1 /*
2 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
3 * http://www.samsung.com/
4 *
5 * samsung - Common hr-timer support (s3c and s5p)
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/samsung-time.h>
29
30 static struct clk *tin_event;
31 static struct clk *tin_source;
32 static struct clk *tdiv_event;
33 static struct clk *tdiv_source;
34 static struct clk *timerclk;
35 static struct samsung_timer_source timer_source;
36 static unsigned long clock_count_per_tick;
37 static void samsung_timer_resume(void);
38
samsung_time_stop(enum samsung_timer_mode mode)39 static void samsung_time_stop(enum samsung_timer_mode mode)
40 {
41 unsigned long tcon;
42
43 tcon = __raw_readl(S3C2410_TCON);
44
45 switch (mode) {
46 case SAMSUNG_PWM0:
47 tcon &= ~S3C2410_TCON_T0START;
48 break;
49
50 case SAMSUNG_PWM1:
51 tcon &= ~S3C2410_TCON_T1START;
52 break;
53
54 case SAMSUNG_PWM2:
55 tcon &= ~S3C2410_TCON_T2START;
56 break;
57
58 case SAMSUNG_PWM3:
59 tcon &= ~S3C2410_TCON_T3START;
60 break;
61
62 case SAMSUNG_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
samsung_time_setup(enum samsung_timer_mode mode,unsigned long tcnt)73 static void samsung_time_setup(enum samsung_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 SAMSUNG_PWM0:
83 tcon &= ~(0x0f << 0);
84 tcon |= S3C2410_TCON_T0MANUALUPD;
85 break;
86
87 case SAMSUNG_PWM1:
88 tcon &= ~(0x0f << 8);
89 tcon |= S3C2410_TCON_T1MANUALUPD;
90 break;
91
92 case SAMSUNG_PWM2:
93 tcon &= ~(0x0f << 12);
94 tcon |= S3C2410_TCON_T2MANUALUPD;
95 break;
96
97 case SAMSUNG_PWM3:
98 tcon &= ~(0x0f << 16);
99 tcon |= S3C2410_TCON_T3MANUALUPD;
100 break;
101
102 case SAMSUNG_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
samsung_time_start(enum samsung_timer_mode mode,bool periodic)117 static void samsung_time_start(enum samsung_timer_mode mode, bool periodic)
118 {
119 unsigned long tcon;
120
121 tcon = __raw_readl(S3C2410_TCON);
122
123 switch (mode) {
124 case SAMSUNG_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 SAMSUNG_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 SAMSUNG_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 SAMSUNG_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 SAMSUNG_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
samsung_set_next_event(unsigned long cycles,struct clock_event_device * evt)181 static int samsung_set_next_event(unsigned long cycles,
182 struct clock_event_device *evt)
183 {
184 samsung_time_setup(timer_source.event_id, cycles);
185 samsung_time_start(timer_source.event_id, NON_PERIODIC);
186
187 return 0;
188 }
189
samsung_set_mode(enum clock_event_mode mode,struct clock_event_device * evt)190 static void samsung_set_mode(enum clock_event_mode mode,
191 struct clock_event_device *evt)
192 {
193 samsung_time_stop(timer_source.event_id);
194
195 switch (mode) {
196 case CLOCK_EVT_MODE_PERIODIC:
197 samsung_time_setup(timer_source.event_id, clock_count_per_tick);
198 samsung_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 samsung_timer_resume();
210 break;
211 }
212 }
213
samsung_timer_resume(void)214 static void samsung_timer_resume(void)
215 {
216 /* event timer restart */
217 samsung_time_setup(timer_source.event_id, clock_count_per_tick);
218 samsung_time_start(timer_source.event_id, PERIODIC);
219
220 /* source timer restart */
221 samsung_time_setup(timer_source.source_id, TCNT_MAX);
222 samsung_time_start(timer_source.source_id, PERIODIC);
223 }
224
samsung_set_timer_source(enum samsung_timer_mode event,enum samsung_timer_mode source)225 void __init samsung_set_timer_source(enum samsung_timer_mode event,
226 enum samsung_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
235 static struct clock_event_device time_event_device = {
236 .name = "samsung_event_timer",
237 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
238 .rating = 200,
239 .set_next_event = samsung_set_next_event,
240 .set_mode = samsung_set_mode,
241 };
242
samsung_clock_event_isr(int irq,void * dev_id)243 static irqreturn_t samsung_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
