(refo->ctrl_reg) & REFO_ON;
259}
260
261static int roclk_enable(struct clk_hw *hw)
262{
263 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
264
265 writel(REFO_ON | REFO_OE, PIC32_SET(refo->ctrl_reg));
266 return 0;
267}
268
269static void roclk_disable(struct clk_hw *hw)
270{
271 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
272
273 writel(REFO_ON | REFO_OE, PIC32_CLR(refo->ctrl_reg));
274}
275
276static void roclk_init(struct clk_hw *hw)
277{
278 /* initialize clock in disabled state */
279 roclk_disable(hw);
280}
281
282static u8 roclk_get_parent(struct clk_hw *hw)
283{
284 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
285 u32 v, i;
286
287 v = (readl(refo->ctrl_reg) >> REFO_SEL_SHIFT) & REFO_SEL_MASK;
288
289 if (!refo->parent_map)
290 return v;
291
292 for (i = 0; i < clk_hw_get_num_parents(hw); i++)
293 if (refo->parent_map[i] == v)
294 return i;
295
296 return -EINVAL;
297}
298
299static unsigned long roclk_calc_rate(unsigned long parent_rate,
300 u32 rodiv, u32 rotrim)
301{
302 u64 rate64;
303
304 /* fout = fin / [2 * {div + (trim / 512)}]
305 * = fin * 512 / [1024 * div + 2 * trim]
306 * = fin * 256 / (512 * div + trim)
307 * = (fin << 8) / ((div << 9) + trim)
308 */
309 if (rotrim) {
310 rodiv = (rodiv << 9) + rotrim;
311 rate64 = parent_rate;
312 rate64 <<= 8;
313 do_div(rate64, rodiv);
314 } else if (rodiv) {
315 rate64 = parent_rate / (rodiv << 1);
316 } else {
317 rate64 = parent_rate;
318 }
319 return rate64;
320}
321
322static void roclk_calc_div_trim(unsigned long rate,
323 unsigned long parent_rate,
324 u32 *rodiv_p, u32 *rotrim_p)
325{
326 u32 div, rotrim, rodiv;
327 u64 frac;
328
329 /* Find integer approximation of floating-point arithmetic.
330 * fout = fin / [2 * {rodiv + (rotrim / 512)}] ... (1)
331 * i.e. fout = fin / 2 * DIV
332 * whereas DIV = rodiv + (rotrim / 512)
333 *
334 * Since kernel does not perform floating-point arithmatic so
335 * (rotrim/512) will be zero. And DIV & rodiv will result same.
336 *
337 * ie. fout = (fin * 256) / [(512 * rodiv) + rotrim] ... from (1)
338 * ie. rotrim = ((fin * 256) / fout) - (512 * DIV)
339 */
340 if (parent_rate <= rate) {
341 div = 0;
342 frac = 0;
343 rodiv = 0;
344 rotrim = 0;
345 } else {
346 div = parent_rate / (rate << 1);
347 frac = parent_rate;
348 frac <<= 8;
349 do_div(frac, rate);
350 frac -= (u64)(div << 9);
351
352 rodiv = (div > REFO_DIV_MASK) ? REFO_DIV_MASK : div;
353 rotrim = (frac >= REFO_TRIM_MAX) ? REFO_TRIM_MAX : frac;
354 }
355
356 if (rodiv_p)
357 *rodiv_p = rodiv;
358
359 if (rotrim_p)
360 *rotrim_p = rotrim;
361}
362
363static unsigned long roclk_recalc_rate(struct clk_hw *hw,
364 unsigned long parent_rate)
365{
366 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
367 u32 v, rodiv, rotrim;
368
369 /* get rodiv */
370 v = readl(refo->ctrl_reg);
371 rodiv = (v >> REFO_DIV_SHIFT) & REFO_DIV_MASK;
372
373 /* get trim */
374 v = readl(refo->ctrl_reg + REFO_TRIM_REG);
375 rotrim = (v >> REFO_TRIM_SHIFT) & REFO_TRIM_MASK;
