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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> |
9570ef20 MD |
33 | |
34 | struct sh_tmu_priv { | |
35 | void __iomem *mapbase; | |
36 | struct clk *clk; | |
37 | struct irqaction irqaction; | |
38 | struct platform_device *pdev; | |
39 | unsigned long rate; | |
40 | unsigned long periodic; | |
41 | struct clock_event_device ced; | |
42 | struct clocksource cs; | |
43 | }; | |
44 | ||
45 | static DEFINE_SPINLOCK(sh_tmu_lock); | |
46 | ||
47 | #define TSTR -1 /* shared register */ | |
48 | #define TCOR 0 /* channel register */ | |
49 | #define TCNT 1 /* channel register */ | |
50 | #define TCR 2 /* channel register */ | |
51 | ||
52 | static inline unsigned long sh_tmu_read(struct sh_tmu_priv *p, int reg_nr) | |
53 | { | |
46a12f74 | 54 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
55 | void __iomem *base = p->mapbase; |
56 | unsigned long offs; | |
57 | ||
58 | if (reg_nr == TSTR) | |
59 | return ioread8(base - cfg->channel_offset); | |
60 | ||
61 | offs = reg_nr << 2; | |
62 | ||
63 | if (reg_nr == TCR) | |
64 | return ioread16(base + offs); | |
65 | else | |
66 | return ioread32(base + offs); | |
67 | } | |
68 | ||
69 | static inline void sh_tmu_write(struct sh_tmu_priv *p, int reg_nr, | |
70 | unsigned long value) | |
71 | { | |
46a12f74 | 72 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
73 | void __iomem *base = p->mapbase; |
74 | unsigned long offs; | |
75 | ||
76 | if (reg_nr == TSTR) { | |
77 | iowrite8(value, base - cfg->channel_offset); | |
78 | return; | |
79 | } | |
80 | ||
81 | offs = reg_nr << 2; | |
82 | ||
83 | if (reg_nr == TCR) | |
84 | iowrite16(value, base + offs); | |
85 | else | |
86 | iowrite32(value, base + offs); | |
87 | } | |
88 | ||
89 | static void sh_tmu_start_stop_ch(struct sh_tmu_priv *p, int start) | |
90 | { | |
46a12f74 | 91 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
92 | unsigned long flags, value; |
93 | ||
94 | /* start stop register shared by multiple timer channels */ | |
95 | spin_lock_irqsave(&sh_tmu_lock, flags); | |
96 | value = sh_tmu_read(p, TSTR); | |
97 | ||
98 | if (start) | |
99 | value |= 1 << cfg->timer_bit; | |
100 | else | |
101 | value &= ~(1 << cfg->timer_bit); | |
102 | ||
103 | sh_tmu_write(p, TSTR, value); | |
104 | spin_unlock_irqrestore(&sh_tmu_lock, flags); | |
105 | } | |
106 | ||
107 | static int sh_tmu_enable(struct sh_tmu_priv *p) | |
108 | { | |
46a12f74 | 109 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
9570ef20 MD |
110 | int ret; |
111 | ||
112 | /* enable clock */ | |
113 | ret = clk_enable(p->clk); | |
114 | if (ret) { | |
115 | pr_err("sh_tmu: cannot enable clock \"%s\"\n", cfg->clk); | |
116 | return ret; | |
117 | } | |
118 | ||
119 | /* make sure channel is disabled */ | |
120 | sh_tmu_start_stop_ch(p, 0); | |
121 | ||
122 | /* maximum timeout */ | |
123 | sh_tmu_write(p, TCOR, 0xffffffff); | |
124 | sh_tmu_write(p, TCNT, 0xffffffff); | |
125 | ||
126 | /* configure channel to parent clock / 4, irq off */ | |
127 | p->rate = clk_get_rate(p->clk) / 4; | |
128 | sh_tmu_write(p, TCR, 0x0000); | |
129 | ||
130 | /* enable channel */ | |
131 | sh_tmu_start_stop_ch(p, 1); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static void sh_tmu_disable(struct sh_tmu_priv *p) | |
137 | { | |
138 | /* disable channel */ | |
139 | sh_tmu_start_stop_ch(p, 0); | |
140 | ||
141 | /* stop clock */ | |
142 | clk_disable(p->clk); | |
143 | } | |
144 | ||
145 | static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta, | |
146 | int periodic) | |
147 | { | |
148 | /* stop timer */ | |
149 | sh_tmu_start_stop_ch(p, 0); | |
150 | ||
151 | /* acknowledge interrupt */ | |
152 | sh_tmu_read(p, TCR); | |
153 | ||
154 | /* enable interrupt */ | |
155 | sh_tmu_write(p, TCR, 0x0020); | |
156 | ||
157 | /* reload delta value in case of periodic timer */ | |
158 | if (periodic) | |
