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543d9378 PW |
1 | /* |
2 | * linux/arch/arm/mach-omap2/clock.c | |
3 | * | |
a16e9703 TL |
4 | * Copyright (C) 2005-2008 Texas Instruments, Inc. |
5 | * Copyright (C) 2004-2008 Nokia Corporation | |
543d9378 | 6 | * |
a16e9703 TL |
7 | * Contacts: |
8 | * Richard Woodruff <r-woodruff2@ti.com> | |
543d9378 PW |
9 | * Paul Walmsley |
10 | * | |
543d9378 PW |
11 | * This program is free software; you can redistribute it and/or modify |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | */ | |
15 | #undef DEBUG | |
16 | ||
17 | #include <linux/module.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/device.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/delay.h> | |
23 | #include <linux/clk.h> | |
fced80c7 | 24 | #include <linux/io.h> |
fbd3bdb2 | 25 | #include <linux/bitops.h> |
543d9378 | 26 | |
a09e64fb | 27 | #include <mach/clock.h> |
333943ba | 28 | #include <mach/clockdomain.h> |
a09e64fb RK |
29 | #include <mach/sram.h> |
30 | #include <mach/cpu.h> | |
543d9378 PW |
31 | #include <asm/div64.h> |
32 | ||
33 | #include "memory.h" | |
34 | #include "sdrc.h" | |
35 | #include "clock.h" | |
36 | #include "prm.h" | |
37 | #include "prm-regbits-24xx.h" | |
38 | #include "cm.h" | |
39 | #include "cm-regbits-24xx.h" | |
40 | #include "cm-regbits-34xx.h" | |
41 | ||
42 | #define MAX_CLOCK_ENABLE_WAIT 100000 | |
43 | ||
88b8ba90 PW |
44 | /* DPLL rate rounding: minimum DPLL multiplier, divider values */ |
45 | #define DPLL_MIN_MULTIPLIER 1 | |
46 | #define DPLL_MIN_DIVIDER 1 | |
47 | ||
48 | /* Possible error results from _dpll_test_mult */ | |
49 | #define DPLL_MULT_UNDERFLOW (1 << 0) | |
50 | ||
51 | /* | |
52 | * Scale factor to mitigate roundoff errors in DPLL rate rounding. | |
53 | * The higher the scale factor, the greater the risk of arithmetic overflow, | |
54 | * but the closer the rounded rate to the target rate. DPLL_SCALE_FACTOR | |
55 | * must be a power of DPLL_SCALE_BASE. | |
56 | */ | |
57 | #define DPLL_SCALE_FACTOR 64 | |
58 | #define DPLL_SCALE_BASE 2 | |
59 | #define DPLL_ROUNDING_VAL ((DPLL_SCALE_BASE / 2) * \ | |
60 | (DPLL_SCALE_FACTOR / DPLL_SCALE_BASE)) | |
61 | ||
543d9378 PW |
62 | u8 cpu_mask; |
63 | ||
64 | /*------------------------------------------------------------------------- | |
333943ba | 65 | * OMAP2/3 specific clock functions |
543d9378 PW |
66 | *-------------------------------------------------------------------------*/ |
67 | ||
333943ba PW |
68 | /** |
69 | * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk | |
70 | * @clk: OMAP clock struct ptr to use | |
71 | * | |
72 | * Convert a clockdomain name stored in a struct clk 'clk' into a | |
73 | * clockdomain pointer, and save it into the struct clk. Intended to be | |
74 | * called during clk_register(). No return value. | |
75 | */ | |
76 | void omap2_init_clk_clkdm(struct clk *clk) | |
77 | { | |
78 | struct clockdomain *clkdm; | |
79 | ||
80 | if (!clk->clkdm_name) | |
81 | return; | |
82 | ||
83 | clkdm = clkdm_lookup(clk->clkdm_name); | |
84 | if (clkdm) { | |
85 | pr_debug("clock: associated clk %s to clkdm %s\n", | |
86 | clk->name, clk->clkdm_name); | |
87 | clk->clkdm = clkdm; | |
88 | } else { | |
89 | pr_debug("clock: could not associate clk %s to " | |
90 | "clkdm %s\n", clk->name, clk->clkdm_name); | |
91 | } | |
92 | } | |
93 | ||
543d9378 PW |
94 | /** |
95 | * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware | |
96 | * @clk: OMAP clock struct ptr to use | |
97 | * | |
98 | * Given a pointer to a source-selectable struct clk, read the hardware | |
99 | * register and determine what its parent is currently set to. Update the | |
100 | * clk->parent field with the appropriate clk ptr. | |
101 | */ | |
102 | void omap2_init_clksel_parent(struct clk *clk) | |
103 | { | |
104 | const struct clksel *clks; | |
105 | const struct clksel_rate *clkr; | |
106 | u32 r, found = 0; | |
107 | ||
108 | if (!clk->clksel) | |
109 | return; | |
110 | ||
111 | r = __raw_readl(clk->clksel_reg) & clk->clksel_mask; | |
112 | r >>= __ffs(clk->clksel_mask); | |
113 | ||
114 | for (clks = clk->clksel; clks->parent && !found; clks++) { | |
115 | for (clkr = clks->rates; clkr->div && !found; clkr++) { | |
116 | if ((clkr->flags & cpu_mask) && (clkr->val == r)) { | |
117 | if (clk->parent != clks->parent) { | |
118 | pr_debug("clock: inited %s parent " | |
119 | "to %s (was %s)\n", | |