376
377 return roclk_calc_rate(parent_rate, rodiv, rotrim);
378}
379
380static long roclk_round_rate(struct clk_hw *hw, unsigned long rate,
381 unsigned long *parent_rate)
382{
383 u32 rotrim, rodiv;
384
385 /* calculate dividers for new rate */
386 roclk_calc_div_trim(rate, *parent_rate, &rodiv, &rotrim);
387
388 /* caclulate new rate (rounding) based on new rodiv & rotrim */
389 return roclk_calc_rate(*parent_rate, rodiv, rotrim);
390}
391
392static int roclk_determine_rate(struct clk_hw *hw,
393 struct clk_rate_request *req)
394{
395 struct clk_hw *parent_clk, *best_parent_clk = NULL;
396 unsigned int i, delta, best_delta = -1;
397 unsigned long parent_rate, best_parent_rate = 0;
398 unsigned long best = 0, nearest_rate;
399
400 /* find a parent which can generate nearest clkrate >= rate */
401 for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
402 /* get parent */
403 parent_clk = clk_hw_get_parent_by_index(hw, i);
404 if (!parent_clk)
405 continue;
406
407 /* skip if parent runs slower than target rate */
408 parent_rate = clk_hw_get_rate(parent_clk);
409 if (req->rate > parent_rate)
410 continue;
411
412 nearest_rate = roclk_round_rate(hw, req->rate, &parent_rate);
413 delta = abs(nearest_rate - req->rate);
414 if ((nearest_rate >= req->rate) && (delta < best_delta)) {
415 best_parent_clk = parent_clk;
416 best_parent_rate = parent_rate;
417 best = nearest_rate;
418 best_delta = delta;
419
420 if (delta == 0)
421 break;
422 }
423 }
424
425 /* if no match found, retain old rate */
426 if (!best_parent_clk) {
427 pr_err("%s:%s, no parent found for rate %lu.\n",
428 __func__, clk_hw_get_name(hw), req->rate);
429 return clk_hw_get_rate(hw);
430 }
431
432 pr_debug("%s,rate %lu, best_parent(%s, %lu), best %lu, delta %d\n",
433 clk_hw_get_name(hw), req->rate,
434 clk_hw_get_name(best_parent_clk), best_parent_rate,
435 best, best_delta);
436
437 if (req->best_parent_rate)
438 req->best_parent_rate = best_parent_rate;
439
440 if (req->best_parent_hw)
441 req->best_parent_hw = best_parent_clk;
442
443 return best;
444}
445
446static int roclk_set_parent(struct clk_hw *hw, u8 index)
447{
448 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
449 unsigned long flags;
450 u32 v;
451 int err;
452
453 if (refo->parent_map)
454 index = refo->parent_map[index];
455
456 /* wait until ACTIVE bit is zero or timeout */
457 err = readl_poll_timeout(refo->ctrl_reg, v, !(v & REFO_ACTIVE),
458 1, LOCK_TIMEOUT_US);
459 if (err) {
460 pr_err("%s: poll failed, clk active\n", clk_hw_get_name(hw));
461 return err;
462 }
463
464 spin_lock_irqsave(&refo->core->reg_lock, flags);
465
466 pic32_syskey_unlock();
467
468 /* calculate & apply new */
469 v = readl(refo->ctrl_reg);
470 v &= ~(REFO_SEL_MASK << REFO_SEL_SHIFT);
471 v |= index << REFO_SEL_SHIFT;
472
473 writel(v, refo->ctrl_reg);
474
475 spin_unlock_irqrestore(&refo->core->reg_lock, flags);
476
477 return 0;
478}
479
480static int roclk_set_rate_and_parent(struct clk_hw *hw,
