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1/*
2 * linux/arch/arm/mach-omap2/timer.c
3 *
4 * OMAP2 GP timer support.
5 *
6 * Copyright (C) 2009 Nokia Corporation
7 *
8 * Update to use new clocksource/clockevent layers
9 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
10 * Copyright (C) 2007 MontaVista Software, Inc.
11 *
12 * Original driver:
13 * Copyright (C) 2005 Nokia Corporation
14 * Author: Paul Mundt <paul.mundt@nokia.com>
15 * Juha Yrjölä <juha.yrjola@nokia.com>
16 * OMAP Dual-mode timer framework support by Timo Teras
17 *
18 * Some parts based off of TI's 24xx code:
19 *
20 * Copyright (C) 2004-2009 Texas Instruments, Inc.
21 *
22 * Roughly modelled after the OMAP1 MPU timer code.
23 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
24 *
25 * This file is subject to the terms and conditions of the GNU General Public
26 * License. See the file "COPYING" in the main directory of this archive
27 * for more details.
28 */
29#include <linux/init.h>
30#include <linux/time.h>
31#include <linux/interrupt.h>
32#include <linux/err.h>
33#include <linux/clk.h>
34#include <linux/delay.h>
35#include <linux/irq.h>
36#include <linux/clocksource.h>
37#include <linux/clockchips.h>
38#include <linux/slab.h>
39
40#include <asm/mach/time.h>
41#include <plat/dmtimer.h>
42#include <asm/smp_twd.h>
43#include <asm/sched_clock.h>
44#include "common.h"
45#include <plat/omap_hwmod.h>
46#include <plat/omap_device.h>
47#include <plat/omap-pm.h>
48
49#include "powerdomain.h"
50
51/* Parent clocks, eventually these will come from the clock framework */
52
53#define OMAP2_MPU_SOURCE "sys_ck"
54#define OMAP3_MPU_SOURCE OMAP2_MPU_SOURCE
55#define OMAP4_MPU_SOURCE "sys_clkin_ck"
56#define OMAP2_32K_SOURCE "func_32k_ck"
57#define OMAP3_32K_SOURCE "omap_32k_fck"
58#define OMAP4_32K_SOURCE "sys_32k_ck"
59
60#ifdef CONFIG_OMAP_32K_TIMER
61#define OMAP2_CLKEV_SOURCE OMAP2_32K_SOURCE
62#define OMAP3_CLKEV_SOURCE OMAP3_32K_SOURCE
63#define OMAP4_CLKEV_SOURCE OMAP4_32K_SOURCE
64#define OMAP3_SECURE_TIMER 12
65#else
66#define OMAP2_CLKEV_SOURCE OMAP2_MPU_SOURCE
67#define OMAP3_CLKEV_SOURCE OMAP3_MPU_SOURCE
68#define OMAP4_CLKEV_SOURCE OMAP4_MPU_SOURCE
69#define OMAP3_SECURE_TIMER 1
70#endif
71
72/* MAX_GPTIMER_ID: number of GPTIMERs on the chip */
73#define MAX_GPTIMER_ID 12
74
75static u32 sys_timer_reserved;
76
77/* Clockevent code */
78
79static struct omap_dm_timer clkev;
80static struct clock_event_device clockevent_gpt;
81
82static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
83{
84 struct clock_event_device *evt = &clockevent_gpt;
85
86 __omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);
87
88 evt->event_handler(evt);
89 return IRQ_HANDLED;
90}
91
92static struct irqaction omap2_gp_timer_irq = {
93 .name = "gp_timer",
94 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
95 .handler = omap2_gp_timer_interrupt,
96};
97
98static int omap2_gp_timer_set_next_event(unsigned long cycles,
99 struct clock_event_device *evt)
100{
101 __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
102 0xffffffff - cycles, 1);
103
104 return 0;
105}
106
107static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
108 struct clock_event_device *evt)
109{
110 u32 period;
111
112 __omap_dm_timer_stop(&clkev, 1, clkev.rate);
113
114 switch (mode) {
115 case CLOCK_EVT_MODE_PERIODIC:
116 period = clkev.rate / HZ;
117 period -= 1;
118 /* Looks like we need to first set the load value separately */
119 __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG,
120 0xffffffff - period, 1);
121 __omap_dm_timer_load_start(&clkev,
122 OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
123 0xffffffff - period, 1);
124 break;
125 case CLOCK_EVT_MODE_ONESHOT:
126 break;
127 case CLOCK_EVT_MODE_UNUSED:
128 case CLOCK_EVT_MODE_SHUTDOWN:
129 case CLOCK_EVT_MODE_RESUME:
130 break;
131 }
132}
133
