Merge branch 'topic/cleanup' into for-linus
[linux-2.6-block.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>
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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>
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27#include "clock.h"
28
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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{
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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{
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42 if (clk->parent)
43 __clk_enable(clk->parent);
44 if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
45 davinci_psc_config(psc_domain(clk), clk->lpsc, 1);
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46}
47
48static void __clk_disable(struct clk *clk)
49{
c5b736d0 50 if (WARN_ON(clk->usecount == 0))
3e062b07 51 return;
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52 if (--clk->usecount == 0 && !(clk->flags & CLK_PLL))
53 davinci_psc_config(psc_domain(clk), clk->lpsc, 0);
54 if (clk->parent)
55 __clk_disable(clk->parent);
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56}
57
58int clk_enable(struct clk *clk)
59{
60 unsigned long flags;
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61
62 if (clk == NULL || IS_ERR(clk))
63 return -EINVAL;
64
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65 spin_lock_irqsave(&clockfw_lock, flags);
66 __clk_enable(clk);
67 spin_unlock_irqrestore(&clockfw_lock, flags);
3e062b07 68
c5b736d0 69 return 0;
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70}
71EXPORT_SYMBOL(clk_enable);
72
73void clk_disable(struct clk *clk)
74{
75 unsigned long flags;
76
77 if (clk == NULL || IS_ERR(clk))
78 return;
79
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80 spin_lock_irqsave(&clockfw_lock, flags);
81 __clk_disable(clk);
82 spin_unlock_irqrestore(&clockfw_lock, flags);
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83}
84EXPORT_SYMBOL(clk_disable);
85
86unsigned long clk_get_rate(struct clk *clk)
87{
88 if (clk == NULL || IS_ERR(clk))
89 return -EINVAL;
90
c5b736d0 91 return clk->rate;
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VB
92}
93EXPORT_SYMBOL(clk_get_rate);
94
95long clk_round_rate(struct clk *clk, unsigned long rate)
96{
97 if (clk == NULL || IS_ERR(clk))
98 return -EINVAL;
99
c5b736d0 100 return clk->rate;
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101}
102EXPORT_SYMBOL(clk_round_rate);
103
104int clk_set_rate(struct clk *clk, unsigned long rate)
105{
106 if (clk == NULL || IS_ERR(clk))
107 return -EINVAL;
108
109 /* changing the clk rate is not supported */
110 return -EINVAL;
111}
112EXPORT_SYMBOL(clk_set_rate);
113
114int clk_register(struct clk *clk)
115{
116 if (clk == NULL || IS_ERR(clk))
117 return -EINVAL;
118
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119 if (WARN(clk->parent && !clk->parent->rate,
120 "CLK: %s parent %s has no rate!\n",
121 clk->name, clk->parent->name))
122 return -EINVAL;
123
3e062b07 124 mutex_lock(&clocks_mutex);
c5b736d0 125 list_add_tail(&clk->node, &clocks);
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126 mutex_unlock(&clocks_mutex);
127
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128 /* If rate is already set, use it */
129 if (clk->rate)
130 return 0;
131
132 /* Otherwise, default to parent rate */
133 if (clk->parent)
134 clk->rate = clk->parent->rate;
135
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136 return 0;
137}
138EXPORT_SYMBOL(clk_register);
139
140void clk_unregister(struct clk *clk)
141{
142 if (clk == NULL || IS_ERR(clk))
143 return;
144
145 mutex_lock(&clocks_mutex);
146 list_del(&clk->node);
147 mutex_unlock(&clocks_mutex);
148}
149EXPORT_SYMBOL(clk_unregister);
150
c5b736d0
KH
151#ifdef CONFIG_DAVINCI_RESET_CLOCKS
152/*
153 * Disable any unused clocks left on by the bootloader
154 */
155static int __init clk_disable_unused(void)
156{
157 struct clk *ck;
158
159 spin_lock_irq(&clockfw_lock);
160 list_for_each_entry(ck, &clocks, node) {
161 if (ck->usecount > 0)
162 continue;
163 if (!(ck->flags & CLK_PSC))
164 continue;
165
166 /* ignore if in Disabled or SwRstDisable states */
167 if (!davinci_psc_is_clk_active(ck->lpsc))
168 continue;
169
170 pr_info("Clocks: disable unused %s\n", ck->name);
171 davinci_psc_config(psc_domain(ck), ck->lpsc, 0);
3e062b07 172 }
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173 spin_unlock_irq(&clockfw_lock);
174
175 return 0;
176}
177late_initcall(clk_disable_unused);
178#endif
3e062b07 179
c5b736d0 180static void clk_sysclk_recalc(struct clk *clk)
3e062b07 181{
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182 u32 v, plldiv;
183 struct pll_data *pll;
184
185 /* If this is the PLL base clock, no more calculations needed */
186 if (clk->pll_data)
187 return;
188
189 if (WARN_ON(!clk->parent))
190 return;
191
192 clk->rate = clk->parent->rate;
193
194 /* Otherwise, the parent must be a PLL */
195 if (WARN_ON(!clk->parent->pll_data))
196 return;
197
198 pll = clk->parent->pll_data;
199
200 /* If pre-PLL, source clock is before the multiplier and divider(s) */
201 if (clk->flags & PRE_PLL)
202 clk->rate = pll->input_rate;
203
204 if (!clk->div_reg)
205 return;
206
