Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatchin...
[linux-2.6-block.git] / drivers / clk / ti / fapll.c
1 /*
2  * This program is free software; you can redistribute it and/or
3  * modify it under the terms of the GNU General Public License as
4  * published by the Free Software Foundation version 2.
5  *
6  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
7  * kind, whether express or implied; without even the implied warranty
8  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9  * GNU General Public License for more details.
10  */
11
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/delay.h>
15 #include <linux/err.h>
16 #include <linux/io.h>
17 #include <linux/math64.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/clk/ti.h>
21
22 /* FAPLL Control Register PLL_CTRL */
23 #define FAPLL_MAIN_MULT_N_SHIFT 16
24 #define FAPLL_MAIN_DIV_P_SHIFT  8
25 #define FAPLL_MAIN_LOCK         BIT(7)
26 #define FAPLL_MAIN_PLLEN        BIT(3)
27 #define FAPLL_MAIN_BP           BIT(2)
28 #define FAPLL_MAIN_LOC_CTL      BIT(0)
29
30 #define FAPLL_MAIN_MAX_MULT_N   0xffff
31 #define FAPLL_MAIN_MAX_DIV_P    0xff
32 #define FAPLL_MAIN_CLEAR_MASK   \
33         ((FAPLL_MAIN_MAX_MULT_N << FAPLL_MAIN_MULT_N_SHIFT) | \
34          (FAPLL_MAIN_DIV_P_SHIFT << FAPLL_MAIN_DIV_P_SHIFT) | \
35          FAPLL_MAIN_LOC_CTL)
36
37 /* FAPLL powerdown register PWD */
38 #define FAPLL_PWD_OFFSET        4
39
40 #define MAX_FAPLL_OUTPUTS       7
41 #define FAPLL_MAX_RETRIES       1000
42
43 #define to_fapll(_hw)           container_of(_hw, struct fapll_data, hw)
44 #define to_synth(_hw)           container_of(_hw, struct fapll_synth, hw)
45
46 /* The bypass bit is inverted on the ddr_pll.. */
47 #define fapll_is_ddr_pll(va)    (((u32)(va) & 0xffff) == 0x0440)
48
49 /*
50  * The audio_pll_clk1 input is hard wired to the 27MHz bypass clock,
51  * and the audio_pll_clk1 synthesizer is hardwared to 32KiHz output.
52  */
53 #define is_ddr_pll_clk1(va)     (((u32)(va) & 0xffff) == 0x044c)
54 #define is_audio_pll_clk1(va)   (((u32)(va) & 0xffff) == 0x04a8)
55
56 /* Synthesizer divider register */
57 #define SYNTH_LDMDIV1           BIT(8)
58
59 /* Synthesizer frequency register */
60 #define SYNTH_LDFREQ            BIT(31)
61
62 #define SYNTH_PHASE_K           8
63 #define SYNTH_MAX_INT_DIV       0xf
64 #define SYNTH_MAX_DIV_M         0xff
65
66 struct fapll_data {
67         struct clk_hw hw;
68         void __iomem *base;
69         const char *name;
70         struct clk *clk_ref;
71         struct clk *clk_bypass;
72         struct clk_onecell_data outputs;
73         bool bypass_bit_inverted;
74 };
75
76 struct fapll_synth {
77         struct clk_hw hw;
78         struct fapll_data *fd;
79         int index;
80         void __iomem *freq;
81         void __iomem *div;
82         const char *name;
83         struct clk *clk_pll;
84 };
85
86 static bool ti_fapll_clock_is_bypass(struct fapll_data *fd)
87 {
88         u32 v = readl_relaxed(fd->base);
89
90         if (fd->bypass_bit_inverted)
91                 return !(v & FAPLL_MAIN_BP);
92         else
93                 return !!(v & FAPLL_MAIN_BP);
94 }
95
96 static void ti_fapll_set_bypass(struct fapll_data *fd)