159 | sh_tmu_write(p, TCOR, delta); | |
160 | else | |
161 | sh_tmu_write(p, TCOR, 0); | |
162 | ||
163 | sh_tmu_write(p, TCNT, delta); | |
164 | ||
165 | /* start timer */ | |
166 | sh_tmu_start_stop_ch(p, 1); | |
167 | } | |
168 | ||
169 | static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id) | |
170 | { | |
171 | struct sh_tmu_priv *p = dev_id; | |
172 | ||
173 | /* disable or acknowledge interrupt */ | |
174 | if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT) | |
175 | sh_tmu_write(p, TCR, 0x0000); | |
176 | else | |
177 | sh_tmu_write(p, TCR, 0x0020); | |
178 | ||
179 | /* notify clockevent layer */ | |
180 | p->ced.event_handler(&p->ced); | |
181 | return IRQ_HANDLED; | |
182 | } | |
183 | ||
184 | static struct sh_tmu_priv *cs_to_sh_tmu(struct clocksource *cs) | |
185 | { | |
186 | return container_of(cs, struct sh_tmu_priv, cs); | |
187 | } | |
188 | ||
189 | static cycle_t sh_tmu_clocksource_read(struct clocksource *cs) | |
190 | { | |
191 | struct sh_tmu_priv *p = cs_to_sh_tmu(cs); | |
192 | ||
193 | return sh_tmu_read(p, TCNT) ^ 0xffffffff; | |
194 | } | |
195 | ||
196 | static int sh_tmu_clocksource_enable(struct clocksource *cs) | |
197 | { | |
198 | struct sh_tmu_priv *p = cs_to_sh_tmu(cs); | |
199 | int ret; | |
200 | ||
201 | ret = sh_tmu_enable(p); | |
202 | if (ret) | |
203 | return ret; | |
204 | ||
205 | /* TODO: calculate good shift from rate and counter bit width */ | |
206 | cs->shift = 10; | |
207 | cs->mult = clocksource_hz2mult(p->rate, cs->shift); | |
208 | return 0; | |
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; | |
228 | pr_info("sh_tmu: %s used as clock source\n", cs->name); | |
229 | clocksource_register(cs); | |
230 | return 0; | |
231 | } | |
232 | ||
233 | static struct sh_tmu_priv *ced_to_sh_tmu(struct clock_event_device *ced) | |
234 | { | |
235 | return container_of(ced, struct sh_tmu_priv, ced); | |
236 | } | |
237 | ||
238 | static void sh_tmu_clock_event_start(struct sh_tmu_priv *p, int periodic) | |
239 | { | |
240 | struct clock_event_device *ced = &p->ced; | |
241 | ||
242 | sh_tmu_enable(p); | |
243 | ||
244 | /* TODO: calculate good shift from rate and counter bit width */ | |
245 | ||
246 | ced->shift = 32; | |
247 | ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift); | |
248 | ced->max_delta_ns = clockevent_delta2ns(0xffffffff, ced); | |
249 | ced->min_delta_ns = 5000; | |
250 | ||
251 | if (periodic) { | |
252 | p->periodic = (p->rate + HZ/2) / HZ; | |
253 | sh_tmu_set_next(p, p->periodic, 1); | |
254 | } | |
255 | } | |
256 | ||
257 | static void sh_tmu_clock_event_mode(enum clock_event_mode mode, | |
258 | struct clock_event_device *ced) | |
259 | { | |
260 | struct sh_tmu_priv *p = ced_to_sh_tmu(ced); | |
261 | int disabled = 0; | |
262 | ||
263 | /* deal with old setting first */ | |
264 | switch (ced->mode) { | |
265 | case CLOCK_EVT_MODE_PERIODIC: | |
266 | case CLOCK_EVT_MODE_ONESHOT: | |
267 | sh_tmu_disable(p); | |
268 | disabled = 1; | |
269 | break; | |
270 | default: | |
271 | break; | |
272 | } | |
273 | ||
274 | switch (mode) { | |
275 | case CLOCK_EVT_MODE_PERIODIC: | |
276 | pr_info("sh_tmu: %s used for periodic clock events\n", | |
277 | ced->name); | |
278 | sh_tmu_clock_event_start(p, 1); | |
279 | break; | |
280 | case CLOCK_EVT_MODE_ONESHOT: | |
281 | pr_info("sh_tmu: %s used for oneshot clock events\n", | |
282 | ced->name); | |
283 | sh_tmu_clock_event_start(p, 0); | |
284 | break; | |
285 | case CLOCK_EVT_MODE_UNUSED: | |
286 | if (!disabled) | |
287 | sh_tmu_disable(p); | |
288 | break; | |
289 | case CLOCK_EVT_MODE_SHUTDOWN: | |
290 | default: | |
291 | break; | |
292 | } | |
293 | } | |
294 | ||
295 | static int sh_tmu_clock_event_next(unsigned long delta, | |
296 | struct clock_event_device *ced) | |
297 | { | |
298 | struct sh_tmu_priv *p = ced_to_sh_tmu(ced); | |
299 | ||
300 | BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT); | |
