Commit | Line | Data |
---|---|---|
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 |
29 | static LIST_HEAD(clocks); |
30 | static DEFINE_MUTEX(clocks_mutex); | |
31 | static DEFINE_SPINLOCK(clockfw_lock); | |
32 | ||
c5b736d0 | 33 | static 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 | 40 | static 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)) | |
45 | davinci_psc_config(psc_domain(clk), clk->lpsc, 1); | |
3e062b07 VB |
46 | } |
47 | ||
48 | static void __clk_disable(struct clk *clk) | |
49 | { | |
c5b736d0 | 50 | if (WARN_ON(clk->usecount == 0)) |
3e062b07 | 51 | return; |
c5b736d0 KH |
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); | |
3e062b07 VB |
56 | } |
57 | ||
58 | int clk_enable(struct clk *clk) | |
59 | { | |
60 | unsigned long flags; | |
3e062b07 VB |
61 | |
62 | if (clk == NULL || IS_ERR(clk)) | |
63 | return -EINVAL; | |
64 | ||
c5b736d0 KH |
65 | spin_lock_irqsave(&clockfw_lock, flags); |
66 | __clk_enable(clk); | |
67 | spin_unlock_irqrestore(&clockfw_lock, flags); | |
3e062b07 | 68 | |
c5b736d0 | 69 | return 0; |
3e062b07 VB |
70 | } |
71 | EXPORT_SYMBOL(clk_enable); | |
72 | ||
73 | void clk_disable(struct clk *clk) | |
74 | { | |
75 | unsigned long flags; | |
76 | ||
77 | if (clk == NULL || IS_ERR(clk)) | |
78 | return; | |
79 | ||
c5b736d0 KH |
80 | spin_lock_irqsave(&clockfw_lock, flags); |
81 | __clk_disable(clk); | |
82 | spin_unlock_irqrestore(&clockfw_lock, flags); | |
3e062b07 VB |
83 | } |
84 | EXPORT_SYMBOL(clk_disable); | |
85 | ||
86 | unsigned long clk_get_rate(struct clk *clk) | |
87 | { | |
88 | if (clk == NULL || IS_ERR(clk)) | |
89 | return -EINVAL; | |
90 | ||
c5b736d0 | 91 | return clk->rate; |
3e062b07 VB |
92 | } |
93 | EXPORT_SYMBOL(clk_get_rate); | |
94 | ||
95 | long 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; |
3e062b07 VB |
101 | } |
102 | EXPORT_SYMBOL(clk_round_rate); | |
103 | ||
104 | int 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 | } | |
112 | EXPORT_SYMBOL(clk_set_rate); | |
113 | ||
114 | int clk_register(struct clk *clk) | |
115 | { | |
116 | if (clk == NULL || IS_ERR(clk)) | |
117 | return -EINVAL; | |
118 | ||
c5b736d0 KH |
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); |
3e062b07 VB |
126 | mutex_unlock(&clocks_mutex); |
127 | ||
c5b736d0 KH |
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 | ||
3e062b07 VB |
136 | return 0; |
137 | } | |
138 | EXPORT_SYMBOL(clk_register); | |
139 | ||
140 | void 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 | } | |
149 | EXPORT_SYMBOL(clk_unregister); | |
150 | ||
c5b736d0 KH |
151 | #ifdef CONFIG_DAVINCI_RESET_CLOCKS |
152 | /* | |
153 | * Disable any unused clocks left on by the bootloader | |
154 | */ | |
155 | static 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 | } |
c5b736d0 KH |
173 | spin_unlock_irq(&clockfw_lock); |
174 | ||
175 | return 0; | |
176 | } | |
177 | late_initcall(clk_disable_unused); | |
178 | #endif | |
3e062b07 | 179 | |
c5b736d0 | 180 | static void clk_sysclk_recalc(struct clk *clk) |
3e062b07 | 181 | { |
c5b736d0 KH |
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 | ||
215 | static 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 | ||
271 | int __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); | |
3e062b07 VB |
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 | ||
304 | static void *davinci_ck_start(struct seq_file *m, loff_t *pos) | |
305 | { | |
306 | return *pos < 1 ? (void *)1 : NULL; | |
307 | } | |
308 | ||
309 | static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos) | |
310 | { | |
311 | ++*pos; | |
312 | return NULL; | |
313 | } | |
314 | ||
315 | static void davinci_ck_stop(struct seq_file *m, void *v) | |
316 | { | |
317 | } | |
318 | ||
c5b736d0 KH |
319 | #define CLKNAME_MAX 10 /* longest clock name */ |
320 | #define NEST_DELTA 2 | |
321 | #define NEST_MAX 4 | |
322 | ||
323 | static void | |
324 | dump_clock(struct seq_file *s, unsigned nest, struct clk *parent) | |
3e062b07 | 325 | { |
c5b736d0 KH |
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 | |
c5b736d0 KH |
356 | static 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); | |
3e062b07 VB |
365 | |
366 | return 0; | |
367 | } | |
368 | ||
2ffd6e18 | 369 | static const struct seq_operations davinci_ck_op = { |
3e062b07 VB |
370 | .start = davinci_ck_start, |
371 | .next = davinci_ck_next, | |
372 | .stop = davinci_ck_stop, | |
373 | .show = davinci_ck_show | |
374 | }; | |
375 | ||
376 | static int davinci_ck_open(struct inode *inode, struct file *file) | |
377 | { | |
378 | return seq_open(file, &davinci_ck_op); | |
379 | } | |
380 | ||
2ffd6e18 | 381 | static const struct file_operations proc_davinci_ck_operations = { |
3e062b07 VB |
382 | .open = davinci_ck_open, |
383 | .read = seq_read, | |
384 | .llseek = seq_lseek, | |
385 | .release = seq_release, | |
386 | }; | |
387 | ||
388 | static int __init davinci_ck_proc_init(void) | |
389 | { | |
40ad35d3 | 390 | proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations); |
3e062b07 VB |
391 | return 0; |
392 | ||
393 | } | |
394 | __initcall(davinci_ck_proc_init); | |
c5b736d0 | 395 | #endif /* CONFIG_DEBUG_PROC_FS */ |