Commit | Line | Data |
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9570ef20 MD |
1 | /* |
2 | * SuperH Timer Support - TMU | |
3 | * | |
4 | * Copyright (C) 2009 Magnus Damm | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/init.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/spinlock.h> | |
23 | #include <linux/interrupt.h> | |
24 | #include <linux/ioport.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/io.h> | |
27 | #include <linux/clk.h> | |
28 | #include <linux/irq.h> | |
29 | #include <linux/err.h> | |
30 | #include <linux/clocksource.h> | |
31 | #include <linux/clockchips.h> | |
46a12f74 | 32 | #include <linux/sh_timer.h> |
5a0e3ad6 | 33 | #include <linux/slab.h> |
7deeab5d | 34 | #include <linux/module.h> |
9570ef20 MD |
35 | |
36 | struct sh_tmu_priv { | |
37 | void __iomem *mapbase; | |
38 | struct clk *clk; | |
39 | struct irqaction irqaction; | |
40 | struct platform_device *pdev; | |
41 | unsigned long rate; | |
42 | unsigned long periodic; | |
43 | struct clock_event_device ced; | |
44 | struct clocksource cs; | |
45 | }; | |
46 | ||
47 | static DEFINE_SPINLOCK(sh_tmu_lock); | |
48 | ||
49 | #define TSTR -1 /* shared register */ | |
50 | #define TCOR 0 /* channel register */ | |
51 | #define TCNT 1 /* channel register */ | |
52 | #define TCR 2 /* channel register */ | |
53 | ||
54 | static inline unsigned long sh_tmu_read(struct sh_tmu_priv *p, int reg_nr) | |
55 | { | |
46a12f74 | 56 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
57 | void __iomem *base = p->mapbase; |
58 | unsigned long offs; | |
59 | ||
60 | if (reg_nr == TSTR) | |
61 | return ioread8(base - cfg->channel_offset); | |
62 | ||
63 | offs = reg_nr << 2; | |
64 | ||
65 | if (reg_nr == TCR) | |
66 | return ioread16(base + offs); | |
67 | else | |
68 | return ioread32(base + offs); | |
69 | } | |
70 | ||
71 | static inline void sh_tmu_write(struct sh_tmu_priv *p, int reg_nr, | |
72 | unsigned long value) | |
73 | { | |
46a12f74 | 74 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
75 | void __iomem *base = p->mapbase; |
76 | unsigned long offs; | |
77 | ||
78 | if (reg_nr == TSTR) { | |
79 | iowrite8(value, base - cfg->channel_offset); | |
80 | return; | |
81 | } | |
82 | ||
83 | offs = reg_nr << 2; | |
84 | ||
85 | if (reg_nr == TCR) | |
86 | iowrite16(value, base + offs); | |
87 | else | |
88 | iowrite32(value, base + offs); | |
89 | } | |
90 | ||
91 | static void sh_tmu_start_stop_ch(struct sh_tmu_priv *p, int start) | |
92 | { | |
46a12f74 | 93 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
94 | unsigned long flags, value; |
95 | ||
96 | /* start stop register shared by multiple timer channels */ | |
97 | spin_lock_irqsave(&sh_tmu_lock, flags); | |
98 | value = sh_tmu_read(p, TSTR); | |
99 | ||
100 | if (start) | |
101 | value |= 1 << cfg->timer_bit; | |
102 | else | |
103 | value &= ~(1 << cfg->timer_bit); | |
104 | ||
105 | sh_tmu_write(p, TSTR, value); | |
106 | spin_unlock_irqrestore(&sh_tmu_lock, flags); | |
107 | } | |
108 | ||
109 | static int sh_tmu_enable(struct sh_tmu_priv *p) | |
110 | { | |
9570ef20 MD |
111 | int ret; |
112 | ||
d4905ce3 | 113 | /* enable clock */ |
9570ef20 MD |
114 | ret = clk_enable(p->clk); |
115 | if (ret) { | |
214a607a | 116 | dev_err(&p->pdev->dev, "cannot enable clock\n"); |
9570ef20 MD |
117 | return ret; |
118 | } | |
119 | ||
120 | /* make sure channel is disabled */ | |
121 | sh_tmu_start_stop_ch(p, 0); | |
122 | ||
123 | /* maximum timeout */ | |
124 | sh_tmu_write(p, TCOR, 0xffffffff); | |
125 | sh_tmu_write(p, TCNT, 0xffffffff); | |
126 | ||
127 | /* configure channel to parent clock / 4, irq off */ | |