97 {
98         u32 v = readl_relaxed(fd->base);
99
100         if (fd->bypass_bit_inverted)
101                 v &= ~FAPLL_MAIN_BP;
102         else
103                 v |= FAPLL_MAIN_BP;
104         writel_relaxed(v, fd->base);
105 }
106
107 static void ti_fapll_clear_bypass(struct fapll_data *fd)
108 {
109         u32 v = readl_relaxed(fd->base);
110
111         if (fd->bypass_bit_inverted)
112                 v |= FAPLL_MAIN_BP;
113         else
114                 v &= ~FAPLL_MAIN_BP;
115         writel_relaxed(v, fd->base);
116 }
117
118 static int ti_fapll_wait_lock(struct fapll_data *fd)
119 {
120         int retries = FAPLL_MAX_RETRIES;
121         u32 v;
122
123         while ((v = readl_relaxed(fd->base))) {
124                 if (v & FAPLL_MAIN_LOCK)
125                         return 0;
126
127                 if (retries-- <= 0)
128                         break;
129
130                 udelay(1);
131         }
132
133         pr_err("%s failed to lock\n", fd->name);
134
135         return -ETIMEDOUT;
136 }
137
138 static int ti_fapll_enable(struct clk_hw *hw)
139 {
140         struct fapll_data *fd = to_fapll(hw);
141         u32 v = readl_relaxed(fd->base);
142
143         v |= FAPLL_MAIN_PLLEN;
144         writel_relaxed(v, fd->base);
145         ti_fapll_wait_lock(fd);
146
147         return 0;
148 }
149
150 static void ti_fapll_disable(struct clk_hw *hw)
151 {
152         struct fapll_data *fd = to_fapll(hw);
153         u32 v = readl_relaxed(fd->base);
154
155         v &= ~FAPLL_MAIN_PLLEN;
156         writel_relaxed(v, fd->base);
157 }
158
159 static int ti_fapll_is_enabled(struct clk_hw *hw)
160 {
161         struct fapll_data *fd = to_fapll(hw);
162         u32 v = readl_relaxed(fd->base);
163
164         return v & FAPLL_MAIN_PLLEN;
165 }
166
167 static unsigned long ti_fapll_recalc_rate(struct clk_hw *hw,
168                                           unsigned long parent_rate)
169 {
170         struct fapll_data *fd = to_fapll(hw);
171         u32 fapll_n, fapll_p, v;
172         u64 rate;
173
174         if (ti_fapll_clock_is_bypass(fd))
175                 return parent_rate;
176
177         rate = parent_rate;
178
179         /* PLL pre-divider is P and multiplier is N */
180         v = readl_relaxed(fd->base);
181         fapll_p = (v >> 8) & 0xff;
182         if (fapll_p)
183                 do_div(rate, fapll_p);
184         fapll_n = v >> 16;
185         if (fapll_n)
186                 rate *= fapll_n;
187
188         return rate;
189 }
190
191 static u8 ti_fapll_get_parent(struct clk_hw *hw)
192 {
193         struct fapll_data *fd = to_fapll(hw);
194
195         if (ti_fapll_clock_is_bypass(fd))
196                 return 1;
197
198         return 0;
199 }
200
201 static int ti_fapll_set_div_mult(unsigned long rate,
202                                  unsigned long parent_rate,
203                                  u32 *pre_div_p, u32 *mult_n)
204 {
205         /*
206          * So far no luck getting decent clock with PLL divider,
207          * PLL does not seem to lock and the signal does not look
208          * right. It seems the divider can only be used together
209          * with the multiplier?
