]> bbs.cooldavid.org Git - net-next-2.6.git/blame - drivers/clocksource/sh_tmu.c
clocksource: Deprecate clock string across the SH drivers.
[net-next-2.6.git] / drivers / clocksource / sh_tmu.c
CommitLineData
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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>
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33
34struct 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
45static 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
52static 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;
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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
69static 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;
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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
89static 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;
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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
107static int sh_tmu_enable(struct sh_tmu_priv *p)
108{
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109 int ret;
110
111 /* enable clock */
112 ret = clk_enable(p->clk);
113 if (ret) {
214a607a 114 dev_err(&p->pdev->dev, "cannot enable clock\n");
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115 return ret;
116 }
117
118 /* make sure channel is disabled */
119 sh_tmu_start_stop_ch(p, 0);
120
121 /* maximum timeout */
122 sh_tmu_write(p, TCOR, 0xffffffff);
123 sh_tmu_write(p, TCNT, 0xffffffff);
124
125 /* configure channel to parent clock / 4, irq off */
126 p->rate = clk_get_rate(p->clk) / 4;
127 sh_tmu_write(p, TCR, 0x0000);
128
129 /* enable channel */
130 sh_tmu_start_stop_ch(p, 1);
131
132 return 0;
133}
134
135static void sh_tmu_disable(struct sh_tmu_priv *p)
136{
137 /* disable channel */
138 sh_tmu_start_stop_ch(p, 0);
139
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140 /* disable interrupts in TMU block */
141 sh_tmu_write(p, TCR, 0x0000);
142
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143 /* stop clock */
144 clk_disable(p->clk);
145}
146
147static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta,
148 int periodic)
149{
150 /* stop timer */
151 sh_tmu_start_stop_ch(p, 0);
152
153 /* acknowledge interrupt */
154 sh_tmu_read(p, TCR);
155
156 /* enable interrupt */
157 sh_tmu_write(p, TCR, 0x0020);
158
159 /* reload delta value in case of periodic timer */
160 if (periodic)
161 sh_tmu_write(p, TCOR, delta);
162 else
6f4b67b8 163 sh_tmu_write(p, TCOR, 0xffffffff);
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164
165 sh_tmu_write(p, TCNT, delta);
166
167 /* start timer */
168 sh_tmu_start_stop_ch(p, 1);
169}
170
171static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
172{
173 struct sh_tmu_priv *p = dev_id;
174
175 /* disable or acknowledge interrupt */
176 if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT)
177 sh_tmu_write(p, TCR, 0x0000);
178 else
179 sh_tmu_write(p, TCR, 0x0020);
180
181 /* notify clockevent layer */
182 p->ced.event_handler(&p->ced);
183 return IRQ_HANDLED;
184}
185
186static struct sh_tmu_priv *cs_to_sh_tmu(struct clocksource *cs)
187{
188 return container_of(cs, struct sh_tmu_priv, cs);
189}
190
191static cycle_t sh_tmu_clocksource_read(struct clocksource *cs)
192{
193 struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
194
195 return sh_tmu_read(p, TCNT) ^ 0xffffffff;
196}
197
198static int sh_tmu_clocksource_enable(struct clocksource *cs)
199{
200 struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
201 int ret;
202
203 ret = sh_tmu_enable(p);
204 if (ret)
205 return ret;
206
207 /* TODO: calculate good shift from rate and counter bit width */
208 cs->shift = 10;
209 cs->mult = clocksource_hz2mult(p->rate, cs->shift);
210 return 0;
211}
212
213static void sh_tmu_clocksource_disable(struct clocksource *cs)
214{
215 sh_tmu_disable(cs_to_sh_tmu(cs));
216}
217
218static int sh_tmu_register_clocksource(struct sh_tmu_priv *p,
219 char *name, unsigned long rating)
220{
221 struct clocksource *cs = &p->cs;
222
223 cs->name = name;
224 cs->rating = rating;
225 cs->read = sh_tmu_clocksource_read;
226 cs->enable = sh_tmu_clocksource_enable;
227 cs->disable = sh_tmu_clocksource_disable;
228 cs->mask = CLOCKSOURCE_MASK(32);
229 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
214a607a 230 dev_info(&p->pdev->dev, "used as clock source\n");
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231 clocksource_register(cs);
232 return 0;
233}
234
235static struct sh_tmu_priv *ced_to_sh_tmu(struct clock_event_device *ced)
236{
237 return container_of(ced, struct sh_tmu_priv, ced);
238}
239
240static void sh_tmu_clock_event_start(struct sh_tmu_priv *p, int periodic)
241{
