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>
33 #include <linux/slab.h>
36 void __iomem
*mapbase
;
38 struct irqaction irqaction
;
39 struct platform_device
*pdev
;
41 unsigned long periodic
;
42 struct clock_event_device ced
;
43 struct clocksource cs
;
46 static DEFINE_SPINLOCK(sh_tmu_lock
);
48 #define TSTR -1 /* shared register */
49 #define TCOR 0 /* channel register */
50 #define TCNT 1 /* channel register */
51 #define TCR 2 /* channel register */
53 static inline unsigned long sh_tmu_read(struct sh_tmu_priv
*p
, int reg_nr
)
55 struct sh_timer_config
*cfg
= p
->pdev
->dev
.platform_data
;
56 void __iomem
*base
= p
->mapbase
;
60 return ioread8(base
- cfg
->channel_offset
);
65 return ioread16(base
+ offs
);
67 return ioread32(base
+ offs
);
70 static inline void sh_tmu_write(struct sh_tmu_priv
*p
, int reg_nr
,
73 struct sh_timer_config
*cfg
= p
->pdev
->dev
.platform_data
;
74 void __iomem
*base
= p
->mapbase
;
78 iowrite8(value
, base
- cfg
->channel_offset
);
85 iowrite16(value
, base
+ offs
);
87 iowrite32(value
, base
+ offs
);
90 static void sh_tmu_start_stop_ch(struct sh_tmu_priv
*p
, int start
)
92 struct sh_timer_config
*cfg
= p
->pdev
->dev
.platform_data
;
93 unsigned long flags
, value
;
95 /* start stop register shared by multiple timer channels */
96 spin_lock_irqsave(&sh_tmu_lock
, flags
);
97 value
= sh_tmu_read(p
, TSTR
);
100 value
|= 1 << cfg
->timer_bit
;
102 value
&= ~(1 << cfg
->timer_bit
);
104 sh_tmu_write(p
, TSTR
, value
);
105 spin_unlock_irqrestore(&sh_tmu_lock
, flags
);
108 static int sh_tmu_enable(struct sh_tmu_priv
*p
)
110 struct sh_timer_config
*cfg
= p
->pdev
->dev
.platform_data
;
114 ret
= clk_enable(p
->clk
);
116 pr_err("sh_tmu: cannot enable clock \"%s\"\n", cfg
->clk
);
120 /* make sure channel is disabled */
121 sh_tmu_start_stop_ch(p
, 0);
123 /* maximum timeout */
124 sh_tmu_write(p
, TCOR
, 0xffffffff);
125 sh_tmu_write(p
, TCNT
, 0xffffffff);
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);
132 sh_tmu_start_stop_ch(p
, 1);
137 static void sh_tmu_disable(struct sh_tmu_priv
*p
)
139 /* disable channel */
140 sh_tmu_start_stop_ch(p
, 0);
142 /* disable interrupts in TMU block */
143 sh_tmu_write(p
, TCR
, 0x0000);
149 static void sh_tmu_set_next(struct sh_tmu_priv
*p
, unsigned long delta
,
153 sh_tmu_start_stop_ch(p
, 0);
155 /* acknowledge interrupt */
158 /* enable interrupt */
159 sh_tmu_write(p
, TCR
, 0x0020);
161 /* reload delta value in case of periodic timer */
163 sh_tmu_write(p
, TCOR
, delta
);
165 sh_tmu_write(p
, TCOR
, 0xffffffff);
167 sh_tmu_write(p
, TCNT
, delta
);
170 sh_tmu_start_stop_ch(p
, 1);
173 static irqreturn_t
sh_tmu_interrupt(int irq
, void *dev_id
)
175 struct sh_tmu_priv
*p
= dev_id
;
177 /* disable or acknowledge interrupt */
178 if (p
->ced
.mode
== CLOCK_EVT_MODE_ONESHOT
)
179 sh_tmu_write(p
, TCR
, 0x0000);
181 sh_tmu_write(p
, TCR
, 0x0020);
183 /* notify clockevent layer */
184 p
->ced
.event_handler(&p
->ced
);
188 static struct sh_tmu_priv
*cs_to_sh_tmu(struct clocksource
*cs
)