210          */
211         if (rate < parent_rate) {
212                 pr_warn("FAPLL main divider rates unsupported\n");
213                 return -EINVAL;
214         }
215
216         *mult_n = rate / parent_rate;
217         if (*mult_n > FAPLL_MAIN_MAX_MULT_N)
218                 return -EINVAL;
219         *pre_div_p = 1;
220
221         return 0;
222 }
223
224 static long ti_fapll_round_rate(struct clk_hw *hw, unsigned long rate,
225                                 unsigned long *parent_rate)
226 {
227         u32 pre_div_p, mult_n;
228         int error;
229
230         if (!rate)
231                 return -EINVAL;
232
233         error = ti_fapll_set_div_mult(rate, *parent_rate,
234                                       &pre_div_p, &mult_n);
235         if (error)
236                 return error;
237
238         rate = *parent_rate / pre_div_p;
239         rate *= mult_n;
240
241         return rate;
242 }
243
244 static int ti_fapll_set_rate(struct clk_hw *hw, unsigned long rate,
245                              unsigned long parent_rate)
246 {
247         struct fapll_data *fd = to_fapll(hw);
248         u32 pre_div_p, mult_n, v;
249         int error;
250
251         if (!rate)
252                 return -EINVAL;
253
254         error = ti_fapll_set_div_mult(rate, parent_rate,
255                                       &pre_div_p, &mult_n);
256         if (error)
257                 return error;
258
259         ti_fapll_set_bypass(fd);
260         v = readl_relaxed(fd->base);
261         v &= ~FAPLL_MAIN_CLEAR_MASK;
262         v |= pre_div_p << FAPLL_MAIN_DIV_P_SHIFT;
263         v |= mult_n << FAPLL_MAIN_MULT_N_SHIFT;
264         writel_relaxed(v, fd->base);
265         if (ti_fapll_is_enabled(hw))
266                 ti_fapll_wait_lock(fd);
267         ti_fapll_clear_bypass(fd);
268
269         return 0;
270 }
271
272 static const struct clk_ops ti_fapll_ops = {
273         .enable = ti_fapll_enable,
274         .disable = ti_fapll_disable,
275         .is_enabled = ti_fapll_is_enabled,
276         .recalc_rate = ti_fapll_recalc_rate,
277         .get_parent = ti_fapll_get_parent,
278         .round_rate = ti_fapll_round_rate,
279         .set_rate = ti_fapll_set_rate,
280 };
281
282 static int ti_fapll_synth_enable(struct clk_hw *hw)
283 {
284         struct fapll_synth *synth = to_synth(hw);
285         u32 v = readl_relaxed(synth->fd->base + FAPLL_PWD_OFFSET);
286
287         v &= ~(1 << synth->index);
288         writel_relaxed(v, synth->fd->base + FAPLL_PWD_OFFSET);
289
290         return 0;
291 }
292
293 static void ti_fapll_synth_disable(struct clk_hw *hw)
294 {
295         struct fapll_synth *synth = to_synth(hw);
296         u32 v = readl_relaxed(synth->fd->base + FAPLL_PWD_OFFSET);
297
298         v |= 1 << synth->index;
299         writel_relaxed(v, synth->fd->base + FAPLL_PWD_OFFSET);
300 }
301
302 static int ti_fapll_synth_is_enabled(struct clk_hw *hw)
303 {
304         struct fapll_synth *synth = to_synth(hw);
305         u32 v = readl_relaxed(synth->fd->base + FAPLL_PWD_OFFSET);
306
307         return !(v & (1 << synth->index));
308 }
309
310 /*
311  * See dm816x TRM chapter 1.10.3 Flying Adder PLL fore more info
312  */
313 static unsigned long ti_fapll_synth_recalc_rate(struct clk_hw *hw,
314                                                 unsigned long parent_rate)
315 {
316         struct fapll_synth *synth = to_synth(hw);
317         u32 synth_div_m;
318         u64 rate;
319
320         /* The audio_pll_clk1 is hardwired to produce 32.768KiHz clock */
321         if (!synth->div)
322                 return 32768;
323
324         /*
325          * PLL in bypass sets the synths in bypass mode too. The PLL rate
326          * can be also be set to 27MHz, so we can't use parent_rate to
327          * check for bypass mode.
328          */
329         if (ti_fapll_clock_is_bypass(synth->fd))
330                 return parent_rate;
331
332         rate = parent_rate;
333
334         /*
335          * Synth frequency integer and fractional divider.
336          * Note that the phase output K is 8, so the result needs
337          * to be multiplied by SYNTH_PHASE_K.