252 static struct irqaction samsung_clock_event_irq = {
253 .name = "samsung_time_irq",
254 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
255 .handler = samsung_clock_event_isr,
256 .dev_id = &time_event_device,
257 };
258
samsung_clockevent_init(void)259 static void __init samsung_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 / TSCALER_DIV);
271 clk_set_rate(tdiv_event, pclk / TDIV);
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 time_event_device.cpumask = cpumask_of(0);
278 clockevents_config_and_register(&time_event_device, clock_rate, 1, -1);
279
280 irq_number = timer_source.event_id + IRQ_TIMER0;
281 setup_irq(irq_number, &samsung_clock_event_irq);
282 }
283
samsung_timer_reg(void)284 static void __iomem *samsung_timer_reg(void)
285 {
286 unsigned long offset = 0;
287
288 switch (timer_source.source_id) {
289 case SAMSUNG_PWM0:
290 case SAMSUNG_PWM1:
291 case SAMSUNG_PWM2:
292 case SAMSUNG_PWM3:
293 offset = (timer_source.source_id * 0x0c) + 0x14;
294 break;
295
296 case SAMSUNG_PWM4:
297 offset = 0x40;
298 break;
299
300 default:
301 printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
302 return NULL;
303 }
304
305 return S3C_TIMERREG(offset);
306 }
307
308 /*
309 * Override the global weak sched_clock symbol with this
310 * local implementation which uses the clocksource to get some
311 * better resolution when scheduling the kernel. We accept that
312 * this wraps around for now, since it is just a relative time
313 * stamp. (Inspired by U300 implementation.)
314 */
samsung_read_sched_clock(void)315 static u32 notrace samsung_read_sched_clock(void)
316 {
317 void __iomem *reg = samsung_timer_reg();
318
319 if (!reg)
320 return 0;
321
322 return ~__raw_readl(reg);
323 }
324
samsung_clocksource_init(void)325 static void __init samsung_clocksource_init(void)
326 {
327 unsigned long pclk;
328 unsigned long clock_rate;
329
330 pclk = clk_get_rate(timerclk);
331
332 clk_set_rate(tdiv_source, pclk / TDIV);
333 clk_set_parent(tin_source, tdiv_source);
334
335 clock_rate = clk_get_rate(tin_source);
336
337 samsung_time_setup(timer_source.source_id, TCNT_MAX);
338 samsung_time_start(timer_source.source_id, PERIODIC);
339
340 setup_sched_clock(samsung_read_sched_clock, TSIZE, clock_rate);
341
342 if (clocksource_mmio_init(samsung_timer_reg(), "samsung_clocksource_timer",
343 clock_rate, 250, TSIZE, clocksource_mmio_readl_down))
344 panic("samsung_clocksource_timer: can't register clocksource\n");
345 }
346
samsung_timer_resources(void)347 static void __init samsung_timer_resources(void)
348 {
349
350 unsigned long event_id = timer_source.event_id;
351 unsigned long source_id = timer_source.source_id;
352 char devname[15];
353
354 timerclk = clk_get(NULL, "timers");
355 if (IS_ERR(timerclk))
356 panic("failed to get timers clock for timer");
357
358 clk_enable(timerclk);
359
360 sprintf(devname, "s3c24xx-pwm.%lu", event_id);
361 s3c_device_timer[event_id].id = event_id;
362 s3c_device_timer[event_id].dev.init_name = devname;
363
364 tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
365 if (IS_ERR(tin_event))
366 panic("failed to get pwm-tin clock for event timer");
367
368 tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
369 if (IS_ERR(tdiv_event))
370 panic("failed to get pwm-tdiv clock for event timer");
371
372 clk_enable(tin_event);
373
374 sprintf(devname, "s3c24xx-pwm.%lu", source_id);
375 s3c_device_timer[source_id].id = source_id;
376 s3c_device_timer[source_id].dev.init_name = devname;
377
378 tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
379 if (IS_ERR(tin_source))
380 panic("failed to get pwm-tin clock for source timer");
381
382 tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
383 if (IS_ERR(tdiv_source))
384 panic("failed to get pwm-tdiv clock for source timer");
385
386 clk_enable(tin_source);
387 }
388
samsung_timer_init(void)389 void __init samsung_timer_init(void)
390 {
391 samsung_timer_resources();
392 samsung_clockevent_init();
393 samsung_clocksource_init();
394 }
395