301 | ||
302 | /* program new delta value */ | |
303 | sh_tmu_set_next(p, delta, 0); | |
304 | return 0; | |
305 | } | |
306 | ||
307 | static void sh_tmu_register_clockevent(struct sh_tmu_priv *p, | |
308 | char *name, unsigned long rating) | |
309 | { | |
310 | struct clock_event_device *ced = &p->ced; | |
311 | int ret; | |
312 | ||
313 | memset(ced, 0, sizeof(*ced)); | |
314 | ||
315 | ced->name = name; | |
316 | ced->features = CLOCK_EVT_FEAT_PERIODIC; | |
317 | ced->features |= CLOCK_EVT_FEAT_ONESHOT; | |
318 | ced->rating = rating; | |
319 | ced->cpumask = cpumask_of(0); | |
320 | ced->set_next_event = sh_tmu_clock_event_next; | |
321 | ced->set_mode = sh_tmu_clock_event_mode; | |
322 | ||
323 | ret = setup_irq(p->irqaction.irq, &p->irqaction); | |
324 | if (ret) { | |
325 | pr_err("sh_tmu: failed to request irq %d\n", | |
326 | p->irqaction.irq); | |
327 | return; | |
328 | } | |
329 | ||
330 | pr_info("sh_tmu: %s used for clock events\n", ced->name); | |
331 | clockevents_register_device(ced); | |
332 | } | |
333 | ||
334 | static int sh_tmu_register(struct sh_tmu_priv *p, char *name, | |
335 | unsigned long clockevent_rating, | |
336 | unsigned long clocksource_rating) | |
337 | { | |
338 | if (clockevent_rating) | |
339 | sh_tmu_register_clockevent(p, name, clockevent_rating); | |
340 | else if (clocksource_rating) | |
341 | sh_tmu_register_clocksource(p, name, clocksource_rating); | |
342 | ||
343 | return 0; | |
344 | } | |
345 | ||
346 | static int sh_tmu_setup(struct sh_tmu_priv *p, struct platform_device *pdev) | |
347 | { | |
46a12f74 | 348 | struct sh_timer_config *cfg = pdev->dev.platform_data; |
9570ef20 MD |
349 | struct resource *res; |
350 | int irq, ret; | |
351 | ret = -ENXIO; | |
352 | ||
353 | memset(p, 0, sizeof(*p)); | |
354 | p->pdev = pdev; | |
355 | ||
356 | if (!cfg) { | |
357 | dev_err(&p->pdev->dev, "missing platform data\n"); | |
358 | goto err0; | |
359 | } | |
360 | ||
361 | platform_set_drvdata(pdev, p); | |
362 | ||
363 | res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0); | |
364 | if (!res) { | |
365 | dev_err(&p->pdev->dev, "failed to get I/O memory\n"); | |
366 | goto err0; | |
367 | } | |
368 | ||
369 | irq = platform_get_irq(p->pdev, 0); | |
370 | if (irq < 0) { | |
371 | dev_err(&p->pdev->dev, "failed to get irq\n"); | |
372 | goto err0; | |
373 | } | |
374 | ||
375 | /* map memory, let mapbase point to our channel */ | |
376 | p->mapbase = ioremap_nocache(res->start, resource_size(res)); | |
377 | if (p->mapbase == NULL) { | |
378 | pr_err("sh_tmu: failed to remap I/O memory\n"); | |
379 | goto err0; | |
380 | } | |
381 | ||
382 | /* setup data for setup_irq() (too early for request_irq()) */ | |
383 | p->irqaction.name = cfg->name; | |
384 | p->irqaction.handler = sh_tmu_interrupt; | |
385 | p->irqaction.dev_id = p; | |
386 | p->irqaction.irq = irq; | |
387 | p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL; | |
388 | p->irqaction.mask = CPU_MASK_NONE; | |
389 | ||
390 | /* get hold of clock */ | |
391 | p->clk = clk_get(&p->pdev->dev, cfg->clk); | |
392 | if (IS_ERR(p->clk)) { | |
393 | pr_err("sh_tmu: cannot get clock \"%s\"\n", cfg->clk); | |
394 | ret = PTR_ERR(p->clk); | |
395 | goto err1; | |
396 | } | |
397 | ||
398 | return sh_tmu_register(p, cfg->name, | |
399 | cfg->clockevent_rating, | |
400 | cfg->clocksource_rating); | |
401 | err1: | |
402 | iounmap(p->mapbase); | |
403 | err0: | |
404 | return ret; | |
405 | } | |
406 | ||
407 | static int __devinit sh_tmu_probe(struct platform_device *pdev) | |
408 | { | |
409 | struct sh_tmu_priv *p = platform_get_drvdata(pdev); | |
46a12f74 | 410 | struct sh_timer_config *cfg = pdev->dev.platform_data; |
9570ef20 MD |
411 | int ret; |
412 | ||
413 | if (p) { | |
414 | pr_info("sh_tmu: %s kept as earlytimer\n", cfg->name); | |
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"); |