338          */
339         if (synth->freq) {
340                 u32 v, synth_int_div, synth_frac_div, synth_div_freq;
341
342                 v = readl_relaxed(synth->freq);
343                 synth_int_div = (v >> 24) & 0xf;
344                 synth_frac_div = v & 0xffffff;
345                 synth_div_freq = (synth_int_div * 10000000) + synth_frac_div;
346                 rate *= 10000000;
347                 do_div(rate, synth_div_freq);
348                 rate *= SYNTH_PHASE_K;
349         }
350
351         /* Synth post-divider M */
352         synth_div_m = readl_relaxed(synth->div) & SYNTH_MAX_DIV_M;
353
354         return DIV_ROUND_UP_ULL(rate, synth_div_m);
355 }
356
357 static unsigned long ti_fapll_synth_get_frac_rate(struct clk_hw *hw,
358                                                   unsigned long parent_rate)
359 {
360         struct fapll_synth *synth = to_synth(hw);
361         unsigned long current_rate, frac_rate;
362         u32 post_div_m;
363
364         current_rate = ti_fapll_synth_recalc_rate(hw, parent_rate);
365         post_div_m = readl_relaxed(synth->div) & SYNTH_MAX_DIV_M;
366         frac_rate = current_rate * post_div_m;
367
368         return frac_rate;
369 }
370
371 static u32 ti_fapll_synth_set_frac_rate(struct fapll_synth *synth,
372                                         unsigned long rate,
373                                         unsigned long parent_rate)
374 {
375         u32 post_div_m, synth_int_div = 0, synth_frac_div = 0, v;
376
377         post_div_m = DIV_ROUND_UP_ULL((u64)parent_rate * SYNTH_PHASE_K, rate);
378         post_div_m = post_div_m / SYNTH_MAX_INT_DIV;
379         if (post_div_m > SYNTH_MAX_DIV_M)
380                 return -EINVAL;
381         if (!post_div_m)
382                 post_div_m = 1;
383
384         for (; post_div_m < SYNTH_MAX_DIV_M; post_div_m++) {
385                 synth_int_div = DIV_ROUND_UP_ULL((u64)parent_rate *
386                                                  SYNTH_PHASE_K *
387                                                  10000000,
388                                                  rate * post_div_m);
389                 synth_frac_div = synth_int_div % 10000000;
390                 synth_int_div /= 10000000;
391
392                 if (synth_int_div <= SYNTH_MAX_INT_DIV)
393                         break;
394         }
395
396         if (synth_int_div > SYNTH_MAX_INT_DIV)
397                 return -EINVAL;
398
399         v = readl_relaxed(synth->freq);
400         v &= ~0x1fffffff;
401         v |= (synth_int_div & SYNTH_MAX_INT_DIV) << 24;
402         v |= (synth_frac_div & 0xffffff);
403         v |= SYNTH_LDFREQ;
404         writel_relaxed(v, synth->freq);
405
406         return post_div_m;
407 }
408
409 static long ti_fapll_synth_round_rate(struct clk_hw *hw, unsigned long rate,
410                                       unsigned long *parent_rate)
411 {
412         struct fapll_synth *synth = to_synth(hw);
413         struct fapll_data *fd = synth->fd;
414         unsigned long r;
415
416         if (ti_fapll_clock_is_bypass(fd) || !synth->div || !rate)
417                 return -EINVAL;
418
419         /* Only post divider m available with no fractional divider? */
420         if (!synth->freq) {
421                 unsigned long frac_rate;
422                 u32 synth_post_div_m;
423
424                 frac_rate = ti_fapll_synth_get_frac_rate(hw, *parent_rate);
425                 synth_post_div_m = DIV_ROUND_UP(frac_rate, rate);
426                 r = DIV_ROUND_UP(frac_rate, synth_post_div_m);
427                 goto out;
428         }
429
430         r = *parent_rate * SYNTH_PHASE_K;
431         if (rate > r)
432                 goto out;
433
434         r = DIV_ROUND_UP_ULL(r, SYNTH_MAX_INT_DIV * SYNTH_MAX_DIV_M);
435         if (rate < r)
436                 goto out;
437
438         r = rate;
439 out:
440         return r;
441 }
442
443 static int ti_fapll_synth_set_rate(struct clk_hw *hw, unsigned long rate,
444                                    unsigned long parent_rate)