134static struct clock_event_device clockevent_gpt = {
135 .name = "gp_timer",
136 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
137 .shift = 32,
138 .set_next_event = omap2_gp_timer_set_next_event,
139 .set_mode = omap2_gp_timer_set_mode,
140};
141
142static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
143 int gptimer_id,
144 const char *fck_source)
145{
146 char name[10]; /* 10 = sizeof("gptXX_Xck0") */
147 struct omap_hwmod *oh;
148 struct resource irq_rsrc, mem_rsrc;
149 size_t size;
150 int res = 0;
151 int r;
152
153 sprintf(name, "timer%d", gptimer_id);
154 omap_hwmod_setup_one(name);
155 oh = omap_hwmod_lookup(name);
156 if (!oh)
157 return -ENODEV;
158
159 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL, &irq_rsrc);
160 if (r)
161 return -ENXIO;
162 timer->irq = irq_rsrc.start;
163
164 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL, &mem_rsrc);
165 if (r)
166 return -ENXIO;
167 timer->phys_base = mem_rsrc.start;
168 size = mem_rsrc.end - mem_rsrc.start;
169
170 /* Static mapping, never released */
171 timer->io_base = ioremap(timer->phys_base, size);
172 if (!timer->io_base)
173 return -ENXIO;
174
175 /* After the dmtimer is using hwmod these clocks won't be needed */
176 sprintf(name, "gpt%d_fck", gptimer_id);
177 timer->fclk = clk_get(NULL, name);
178 if (IS_ERR(timer->fclk))
179 return -ENODEV;
180
181 omap_hwmod_enable(oh);
182
183 sys_timer_reserved |= (1 << (gptimer_id - 1));
184
185 if (gptimer_id != 12) {
186 struct clk *src;
187
188 src = clk_get(NULL, fck_source);
189 if (IS_ERR(src)) {
190 res = -EINVAL;
191 } else {
192 res = __omap_dm_timer_set_source(timer->fclk, src);
193 if (IS_ERR_VALUE(res))
194 pr_warning("%s: timer%i cannot set source\n",
195 __func__, gptimer_id);
196 clk_put(src);
197 }
198 }
199 __omap_dm_timer_init_regs(timer);
200 __omap_dm_timer_reset(timer, 1, 1);
201 timer->posted = 1;
202
203 timer->rate = clk_get_rate(timer->fclk);
204
205 timer->reserved = 1;
206
207 return res;
208}
209
210static void __init omap2_gp_clockevent_init(int gptimer_id,
211 const char *fck_source)
212{
213 int res;
214
215 res = omap_dm_timer_init_one(&clkev, gptimer_id, fck_source);
216 BUG_ON(res);
217
218 omap2_gp_timer_irq.dev_id = (void *)&clkev;
219 setup_irq(clkev.irq, &omap2_gp_timer_irq);
220
221 __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
222
223 clockevent_gpt.mult = div_sc(clkev.rate, NSEC_PER_SEC,
224 clockevent_gpt.shift);
225 clockevent_gpt.max_delta_ns =
226 clockevent_delta2ns(0xffffffff, &clockevent_gpt);
227 clockevent_gpt.min_delta_ns =
228 clockevent_delta2ns(3, &clockevent_gpt);
229 /* Timer internal resynch latency. */
230
231 clockevent_gpt.cpumask = cpumask_of(0);
232 clockevents_register_device(&clockevent_gpt);
233
234 pr_info("OMAP clockevent source: GPTIMER%d at %lu Hz\n",
235 gptimer_id, clkev.rate);
236}
237
238/* Clocksource code */
239static struct omap_dm_timer clksrc;
240static bool use_gptimer_clksrc;
241
242/*
243 * clocksource
244 */
245static cycle_t clocksource_read_cycles(struct clocksource *cs)
246{
247 return (cycle_t)__omap_dm_timer_read_counter(&clksrc, 1);
248}
249
250static struct clocksource clocksource_gpt = {
251 .name = "gp_timer",
252 .rating = 300,
253 .read = clocksource_read_cycles,
254 .mask = CLOCKSOURCE_MASK(32),
255 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
256};
257
258static u32 notrace dmtimer_read_sched_clock(void)
259{
260 if (clksrc.reserved)
261 return __omap_dm_timer_read_counter(&clksrc, 1);
262
263 return 0;
264}
265
266#ifdef CONFIG_OMAP_32K_TIMER
267/* Setup free-running counter for clocksource */
268static int __init omap2_sync32k_clocksource_init(void)
269{
270 int ret;
271 struct omap_hwmod *oh;
272 void __iomem *vbase;
273 const char *oh_name = "counter_32k";
274
275 /*
276 * First check hwmod data is available for sync32k counter
277 */
