davinci: make clock rate re-calculation easy
[deliverable/linux.git] / arch / arm / mach-davinci / clock.c
CommitLineData
3e062b07 1/*
c5b736d0 2 * Clock and PLL control for DaVinci devices
3e062b07 3 *
c5b736d0
KH
4 * Copyright (C) 2006-2007 Texas Instruments.
5 * Copyright (C) 2008-2009 Deep Root Systems, LLC
3e062b07
VB
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/init.h>
16#include <linux/errno.h>
c5b736d0 17#include <linux/clk.h>
3e062b07
VB
18#include <linux/err.h>
19#include <linux/mutex.h>
20#include <linux/platform_device.h>
fced80c7 21#include <linux/io.h>
3e062b07 22
a09e64fb 23#include <mach/hardware.h>
3e062b07 24
a09e64fb 25#include <mach/psc.h>
c5b736d0 26#include <mach/cputype.h>
3e062b07
VB
27#include "clock.h"
28
3e062b07
VB
29static LIST_HEAD(clocks);
30static DEFINE_MUTEX(clocks_mutex);
31static DEFINE_SPINLOCK(clockfw_lock);
32
c5b736d0 33static unsigned psc_domain(struct clk *clk)
3e062b07 34{
c5b736d0
KH
35 return (clk->flags & PSC_DSP)
36 ? DAVINCI_GPSC_DSPDOMAIN
37 : DAVINCI_GPSC_ARMDOMAIN;
3e062b07 38}
3e062b07 39
c5b736d0 40static void __clk_enable(struct clk *clk)
3e062b07 41{
c5b736d0
KH
42 if (clk->parent)
43 __clk_enable(clk->parent);
44 if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
d81d188c
MG
45 davinci_psc_config(psc_domain(clk), clk->psc_ctlr,
46 clk->lpsc, 1);
3e062b07
VB
47}
48
49static void __clk_disable(struct clk *clk)
50{
c5b736d0 51 if (WARN_ON(clk->usecount == 0))
3e062b07 52 return;
c5b736d0 53 if (--clk->usecount == 0 && !(clk->flags & CLK_PLL))
d81d188c
MG
54 davinci_psc_config(psc_domain(clk), clk->psc_ctlr,
55 clk->lpsc, 0);
c5b736d0
KH
56 if (clk->parent)
57 __clk_disable(clk->parent);
3e062b07
VB
58}
59
60int clk_enable(struct clk *clk)
61{
62 unsigned long flags;
3e062b07
VB
63
64 if (clk == NULL || IS_ERR(clk))
65 return -EINVAL;
66
c5b736d0
KH
67 spin_lock_irqsave(&clockfw_lock, flags);
68 __clk_enable(clk);
69 spin_unlock_irqrestore(&clockfw_lock, flags);
3e062b07 70
c5b736d0 71 return 0;
3e062b07
VB
72}
73EXPORT_SYMBOL(clk_enable);
74
75void clk_disable(struct clk *clk)
76{
77 unsigned long flags;
78
79 if (clk == NULL || IS_ERR(clk))
80 return;
81
c5b736d0
KH
82 spin_lock_irqsave(&clockfw_lock, flags);
83 __clk_disable(clk);
84 spin_unlock_irqrestore(&clockfw_lock, flags);
3e062b07
VB
85}
86EXPORT_SYMBOL(clk_disable);
87
88unsigned long clk_get_rate(struct clk *clk)
89{
90 if (clk == NULL || IS_ERR(clk))
91 return -EINVAL;
92
c5b736d0 93 return clk->rate;
3e062b07
VB
94}
95EXPORT_SYMBOL(clk_get_rate);
96
97long clk_round_rate(struct clk *clk, unsigned long rate)
98{
99 if (clk == NULL || IS_ERR(clk))
100 return -EINVAL;
101
c5b736d0 102 return clk->rate;
3e062b07
VB
103}
104EXPORT_SYMBOL(clk_round_rate);
105
106int clk_set_rate(struct clk *clk, unsigned long rate)
107{
108 if (clk == NULL || IS_ERR(clk))
109 return -EINVAL;
110
111 /* changing the clk rate is not supported */