445 {
446         struct fapll_synth *synth = to_synth(hw);
447         struct fapll_data *fd = synth->fd;
448         unsigned long frac_rate, post_rate = 0;
449         u32 post_div_m = 0, v;
450
451         if (ti_fapll_clock_is_bypass(fd) || !synth->div || !rate)
452                 return -EINVAL;
453
454         /* Produce the rate with just post divider M? */
455         frac_rate = ti_fapll_synth_get_frac_rate(hw, parent_rate);
456         if (frac_rate < rate) {
457                 if (!synth->freq)
458                         return -EINVAL;
459         } else {
460                 post_div_m = DIV_ROUND_UP(frac_rate, rate);
461                 if (post_div_m && (post_div_m <= SYNTH_MAX_DIV_M))
462                         post_rate = DIV_ROUND_UP(frac_rate, post_div_m);
463                 if (!synth->freq && !post_rate)
464                         return -EINVAL;
465         }
466
467         /* Need to recalculate the fractional divider? */
468         if ((post_rate != rate) && synth->freq)
469                 post_div_m = ti_fapll_synth_set_frac_rate(synth,
470                                                           rate,
471                                                           parent_rate);
472
473         v = readl_relaxed(synth->div);
474         v &= ~SYNTH_MAX_DIV_M;
475         v |= post_div_m;
476         v |= SYNTH_LDMDIV1;
477         writel_relaxed(v, synth->div);
478
479         return 0;
480 }
481
482 static const struct clk_ops ti_fapll_synt_ops = {
483         .enable = ti_fapll_synth_enable,
484         .disable = ti_fapll_synth_disable,
485         .is_enabled = ti_fapll_synth_is_enabled,
486         .recalc_rate = ti_fapll_synth_recalc_rate,
487         .round_rate = ti_fapll_synth_round_rate,
488         .set_rate = ti_fapll_synth_set_rate,
489 };
490
491 static struct clk * __init ti_fapll_synth_setup(struct fapll_data *fd,
492                                                 void __iomem *freq,
493                                                 void __iomem *div,
494                                                 int index,
495                                                 const char *name,
496                                                 const char *parent,
497                                                 struct clk *pll_clk)
498 {
499         struct clk_init_data *init;
500         struct fapll_synth *synth;
501
502         init = kzalloc(sizeof(*init), GFP_KERNEL);
503         if (!init)
504                 return ERR_PTR(-ENOMEM);
505
506         init->ops = &ti_fapll_synt_ops;
507         init->name = name;
508         init->parent_names = &parent;
509         init->num_parents = 1;
510
511         synth = kzalloc(sizeof(*synth), GFP_KERNEL);
512         if (!synth)
513                 goto free;
514
515         synth->fd = fd;
516         synth->index = index;
517         synth->freq = freq;
518         synth->div = div;
519         synth->name = name;
520         synth->hw.init = init;
521         synth->clk_pll = pll_clk;
522
523         return clk_register(NULL, &synth->hw);
524
525 free:
526         kfree(synth);
527         kfree(init);
528
529         return ERR_PTR(-ENOMEM);
530 }
531
532 static void __init ti_fapll_setup(struct device_node *node)
533 {
534         struct fapll_data *fd;
535         struct clk_init_data *init = NULL;
536         const char *parent_name[2];
537         struct clk *pll_clk;
538         int i;
539
540         fd = kzalloc(sizeof(*fd), GFP_KERNEL);
541         if (!fd)
542                 return;
543
544         fd->outputs.clks = kzalloc(sizeof(struct clk *) *
545                                    MAX_FAPLL_OUTPUTS + 1,
546                                    GFP_KERNEL);
547         if (!fd->outputs.clks)
548                 goto free;
549
550         init = kzalloc(sizeof(*init), GFP_KERNEL);
551         if (!init)
552                 goto free;
553
554         init->ops = &ti_fapll_ops;
555         init->name = node->name;
556