120 | clk->name, clks->parent->name, | |
121 | ((clk->parent) ? | |
122 | clk->parent->name : "NULL")); | |
123 | clk->parent = clks->parent; | |
124 | }; | |
125 | found = 1; | |
126 | } | |
127 | } | |
128 | } | |
129 | ||
130 | if (!found) | |
131 | printk(KERN_ERR "clock: init parent: could not find " | |
132 | "regval %0x for clock %s\n", r, clk->name); | |
133 | ||
134 | return; | |
135 | } | |
136 | ||
137 | /* Returns the DPLL rate */ | |
138 | u32 omap2_get_dpll_rate(struct clk *clk) | |
139 | { | |
140 | long long dpll_clk; | |
141 | u32 dpll_mult, dpll_div, dpll; | |
88b8ba90 | 142 | struct dpll_data *dd; |
543d9378 PW |
143 | |
144 | dd = clk->dpll_data; | |
145 | /* REVISIT: What do we return on error? */ | |
146 | if (!dd) | |
147 | return 0; | |
148 | ||
149 | dpll = __raw_readl(dd->mult_div1_reg); | |
150 | dpll_mult = dpll & dd->mult_mask; | |
151 | dpll_mult >>= __ffs(dd->mult_mask); | |
152 | dpll_div = dpll & dd->div1_mask; | |
153 | dpll_div >>= __ffs(dd->div1_mask); | |
154 | ||
155 | dpll_clk = (long long)clk->parent->rate * dpll_mult; | |
156 | do_div(dpll_clk, dpll_div + 1); | |
157 | ||
543d9378 PW |
158 | return dpll_clk; |
159 | } | |
160 | ||
161 | /* | |
162 | * Used for clocks that have the same value as the parent clock, | |
163 | * divided by some factor | |
164 | */ | |
165 | void omap2_fixed_divisor_recalc(struct clk *clk) | |
166 | { | |
167 | WARN_ON(!clk->fixed_div); | |
168 | ||
169 | clk->rate = clk->parent->rate / clk->fixed_div; | |
170 | ||
171 | if (clk->flags & RATE_PROPAGATES) | |
172 | propagate_rate(clk); | |
173 | } | |
174 | ||
175 | /** | |
176 | * omap2_wait_clock_ready - wait for clock to enable | |
177 | * @reg: physical address of clock IDLEST register | |
178 | * @mask: value to mask against to determine if the clock is active | |
179 | * @name: name of the clock (for printk) | |
180 | * | |
181 | * Returns 1 if the clock enabled in time, or 0 if it failed to enable | |
182 | * in roughly MAX_CLOCK_ENABLE_WAIT microseconds. | |
183 | */ | |
184 | int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name) | |
185 | { | |
186 | int i = 0; | |
187 | int ena = 0; | |
188 | ||
189 | /* | |
190 | * 24xx uses 0 to indicate not ready, and 1 to indicate ready. | |
191 | * 34xx reverses this, just to keep us on our toes | |
192 | */ | |
193 | if (cpu_mask & (RATE_IN_242X | RATE_IN_243X)) { | |
194 | ena = mask; | |
195 | } else if (cpu_mask & RATE_IN_343X) { | |
196 | ena = 0; | |
197 | } | |
198 | ||
199 | /* Wait for lock */ | |
200 | while (((__raw_readl(reg) & mask) != ena) && | |
201 | (i++ < MAX_CLOCK_ENABLE_WAIT)) { | |
202 | udelay(1); | |
203 | } | |
204 | ||
205 | if (i < MAX_CLOCK_ENABLE_WAIT) | |
206 | pr_debug("Clock %s stable after %d loops\n", name, i); | |
207 | else | |
208 | printk(KERN_ERR "Clock %s didn't enable in %d tries\n", | |
209 | name, MAX_CLOCK_ENABLE_WAIT); | |
210 | ||
211 | ||
212 | return (i < MAX_CLOCK_ENABLE_WAIT) ? 1 : 0; | |
213 | }; | |
214 | ||
215 | ||
216 | /* | |
217 | * Note: We don't need special code here for INVERT_ENABLE | |
218 | * for the time being since INVERT_ENABLE only applies to clocks enabled by | |
219 | * CM_CLKEN_PLL | |
220 | */ | |
221 | static void omap2_clk_wait_ready(struct clk *clk) | |
222 | { | |
223 | void __iomem *reg, *other_reg, *st_reg; | |
224 | u32 bit; | |
225 | ||
226 | /* | |
227 | * REVISIT: This code is pretty ugly. It would be nice to generalize | |
228 | * it and pull it into struct clk itself somehow. | |
229 | */ | |
230 | reg = clk->enable_reg; | |
231 | if ((((u32)reg & 0xff) >= CM_FCLKEN1) && | |
232 | (((u32)reg & 0xff) <= OMAP24XX_CM_FCLKEN2)) | |
233 | other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x10); /* CM_ICLKEN* */ | |
234 | else if ((((u32)reg & 0xff) >= CM_ICLKEN1) && | |
235 | (((u32)reg & 0xff) <= OMAP24XX_CM_ICLKEN4)) | |
236 | other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x00); /* CM_FCLKEN* */ | |
237 | else | |
238 | return; | |
239 | ||
240 | /* REVISIT: What are the appropriate exclusions for 34XX? */ | |
241 | /* No check for DSS or cam clocks */ | |
242 | if (cpu_is_omap24xx() && ((u32)reg & 0x0f) == 0) { /* CM_{F,I}CLKEN1 */ | |
243 | if (clk->enable_bit == OMAP24XX_EN_DSS2_SHIFT || | |
244 | clk->enable_bit == OMAP24XX_EN_DSS1_SHIFT || | |
245 | clk->enable_bit == OMAP24XX_EN_CAM_SHIFT) | |
246 | return; | |
247 | } | |
248 | ||
