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-rw-r--r--arch/arm/plat-samsung/s5p-time.c405
1 files changed, 405 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/s5p-time.c b/arch/arm/plat-samsung/s5p-time.c
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1/*
2 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
3 * http://www.samsung.com/
4 *
5 * S5P - Common hr-timer support
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10*/
11
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <linux/err.h>
15#include <linux/clk.h>
16#include <linux/clockchips.h>
17#include <linux/platform_device.h>
18
19#include <asm/smp_twd.h>
20#include <asm/mach/time.h>
21#include <asm/mach/arch.h>
22#include <asm/mach/map.h>
23#include <asm/sched_clock.h>
24
25#include <mach/map.h>
26#include <plat/devs.h>
27#include <plat/regs-timer.h>
28#include <plat/s5p-time.h>
29
30static struct clk *tin_event;
31static struct clk *tin_source;
32static struct clk *tdiv_event;
33static struct clk *tdiv_source;
34static struct clk *timerclk;
35static struct s5p_timer_source timer_source;
36static unsigned long clock_count_per_tick;
37static void s5p_timer_resume(void);
38
39static void s5p_time_stop(enum s5p_timer_mode mode)
40{
41 unsigned long tcon;
42
43 tcon = __raw_readl(S3C2410_TCON);
44
45 switch (mode) {
46 case S5P_PWM0:
47 tcon &= ~S3C2410_TCON_T0START;
48 break;
49
50 case S5P_PWM1:
51 tcon &= ~S3C2410_TCON_T1START;
52 break;
53
54 case S5P_PWM2:
55 tcon &= ~S3C2410_TCON_T2START;
56 break;
57
58 case S5P_PWM3:
59 tcon &= ~S3C2410_TCON_T3START;
60 break;
61
62 case S5P_PWM4:
63 tcon &= ~S3C2410_TCON_T4START;
64 break;
65
66 default:
67 printk(KERN_ERR "Invalid Timer %d\n", mode);
68 break;
69 }
70 __raw_writel(tcon, S3C2410_TCON);
71}
72
73static void s5p_time_setup(enum s5p_timer_mode mode, unsigned long tcnt)
74{
75 unsigned long tcon;
76
77 tcon = __raw_readl(S3C2410_TCON);
78
79 tcnt--;
80
81 switch (mode) {
82 case S5P_PWM0:
83 tcon &= ~(0x0f << 0);
84 tcon |= S3C2410_TCON_T0MANUALUPD;
85 break;
86
87 case S5P_PWM1:
88 tcon &= ~(0x0f << 8);
89 tcon |= S3C2410_TCON_T1MANUALUPD;
90 break;
91
92 case S5P_PWM2:
93 tcon &= ~(0x0f << 12);
94 tcon |= S3C2410_TCON_T2MANUALUPD;
95 break;
96
97 case S5P_PWM3:
98 tcon &= ~(0x0f << 16);
99 tcon |= S3C2410_TCON_T3MANUALUPD;
100 break;
101
102 case S5P_PWM4:
103 tcon &= ~(0x07 << 20);
104 tcon |= S3C2410_TCON_T4MANUALUPD;
105 break;
106
107 default:
108 printk(KERN_ERR "Invalid Timer %d\n", mode);
109 break;
110 }
111
112 __raw_writel(tcnt, S3C2410_TCNTB(mode));
113 __raw_writel(tcnt, S3C2410_TCMPB(mode));
114 __raw_writel(tcon, S3C2410_TCON);
115}
116
117static void s5p_time_start(enum s5p_timer_mode mode, bool periodic)
118{
119 unsigned long tcon;
120
121 tcon = __raw_readl(S3C2410_TCON);
122
123 switch (mode) {
124 case S5P_PWM0:
125 tcon |= S3C2410_TCON_T0START;
126 tcon &= ~S3C2410_TCON_T0MANUALUPD;
127
128 if (periodic)
129 tcon |= S3C2410_TCON_T0RELOAD;
130 else
131 tcon &= ~S3C2410_TCON_T0RELOAD;
132 break;
133
134 case S5P_PWM1:
135 tcon |= S3C2410_TCON_T1START;
136 tcon &= ~S3C2410_TCON_T1MANUALUPD;
137
138 if (periodic)
139 tcon |= S3C2410_TCON_T1RELOAD;
140 else
141 tcon &= ~S3C2410_TCON_T1RELOAD;
142 break;
143
144 case S5P_PWM2:
145 tcon |= S3C2410_TCON_T2START;
146 tcon &= ~S3C2410_TCON_T2MANUALUPD;
147
148 if (periodic)
149 tcon |= S3C2410_TCON_T2RELOAD;
150 else