112 return -EINVAL;
113}
114EXPORT_SYMBOL(clk_set_rate);
115
116int clk_register(struct clk *clk)
117{
118 if (clk == NULL || IS_ERR(clk))
119 return -EINVAL;
120
c5b736d0
KH
121 if (WARN(clk->parent && !clk->parent->rate,
122 "CLK: %s parent %s has no rate!\n",
123 clk->name, clk->parent->name))
124 return -EINVAL;
125
f02bf3b3
SN
126 INIT_LIST_HEAD(&clk->children);
127
3e062b07 128 mutex_lock(&clocks_mutex);
c5b736d0 129 list_add_tail(&clk->node, &clocks);
f02bf3b3
SN
130 if (clk->parent)
131 list_add_tail(&clk->childnode, &clk->parent->children);
3e062b07
VB
132 mutex_unlock(&clocks_mutex);
133
c5b736d0
KH
134 /* If rate is already set, use it */
135 if (clk->rate)
136 return 0;
137
de381a91
SN
138 /* Else, see if there is a way to calculate it */
139 if (clk->recalc)
140 clk->rate = clk->recalc(clk);
141
c5b736d0 142 /* Otherwise, default to parent rate */
de381a91 143 else if (clk->parent)
c5b736d0
KH
144 clk->rate = clk->parent->rate;
145
3e062b07
VB
146 return 0;
147}
148EXPORT_SYMBOL(clk_register);
149
150void clk_unregister(struct clk *clk)
151{
152 if (clk == NULL || IS_ERR(clk))
153 return;
154
155 mutex_lock(&clocks_mutex);
156 list_del(&clk->node);
f02bf3b3 157 list_del(&clk->childnode);
3e062b07
VB
158 mutex_unlock(&clocks_mutex);
159}
160EXPORT_SYMBOL(clk_unregister);
161
c5b736d0
KH
162#ifdef CONFIG_DAVINCI_RESET_CLOCKS
163/*
164 * Disable any unused clocks left on by the bootloader
165 */
166static int __init clk_disable_unused(void)
167{
168 struct clk *ck;
169
170 spin_lock_irq(&clockfw_lock);
171 list_for_each_entry(ck, &clocks, node) {
172 if (ck->usecount > 0)
173 continue;
174 if (!(ck->flags & CLK_PSC))
175 continue;
176
177 /* ignore if in Disabled or SwRstDisable states */
d81d188c 178 if (!davinci_psc_is_clk_active(ck->psc_ctlr, ck->lpsc))
c5b736d0
KH
179 continue;
180
181 pr_info("Clocks: disable unused %s\n", ck->name);
d81d188c 182 davinci_psc_config(psc_domain(ck), ck->psc_ctlr, ck->lpsc, 0);
3e062b07 183 }
c5b736d0
KH
184 spin_unlock_irq(&clockfw_lock);
185
186 return 0;
187}
188late_initcall(clk_disable_unused);
189#endif
3e062b07 190
de381a91 191static unsigned long clk_sysclk_recalc(struct clk *clk)
3e062b07 192{
c5b736d0
KH
193 u32 v, plldiv;
194 struct pll_data *pll;
de381a91 195 unsigned long rate = clk->rate;
c5b736d0
KH
196
197 /* If this is the PLL base clock, no more calculations needed */
198 if (clk->pll_data)
de381a91 199 return rate;
c5b736d0
KH
200
201 if (WARN_ON(!clk->parent))
de381a91 202 return rate;
c5b736d0 203
de381a91 204 rate = clk->parent->rate;
c5b736d0
KH
205
206 /* Otherwise, the parent must be a PLL */
207 if (WARN_ON(!clk->parent->pll_data))
de381a91 208 return rate;
c5b736d0
KH
209
210 pll = clk->parent->pll_data;
211
212 /* If pre-PLL, source clock is before the multiplier and divider(s) */
213 if (clk->flags & PRE_PLL)
de381a91 214 rate = pll->input_rate;
c5b736d0
KH
215
216 if (!clk->div_reg)