190 return container_of(cs
, struct sh_tmu_priv
, cs
);
193 static cycle_t
sh_tmu_clocksource_read(struct clocksource
*cs
)
195 struct sh_tmu_priv
*p
= cs_to_sh_tmu(cs
);
197 return sh_tmu_read(p
, TCNT
) ^ 0xffffffff;
200 static int sh_tmu_clocksource_enable(struct clocksource
*cs
)
202 struct sh_tmu_priv
*p
= cs_to_sh_tmu(cs
);
204 return sh_tmu_enable(p
);
207 static void sh_tmu_clocksource_disable(struct clocksource
*cs
)
209 sh_tmu_disable(cs_to_sh_tmu(cs
));
212 static int sh_tmu_register_clocksource(struct sh_tmu_priv
*p
,
213 char *name
, unsigned long rating
)
215 struct clocksource
*cs
= &p
->cs
;
219 cs
->read
= sh_tmu_clocksource_read
;
220 cs
->enable
= sh_tmu_clocksource_enable
;
221 cs
->disable
= sh_tmu_clocksource_disable
;
222 cs
->mask
= CLOCKSOURCE_MASK(32);
223 cs
->flags
= CLOCK_SOURCE_IS_CONTINUOUS
;
225 /* clk_get_rate() needs an enabled clock */
227 /* channel will be configured at parent clock / 4 */
228 p
->rate
= clk_get_rate(p
->clk
) / 4;
230 /* TODO: calculate good shift from rate and counter bit width */
232 cs
->mult
= clocksource_hz2mult(p
->rate
, cs
->shift
);
234 pr_info("sh_tmu: %s used as clock source\n", cs
->name
);
235 clocksource_register(cs
);
239 static struct sh_tmu_priv
*ced_to_sh_tmu(struct clock_event_device
*ced
)
241 return container_of(ced
, struct sh_tmu_priv
, ced
);
244 static void sh_tmu_clock_event_start(struct sh_tmu_priv
*p
, int periodic
)
246 struct clock_event_device
*ced
= &p
->ced
;
250 /* TODO: calculate good shift from rate and counter bit width */
253 ced
->mult
= div_sc(p
->rate
, NSEC_PER_SEC
, ced
->shift
);
254 ced
->max_delta_ns
= clockevent_delta2ns(0xffffffff, ced
);
255 ced
->min_delta_ns
= 5000;
258 p
->periodic
= (p
->rate
+ HZ
/2) / HZ
;
259 sh_tmu_set_next(p
, p
->periodic
, 1);
263 static void sh_tmu_clock_event_mode(enum clock_event_mode mode
,
264 struct clock_event_device
*ced
)
266 struct sh_tmu_priv
*p
= ced_to_sh_tmu(ced
);
269 /* deal with old setting first */
271 case CLOCK_EVT_MODE_PERIODIC
:
272 case CLOCK_EVT_MODE_ONESHOT
:
281 case CLOCK_EVT_MODE_PERIODIC
:
282 pr_info("sh_tmu: %s used for periodic clock events\n",
284 sh_tmu_clock_event_start(p
, 1);
286 case CLOCK_EVT_MODE_ONESHOT
:
287 pr_info("sh_tmu: %s used for oneshot clock events\n",
289 sh_tmu_clock_event_start(p
, 0);
291 case CLOCK_EVT_MODE_UNUSED
:
295 case CLOCK_EVT_MODE_SHUTDOWN
:
301 static int sh_tmu_clock_event_next(unsigned long delta
,
302 struct clock_event_device
*ced
)
304 struct sh_tmu_priv
*p
= ced_to_sh_tmu(ced
);
306 BUG_ON(ced
->mode
!= CLOCK_EVT_MODE_ONESHOT
);
308 /* program new delta value */
309 sh_tmu_set_next(p
, delta
, 0);
313 static void sh_tmu_register_clockevent(struct sh_tmu_priv
*p
,
314 char *name
, unsigned long rating
)
316 struct clock_event_device
*ced
= &p
->ced
;
319 memset(ced
, 0, sizeof(*ced
));
322 ced
->features
= CLOCK_EVT_FEAT_PERIODIC
;
323 ced
->features
|= CLOCK_EVT_FEAT_ONESHOT
;
324 ced
->rating
= rating
;
325 ced
->cpumask
= cpumask_of(0);
326 ced
->set_next_event
= sh_tmu_clock_event_next
;
327 ced