151 tcon &= ~S3C2410_TCON_T2RELOAD;
152 break;
153
154 case S5P_PWM3:
155 tcon |= S3C2410_TCON_T3START;
156 tcon &= ~S3C2410_TCON_T3MANUALUPD;
157
158 if (periodic)
159 tcon |= S3C2410_TCON_T3RELOAD;
160 else
161 tcon &= ~S3C2410_TCON_T3RELOAD;
162 break;
163
164 case S5P_PWM4:
165 tcon |= S3C2410_TCON_T4START;
166 tcon &= ~S3C2410_TCON_T4MANUALUPD;
167
168 if (periodic)
169 tcon |= S3C2410_TCON_T4RELOAD;
170 else
171 tcon &= ~S3C2410_TCON_T4RELOAD;
172 break;
173
174 default:
175 printk(KERN_ERR "Invalid Timer %d\n", mode);
176 break;
177 }
178 __raw_writel(tcon, S3C2410_TCON);
179}
180
181static int s5p_set_next_event(unsigned long cycles,
182 struct clock_event_device *evt)
183{
184 s5p_time_setup(timer_source.event_id, cycles);
185 s5p_time_start(timer_source.event_id, NON_PERIODIC);
186
187 return 0;
188}
189
190static void s5p_set_mode(enum clock_event_mode mode,
191 struct clock_event_device *evt)
192{
193 s5p_time_stop(timer_source.event_id);
194
195 switch (mode) {
196 case CLOCK_EVT_MODE_PERIODIC:
197 s5p_time_setup(timer_source.event_id, clock_count_per_tick);
198 s5p_time_start(timer_source.event_id, PERIODIC);
199 break;
200
201 case CLOCK_EVT_MODE_ONESHOT:
202 break;
203
204 case CLOCK_EVT_MODE_UNUSED:
205 case CLOCK_EVT_MODE_SHUTDOWN:
206 break;
207
208 case CLOCK_EVT_MODE_RESUME:
209 s5p_timer_resume();
210 break;
211 }
212}
213
214static void s5p_timer_resume(void)
215{
216 /* event timer restart */
217 s5p_time_setup(timer_source.event_id, clock_count_per_tick);
218 s5p_time_start(timer_source.event_id, PERIODIC);
219
220 /* source timer restart */
221 s5p_time_setup(timer_source.source_id, TCNT_MAX);
222 s5p_time_start(timer_source.source_id, PERIODIC);
223}
224
225void __init s5p_set_timer_source(enum s5p_timer_mode event,
226 enum s5p_timer_mode source)
227{
228 s3c_device_timer[event].dev.bus = &platform_bus_type;
229 s3c_device_timer[source].dev.bus = &platform_bus_type;
230
231 timer_source.event_id = event;
232 timer_source.source_id = source;
233}
234
235static struct clock_event_device time_event_device = {
236 .name = "s5p_event_timer",
237 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
238 .rating = 200,
239 .set_next_event = s5p_set_next_event,
240 .set_mode = s5p_set_mode,
241};
242
243static irqreturn_t s5p_clock_event_isr(int irq, void *dev_id)
244{
245 struct clock_event_device *evt = dev_id;
246
247 evt->event_handler(evt);
248
249 return IRQ_HANDLED;
250}
251
252static struct irqaction s5p_clock_event_irq = {
253 .name = "s5p_time_irq",
254 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
255 .handler = s5p_clock_event_isr,
256 .dev_id = &time_event_device,
257};
258
259static void __init s5p_clockevent_init(void)
260{
261 unsigned long pclk;
262 unsigned long clock_rate;
263 unsigned int irq_number;
264 struct clk *tscaler;
265
266 pclk = clk_get_rate(timerclk);
267
268 tscaler = clk_get_parent(tdiv_event);
269
270 clk_set_rate(tscaler, pclk / 2);
271 clk_set_rate(tdiv_event, pclk / 2);
272 clk_set_parent(tin_event, tdiv_event);
273
274 clock_rate = clk_get_rate(tin_event);
275 clock_count_per_tick = clock_rate / HZ;
276
277 clockevents_calc_mult_shift(&time_event_device,
278 clock_rate, S5PTIMER_MIN_RANGE);
279 time_event_device.max_delta_ns =
280 clockevent_delta2ns(-1, &time_event_device);
281 time_event_device.min_delta_ns =
282 clockevent_delta2ns(1, &time_event_device);