481 unsigned long rate,
482 unsigned long parent_rate,
483 u8 index)
484{
485 struct pic32_ref_osc *refo = clkhw_to_refosc(hw);
486 unsigned long flags;
487 u32 trim, rodiv, v;
488 int err;
489
490 /* calculate new rodiv & rotrim for new rate */
491 roclk_calc_div_trim(rate, parent_rate, &rodiv, &trim);
492
493 pr_debug("parent_rate = %lu, rate = %lu, div = %d, trim = %d\n",
494 parent_rate, rate, rodiv, trim);
495
496 /* wait till source change is active */
497 err = readl_poll_timeout(refo->ctrl_reg, v,
498 !(v & (REFO_ACTIVE | REFO_DIVSW_EN)),
499 1, LOCK_TIMEOUT_US);
500 if (err) {
501 pr_err("%s: poll timedout, clock is still active\n", __func__);
502 return err;
503 }
504
505 spin_lock_irqsave(&refo->core->reg_lock, flags);
506 v = readl(refo->ctrl_reg);
507
508 pic32_syskey_unlock();
509
510 /* apply parent, if required */
511 if (refo->parent_map)
512 index = refo->parent_map[index];
513
514 v &= ~(REFO_SEL_MASK << REFO_SEL_SHIFT);
515 v |= index << REFO_SEL_SHIFT;
516
517 /* apply RODIV */
518 v &= ~(REFO_DIV_MASK << REFO_DIV_SHIFT);
519 v |= rodiv << REFO_DIV_SHIFT;
520 writel(v, refo->ctrl_reg);
521
522 /* apply ROTRIM */
523 v = readl(refo->ctrl_reg + REFO_TRIM_REG);
524 v &= ~(REFO_TRIM_MASK << REFO_TRIM_SHIFT);
525 v |= trim << REFO_TRIM_SHIFT;
526 writel(v, refo->ctrl_reg + REFO_TRIM_REG);
527
528 /* enable & activate divider switching */
529 writel(REFO_ON | REFO_DIVSW_EN, PIC32_SET(refo->ctrl_reg));
530
531 /* wait till divswen is in-progress */
532 err = readl_poll_timeout_atomic(refo->ctrl_reg, v, !(v & REFO_DIVSW_EN),
533 1, LOCK_TIMEOUT_US);
534 /* leave the clk gated as it was */
535 writel(REFO_ON, PIC32_CLR(refo->ctrl_reg));
536
537 spin_unlock_irqrestore(&refo->core->reg_lock, flags);
538
539 return err;
540}
541
542static int roclk_set_rate(struct clk_hw *hw, unsigned long rate,
543 unsigned long parent_rate)
544{
545 u8 index = roclk_get_parent(hw);
546
547 return roclk_set_rate_and_parent(hw, rate, parent_rate, index);
548}
549
550const struct clk_ops pic32_roclk_ops = {
551 .enable = roclk_enable,
552 .disable = roclk_disable,
553 .is_enabled = roclk_is_enabled,
554 .get_parent = roclk_get_parent,
555 .set_parent = roclk_set_parent,
556 .determine_rate = roclk_determine_rate,
557 .recalc_rate = roclk_recalc_rate,
558 .set_rate_and_parent = roclk_set_rate_and_parent,
559 .set_rate = roclk_set_rate,
560 .init = roclk_init,
561};
562
563struct clk *pic32_refo_clk_register(const struct pic32_ref_osc_data *data,
564 struct pic32_clk_common *core)
565{
566 struct pic32_ref_osc *refo;
567 struct clk *clk;
568
569 refo = devm_kzalloc(core->dev, sizeof(*refo), GFP_KERNEL);
570 if (!refo)
571 return ERR_PTR(-ENOMEM);
572
573 refo->core = core;
574 refo->hw.init = &data->init_data;
575 refo->ctrl_reg = data->ctrl_reg + core->iobase;
576 refo->parent_map = data->parent_map;
577
578 clk = devm_clk_register(core->dev, &refo->hw);
579 if (IS_ERR(clk))
580 dev_err(core->dev, "%s: clk_register() failed\n", __func__);