128 | p->rate = clk_get_rate(p->clk) / 4; | |
129 | sh_tmu_write(p, TCR, 0x0000); | |
130 | ||
131 | /* enable channel */ | |
132 | sh_tmu_start_stop_ch(p, 1); | |
133 | ||
134 | return 0; | |
135 | } | |
136 | ||
137 | static void sh_tmu_disable(struct sh_tmu_priv *p) | |
138 | { | |
139 | /* disable channel */ | |
140 | sh_tmu_start_stop_ch(p, 0); | |
141 | ||
be890a1a MD |
142 | /* disable interrupts in TMU block */ |
143 | sh_tmu_write(p, TCR, 0x0000); | |
144 | ||
d4905ce3 | 145 | /* stop clock */ |
9570ef20 MD |
146 | clk_disable(p->clk); |
147 | } | |
148 | ||
149 | static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta, | |
150 | int periodic) | |
151 | { | |
152 | /* stop timer */ | |
153 | sh_tmu_start_stop_ch(p, 0); | |
154 | ||
155 | /* acknowledge interrupt */ | |
156 | sh_tmu_read(p, TCR); | |
157 | ||
158 | /* enable interrupt */ | |
159 | sh_tmu_write(p, TCR, 0x0020); | |
160 | ||
161 | /* reload delta value in case of periodic timer */ | |
162 | if (periodic) | |
163 | sh_tmu_write(p, TCOR, delta); | |
164 | else | |
6f4b67b8 | 165 | sh_tmu_write(p, TCOR, 0xffffffff); |
9570ef20 MD |
166 | |
167 | sh_tmu_write(p, TCNT, delta); | |
168 | ||
169 | /* start timer */ | |
170 | sh_tmu_start_stop_ch(p, 1); | |
171 | } | |
172 | ||
173 | static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id) | |
174 | { | |
175 | struct sh_tmu_priv *p = dev_id; | |
176 | ||
177 | /* disable or acknowledge interrupt */ | |
178 | if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT) | |
179 | sh_tmu_write(p, TCR, 0x0000); | |
180 | else | |
181 | sh_tmu_write(p, TCR, 0x0020); | |
182 | ||
183 | /* notify clockevent layer */ | |
184 | p->ced.event_handler(&p->ced); | |
185 | return IRQ_HANDLED; | |
186 | } | |
187 | ||
188 | static struct sh_tmu_priv *cs_to_sh_tmu(struct clocksource *cs) | |
189 | { | |
190 | return container_of(cs, struct sh_tmu_priv, cs); | |
191 | } | |
192 | ||
193 | static cycle_t sh_tmu_clocksource_read(struct clocksource *cs) | |
194 | { | |
195 | struct sh_tmu_priv *p = cs_to_sh_tmu(cs); | |
196 | ||
197 | return sh_tmu_read(p, TCNT) ^ 0xffffffff; | |
198 | } | |
199 | ||
200 | static int sh_tmu_clocksource_enable(struct clocksource *cs) | |
201 | { | |
202 | struct sh_tmu_priv *p = cs_to_sh_tmu(cs); | |
0aeac458 | 203 | int ret; |
9570ef20 | 204 | |
0aeac458 MD |
205 | ret = sh_tmu_enable(p); |
206 | if (!ret) | |
207 | __clocksource_updatefreq_hz(cs, p->rate); | |
208 | return ret; | |
9570ef20 MD |
209 | } |
210 | ||
211 | static void sh_tmu_clocksource_disable(struct clocksource *cs) | |
212 | { | |
213 | sh_tmu_disable(cs_to_sh_tmu(cs)); | |
214 | } | |
215 | ||
216 | static int sh_tmu_register_clocksource(struct sh_tmu_priv *p, | |
217 | char *name, unsigned long rating) | |
218 | { | |
219 | struct clocksource *cs = &p->cs; | |
220 | ||
221 | cs->name = name; | |
222 | cs->rating = rating; | |
223 | cs->read = sh_tmu_clocksource_read; | |
224 | cs->enable = sh_tmu_clocksource_enable; | |
225 | cs->disable = sh_tmu_clocksource_disable; | |
226 | cs->mask = CLOCKSOURCE_MASK(32); | |
227 | cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; | |
66f49121 | 228 | |
214a607a | 229 | dev_info(&p->pdev->dev, "used as clock source\n"); |
0aeac458 MD |
230 | |
231 | /* Register with dummy 1 Hz value, gets updated in ->enable() */ | |
232 | clocksource_register_hz(cs, 1); | |
9570ef20 MD |
233 | return 0; |
234 | } | |
235 | ||
236 | static struct sh_tmu_priv *ced_to_sh_tmu(struct clock_event_device *ced) | |
237 | { | |
238 | return container_of(ced, struct sh_tmu_priv, ced); | |
239 | } | |
240 | ||
241 | static void sh_tmu_clock_event_start(struct sh_tmu_priv *p, int periodic) | |