249 | /* REVISIT: What are the appropriate exclusions for 34XX? */ | |
250 | /* OMAP3: ignore DSS-mod clocks */ | |
251 | if (cpu_is_omap34xx() && | |
1971a390 JH |
252 | (((u32)reg & ~0xff) == (u32)OMAP_CM_REGADDR(OMAP3430_DSS_MOD, 0) || |
253 | ((((u32)reg & ~0xff) == (u32)OMAP_CM_REGADDR(CORE_MOD, 0)) && | |
254 | clk->enable_bit == OMAP3430_EN_SSI_SHIFT))) | |
543d9378 PW |
255 | return; |
256 | ||
257 | /* Check if both functional and interface clocks | |
258 | * are running. */ | |
259 | bit = 1 << clk->enable_bit; | |
260 | if (!(__raw_readl(other_reg) & bit)) | |
261 | return; | |
262 | st_reg = (void __iomem *)(((u32)other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */ | |
263 | ||
264 | omap2_wait_clock_ready(st_reg, bit, clk->name); | |
265 | } | |
266 | ||
267 | /* Enables clock without considering parent dependencies or use count | |
268 | * REVISIT: Maybe change this to use clk->enable like on omap1? | |
269 | */ | |
270 | int _omap2_clk_enable(struct clk *clk) | |
271 | { | |
272 | u32 regval32; | |
273 | ||
274 | if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK)) | |
275 | return 0; | |
276 | ||
277 | if (clk->enable) | |
278 | return clk->enable(clk); | |
279 | ||
c0fc18c5 | 280 | if (unlikely(clk->enable_reg == NULL)) { |
543d9378 PW |
281 | printk(KERN_ERR "clock.c: Enable for %s without enable code\n", |
282 | clk->name); | |
283 | return 0; /* REVISIT: -EINVAL */ | |
284 | } | |
285 | ||
286 | regval32 = __raw_readl(clk->enable_reg); | |
287 | if (clk->flags & INVERT_ENABLE) | |
288 | regval32 &= ~(1 << clk->enable_bit); | |
289 | else | |
290 | regval32 |= (1 << clk->enable_bit); | |
291 | __raw_writel(regval32, clk->enable_reg); | |
292 | wmb(); | |
293 | ||
294 | omap2_clk_wait_ready(clk); | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
299 | /* Disables clock without considering parent dependencies or use count */ | |
300 | void _omap2_clk_disable(struct clk *clk) | |
301 | { | |
302 | u32 regval32; | |
303 | ||
304 | if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK)) | |
305 | return; | |
306 | ||
307 | if (clk->disable) { | |
308 | clk->disable(clk); | |
309 | return; | |
310 | } | |
311 | ||
c0fc18c5 | 312 | if (clk->enable_reg == NULL) { |
543d9378 PW |
313 | /* |
314 | * 'Independent' here refers to a clock which is not | |
315 | * controlled by its parent. | |
316 | */ | |
317 | printk(KERN_ERR "clock: clk_disable called on independent " | |
318 | "clock %s which has no enable_reg\n", clk->name); | |
319 | return; | |
320 | } | |
321 | ||
322 | regval32 = __raw_readl(clk->enable_reg); | |
323 | if (clk->flags & INVERT_ENABLE) | |
324 | regval32 |= (1 << clk->enable_bit); | |
325 | else | |
326 | regval32 &= ~(1 << clk->enable_bit); | |
327 | __raw_writel(regval32, clk->enable_reg); | |
328 | wmb(); | |
329 | } | |
330 | ||
331 | void omap2_clk_disable(struct clk *clk) | |
332 | { | |
333 | if (clk->usecount > 0 && !(--clk->usecount)) { | |
334 | _omap2_clk_disable(clk); | |
335 | if (likely((u32)clk->parent)) | |
336 | omap2_clk_disable(clk->parent); | |
333943ba PW |
337 | if (clk->clkdm) |
338 | omap2_clkdm_clk_disable(clk->clkdm, clk); | |
339 | ||
543d9378 PW |
340 | } |
341 | } | |
342 | ||
343 | int omap2_clk_enable(struct clk *clk) | |
344 | { | |
345 | int ret = 0; | |
346 | ||
347 | if (clk->usecount++ == 0) { | |
348 | if (likely((u32)clk->parent)) | |
349 | ret = omap2_clk_enable(clk->parent); | |
350 | ||
351 | if (unlikely(ret != 0)) { | |
352 | clk->usecount--; | |
353 | return ret; | |
354 | } | |
355 | ||
333943ba PW |
356 | if (clk->clkdm) |
357 | omap2_clkdm_clk_enable(clk->clkdm, clk); | |
358 | ||
543d9378 PW |
359 | ret = _omap2_clk_enable(clk); |
360 | ||
333943ba PW |
361 | if (unlikely(ret != 0)) { |
362 | if (clk->clkdm) | |
363 | omap2_clkdm_clk_disable(clk->clkdm, clk); | |
364 | ||
365 | if (clk->parent) { | |
366 | omap2_clk_disable(clk->parent); | |
367 | clk->usecount--; | |
368 | } | |
543d9378 PW |
369 | } |
370 | } | |
371 | ||
372 | return ret; | |
373 | } | |
374 | ||
375 | /* | |
376 | * Used for clocks that are part of CLKSEL_xyz governed clocks. | |
377 | * REVISIT: Maybe change to use clk->enable() functions like on omap1? | |
378 | */ | |
379 | void omap2_clksel_recalc(struct clk *clk) | |
380 | { | |
381 | u32 div = 0; | |
382 | ||
383 | pr_debug("clock: recalc'ing clksel clk %s\n", clk->name); | |
384 | ||