581
582 return clk;
583}
584
585struct pic32_sys_pll {
586 struct clk_hw hw;
587 void __iomem *ctrl_reg;
588 void __iomem *status_reg;
589 u32 lock_mask;
590 u32 idiv; /* PLL iclk divider, treated fixed */
591 struct pic32_clk_common *core;
592};
593
594#define clkhw_to_spll(_hw) container_of(_hw, struct pic32_sys_pll, hw)
595
596static inline u32 spll_odiv_to_divider(u32 odiv)
597{
598 odiv = clamp_val(odiv, PLL_ODIV_MIN, PLL_ODIV_MAX);
599
600 return 1 << odiv;
601}
602
603static unsigned long spll_calc_mult_div(struct pic32_sys_pll *pll,
604 unsigned long rate,
605 unsigned long parent_rate,
606 u32 *mult_p, u32 *odiv_p)
607{
608 u32 mul, div, best_mul = 1, best_div = 1;
609 unsigned long new_rate, best_rate = rate;
610 unsigned int best_delta = -1, delta, match_found = 0;
611 u64 rate64;
612
613 parent_rate /= pll->idiv;
614
615 for (mul = 1; mul <= PLL_MULT_MAX; mul++) {
616 for (div = PLL_ODIV_MIN; div <= PLL_ODIV_MAX; div++) {
617 rate64 = parent_rate;
618 rate64 *= mul;
619 do_div(rate64, 1 << div);
620 new_rate = rate64;
621 delta = abs(rate - new_rate);
622 if ((new_rate >= rate) && (delta < best_delta)) {
623 best_delta = delta;
624 best_rate = new_rate;
625 best_mul = mul;
626 best_div = div;
627 match_found = 1;
628 }
629 }
630 }
631
632 if (!match_found) {
633 pr_warn("spll: no match found\n");
634 return 0;
635 }
636
637 pr_debug("rate %lu, par_rate %lu/mult %u, div %u, best_rate %lu\n",
638 rate, parent_rate, best_mul, best_div, best_rate);
639
640 if (mult_p)
641 *mult_p = best_mul - 1;
642
643 if (odiv_p)
644 *odiv_p = best_div;
645
646 return best_rate;
647}
648
649static unsigned long spll_clk_recalc_rate(struct clk_hw *hw,
650 unsigned long parent_rate)
651{
652 struct pic32_sys_pll *pll = clkhw_to_spll(hw);
653 unsigned long pll_in_rate;
654 u32 mult, odiv, div, v;
655 u64 rate64;
656
657 v = readl(pll->ctrl_reg);
658 odiv = ((v >> PLL_ODIV_SHIFT) & PLL_ODIV_MASK);
659 mult = ((v >> PLL_MULT_SHIFT) & PLL_MULT_MASK) + 1;
660 div = spll_odiv_to_divider(odiv);
661
662 /* pll_in_rate = parent_rate / idiv
663 * pll_out_rate = pll_in_rate * mult / div;
664 */
665 pll_in_rate = parent_rate / pll->idiv;
666 rate64 = pll_in_rate;
667 rate64 *= mult;
668 do_div(rate64, div);
669
670 return rate64;
671}
672
673static long spll_clk_round_rate(struct clk_hw *hw, unsigned long rate,
674 unsigned long *parent_rate)
675{
676 struct pic32_sys_pll *pll = clkhw_to_spll(hw);
677
678 return spll_calc_mult_div(pll, rate, *parent_rate, NULL, NULL);
679}
680
681static int spll_clk_set_rate(struct clk_hw *hw, unsigned long rate,
682 unsigned long parent_rate)
683{
684 struct pic32_sys_pll *pll = clkhw_to_spll(hw);
685 unsigned long ret, flags;
686 u32 mult, odiv, v;
687 int err;
688
689 ret = spll_calc_mult_div(pll, rate, parent_rate, &mult, &odiv);
690 if (!ret)
691 return -EINVAL;
692
693 /*
694 * We can't change SPLL counters when it is in-active use
695 * by SYSCLK. So check before applying new counters/rate.