->set_mode
= sh_tmu_clock_event_mode
;
329 pr_info("sh_tmu: %s used for clock events\n", ced
->name
);
330 clockevents_register_device(ced
);
332 ret
= setup_irq(p
->irqaction
.irq
, &p
->irqaction
);
334 pr_err("sh_tmu: failed to request irq %d\n",
340 static int sh_tmu_register(struct sh_tmu_priv
*p
, char *name
,
341 unsigned long clockevent_rating
,
342 unsigned long clocksource_rating
)
344 if (clockevent_rating
)
345 sh_tmu_register_clockevent(p
, name
, clockevent_rating
);
346 else if (clocksource_rating
)
347 sh_tmu_register_clocksource(p
, name
, clocksource_rating
);
352 static int sh_tmu_setup(struct sh_tmu_priv
*p
, struct platform_device
*pdev
)
354 struct sh_timer_config
*cfg
= pdev
->dev
.platform_data
;
355 struct resource
*res
;
359 memset(p
, 0, sizeof(*p
));
363 dev_err(&p
->pdev
->dev
, "missing platform data\n");
367 platform_set_drvdata(pdev
, p
);
369 res
= platform_get_resource(p
->pdev
, IORESOURCE_MEM
, 0);
371 dev_err(&p
->pdev
->dev
, "failed to get I/O memory\n");
375 irq
= platform_get_irq(p
->pdev
, 0);
377 dev_err(&p
->pdev
->dev
, "failed to get irq\n");
381 /* map memory, let mapbase point to our channel */
382 p
->mapbase
= ioremap_nocache(res
->start
, resource_size(res
));
383 if (p
->mapbase
== NULL
) {
384 pr_err("sh_tmu: failed to remap I/O memory\n");
388 /* setup data for setup_irq() (too early for request_irq()) */
389 p
->irqaction
.name
= cfg
->name
;
390 p
->irqaction
.handler
= sh_tmu_interrupt
;
391 p
->irqaction
.dev_id
= p
;
392 p
->irqaction
.irq
= irq
;
393 p
->irqaction
.flags
= IRQF_DISABLED
| IRQF_TIMER
| IRQF_IRQPOLL
;
395 /* get hold of clock */
396 p
->clk
= clk_get(&p
->pdev
->dev
, cfg
->clk
);
397 if (IS_ERR(p
->clk
)) {
398 pr_err("sh_tmu: cannot get clock \"%s\"\n", cfg
->clk
);
399 ret
= PTR_ERR(p
->clk
);
403 return sh_tmu_register(p
, cfg
->name
,
404 cfg
->clockevent_rating
,
405 cfg
->clocksource_rating
);
412 static int __devinit
sh_tmu_probe(struct platform_device
*pdev
)
414 struct sh_tmu_priv
*p
= platform_get_drvdata(pdev
);
415 struct sh_timer_config
*cfg
= pdev
->dev
.platform_data
;
419 pr_info("sh_tmu: %s kept as earlytimer\n", cfg
->name
);
423 p
= kmalloc(sizeof(*p
), GFP_KERNEL
);
425 dev_err(&pdev
->dev
, "failed to allocate driver data\n");
429 ret
= sh_tmu_setup(p
, pdev
);
432 platform_set_drvdata(pdev
, NULL
);
437 static int __devexit
sh_tmu_remove(struct platform_device
*pdev
)
439 return -EBUSY
; /* cannot unregister clockevent and clocksource */
442 static struct platform_driver sh_tmu_device_driver
= {
443 .probe
= sh_tmu_probe
,
444 .remove
= __devexit_p(sh_tmu_remove
),
450 static int __init
sh_tmu_init(void)
452 return platform_driver_register(&sh_tmu_device_driver
);
455 static void __exit
sh_tmu_exit(void)
457 platform_driver_unregister(&sh_tmu_device_driver
);
460 early_platform_init("earlytimer", &sh_tmu_device_driver
);
461 module_init(sh_tmu_init
);
462 module_exit(sh_tmu_exit
);
464 MODULE_AUTHOR("Magnus Damm");
465 MODULE_DESCRIPTION("SuperH TMU Timer Driver");
466 MODULE_LICENSE("GPL v2");