385 | div = omap2_clksel_get_divisor(clk); | |
386 | if (div == 0) | |
387 | return; | |
388 | ||
389 | if (unlikely(clk->rate == clk->parent->rate / div)) | |
390 | return; | |
391 | clk->rate = clk->parent->rate / div; | |
392 | ||
393 | pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div); | |
394 | ||
395 | if (unlikely(clk->flags & RATE_PROPAGATES)) | |
396 | propagate_rate(clk); | |
397 | } | |
398 | ||
399 | /** | |
400 | * omap2_get_clksel_by_parent - return clksel struct for a given clk & parent | |
401 | * @clk: OMAP struct clk ptr to inspect | |
402 | * @src_clk: OMAP struct clk ptr of the parent clk to search for | |
403 | * | |
404 | * Scan the struct clksel array associated with the clock to find | |
405 | * the element associated with the supplied parent clock address. | |
406 | * Returns a pointer to the struct clksel on success or NULL on error. | |
407 | */ | |
408 | const struct clksel *omap2_get_clksel_by_parent(struct clk *clk, | |
409 | struct clk *src_clk) | |
410 | { | |
411 | const struct clksel *clks; | |
412 | ||
413 | if (!clk->clksel) | |
414 | return NULL; | |
415 | ||
416 | for (clks = clk->clksel; clks->parent; clks++) { | |
417 | if (clks->parent == src_clk) | |
418 | break; /* Found the requested parent */ | |
419 | } | |
420 | ||
421 | if (!clks->parent) { | |
422 | printk(KERN_ERR "clock: Could not find parent clock %s in " | |
423 | "clksel array of clock %s\n", src_clk->name, | |
424 | clk->name); | |
425 | return NULL; | |
426 | } | |
427 | ||
428 | return clks; | |
429 | } | |
430 | ||
431 | /** | |
432 | * omap2_clksel_round_rate_div - find divisor for the given clock and rate | |
433 | * @clk: OMAP struct clk to use | |
434 | * @target_rate: desired clock rate | |
435 | * @new_div: ptr to where we should store the divisor | |
436 | * | |
437 | * Finds 'best' divider value in an array based on the source and target | |
438 | * rates. The divider array must be sorted with smallest divider first. | |
439 | * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT, | |
440 | * they are only settable as part of virtual_prcm set. | |
441 | * | |
442 | * Returns the rounded clock rate or returns 0xffffffff on error. | |
443 | */ | |
444 | u32 omap2_clksel_round_rate_div(struct clk *clk, unsigned long target_rate, | |
445 | u32 *new_div) | |
446 | { | |
447 | unsigned long test_rate; | |
448 | const struct clksel *clks; | |
449 | const struct clksel_rate *clkr; | |
450 | u32 last_div = 0; | |
451 | ||
452 | printk(KERN_INFO "clock: clksel_round_rate_div: %s target_rate %ld\n", | |
453 | clk->name, target_rate); | |
454 | ||
455 | *new_div = 1; | |
456 | ||
457 | clks = omap2_get_clksel_by_parent(clk, clk->parent); | |
458 | if (clks == NULL) | |
459 | return ~0; | |
460 | ||
461 | for (clkr = clks->rates; clkr->div; clkr++) { | |
462 | if (!(clkr->flags & cpu_mask)) | |
463 | continue; | |
464 | ||
465 | /* Sanity check */ | |
466 | if (clkr->div <= last_div) | |
467 | printk(KERN_ERR "clock: clksel_rate table not sorted " | |
468 | "for clock %s", clk->name); | |
469 | ||
470 | last_div = clkr->div; | |
471 | ||
472 | test_rate = clk->parent->rate / clkr->div; | |
473 | ||
474 | if (test_rate <= target_rate) | |
475 | break; /* found it */ | |
476 | } | |
477 | ||
478 | if (!clkr->div) { | |
479 | printk(KERN_ERR "clock: Could not find divisor for target " | |
480 | "rate %ld for clock %s parent %s\n", target_rate, | |
481 | clk->name, clk->parent->name); | |
482 | return ~0; | |
483 | } | |
484 | ||
485 | *new_div = clkr->div; | |
486 | ||
487 | printk(KERN_INFO "clock: new_div = %d, new_rate = %ld\n", *new_div, | |
488 | (clk->parent->rate / clkr->div)); | |
489 | ||
490 | return (clk->parent->rate / clkr->div); | |
491 | } | |
492 | ||
493 | /** | |
494 | * omap2_clksel_round_rate - find rounded rate for the given clock and rate | |
495 | * @clk: OMAP struct clk to use | |
496 | * @target_rate: desired clock rate | |
497 | * | |
498 | * Compatibility wrapper for OMAP clock framework | |
499 | * Finds best target rate based on the source clock and possible dividers. | |
500 | * rates. The divider array must be sorted with smallest divider first. | |
501 | * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT, | |
502 | * they are only settable as part of virtual_prcm set. | |
503 | * | |
504 | * Returns the rounded clock rate or returns 0xffffffff on error. | |
505 | */ | |