557         init->num_parents = of_clk_get_parent_count(node);
558         if (init->num_parents != 2) {
559                 pr_err("%pOFn must have two parents\n", node);
560                 goto free;
561         }
562
563         of_clk_parent_fill(node, parent_name, 2);
564         init->parent_names = parent_name;
565
566         fd->clk_ref = of_clk_get(node, 0);
567         if (IS_ERR(fd->clk_ref)) {
568                 pr_err("%pOFn could not get clk_ref\n", node);
569                 goto free;
570         }
571
572         fd->clk_bypass = of_clk_get(node, 1);
573         if (IS_ERR(fd->clk_bypass)) {
574                 pr_err("%pOFn could not get clk_bypass\n", node);
575                 goto free;
576         }
577
578         fd->base = of_iomap(node, 0);
579         if (!fd->base) {
580                 pr_err("%pOFn could not get IO base\n", node);
581                 goto free;
582         }
583
584         if (fapll_is_ddr_pll(fd->base))
585                 fd->bypass_bit_inverted = true;
586
587         fd->name = node->name;
588         fd->hw.init = init;
589
590         /* Register the parent PLL */
591         pll_clk = clk_register(NULL, &fd->hw);
592         if (IS_ERR(pll_clk))
593                 goto unmap;
594
595         fd->outputs.clks[0] = pll_clk;
596         fd->outputs.clk_num++;
597
598         /*
599          * Set up the child synthesizers starting at index 1 as the
600          * PLL output is at index 0. We need to check the clock-indices
601          * for numbering in case there are holes in the synth mapping,
602          * and then probe the synth register to see if it has a FREQ
603          * register available.
604          */
605         for (i = 0; i < MAX_FAPLL_OUTPUTS; i++) {
606                 const char *output_name;
607                 void __iomem *freq, *div;
608                 struct clk *synth_clk;
609                 int output_instance;
610                 u32 v;
611
612                 if (of_property_read_string_index(node, "clock-output-names",
613                                                   i, &output_name))
614                         continue;
615
616                 if (of_property_read_u32_index(node, "clock-indices", i,
617                                                &output_instance))
618                         output_instance = i;
619
620                 freq = fd->base + (output_instance * 8);
621                 div = freq + 4;
622
623                 /* Check for hardwired audio_pll_clk1 */
624                 if (is_audio_pll_clk1(freq)) {
625                         freq = NULL;
626                         div = NULL;
627                 } else {
628                         /* Does the synthesizer have a FREQ register? */
629                         v = readl_relaxed(freq);
630                         if (!v)
631                                 freq = NULL;
632                 }
633                 synth_clk = ti_fapll_synth_setup(fd, freq, div, output_instance,
634                                                  output_name, node->name,
635                                                  pll_clk);
636                 if (IS_ERR(synth_clk))
637                         continue;
638
639                 fd->outputs.clks[output_instance] = synth_clk;
640                 fd->outputs.clk_num++;
641
642                 clk_register_clkdev(synth_clk, output_name, NULL);
643         }
644
645         /* Register the child synthesizers as the FAPLL outputs */
646         of_clk_add_provider(node, of_clk_src_onecell_get, &fd->outputs);
647         /* Add clock alias for the outputs */
648
649         kfree(init);
650
651         return;
652
653 unmap:
654         iounmap(fd->base);
655 free:
656         if (fd->clk_bypass)
657                 clk_put(fd->clk_bypass);
658         if (fd->clk_ref)
659                 clk_put(fd->clk_ref);
660         kfree(fd->outputs.clks);
661         kfree(fd);
662         kfree(init);
663 }
664
665 CLK_OF_DECLARE(ti_fapll_clock, "ti,dm816-fapll-clock", ti_fapll_setup);