278 oh = omap_hwmod_lookup(oh_name);
279 if (!oh || oh->slaves_cnt == 0)
280 return -ENODEV;
281
282 omap_hwmod_setup_one(oh_name);
283
284 vbase = omap_hwmod_get_mpu_rt_va(oh);
285 if (!vbase) {
286 pr_warn("%s: failed to get counter_32k resource\n", __func__);
287 return -ENXIO;
288 }
289
290 ret = omap_hwmod_enable(oh);
291 if (ret) {
292 pr_warn("%s: failed to enable counter_32k module (%d)\n",
293 __func__, ret);
294 return ret;
295 }
296
297 ret = omap_init_clocksource_32k(vbase);
298 if (ret) {
299 pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
300 __func__, ret);
301 omap_hwmod_idle(oh);
302 }
303
304 return ret;
305}
306#else
307static inline int omap2_sync32k_clocksource_init(void)
308{
309 return -ENODEV;
310}
311#endif
312
313static void __init omap2_gptimer_clocksource_init(int gptimer_id,
314 const char *fck_source)
315{
316 int res;
317
318 res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source);
319 BUG_ON(res);
320
321 __omap_dm_timer_load_start(&clksrc,
322 OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
323 setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
324
325 if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
326 pr_err("Could not register clocksource %s\n",
327 clocksource_gpt.name);
328 else
329 pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
330 gptimer_id, clksrc.rate);
331}
332
333static void __init omap2_clocksource_init(int gptimer_id,
334 const char *fck_source)
335{
336 /*
337 * First give preference to kernel parameter configuration
338 * by user (clocksource="gp_timer").
339 *
340 * In case of missing kernel parameter for clocksource,
341 * first check for availability for 32k-sync timer, in case
342 * of failure in finding 32k_counter module or registering
343 * it as clocksource, execution will fallback to gp-timer.
344 */
345 if (use_gptimer_clksrc == true)
346 omap2_gptimer_clocksource_init(gptimer_id, fck_source);
347 else if (omap2_sync32k_clocksource_init())
348 /* Fall back to gp-timer code */
349 omap2_gptimer_clocksource_init(gptimer_id, fck_source);
350}
351
352#define OMAP_SYS_TIMER_INIT(name, clkev_nr, clkev_src, \
353 clksrc_nr, clksrc_src) \
354static void __init omap##name##_timer_init(void) \
355{ \
356 omap2_gp_clockevent_init((clkev_nr), clkev_src); \
357 omap2_clocksource_init((clksrc_nr), clksrc_src); \
358}
359
360#define OMAP_SYS_TIMER(name) \
361struct sys_timer omap##name##_timer = { \
362 .init = omap##name##_timer_init, \
363};
364
365#ifdef CONFIG_ARCH_OMAP2
366OMAP_SYS_TIMER_INIT(2, 1, OMAP2_CLKEV_SOURCE, 2, OMAP2_MPU_SOURCE)
367OMAP_SYS_TIMER(2)
368#endif
369
370#ifdef CONFIG_ARCH_OMAP3
371OMAP_SYS_TIMER_INIT(3, 1, OMAP3_CLKEV_SOURCE, 2, OMAP3_MPU_SOURCE)
372OMAP_SYS_TIMER(3)
373OMAP_SYS_TIMER_INIT(3_secure, OMAP3_SECURE_TIMER, OMAP3_CLKEV_SOURCE,
374 2, OMAP3_MPU_SOURCE)
375OMAP_SYS_TIMER(3_secure)
376#endif
377
378#ifdef CONFIG_ARCH_OMAP4
379#ifdef CONFIG_LOCAL_TIMERS
380static DEFINE_TWD_LOCAL_TIMER(twd_local_timer,
381 OMAP44XX_LOCAL_TWD_BASE,
382 OMAP44XX_IRQ_LOCALTIMER);
383#endif
384
385static void __init omap4_timer_init(void)
386{
387 omap2_gp_clockevent_init(1, OMAP4_CLKEV_SOURCE);
388 omap2_clocksource_init(2, OMAP4_MPU_SOURCE);
389#ifdef CONFIG_LOCAL_TIMERS
390 /* Local timers are not supprted on OMAP4430 ES1.0 */
391 if (omap_rev() != OMAP4430_REV_ES1_0) {
392 int err;
393
394 err = twd_local_timer_register(&twd_local_timer);
395 if (err)
396 pr_err("twd_local_timer_register failed %d\n", err);
397 }
398#endif
399}
400OMAP_SYS_TIMER(4)
401#endif
402
403/**
404 * omap2_dm_timer_set_src - change the timer input clock source
405 * @pdev: timer platform device pointer
406 * @source: array index of parent clock source
407 */
408static int omap2_dm_timer_set_src(struct platform_device *pdev, int source)
409{
410 int ret;
411 struct dmtimer_platform_data *pdata = pdev->dev.platform_data;