242 struct clock_event_device *ced = &p->ced;
243
244 sh_tmu_enable(p);
245
246 /* TODO: calculate good shift from rate and counter bit width */
247
248 ced->shift = 32;
249 ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
250 ced->max_delta_ns = clockevent_delta2ns(0xffffffff, ced);
251 ced->min_delta_ns = 5000;
252
253 if (periodic) {
254 p->periodic = (p->rate + HZ/2) / HZ;
255 sh_tmu_set_next(p, p->periodic, 1);
256 }
257}
258
259static void sh_tmu_clock_event_mode(enum clock_event_mode mode,
260 struct clock_event_device *ced)
261{
262 struct sh_tmu_priv *p = ced_to_sh_tmu(ced);
263 int disabled = 0;
264
265 /* deal with old setting first */
266 switch (ced->mode) {
267 case CLOCK_EVT_MODE_PERIODIC:
268 case CLOCK_EVT_MODE_ONESHOT:
269 sh_tmu_disable(p);
270 disabled = 1;
271 break;
272 default:
273 break;
274 }
275
276 switch (mode) {
277 case CLOCK_EVT_MODE_PERIODIC:
214a607a 278 dev_info(&p->pdev->dev, "used for periodic clock events\n");
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279 sh_tmu_clock_event_start(p, 1);
280 break;
281 case CLOCK_EVT_MODE_ONESHOT:
214a607a 282 dev_info(&p->pdev->dev, "used for oneshot clock events\n");
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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
295static 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
307static 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
214a607a 323 dev_info(&p->pdev->dev, "used for clock events\n");
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324 clockevents_register_device(ced);
325
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326 ret = setup_irq(p->irqaction.irq, &p->irqaction);
327 if (ret) {
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328 dev_err(&p->pdev->dev, "failed to request irq %d\n",
329 p->irqaction.irq);
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330 return;
331 }
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332}
333
334static 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
346static 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;
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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) {
214a607a 378 dev_err(&p->pdev->dev, "failed to remap I/O memory\n");
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379 goto err0;
380 }
381
382 /* setup data for setup_irq() (too early for request_irq()) */
214a607a 383 p->irqaction.name = dev_name(&p->pdev->dev);
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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;
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388
389 /* get hold of clock */
c2a25e81 390 p->clk = clk_get(&p->pdev->dev, "tmu_fck");
9570ef20 391 if (IS_ERR(p->clk)) {
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392 dev_warn(&p->pdev->dev, "using deprecated clock lookup\n");
393 p->clk = clk_get(&p->pdev->dev, cfg->clk);
394 if (IS_ERR(p->clk)) {
395 dev_err(&p->pdev->dev, "cannot get clock\n");
396 ret = PTR_ERR(p->clk);
397 goto err1;
398 }
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399 }
400
214a607a 401 return sh_tmu_register(p, (char *)dev_name(&p->pdev->dev),
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402 cfg->clockevent_rating,
403 cfg->clocksource_rating);
404 err1:
405 iounmap(p->mapbase);
406 err0:
407 return ret;
408}
409
410static int __devinit sh_tmu_probe(struct platform_device *pdev)
411{
412 struct sh_tmu_priv *p = platform_get_drvdata(pdev);
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413 int ret;
414
415 if (p) {
214a607a 416 dev_info(&pdev->dev, "kept as earlytimer\n");
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417 return 0;
418 }
419
420 p = kmalloc(sizeof(*p), GFP_KERNEL);
421 if (p == NULL) {
422 dev_err(&pdev->dev, "failed to allocate driver data\n");
423 return -ENOMEM;
424 }
425
426 ret = sh_tmu_setup(p, pdev);
427 if (ret) {
428 kfree(p);
429 platform_set_drvdata(pdev, NULL);
430 }
431 return ret;
432}
433
434static int __devexit sh_tmu_remove(struct platform_device *pdev)
435{
436 return -EBUSY; /* cannot unregister clockevent and clocksource */
437}
438
439static struct platform_driver sh_tmu_device_driver = {
440 .probe = sh_tmu_probe,
441 .remove = __devexit_p(sh_tmu_remove),
442 .driver = {
443 .name = "sh_tmu",
444 }
445};
446
447static int __init sh_tmu_init(void)
448{
449 return platform_driver_register(&sh_tmu_device_driver);
450}
451
452static void __exit sh_tmu_exit(void)
453{
454 platform_driver_unregister(&sh_tmu_device_driver);
455}
456
457early_platform_init("earlytimer", &sh_tmu_device_driver);
458module_init(sh_tmu_init);
459module_exit(sh_tmu_exit);
460
461MODULE_AUTHOR("Magnus Damm");
462MODULE_DESCRIPTION("SuperH TMU Timer Driver");
463MODULE_LICENSE("GPL v2");