506 | long omap2_clksel_round_rate(struct clk *clk, unsigned long target_rate) | |
507 | { | |
508 | u32 new_div; | |
509 | ||
510 | return omap2_clksel_round_rate_div(clk, target_rate, &new_div); | |
511 | } | |
512 | ||
513 | ||
514 | /* Given a clock and a rate apply a clock specific rounding function */ | |
515 | long omap2_clk_round_rate(struct clk *clk, unsigned long rate) | |
516 | { | |
c0fc18c5 | 517 | if (clk->round_rate != NULL) |
543d9378 PW |
518 | return clk->round_rate(clk, rate); |
519 | ||
520 | if (clk->flags & RATE_FIXED) | |
521 | printk(KERN_ERR "clock: generic omap2_clk_round_rate called " | |
522 | "on fixed-rate clock %s\n", clk->name); | |
523 | ||
524 | return clk->rate; | |
525 | } | |
526 | ||
527 | /** | |
528 | * omap2_clksel_to_divisor() - turn clksel field value into integer divider | |
529 | * @clk: OMAP struct clk to use | |
530 | * @field_val: register field value to find | |
531 | * | |
532 | * Given a struct clk of a rate-selectable clksel clock, and a register field | |
533 | * value to search for, find the corresponding clock divisor. The register | |
534 | * field value should be pre-masked and shifted down so the LSB is at bit 0 | |
535 | * before calling. Returns 0 on error | |
536 | */ | |
537 | u32 omap2_clksel_to_divisor(struct clk *clk, u32 field_val) | |
538 | { | |
539 | const struct clksel *clks; | |
540 | const struct clksel_rate *clkr; | |
541 | ||
542 | clks = omap2_get_clksel_by_parent(clk, clk->parent); | |
543 | if (clks == NULL) | |
544 | return 0; | |
545 | ||
546 | for (clkr = clks->rates; clkr->div; clkr++) { | |
547 | if ((clkr->flags & cpu_mask) && (clkr->val == field_val)) | |
548 | break; | |
549 | } | |
550 | ||
551 | if (!clkr->div) { | |
552 | printk(KERN_ERR "clock: Could not find fieldval %d for " | |
553 | "clock %s parent %s\n", field_val, clk->name, | |
554 | clk->parent->name); | |
555 | return 0; | |
556 | } | |
557 | ||
558 | return clkr->div; | |
559 | } | |
560 | ||
561 | /** | |
562 | * omap2_divisor_to_clksel() - turn clksel integer divisor into a field value | |
563 | * @clk: OMAP struct clk to use | |
564 | * @div: integer divisor to search for | |
565 | * | |
566 | * Given a struct clk of a rate-selectable clksel clock, and a clock divisor, | |
567 | * find the corresponding register field value. The return register value is | |
9132f1b4 | 568 | * the value before left-shifting. Returns ~0 on error |
543d9378 PW |
569 | */ |
570 | u32 omap2_divisor_to_clksel(struct clk *clk, u32 div) | |
571 | { | |
572 | const struct clksel *clks; | |
573 | const struct clksel_rate *clkr; | |
574 | ||
575 | /* should never happen */ | |
576 | WARN_ON(div == 0); | |
577 | ||
578 | clks = omap2_get_clksel_by_parent(clk, clk->parent); | |
579 | if (clks == NULL) | |
9132f1b4 | 580 | return ~0; |
543d9378 PW |
581 | |
582 | for (clkr = clks->rates; clkr->div; clkr++) { | |
583 | if ((clkr->flags & cpu_mask) && (clkr->div == div)) | |
584 | break; | |
585 | } | |
586 | ||
587 | if (!clkr->div) { | |
588 | printk(KERN_ERR "clock: Could not find divisor %d for " | |
589 | "clock %s parent %s\n", div, clk->name, | |
590 | clk->parent->name); | |
9132f1b4 | 591 | return ~0; |
543d9378 PW |
592 | } |
593 | ||
594 | return clkr->val; | |
595 | } | |
596 | ||
597 | /** | |
598 | * omap2_get_clksel - find clksel register addr & field mask for a clk | |
599 | * @clk: struct clk to use | |
600 | * @field_mask: ptr to u32 to store the register field mask | |
601 | * | |
602 | * Returns the address of the clksel register upon success or NULL on error. | |
603 | */ | |
604 | void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask) | |
605 | { | |
c0fc18c5 | 606 | if (unlikely((clk->clksel_reg == NULL) || (clk->clksel_mask == NULL))) |
543d9378 PW |
607 | return NULL; |
608 | ||
609 | *field_mask = clk->clksel_mask; | |
610 | ||
611 | return clk->clksel_reg; | |
612 | } | |
613 | ||
614 | /** | |
615 | * omap2_clksel_get_divisor - get current divider applied to parent clock. | |
616 | * @clk: OMAP struct clk to use. | |
617 | * | |
618 | * Returns the integer divisor upon success or 0 on error. | |
619 | */ | |
620 | u32 omap2_clksel_get_divisor(struct clk *clk) | |
621 | { | |
622 | u32 field_mask, field_val; | |
623 | void __iomem *div_addr; | |
624 | ||
625 | div_addr = omap2_get_clksel(clk, &field_mask); | |
c0fc18c5 | 626 | if (div_addr == NULL) |
543d9378 PW |
627 | return 0; |
628 | ||