de381a91 217 return rate;
c5b736d0
KH
218
219 v = __raw_readl(pll->base + clk->div_reg);
220 if (v & PLLDIV_EN) {
221 plldiv = (v & PLLDIV_RATIO_MASK) + 1;
222 if (plldiv)
de381a91 223 rate /= plldiv;
c5b736d0 224 }
de381a91
SN
225
226 return rate;
227}
228
229static unsigned long clk_leafclk_recalc(struct clk *clk)
230{
231 if (WARN_ON(!clk->parent))
232 return clk->rate;
233
234 return clk->parent->rate;
c5b736d0
KH
235}
236
de381a91 237static unsigned long clk_pllclk_recalc(struct clk *clk)
c5b736d0
KH
238{
239 u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
240 u8 bypass;
241 struct pll_data *pll = clk->pll_data;
de381a91 242 unsigned long rate = clk->rate;
c5b736d0
KH
243
244 pll->base = IO_ADDRESS(pll->phys_base);
245 ctrl = __raw_readl(pll->base + PLLCTL);
de381a91 246 rate = pll->input_rate = clk->parent->rate;
c5b736d0
KH
247
248 if (ctrl & PLLCTL_PLLEN) {
249 bypass = 0;
250 mult = __raw_readl(pll->base + PLLM);
fb8fcb89
SP
251 if (cpu_is_davinci_dm365())
252 mult = 2 * (mult & PLLM_PLLM_MASK);
253 else
254 mult = (mult & PLLM_PLLM_MASK) + 1;
c5b736d0
KH
255 } else
256 bypass = 1;
257
258 if (pll->flags & PLL_HAS_PREDIV) {
259 prediv = __raw_readl(pll->base + PREDIV);
260 if (prediv & PLLDIV_EN)
261 prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
262 else
263 prediv = 1;
264 }
265
266 /* pre-divider is fixed, but (some?) chips won't report that */
267 if (cpu_is_davinci_dm355() && pll->num == 1)
268 prediv = 8;
269
270 if (pll->flags & PLL_HAS_POSTDIV) {
271 postdiv = __raw_readl(pll->base + POSTDIV);
272 if (postdiv & PLLDIV_EN)
273 postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
274 else
275 postdiv = 1;
276 }
277
278 if (!bypass) {
de381a91
SN
279 rate /= prediv;
280 rate *= mult;
281 rate /= postdiv;
c5b736d0
KH
282 }
283
284 pr_debug("PLL%d: input = %lu MHz [ ",
285 pll->num, clk->parent->rate / 1000000);
286 if (bypass)
287 pr_debug("bypass ");
288 if (prediv > 1)
289 pr_debug("/ %d ", prediv);
290 if (mult > 1)
291 pr_debug("* %d ", mult);
292 if (postdiv > 1)
293 pr_debug("/ %d ", postdiv);
de381a91
SN
294 pr_debug("] --> %lu MHz output.\n", rate / 1000000);
295
296 return rate;
c5b736d0
KH
297}
298
299int __init davinci_clk_init(struct davinci_clk *clocks)
300 {
301 struct davinci_clk *c;
302 struct clk *clk;
303
304 for (c = clocks; c->lk.clk; c++) {
305 clk = c->lk.clk;
306
de381a91
SN
307 if (!clk->recalc) {
308
309 /* Check if clock is a PLL */
310 if (clk->pll_data)
311 clk->recalc = clk_pllclk_recalc;
312
313 /* Else, if it is a PLL-derived clock */
314 else if (clk->flags & CLK_PLL)
315 clk->recalc = clk_sysclk_recalc;
316
317 /* Otherwise, it is a leaf clock (PSC clock) */
318 else if (clk->parent)
319 clk->recalc = clk_leafclk_recalc;
320 }
c5b736d0 321
de381a91
SN
322 if (clk->recalc)
323 clk->rate = clk->recalc(clk);
c5b736d0
KH
324
325 if (clk->lpsc)
326 clk->flags |= CLK_PSC;
327
328 clkdev_add(&c->lk);