696 */
697
698 /* Is spll_clk active parent of sys_clk ? */
699 if (unlikely(clk_hw_get_parent(pic32_sclk_hw) == hw)) {
700 pr_err("%s: failed, clk in-use\n", __func__);
701 return -EBUSY;
702 }
703
704 spin_lock_irqsave(&pll->core->reg_lock, flags);
705
706 /* apply new multiplier & divisor */
707 v = readl(pll->ctrl_reg);
708 v &= ~(PLL_MULT_MASK << PLL_MULT_SHIFT);
709 v &= ~(PLL_ODIV_MASK << PLL_ODIV_SHIFT);
710 v |= (mult << PLL_MULT_SHIFT) | (odiv << PLL_ODIV_SHIFT);
711
712 /* sys unlock before write */
713 pic32_syskey_unlock();
714
715 writel(v, pll->ctrl_reg);
716 cpu_relax();
717
718 /* insert few nops (5-stage) to ensure CPU does not hang */
719 cpu_nop5();
720 cpu_nop5();
721
722 /* Wait until PLL is locked (maximum 100 usecs). */
723 err = readl_poll_timeout_atomic(pll->status_reg, v,
724 v & pll->lock_mask, 1, 100);
725 spin_unlock_irqrestore(&pll->core->reg_lock, flags);
726
727 return err;
728}
729
730/* SPLL clock operation */
731const struct clk_ops pic32_spll_ops = {
732 .recalc_rate = spll_clk_recalc_rate,
733 .round_rate = spll_clk_round_rate,
734 .set_rate = spll_clk_set_rate,
735};
736
737struct clk *pic32_spll_clk_register(const struct pic32_sys_pll_data *data,
738 struct pic32_clk_common *core)
739{
740 struct pic32_sys_pll *spll;
741 struct clk *clk;
742
743 spll = devm_kzalloc(core->dev, sizeof(*spll), GFP_KERNEL);
744 if (!spll)
745 return ERR_PTR(-ENOMEM);
746
747 spll->core = core;
748 spll->hw.init = &data->init_data;
749 spll->ctrl_reg = data->ctrl_reg + core->iobase;
750 spll->status_reg = data->status_reg + core->iobase;
751 spll->lock_mask = data->lock_mask;
752
753 /* cache PLL idiv; PLL driver uses it as constant.*/
754 spll->idiv = (readl(spll->ctrl_reg) >> PLL_IDIV_SHIFT) & PLL_IDIV_MASK;
755 spll->idiv += 1;
756
757 clk = devm_clk_register(core->dev, &spll->hw);
758 if (IS_ERR(clk))
759 dev_err(core->dev, "sys_pll: clk_register() failed\n");
760
761 return clk;
762}
763
764/* System mux clock(aka SCLK) */
765
766struct pic32_sys_clk {
767 struct clk_hw hw;
768 void __iomem *mux_reg;
769 void __iomem *slew_reg;
770 u32 slew_div;
771 const u32 *parent_map;
772 struct pic32_clk_common *core;
773};
774
775#define clkhw_to_sys_clk(_hw) container_of(_hw, struct pic32_sys_clk, hw)
776
777static unsigned long sclk_get_rate(struct clk_hw *hw, unsigned long parent_rate)
778{
779 struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw);
780 u32 div;
781
782 div = (readl(sclk->slew_reg) >> SLEW_SYSDIV_SHIFT) & SLEW_SYSDIV;
783 div += 1; /* sys-div to divider */
784
785 return parent_rate / div;
786}
787
788static long sclk_round_rate(struct clk_hw *hw, unsigned long rate,
789 unsigned long *parent_rate)
790{
791 return calc_best_divided_rate(rate, *parent_rate, SLEW_SYSDIV, 1);
792}
793
794static int sclk_set_rate(struct clk_hw *hw,
795 unsigned long rate, unsigned long parent_rate)
796{
797 struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw);
798 unsigned long flags;
799 u32 v, div;
800 int err;
801
802 div = parent_rate / rate;
803
804 spin_lock_irqsave(&sclk->core->reg_lock, flags);
805
806 /* apply new div */
807 v = readl(sclk->slew_reg);