207 v = __raw_readl(pll->base + clk->div_reg);
208 if (v & PLLDIV_EN) {
209 plldiv = (v & PLLDIV_RATIO_MASK) + 1;
210 if (plldiv)
211 clk->rate /= plldiv;
212 }
213}
214
215static void __init clk_pll_init(struct clk *clk)
216{
217 u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
218 u8 bypass;
219 struct pll_data *pll = clk->pll_data;
220
221 pll->base = IO_ADDRESS(pll->phys_base);
222 ctrl = __raw_readl(pll->base + PLLCTL);
223 clk->rate = pll->input_rate = clk->parent->rate;
224
225 if (ctrl & PLLCTL_PLLEN) {
226 bypass = 0;
227 mult = __raw_readl(pll->base + PLLM);
228 mult = (mult & PLLM_PLLM_MASK) + 1;
229 } else
230 bypass = 1;
231
232 if (pll->flags & PLL_HAS_PREDIV) {
233 prediv = __raw_readl(pll->base + PREDIV);
234 if (prediv & PLLDIV_EN)
235 prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
236 else
237 prediv = 1;
238 }
239
240 /* pre-divider is fixed, but (some?) chips won't report that */
241 if (cpu_is_davinci_dm355() && pll->num == 1)
242 prediv = 8;
243
244 if (pll->flags & PLL_HAS_POSTDIV) {
245 postdiv = __raw_readl(pll->base + POSTDIV);
246 if (postdiv & PLLDIV_EN)
247 postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
248 else
249 postdiv = 1;
250 }
251
252 if (!bypass) {
253 clk->rate /= prediv;
254 clk->rate *= mult;
255 clk->rate /= postdiv;
256 }
257
258 pr_debug("PLL%d: input = %lu MHz [ ",
259 pll->num, clk->parent->rate / 1000000);
260 if (bypass)
261 pr_debug("bypass ");
262 if (prediv > 1)
263 pr_debug("/ %d ", prediv);
264 if (mult > 1)
265 pr_debug("* %d ", mult);
266 if (postdiv > 1)
267 pr_debug("/ %d ", postdiv);
268 pr_debug("] --> %lu MHz output.\n", clk->rate / 1000000);
269}
270
271int __init davinci_clk_init(struct davinci_clk *clocks)
272 {
273 struct davinci_clk *c;
274 struct clk *clk;
275
276 for (c = clocks; c->lk.clk; c++) {
277 clk = c->lk.clk;
278
279 if (clk->pll_data)
280 clk_pll_init(clk);
281
282 /* Calculate rates for PLL-derived clocks */
283 else if (clk->flags & CLK_PLL)
284 clk_sysclk_recalc(clk);
285
286 if (clk->lpsc)
287 clk->flags |= CLK_PSC;
288
289 clkdev_add(&c->lk);
290 clk_register(clk);
291
292 /* Turn on clocks that Linux doesn't otherwise manage */
293 if (clk->flags & ALWAYS_ENABLED)
294 clk_enable(clk);
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295 }
296
297 return 0;
298}
299
300#ifdef CONFIG_PROC_FS
301#include <linux/proc_fs.h>
302#include <linux/seq_file.h>
303
304static void *davinci_ck_start(struct seq_file *m, loff_t *pos)
305{
306 return *pos < 1 ? (void *)1 : NULL;
307}
308
309static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos)
310{
311 ++*pos;
312 return NULL;
313}
314
315static void davinci_ck_stop(struct seq_file *m, void *v)
316{
317}
318
c5b736d0
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319#define CLKNAME_MAX 10 /* longest clock name */
320#define NEST_DELTA 2
321#define NEST_MAX 4
322
323static void
324dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
3e062b07 325{
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326 char *state;
327 char buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
328 struct clk *clk;
329 unsigned i;
330
331 if (parent->flags & CLK_PLL)
332 state = "pll";
333 else if (parent->flags & CLK_PSC)
334 state = "psc";
335 else
336 state = "";
337
338 /* <nest spaces> name <pad to end> */
339 memset(buf, ' ', sizeof(buf) - 1);
340 buf[sizeof(buf) - 1] = 0;
341 i = strlen(parent->name);
342 memcpy(buf + nest, parent->name,
343 min(i, (unsigned)(sizeof(buf) - 1 - nest)));
344
345 seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
346 buf, parent->usecount, state, clk_get_rate(parent));
347 /* REVISIT show device associations too */
348
349 /* cost is now small, but not linear... */
350 list_for_each_entry(clk, &clocks, node) {
351 if (clk->parent == parent)
352 dump_clock(s, nest + NEST_DELTA, clk);
353 }
354}
3e062b07 355
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356static int davinci_ck_show(struct seq_file *m, void *v)
357{
358 /* Show clock tree; we know the main oscillator is first.
359 * We trust nonzero usecounts equate to PSC enables...
360 */
361 mutex_lock(&clocks_mutex);
362 if (!list_empty(&clocks))
363 dump_clock(m, 0, list_first_entry(&clocks, struct clk, node));
364 mutex_unlock(&clocks_mutex);
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365
366 return 0;
367}
368
2ffd6e18 369static const struct seq_operations davinci_ck_op = {
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370 .start = davinci_ck_start,
371 .next = davinci_ck_next,
372 .stop = davinci_ck_stop,
373 .show = davinci_ck_show
374};
375
376static int davinci_ck_open(struct inode *inode, struct file *file)
377{
378 return seq_open(file, &davinci_ck_op);
379}
380
2ffd6e18 381static const struct file_operations proc_davinci_ck_operations = {
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382 .open = davinci_ck_open,
383 .read = seq_read,
384 .llseek = seq_lseek,
385 .release = seq_release,
386};
387
388static int __init davinci_ck_proc_init(void)
389{
40ad35d3 390 proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations);
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391 return 0;
392
393}
394__initcall(davinci_ck_proc_init);
c5b736d0 395#endif /* CONFIG_DEBUG_PROC_FS */