629 | field_val = __raw_readl(div_addr) & field_mask; | |
630 | field_val >>= __ffs(field_mask); | |
631 | ||
632 | return omap2_clksel_to_divisor(clk, field_val); | |
633 | } | |
634 | ||
635 | int omap2_clksel_set_rate(struct clk *clk, unsigned long rate) | |
636 | { | |
637 | u32 field_mask, field_val, reg_val, validrate, new_div = 0; | |
638 | void __iomem *div_addr; | |
639 | ||
640 | validrate = omap2_clksel_round_rate_div(clk, rate, &new_div); | |
641 | if (validrate != rate) | |
642 | return -EINVAL; | |
643 | ||
644 | div_addr = omap2_get_clksel(clk, &field_mask); | |
c0fc18c5 | 645 | if (div_addr == NULL) |
543d9378 PW |
646 | return -EINVAL; |
647 | ||
648 | field_val = omap2_divisor_to_clksel(clk, new_div); | |
649 | if (field_val == ~0) | |
650 | return -EINVAL; | |
651 | ||
652 | reg_val = __raw_readl(div_addr); | |
653 | reg_val &= ~field_mask; | |
654 | reg_val |= (field_val << __ffs(field_mask)); | |
655 | __raw_writel(reg_val, div_addr); | |
656 | wmb(); | |
657 | ||
658 | clk->rate = clk->parent->rate / new_div; | |
659 | ||
660 | if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) { | |
c2d43e39 TL |
661 | prm_write_mod_reg(OMAP24XX_VALID_CONFIG, |
662 | OMAP24XX_GR_MOD, OMAP24XX_PRCM_CLKCFG_CTRL_OFFSET); | |
543d9378 PW |
663 | wmb(); |
664 | } | |
665 | ||
666 | return 0; | |
667 | } | |
668 | ||
669 | ||
670 | /* Set the clock rate for a clock source */ | |
671 | int omap2_clk_set_rate(struct clk *clk, unsigned long rate) | |
672 | { | |
673 | int ret = -EINVAL; | |
674 | ||
675 | pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate); | |
676 | ||
677 | /* CONFIG_PARTICIPANT clocks are changed only in sets via the | |
678 | rate table mechanism, driven by mpu_speed */ | |
679 | if (clk->flags & CONFIG_PARTICIPANT) | |
680 | return -EINVAL; | |
681 | ||
682 | /* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */ | |
c0fc18c5 | 683 | if (clk->set_rate != NULL) |
543d9378 PW |
684 | ret = clk->set_rate(clk, rate); |
685 | ||
686 | if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES))) | |
687 | propagate_rate(clk); | |
688 | ||
689 | return ret; | |
690 | } | |
691 | ||
692 | /* | |
693 | * Converts encoded control register address into a full address | |
694 | * On error, *src_addr will be returned as 0. | |
695 | */ | |
696 | static u32 omap2_clksel_get_src_field(void __iomem **src_addr, | |
697 | struct clk *src_clk, u32 *field_mask, | |
698 | struct clk *clk, u32 *parent_div) | |
699 | { | |
700 | const struct clksel *clks; | |
701 | const struct clksel_rate *clkr; | |
702 | ||
703 | *parent_div = 0; | |
c0fc18c5 | 704 | *src_addr = NULL; |
543d9378 PW |
705 | |
706 | clks = omap2_get_clksel_by_parent(clk, src_clk); | |
707 | if (clks == NULL) | |
708 | return 0; | |
709 | ||
710 | for (clkr = clks->rates; clkr->div; clkr++) { | |
abf23965 | 711 | if (clkr->flags & cpu_mask && clkr->flags & DEFAULT_RATE) |
543d9378 PW |
712 | break; /* Found the default rate for this platform */ |
713 | } | |
714 | ||
715 | if (!clkr->div) { | |
716 | printk(KERN_ERR "clock: Could not find default rate for " | |
717 | "clock %s parent %s\n", clk->name, | |
718 | src_clk->parent->name); | |
719 | return 0; | |
720 | } | |
721 | ||
722 | /* Should never happen. Add a clksel mask to the struct clk. */ | |
723 | WARN_ON(clk->clksel_mask == 0); | |
724 | ||
725 | *field_mask = clk->clksel_mask; | |
726 | *src_addr = clk->clksel_reg; | |
727 | *parent_div = clkr->div; | |
728 | ||
729 | return clkr->val; | |
730 | } | |
731 | ||
732 | int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent) | |
733 | { | |
734 | void __iomem *src_addr; | |
735 | u32 field_val, field_mask, reg_val, parent_div; | |
736 | ||
737 | if (unlikely(clk->flags & CONFIG_PARTICIPANT)) | |
738 | return -EINVAL; | |
739 | ||
740 | if (!clk->clksel) | |
741 | return -EINVAL; | |
742 | ||
743 | field_val = omap2_clksel_get_src_field(&src_addr, new_parent, | |
744 | &field_mask, clk, &parent_div); | |
c0fc18c5 | 745 | if (src_addr == NULL) |
543d9378 PW |
746 | return -EINVAL; |
747 | ||
748 | if (clk->usecount > 0) | |
41f3103f | 749 | omap2_clk_disable(clk); |
543d9378 PW |
750 | |
751 | /* Set new source value (previous dividers if any in effect) */ | |
752 | reg_val = __raw_readl(src_addr) & ~field_mask; | |
753 | reg_val |= (field_val << __ffs(field_mask)); | |
754 | __raw_writel(reg_val, src_addr); | |
755 | wmb(); | |