808 v &= ~(SLEW_SYSDIV << SLEW_SYSDIV_SHIFT);
809 v |= (div - 1) << SLEW_SYSDIV_SHIFT;
810
811 pic32_syskey_unlock();
812
813 writel(v, sclk->slew_reg);
814
815 /* wait until BUSY is cleared */
816 err = readl_poll_timeout_atomic(sclk->slew_reg, v,
817 !(v & SLEW_BUSY), 1, LOCK_TIMEOUT_US);
818
819 spin_unlock_irqrestore(&sclk->core->reg_lock, flags);
820
821 return err;
822}
823
824static u8 sclk_get_parent(struct clk_hw *hw)
825{
826 struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw);
827 u32 i, v;
828
829 v = (readl(sclk->mux_reg) >> OSC_CUR_SHIFT) & OSC_CUR_MASK;
830
831 if (!sclk->parent_map)
832 return v;
833
834 for (i = 0; i < clk_hw_get_num_parents(hw); i++)
835 if (sclk->parent_map[i] == v)
836 return i;
837 return -EINVAL;
838}
839
840static int sclk_set_parent(struct clk_hw *hw, u8 index)
841{
842 struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw);
843 unsigned long flags;
844 u32 nosc, cosc, v;
845 int err;
846
847 spin_lock_irqsave(&sclk->core->reg_lock, flags);
848
849 /* find new_osc */
850 nosc = sclk->parent_map ? sclk->parent_map[index] : index;
851
852 /* set new parent */
853 v = readl(sclk->mux_reg);
854 v &= ~(OSC_NEW_MASK << OSC_NEW_SHIFT);
855 v |= nosc << OSC_NEW_SHIFT;
856
857 pic32_syskey_unlock();
858
859 writel(v, sclk->mux_reg);
860
861 /* initate switch */
862 writel(OSC_SWEN, PIC32_SET(sclk->mux_reg));
863 cpu_relax();
864
865 /* add nop to flush pipeline (as cpu_clk is in-flux) */
866 cpu_nop5();
867
868 /* wait for SWEN bit to clear */
869 err = readl_poll_timeout_atomic(sclk->slew_reg, v,
870 !(v & OSC_SWEN), 1, LOCK_TIMEOUT_US);
871
872 spin_unlock_irqrestore(&sclk->core->reg_lock, flags);
873
874 /*
875 * SCLK clock-switching logic might reject a clock switching request
876 * if pre-requisites (like new clk_src not present or unstable) are
877 * not met.
878 * So confirm before claiming success.
879 */
880 cosc = (readl(sclk->mux_reg) >> OSC_CUR_SHIFT) & OSC_CUR_MASK;
881 if (cosc != nosc) {
882 pr_err("%s: err, failed to set_parent() to %d, current %d\n",
883 clk_hw_get_name(hw), nosc, cosc);
884 err = -EBUSY;
885 }
886
887 return err;
888}
889
890static void sclk_init(struct clk_hw *hw)
891{
892 struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw);
893 unsigned long flags;
894 u32 v;
895
896 /* Maintain reference to this clk, required in spll_clk_set_rate() */
897 pic32_sclk_hw = hw;
898
899 /* apply slew divider on both up and down scaling */
900 if (sclk->slew_div) {
901 spin_lock_irqsave(&sclk->core->reg_lock, flags);
902 v = readl(sclk->slew_reg);
903 v &= ~(SLEW_DIV << SLEW_DIV_SHIFT);
904 v |= sclk->slew_div << SLEW_DIV_SHIFT;
905 v |= SLEW_DOWNEN | SLEW_UPEN;
906 writel(v, sclk->slew_reg);
907 spin_unlock_irqrestore(&sclk->core->reg_lock, flags);
908 }
909}
910
911/* sclk with post-divider */
912const struct clk_ops pic32_sclk_ops = {
913 .get_parent = sclk_get_parent,
914 .set_parent = sclk_set_parent,
915 .round_rate = sclk_round_rate,
916 .set_rate = sclk_set_rate,
917 .recalc_rate = sclk_get_rate,
918 .init = sclk_init,
919 .determine_rate = __clk_mux_determine_rate,
920};
921
922/* sclk with no slew and no post-divider */