329 clk_register(clk);
330
331 /* Turn on clocks that Linux doesn't otherwise manage */
332 if (clk->flags & ALWAYS_ENABLED)
333 clk_enable(clk);
3e062b07
VB
334 }
335
336 return 0;
337}
338
339#ifdef CONFIG_PROC_FS
340#include <linux/proc_fs.h>
341#include <linux/seq_file.h>
342
343static void *davinci_ck_start(struct seq_file *m, loff_t *pos)
344{
345 return *pos < 1 ? (void *)1 : NULL;
346}
347
348static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos)
349{
350 ++*pos;
351 return NULL;
352}
353
354static void davinci_ck_stop(struct seq_file *m, void *v)
355{
356}
357
c5b736d0
KH
358#define CLKNAME_MAX 10 /* longest clock name */
359#define NEST_DELTA 2
360#define NEST_MAX 4
361
362static void
363dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
3e062b07 364{
c5b736d0
KH
365 char *state;
366 char buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
367 struct clk *clk;
368 unsigned i;
369
370 if (parent->flags & CLK_PLL)
371 state = "pll";
372 else if (parent->flags & CLK_PSC)
373 state = "psc";
374 else
375 state = "";
376
377 /* <nest spaces> name <pad to end> */
378 memset(buf, ' ', sizeof(buf) - 1);
379 buf[sizeof(buf) - 1] = 0;
380 i = strlen(parent->name);
381 memcpy(buf + nest, parent->name,
382 min(i, (unsigned)(sizeof(buf) - 1 - nest)));
383
384 seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
385 buf, parent->usecount, state, clk_get_rate(parent));
386 /* REVISIT show device associations too */
387
388 /* cost is now small, but not linear... */
f02bf3b3
SN
389 list_for_each_entry(clk, &parent->children, childnode) {
390 dump_clock(s, nest + NEST_DELTA, clk);
c5b736d0
KH
391 }
392}
3e062b07 393
c5b736d0
KH
394static int davinci_ck_show(struct seq_file *m, void *v)
395{
396 /* Show clock tree; we know the main oscillator is first.
397 * We trust nonzero usecounts equate to PSC enables...
398 */
399 mutex_lock(&clocks_mutex);
400 if (!list_empty(&clocks))
401 dump_clock(m, 0, list_first_entry(&clocks, struct clk, node));
402 mutex_unlock(&clocks_mutex);
3e062b07
VB
403
404 return 0;
405}
406
2ffd6e18 407static const struct seq_operations davinci_ck_op = {
3e062b07
VB
408 .start = davinci_ck_start,
409 .next = davinci_ck_next,
410 .stop = davinci_ck_stop,
411 .show = davinci_ck_show
412};
413
414static int davinci_ck_open(struct inode *inode, struct file *file)
415{
416 return seq_open(file, &davinci_ck_op);
417}
418
2ffd6e18 419static const struct file_operations proc_davinci_ck_operations = {
3e062b07
VB
420 .open = davinci_ck_open,
421 .read = seq_read,
422 .llseek = seq_lseek,
423 .release = seq_release,
424};
425
426static int __init davinci_ck_proc_init(void)
427{
40ad35d3 428 proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations);
3e062b07
VB
429 return 0;
430
431}
432__initcall(davinci_ck_proc_init);
c5b736d0 433#endif /* CONFIG_DEBUG_PROC_FS */
This page took 0.226887 seconds and 5 git commands to generate.