242 | { | |
243 | struct clock_event_device *ced = &p->ced; | |
244 | ||
245 | sh_tmu_enable(p); | |
246 | ||
247 | /* TODO: calculate good shift from rate and counter bit width */ | |
248 | ||
249 | ced->shift = 32; | |
250 | ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift); | |
251 | ced->max_delta_ns = clockevent_delta2ns(0xffffffff, ced); | |
252 | ced->min_delta_ns = 5000; | |
253 | ||
254 | if (periodic) { | |
255 | p->periodic = (p->rate + HZ/2) / HZ; | |
256 | sh_tmu_set_next(p, p->periodic, 1); | |
257 | } | |
258 | } | |
259 | ||
260 | static void sh_tmu_clock_event_mode(enum clock_event_mode mode, | |
261 | struct clock_event_device *ced) | |
262 | { | |
263 | struct sh_tmu_priv *p = ced_to_sh_tmu(ced); | |
264 | int disabled = 0; | |
265 | ||
266 | /* deal with old setting first */ | |
267 | switch (ced->mode) { | |
268 | case CLOCK_EVT_MODE_PERIODIC: | |
269 | case CLOCK_EVT_MODE_ONESHOT: | |
270 | sh_tmu_disable(p); | |
271 | disabled = 1; | |
272 | break; | |
273 | default: | |
274 | break; | |
275 | } | |
276 | ||
277 | switch (mode) { | |
278 | case CLOCK_EVT_MODE_PERIODIC: | |
214a607a | 279 | dev_info(&p->pdev->dev, "used for periodic clock events\n"); |
9570ef20 MD |
280 | sh_tmu_clock_event_start(p, 1); |
281 | break; | |
282 | case CLOCK_EVT_MODE_ONESHOT: | |
214a607a | 283 | dev_info(&p->pdev->dev, "used for oneshot clock events\n"); |
9570ef20 MD |
284 | sh_tmu_clock_event_start(p, 0); |
285 | break; | |
286 | case CLOCK_EVT_MODE_UNUSED: | |
287 | if (!disabled) | |
288 | sh_tmu_disable(p); | |
289 | break; | |
290 | case CLOCK_EVT_MODE_SHUTDOWN: | |
291 | default: | |
292 | break; | |
293 | } | |
294 | } | |
295 | ||
296 | static int sh_tmu_clock_event_next(unsigned long delta, | |
297 | struct clock_event_device *ced) | |
298 | { | |
299 | struct sh_tmu_priv *p = ced_to_sh_tmu(ced); | |
300 | ||
301 | BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT); | |
302 | ||
303 | /* program new delta value */ | |
304 | sh_tmu_set_next(p, delta, 0); | |
305 | return 0; | |
306 | } | |
307 | ||
308 | static void sh_tmu_register_clockevent(struct sh_tmu_priv *p, | |
309 | char *name, unsigned long rating) | |
310 | { | |
311 | struct clock_event_device *ced = &p->ced; | |
312 | int ret; | |
313 | ||
314 | memset(ced, 0, sizeof(*ced)); | |
315 | ||
316 | ced->name = name; | |
317 | ced->features = CLOCK_EVT_FEAT_PERIODIC; | |
318 | ced->features |= CLOCK_EVT_FEAT_ONESHOT; | |
319 | ced->rating = rating; | |
320 | ced->cpumask = cpumask_of(0); | |
321 | ced->set_next_event = sh_tmu_clock_event_next; | |
322 | ced->set_mode = sh_tmu_clock_event_mode; | |
323 | ||
214a607a | 324 | dev_info(&p->pdev->dev, "used for clock events\n"); |
da64c2a8 PM |
325 | clockevents_register_device(ced); |
326 | ||
9570ef20 MD |
327 | ret = setup_irq(p->irqaction.irq, &p->irqaction); |
328 | if (ret) { | |
214a607a PM |
329 | dev_err(&p->pdev->dev, "failed to request irq %d\n", |
330 | p->irqaction.irq); | |
9570ef20 MD |
331 | return; |
332 | } | |
9570ef20 MD |
333 | } |
334 | ||
335 | static int sh_tmu_register(struct sh_tmu_priv *p, char *name, | |
336 | unsigned long clockevent_rating, | |
337 | unsigned long clocksource_rating) | |
338 | { | |
339 | if (clockevent_rating) | |
340 | sh_tmu_register_clockevent(p, name, clockevent_rating); | |
341 | else if (clocksource_rating) | |
342 | sh_tmu_register_clocksource(p, name, clocksource_rating); | |
343 | ||
344 | return 0; | |
345 | } | |
346 | ||
347 | static int sh_tmu_setup(struct sh_tmu_priv *p, struct platform_device *pdev) | |
348 | { | |
46a12f74 | 349 | struct sh_timer_config *cfg = pdev->dev.platform_data; |
