2 * SuperH Timer Support - TMU
4 * Copyright (C) 2009 Magnus Damm
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
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.
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
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>
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>
32 #include <linux/sh_timer.h>
35 void __iomem *mapbase;
37 struct irqaction irqaction;
38 struct platform_device *pdev;
40 unsigned long periodic;
41 struct clock_event_device ced;
42 struct clocksource cs;
45 static DEFINE_SPINLOCK(sh_tmu_lock);
47 #define TSTR -1 /* shared register */
48 #define TCOR 0 /* channel register */
49 #define TCNT 1 /* channel register */
50 #define TCR 2 /* channel register */
52 static inline unsigned long sh_tmu_read(struct sh_tmu_priv *p, int reg_nr)
54 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
55 void __iomem *base = p->mapbase;
59 return ioread8(base - cfg->channel_offset);
64 return ioread16(base + offs);
66 return ioread32(base + offs);
69 static inline void sh_tmu_write(struct sh_tmu_priv *p, int reg_nr,
72 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
73 void __iomem *base = p->mapbase;
77 iowrite8(value, base - cfg->channel_offset);
84 iowrite16(value, base + offs);
86 iowrite32(value, base + offs);
89 static void sh_tmu_start_stop_ch(struct sh_tmu_priv *p, int start)
91 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
92 unsigned long flags, value;
94 /* start stop register shared by multiple timer channels */
95 spin_lock_irqsave(&sh_tmu_lock, flags);
96 value = sh_tmu_read(p, TSTR);
99 value |= 1 << cfg->timer_bit;
101 value &= ~(1 << cfg->timer_bit);
103 sh_tmu_write(p, TSTR, value);
104 spin_unlock_irqrestore(&sh_tmu_lock, flags);
107 static int sh_tmu_enable(struct sh_tmu_priv *p)
109 struct sh_timer_config *cfg = p->pdev->dev.platform_data;
113 ret = clk_enable(p->clk);
115 pr_err("sh_tmu: cannot enable clock \"%s\"\n", cfg->clk);
119 /* make sure channel is disabled */
120 sh_tmu_start_stop_ch(p, 0);
122 /* maximum timeout */
123 sh_tmu_write(p, TCOR, 0xffffffff);
124 sh_tmu_write(p, TCNT, 0xffffffff);
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);
131 sh_tmu_start_stop_ch(p, 1);
136 static void sh_tmu_disable(struct sh_tmu_priv *p)
138 /* disable channel */
139 sh_tmu_start_stop_ch(p, 0);
145 static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta,
149 sh_tmu_start_stop_ch(p, 0);
151 /* acknowledge interrupt */
154 /* enable interrupt */
155 sh_tmu_write(p, TCR, 0x0020);
157 /* reload delta value in case of periodic timer */
159 sh_tmu_write(p, TCOR, delta);
161 sh_tmu_write(p, TCOR, 0);
163 sh_tmu_write(p, TCNT, delta);
166 sh_tmu_start_stop_ch(p, 1);
169 static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
171 struct sh_tmu_priv *p = dev_id;
173 /* disable or acknowledge interrupt */
174 if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT)
175 sh_tmu_write(p, TCR, 0x0000);
177 sh_tmu_write(p, TCR, 0x0020);
179 /* notify clockevent layer */
180 p->ced.event_handler(&p->ced);
184 static struct sh_tmu_priv *cs_to_sh_tmu(struct clocksource *cs)
186 return container_of(cs, struct sh_tmu_priv, cs);
189 static cycle_t sh_tmu_clocksource_read(struct clocksource *cs)
191 struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
193 return sh_tmu_read(p, TCNT) ^ 0xffffffff;
196 static int sh_tmu_clocksource_enable(struct clocksource *cs)
198 struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
201 ret = sh_tmu_enable(p);
205 /* TODO: calculate good shift from rate and counter bit width */
207 cs->mult = clocksource_hz2mult(p->rate, cs->shift);
211 static void sh_tmu_clocksource_disable(struct clocksource *cs)
213 sh_tmu_disable(cs_to_sh_tmu(cs));
216 static int sh_tmu_register_clocksource(struct sh_tmu_priv *p,
217 char *name, unsigned long rating)
219 struct clocksource *cs = &p->cs;
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);