756 | ||
757 | if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) { | |
758 | __raw_writel(OMAP24XX_VALID_CONFIG, OMAP24XX_PRCM_CLKCFG_CTRL); | |
759 | wmb(); | |
760 | } | |
761 | ||
543d9378 PW |
762 | clk->parent = new_parent; |
763 | ||
41f3103f RK |
764 | if (clk->usecount > 0) |
765 | omap2_clk_enable(clk); | |
766 | ||
543d9378 PW |
767 | /* CLKSEL clocks follow their parents' rates, divided by a divisor */ |
768 | clk->rate = new_parent->rate; | |
769 | ||
770 | if (parent_div > 0) | |
771 | clk->rate /= parent_div; | |
772 | ||
773 | pr_debug("clock: set parent of %s to %s (new rate %ld)\n", | |
774 | clk->name, clk->parent->name, clk->rate); | |
775 | ||
776 | if (unlikely(clk->flags & RATE_PROPAGATES)) | |
777 | propagate_rate(clk); | |
778 | ||
779 | return 0; | |
780 | } | |
781 | ||
88b8ba90 PW |
782 | /* DPLL rate rounding code */ |
783 | ||
784 | /** | |
785 | * omap2_dpll_set_rate_tolerance: set the error tolerance during rate rounding | |
786 | * @clk: struct clk * of the DPLL | |
787 | * @tolerance: maximum rate error tolerance | |
788 | * | |
789 | * Set the maximum DPLL rate error tolerance for the rate rounding | |
790 | * algorithm. The rate tolerance is an attempt to balance DPLL power | |
791 | * saving (the least divider value "n") vs. rate fidelity (the least | |
792 | * difference between the desired DPLL target rate and the rounded | |
793 | * rate out of the algorithm). So, increasing the tolerance is likely | |
794 | * to decrease DPLL power consumption and increase DPLL rate error. | |
795 | * Returns -EINVAL if provided a null clock ptr or a clk that is not a | |
796 | * DPLL; or 0 upon success. | |
797 | */ | |
798 | int omap2_dpll_set_rate_tolerance(struct clk *clk, unsigned int tolerance) | |
799 | { | |
800 | if (!clk || !clk->dpll_data) | |
801 | return -EINVAL; | |
802 | ||
803 | clk->dpll_data->rate_tolerance = tolerance; | |
804 | ||
805 | return 0; | |
806 | } | |
807 | ||
808 | static unsigned long _dpll_compute_new_rate(unsigned long parent_rate, unsigned int m, unsigned int n) | |
809 | { | |
810 | unsigned long long num; | |
811 | ||
812 | num = (unsigned long long)parent_rate * m; | |
813 | do_div(num, n); | |
814 | return num; | |
815 | } | |
816 | ||
817 | /* | |
818 | * _dpll_test_mult - test a DPLL multiplier value | |
819 | * @m: pointer to the DPLL m (multiplier) value under test | |
820 | * @n: current DPLL n (divider) value under test | |
821 | * @new_rate: pointer to storage for the resulting rounded rate | |
822 | * @target_rate: the desired DPLL rate | |
823 | * @parent_rate: the DPLL's parent clock rate | |
824 | * | |
825 | * This code tests a DPLL multiplier value, ensuring that the | |
826 | * resulting rate will not be higher than the target_rate, and that | |
827 | * the multiplier value itself is valid for the DPLL. Initially, the | |
828 | * integer pointed to by the m argument should be prescaled by | |
829 | * multiplying by DPLL_SCALE_FACTOR. The code will replace this with | |
830 | * a non-scaled m upon return. This non-scaled m will result in a | |
831 | * new_rate as close as possible to target_rate (but not greater than | |
832 | * target_rate) given the current (parent_rate, n, prescaled m) | |
833 | * triple. Returns DPLL_MULT_UNDERFLOW in the event that the | |
834 | * non-scaled m attempted to underflow, which can allow the calling | |
835 | * function to bail out early; or 0 upon success. | |
836 | */ | |
837 | static int _dpll_test_mult(int *m, int n, unsigned long *new_rate, | |
838 | unsigned long target_rate, | |
839 | unsigned long parent_rate) | |
840 | { | |
841 | int flags = 0, carry = 0; | |
842 | ||
843 | /* Unscale m and round if necessary */ | |
844 | if (*m % DPLL_SCALE_FACTOR >= DPLL_ROUNDING_VAL) | |
845 | carry = 1; | |
846 | *m = (*m / DPLL_SCALE_FACTOR) + carry; | |
847 | ||
848 | /* | |
849 | * The new rate must be <= the target rate to avoid programming | |
850 | * a rate that is impossible for the hardware to handle | |
851 | */ | |
852 | *new_rate = _dpll_compute_new_rate(parent_rate, *m, n); | |
853 | if (*new_rate > target_rate) { | |
854 | (*m)--; | |
855 | *new_rate = 0; | |
856 | } | |
857 | ||
858 | /* Guard against m underflow */ | |
859 | if (*m < DPLL_MIN_MULTIPLIER) { | |
860 | *m = DPLL_MIN_MULTIPLIER; | |
861 | *new_rate = 0; | |
862 | flags = DPLL_MULT_UNDERFLOW; | |
863 | } | |
864 | ||
865 | if (*new_rate == 0) | |