283
284 time_event_device.cpumask = cpumask_of(0);
285 clockevents_register_device(&time_event_device);
286
287 irq_number = timer_source.event_id + IRQ_TIMER0;
288 setup_irq(irq_number, &s5p_clock_event_irq);
289}
290
291static void __iomem *s5p_timer_reg(void)
292{
293 unsigned long offset = 0;
294
295 switch (timer_source.source_id) {
296 case S5P_PWM0:
297 case S5P_PWM1:
298 case S5P_PWM2:
299 case S5P_PWM3:
300 offset = (timer_source.source_id * 0x0c) + 0x14;
301 break;
302
303 case S5P_PWM4:
304 offset = 0x40;
305 break;
306
307 default:
308 printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
309 return NULL;
310 }
311
312 return S3C_TIMERREG(offset);
313}
314
315/*
316 * Override the global weak sched_clock symbol with this
317 * local implementation which uses the clocksource to get some
318 * better resolution when scheduling the kernel. We accept that
319 * this wraps around for now, since it is just a relative time
320 * stamp. (Inspired by U300 implementation.)
321 */
322static u32 notrace s5p_read_sched_clock(void)
323{
324 void __iomem *reg = s5p_timer_reg();
325
326 if (!reg)
327 return 0;
328
329 return ~__raw_readl(reg);
330}
331
332static void __init s5p_clocksource_init(void)
333{
334 unsigned long pclk;
335 unsigned long clock_rate;
336
337 pclk = clk_get_rate(timerclk);
338
339 clk_set_rate(tdiv_source, pclk / 2);
340 clk_set_parent(tin_source, tdiv_source);
341
342 clock_rate = clk_get_rate(tin_source);
343
344 s5p_time_setup(timer_source.source_id, TCNT_MAX);
345 s5p_time_start(timer_source.source_id, PERIODIC);
346
347 setup_sched_clock(s5p_read_sched_clock, 32, clock_rate);
348
349 if (clocksource_mmio_init(s5p_timer_reg(), "s5p_clocksource_timer",
350 clock_rate, 250, 32, clocksource_mmio_readl_down))
351 panic("s5p_clocksource_timer: can't register clocksource\n");
352}
353
354static void __init s5p_timer_resources(void)
355{
356
357 unsigned long event_id = timer_source.event_id;
358 unsigned long source_id = timer_source.source_id;
359 char devname[15];
360
361 timerclk = clk_get(NULL, "timers");
362 if (IS_ERR(timerclk))
363 panic("failed to get timers clock for timer");
364
365 clk_enable(timerclk);
366
367 sprintf(devname, "s3c24xx-pwm.%lu", event_id);
368 s3c_device_timer[event_id].id = event_id;
369 s3c_device_timer[event_id].dev.init_name = devname;
370
371 tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
372 if (IS_ERR(tin_event))
373 panic("failed to get pwm-tin clock for event timer");
374
375 tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
376 if (IS_ERR(tdiv_event))
377 panic("failed to get pwm-tdiv clock for event timer");
378
379 clk_enable(tin_event);
380
381 sprintf(devname, "s3c24xx-pwm.%lu", source_id);
382 s3c_device_timer[source_id].id = source_id;
383 s3c_device_timer[source_id].dev.init_name = devname;
384
385 tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
386 if (IS_ERR(tin_source))
387 panic("failed to get pwm-tin clock for source timer");
388
389 tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
390 if (IS_ERR(tdiv_source))
391 panic("failed to get pwm-tdiv clock for source timer");
392
393 clk_enable(tin_source);
394}
395
396static void __init s5p_timer_init(void)
397{
398 s5p_timer_resources();
399 s5p_clockevent_init();
400 s5p_clocksource_init();
401}
402
403struct sys_timer s5p_timer = {
404 .init = s5p_timer_init,
405};