233 static struct sh_tmu_priv *ced_to_sh_tmu(struct clock_event_device *ced)
235 return container_of(ced, struct sh_tmu_priv, ced);
238 static void sh_tmu_clock_event_start(struct sh_tmu_priv *p, int periodic)
240 struct clock_event_device *ced = &p->ced;
244 /* TODO: calculate good shift from rate and counter bit width */
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;
252 p->periodic = (p->rate + HZ/2) / HZ;
253 sh_tmu_set_next(p, p->periodic, 1);
257 static void sh_tmu_clock_event_mode(enum clock_event_mode mode,
258 struct clock_event_device *ced)
260 struct sh_tmu_priv *p = ced_to_sh_tmu(ced);
263 /* deal with old setting first */
265 case CLOCK_EVT_MODE_PERIODIC:
266 case CLOCK_EVT_MODE_ONESHOT:
275 case CLOCK_EVT_MODE_PERIODIC:
276 pr_info("sh_tmu: %s used for periodic clock events\n",
278 sh_tmu_clock_event_start(p, 1);
280 case CLOCK_EVT_MODE_ONESHOT:
281 pr_info("sh_tmu: %s used for oneshot clock events\n",
283 sh_tmu_clock_event_start(p, 0);
285 case CLOCK_EVT_MODE_UNUSED:
289 case CLOCK_EVT_MODE_SHUTDOWN:
295 static int sh_tmu_clock_event_next(unsigned long delta,
296 struct clock_event_device *ced)
298 struct sh_tmu_priv *p = ced_to_sh_tmu(ced);
300 BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);
302 /* program new delta value */
303 sh_tmu_set_next(p, delta, 0);
307 static void sh_tmu_register_clockevent(struct sh_tmu_priv *p,
308 char *name, unsigned long rating)
310 struct clock_event_device *ced = &p->ced;
313 memset(ced, 0, sizeof(*ced));
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;
323 ret = setup_irq(p->irqaction.irq, &p->irqaction);
325 pr_err("sh_tmu: failed to request irq %d\n",
330 pr_info("sh_tmu: %s used for clock events\n", ced->name);
331 clockevents_register_device(ced);
334 static int sh_tmu_register(struct sh_tmu_priv *p, char *name,
335 unsigned long clockevent_rating,
336 unsigned long clocksource_rating)
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);
346 static int sh_tmu_setup(struct sh_tmu_priv *p, struct platform_device *pdev)
348 struct sh_timer_config *cfg = pdev->dev.platform_data;
349 struct resource *res;
353 memset(p, 0, sizeof(*p));
357 dev_err(&p->pdev->dev, "missing platform data\n");
361 platform_set_drvdata(pdev, p);
363 res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0);
365 dev_err(&p->pdev->dev, "failed to get I/O memory\n");
369 irq = platform_get_irq(p->pdev, 0);
371 dev_err(&p->pdev->dev, "failed to get irq\n");
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");
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;
389 /* get hold of clock */
390 p->clk = clk_get(&p->pdev->dev, cfg->clk);
391 if (IS_ERR(p->clk)) {
392 pr_err("sh_tmu: cannot get clock \"%s\"\n", cfg->clk);
393 ret = PTR_ERR(p->clk);
397 return sh_tmu_register(p, cfg->name,
398 cfg->clockevent_rating,
399 cfg->clocksource_rating);
406 static int __devinit sh_tmu_probe(struct platform_device *pdev)
408 struct sh_tmu_priv *p = platform_get_drvdata(pdev);
409 struct sh_timer_config *cfg = pdev->dev.platform_data;
413 pr_info("sh_tmu: %s kept as earlytimer\n", cfg->name);
417 p = kmalloc(sizeof(*p), GFP_KERNEL);
419 dev_err(&pdev->dev, "failed to allocate driver data\n");
423 ret = sh_tmu_setup(p, pdev);
426 platform_set_drvdata(pdev, NULL);
431 static int __devexit sh_tmu_remove(struct platform_device *pdev)
433 return -EBUSY; /* cannot unregister clockevent and clocksource */
436 static struct platform_driver sh_tmu_device_driver = {
437 .probe = sh_tmu_probe,
438 .remove = __devexit_p(sh_tmu_remove),
444 static int __init sh_tmu_init(void)
446 return platform_driver_register(&sh_tmu_device_driver);
449 static void __exit sh_tmu_exit(void)
451 platform_driver_unregister(&sh_tmu_device_driver);
454 early_platform_init("earlytimer", &sh_tmu_device_driver);
455 module_init(sh_tmu_init);
456 module_exit(sh_tmu_exit);
458 MODULE_AUTHOR("Magnus Damm");
459 MODULE_DESCRIPTION("SuperH TMU Timer Driver");
460 MODULE_LICENSE("GPL v2");