923const struct clk_ops pic32_sclk_no_div_ops = {
924 .get_parent = sclk_get_parent,
925 .set_parent = sclk_set_parent,
926 .init = sclk_init,
927 .determine_rate = __clk_mux_determine_rate,
928};
929
930struct clk *pic32_sys_clk_register(const struct pic32_sys_clk_data *data,
931 struct pic32_clk_common *core)
932{
933 struct pic32_sys_clk *sclk;
934 struct clk *clk;
935
936 sclk = devm_kzalloc(core->dev, sizeof(*sclk), GFP_KERNEL);
937 if (!sclk)
938 return ERR_PTR(-ENOMEM);
939
940 sclk->core = core;
941 sclk->hw.init = &data->init_data;
942 sclk->mux_reg = data->mux_reg + core->iobase;
943 sclk->slew_reg = data->slew_reg + core->iobase;
944 sclk->slew_div = data->slew_div;
945 sclk->parent_map = data->parent_map;
946
947 clk = devm_clk_register(core->dev, &sclk->hw);
948 if (IS_ERR(clk))
949 dev_err(core->dev, "%s: clk register failed\n", __func__);
950
951 return clk;
952}
953
954/* secondary oscillator */
955struct pic32_sec_osc {
956 struct clk_hw hw;
957 void __iomem *enable_reg;
958 void __iomem *status_reg;
959 u32 enable_mask;
960 u32 status_mask;
961 unsigned long fixed_rate;
962 struct pic32_clk_common *core;
963};
964
965#define clkhw_to_sosc(_hw) container_of(_hw, struct pic32_sec_osc, hw)
966static int sosc_clk_enable(struct clk_hw *hw)
967{
968 struct pic32_sec_osc *sosc = clkhw_to_sosc(hw);
969 u32 v;
970
971 /* enable SOSC */
972 pic32_syskey_unlock();
973 writel(sosc->enable_mask, PIC32_SET(sosc->enable_reg));
974
975 /* wait till warm-up period expires or ready-status is updated */
976 return readl_poll_timeout_atomic(sosc->status_reg, v,
977 v & sosc->status_mask, 1, 100);
978}
979
980static void sosc_clk_disable(struct clk_hw *hw)
981{
982 struct pic32_sec_osc *sosc = clkhw_to_sosc(hw);
983
984 pic32_syskey_unlock();
985 writel(sosc->enable_mask, PIC32_CLR(sosc->enable_reg));
986}
987
988static int sosc_clk_is_enabled(struct clk_hw *hw)
989{
990 struct pic32_sec_osc *sosc = clkhw_to_sosc(hw);
991 u32 enabled, ready;
992
993 /* check enabled and ready status */
994 enabled = readl(sosc->enable_reg) & sosc->enable_mask;
995 ready = readl(sosc->status_reg) & sosc->status_mask;
996
997 return enabled && ready;
998}
999
1000static unsigned long sosc_clk_calc_rate(struct clk_hw *hw,
1001 unsigned long parent_rate)
1002{
1003 return clkhw_to_sosc(hw)->fixed_rate;
1004}
1005
1006const struct clk_ops pic32_sosc_ops = {
1007 .enable = sosc_clk_enable,
1008 .disable = sosc_clk_disable,
1009 .is_enabled = sosc_clk_is_enabled,
1010 .recalc_rate = sosc_clk_calc_rate,
1011};
1012
1013struct clk *pic32_sosc_clk_register(const struct pic32_sec_osc_data *data,
1014 struct pic32_clk_common *core)
1015{
1016 struct pic32_sec_osc *sosc;
1017
1018 sosc = devm_kzalloc(core->dev, sizeof(*sosc), GFP_KERNEL);
1019 if (!sosc)
1020 return ERR_PTR(-ENOMEM);
1021
1022 sosc->core = core;
1023 sosc->hw.init = &data->init_data;
1024 sosc->fixed_rate = data->fixed_rate;
1025 sosc->enable_mask = data->enable_mask;
1026 sosc->status_mask = data->status_mask;
1027 sosc->enable_reg = data->enable_reg + core->iobase;
1028 sosc->status_reg = data->status_reg + core->iobase;
1029
1030 return devm_clk_register(core->dev, &sosc->hw);
1031}