866 | *new_rate = _dpll_compute_new_rate(parent_rate, *m, n); | |
867 | ||
868 | return flags; | |
869 | } | |
870 | ||
871 | /** | |
872 | * omap2_dpll_round_rate - round a target rate for an OMAP DPLL | |
873 | * @clk: struct clk * for a DPLL | |
874 | * @target_rate: desired DPLL clock rate | |
875 | * | |
876 | * Given a DPLL, a desired target rate, and a rate tolerance, round | |
877 | * the target rate to a possible, programmable rate for this DPLL. | |
878 | * Rate tolerance is assumed to be set by the caller before this | |
879 | * function is called. Attempts to select the minimum possible n | |
880 | * within the tolerance to reduce power consumption. Stores the | |
881 | * computed (m, n) in the DPLL's dpll_data structure so set_rate() | |
882 | * will not need to call this (expensive) function again. Returns ~0 | |
883 | * if the target rate cannot be rounded, either because the rate is | |
884 | * too low or because the rate tolerance is set too tightly; or the | |
885 | * rounded rate upon success. | |
886 | */ | |
887 | long omap2_dpll_round_rate(struct clk *clk, unsigned long target_rate) | |
888 | { | |
889 | int m, n, r, e, scaled_max_m; | |
890 | unsigned long scaled_rt_rp, new_rate; | |
891 | int min_e = -1, min_e_m = -1, min_e_n = -1; | |
892 | ||
893 | if (!clk || !clk->dpll_data) | |
894 | return ~0; | |
895 | ||
896 | pr_debug("clock: starting DPLL round_rate for clock %s, target rate " | |
897 | "%ld\n", clk->name, target_rate); | |
898 | ||
899 | scaled_rt_rp = target_rate / (clk->parent->rate / DPLL_SCALE_FACTOR); | |
900 | scaled_max_m = clk->dpll_data->max_multiplier * DPLL_SCALE_FACTOR; | |
901 | ||
902 | clk->dpll_data->last_rounded_rate = 0; | |
903 | ||
904 | for (n = clk->dpll_data->max_divider; n >= DPLL_MIN_DIVIDER; n--) { | |
905 | ||
906 | /* Compute the scaled DPLL multiplier, based on the divider */ | |
907 | m = scaled_rt_rp * n; | |
908 | ||
909 | /* | |
910 | * Since we're counting n down, a m overflow means we can | |
911 | * can immediately skip to the next n | |
912 | */ | |
913 | if (m > scaled_max_m) | |
914 | continue; | |
915 | ||
916 | r = _dpll_test_mult(&m, n, &new_rate, target_rate, | |
917 | clk->parent->rate); | |
918 | ||
919 | e = target_rate - new_rate; | |
920 | pr_debug("clock: n = %d: m = %d: rate error is %d " | |
921 | "(new_rate = %ld)\n", n, m, e, new_rate); | |
922 | ||
923 | if (min_e == -1 || | |
924 | min_e >= (int)(abs(e) - clk->dpll_data->rate_tolerance)) { | |
925 | min_e = e; | |
926 | min_e_m = m; | |
927 | min_e_n = n; | |
928 | ||
929 | pr_debug("clock: found new least error %d\n", min_e); | |
930 | } | |
931 | ||
932 | /* | |
933 | * Since we're counting n down, a m underflow means we | |
934 | * can bail out completely (since as n decreases in | |
935 | * the next iteration, there's no way that m can | |
936 | * increase beyond the current m) | |
937 | */ | |
938 | if (r & DPLL_MULT_UNDERFLOW) | |
939 | break; | |
940 | } | |
941 | ||
942 | if (min_e < 0) { | |
943 | pr_debug("clock: error: target rate or tolerance too low\n"); | |
944 | return ~0; | |
945 | } | |
946 | ||
947 | clk->dpll_data->last_rounded_m = min_e_m; | |
948 | clk->dpll_data->last_rounded_n = min_e_n; | |
949 | clk->dpll_data->last_rounded_rate = | |
950 | _dpll_compute_new_rate(clk->parent->rate, min_e_m, min_e_n); | |
951 | ||
952 | pr_debug("clock: final least error: e = %d, m = %d, n = %d\n", | |
953 | min_e, min_e_m, min_e_n); | |
954 | pr_debug("clock: final rate: %ld (target rate: %ld)\n", | |
955 | clk->dpll_data->last_rounded_rate, target_rate); | |
956 | ||
957 | return clk->dpll_data->last_rounded_rate; | |
958 | } | |
959 | ||
543d9378 PW |
960 | /*------------------------------------------------------------------------- |
961 | * Omap2 clock reset and init functions | |
962 | *-------------------------------------------------------------------------*/ | |
963 | ||
964 | #ifdef CONFIG_OMAP_RESET_CLOCKS | |
965 | void omap2_clk_disable_unused(struct clk *clk) | |
966 | { | |
967 | u32 regval32, v; | |
968 | ||
969 | v = (clk->flags & INVERT_ENABLE) ? (1 << clk->enable_bit) : 0; | |
970 | ||
971 | regval32 = __raw_readl(clk->enable_reg); | |
972 | if ((regval32 & (1 << clk->enable_bit)) == v) | |
973 | return; | |
974 | ||
975 | printk(KERN_INFO "Disabling unused clock \"%s\"\n", clk->name); | |
976 | _omap2_clk_disable(clk); | |
977 | } | |
978 | #endif |