9570ef20 MD |
350 | struct resource *res; |
351 | int irq, ret; | |
352 | ret = -ENXIO; | |
353 | ||
354 | memset(p, 0, sizeof(*p)); | |
355 | p->pdev = pdev; | |
356 | ||
357 | if (!cfg) { | |
358 | dev_err(&p->pdev->dev, "missing platform data\n"); | |
359 | goto err0; | |
360 | } | |
361 | ||
362 | platform_set_drvdata(pdev, p); | |
363 | ||
364 | res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0); | |
365 | if (!res) { | |
366 | dev_err(&p->pdev->dev, "failed to get I/O memory\n"); | |
367 | goto err0; | |
368 | } | |
369 | ||
370 | irq = platform_get_irq(p->pdev, 0); | |
371 | if (irq < 0) { | |
372 | dev_err(&p->pdev->dev, "failed to get irq\n"); | |
373 | goto err0; | |
374 | } | |
375 | ||
376 | /* map memory, let mapbase point to our channel */ | |
377 | p->mapbase = ioremap_nocache(res->start, resource_size(res)); | |
378 | if (p->mapbase == NULL) { | |
214a607a | 379 | dev_err(&p->pdev->dev, "failed to remap I/O memory\n"); |
9570ef20 MD |
380 | goto err0; |
381 | } | |
382 | ||
383 | /* setup data for setup_irq() (too early for request_irq()) */ | |
214a607a | 384 | p->irqaction.name = dev_name(&p->pdev->dev); |
9570ef20 MD |
385 | p->irqaction.handler = sh_tmu_interrupt; |
386 | p->irqaction.dev_id = p; | |
387 | p->irqaction.irq = irq; | |
fecf066c PM |
388 | p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | \ |
389 | IRQF_IRQPOLL | IRQF_NOBALANCING; | |
9570ef20 MD |
390 | |
391 | /* get hold of clock */ | |
c2a25e81 | 392 | p->clk = clk_get(&p->pdev->dev, "tmu_fck"); |
9570ef20 | 393 | if (IS_ERR(p->clk)) { |
03ff858c MD |
394 | dev_err(&p->pdev->dev, "cannot get clock\n"); |
395 | ret = PTR_ERR(p->clk); | |
396 | goto err1; | |
9570ef20 MD |
397 | } |
398 | ||
214a607a | 399 | return sh_tmu_register(p, (char *)dev_name(&p->pdev->dev), |
9570ef20 MD |
400 | cfg->clockevent_rating, |
401 | cfg->clocksource_rating); | |
402 | err1: | |
403 | iounmap(p->mapbase); | |
404 | err0: | |
405 | return ret; | |
406 | } | |
407 | ||
408 | static int __devinit sh_tmu_probe(struct platform_device *pdev) | |
409 | { | |
410 | struct sh_tmu_priv *p = platform_get_drvdata(pdev); | |
9570ef20 MD |
411 | int ret; |
412 | ||
413 | if (p) { | |
214a607a | 414 | dev_info(&pdev->dev, "kept as earlytimer\n"); |
9570ef20 MD |
415 | return 0; |
416 | } | |
417 | ||
418 | p = kmalloc(sizeof(*p), GFP_KERNEL); | |
419 | if (p == NULL) { | |
420 | dev_err(&pdev->dev, "failed to allocate driver data\n"); | |
421 | return -ENOMEM; | |
422 | } | |
423 | ||
424 | ret = sh_tmu_setup(p, pdev); | |
425 | if (ret) { | |
426 | kfree(p); | |
427 | platform_set_drvdata(pdev, NULL); | |
428 | } | |
429 | return ret; | |
430 | } | |
431 | ||
432 | static int __devexit sh_tmu_remove(struct platform_device *pdev) | |
433 | { | |
434 | return -EBUSY; /* cannot unregister clockevent and clocksource */ | |
435 | } | |
436 | ||
437 | static struct platform_driver sh_tmu_device_driver = { | |
438 | .probe = sh_tmu_probe, | |
439 | .remove = __devexit_p(sh_tmu_remove), | |
440 | .driver = { | |
441 | .name = "sh_tmu", | |
442 | } | |
443 | }; | |
444 | ||
445 | static int __init sh_tmu_init(void) | |
446 | { | |
447 | return platform_driver_register(&sh_tmu_device_driver); | |
448 | } | |
449 | ||
450 | static void __exit sh_tmu_exit(void) | |
451 | { | |
452 | platform_driver_unregister(&sh_tmu_device_driver); | |
453 | } | |
454 | ||
455 | early_platform_init("earlytimer", &sh_tmu_device_driver); | |
456 | module_init(sh_tmu_init); | |
457 | module_exit(sh_tmu_exit); | |
458 | ||
459 | MODULE_AUTHOR("Magnus Damm"); | |
460 | MODULE_DESCRIPTION("SuperH TMU Timer Driver"); | |
461 | MODULE_LICENSE("GPL v2"); |