412 struct clk *fclk, *parent;
413 char *parent_name = NULL;
414
415 fclk = clk_get(&pdev->dev, "fck");
416 if (IS_ERR_OR_NULL(fclk)) {
417 dev_err(&pdev->dev, "%s: %d: clk_get() FAILED\n",
418 __func__, __LINE__);
419 return -EINVAL;
420 }
421
422 switch (source) {
423 case OMAP_TIMER_SRC_SYS_CLK:
424 parent_name = "sys_ck";
425 break;
426
427 case OMAP_TIMER_SRC_32_KHZ:
428 parent_name = "32k_ck";
429 break;
430
431 case OMAP_TIMER_SRC_EXT_CLK:
432 if (pdata->timer_ip_version == OMAP_TIMER_IP_VERSION_1) {
433 parent_name = "alt_ck";
434 break;
435 }
436 dev_err(&pdev->dev, "%s: %d: invalid clk src.\n",
437 __func__, __LINE__);
438 clk_put(fclk);
439 return -EINVAL;
440 }
441
442 parent = clk_get(&pdev->dev, parent_name);
443 if (IS_ERR_OR_NULL(parent)) {
444 dev_err(&pdev->dev, "%s: %d: clk_get() %s FAILED\n",
445 __func__, __LINE__, parent_name);
446 clk_put(fclk);
447 return -EINVAL;
448 }
449
450 ret = clk_set_parent(fclk, parent);
451 if (IS_ERR_VALUE(ret)) {
452 dev_err(&pdev->dev, "%s: clk_set_parent() to %s FAILED\n",
453 __func__, parent_name);
454 ret = -EINVAL;
455 }
456
457 clk_put(parent);
458 clk_put(fclk);
459
460 return ret;
461}
462
463/**
464 * omap_timer_init - build and register timer device with an
465 * associated timer hwmod
466 * @oh: timer hwmod pointer to be used to build timer device
467 * @user: parameter that can be passed from calling hwmod API
468 *
469 * Called by omap_hwmod_for_each_by_class to register each of the timer
470 * devices present in the system. The number of timer devices is known
471 * by parsing through the hwmod database for a given class name. At the
472 * end of function call memory is allocated for timer device and it is
473 * registered to the framework ready to be proved by the driver.
474 */
475static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
476{
477 int id;
478 int ret = 0;
479 char *name = "omap_timer";
480 struct dmtimer_platform_data *pdata;
481 struct platform_device *pdev;
482 struct omap_timer_capability_dev_attr *timer_dev_attr;
483 struct powerdomain *pwrdm;
484
485 pr_debug("%s: %s\n", __func__, oh->name);
486
487 /* on secure device, do not register secure timer */
488 timer_dev_attr = oh->dev_attr;
489 if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
490 if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
491 return ret;
492
493 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
494 if (!pdata) {
495 pr_err("%s: No memory for [%s]\n", __func__, oh->name);
496 return -ENOMEM;
497 }
498
499 /*
500 * Extract the IDs from name field in hwmod database
501 * and use the same for constructing ids' for the
502 * timer devices. In a way, we are avoiding usage of
503 * static variable witin the function to do the same.
504 * CAUTION: We have to be careful and make sure the
505 * name in hwmod database does not change in which case
506 * we might either make corresponding change here or
507 * switch back static variable mechanism.
508 */
509 sscanf(oh->name, "timer%2d", &id);
510
511 pdata->set_timer_src = omap2_dm_timer_set_src;
512 pdata->timer_ip_version = oh->class->rev;
513
514 /* Mark clocksource and clockevent timers as reserved */
515 if ((sys_timer_reserved >> (id - 1)) & 0x1)
516 pdata->reserved = 1;
517
518 pwrdm = omap_hwmod_get_pwrdm(oh);
519 pdata->loses_context = pwrdm_can_ever_lose_context(pwrdm);
520#ifdef CONFIG_PM
521 pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
522#endif
523 pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata),
524 NULL, 0, 0);
525
526 if (IS_ERR(pdev)) {
527 pr_err("%s: Can't build omap_device for %s: %s.\n",
528 __func__, name, oh->name);
529 ret = -EINVAL;
530 }
531
532 kfree(pdata);
533
534 return ret;
535}
536
537/**
538 * omap2_dm_timer_init - top level regular device initialization
539 *
540 * Uses dedicated hwmod api to parse through hwmod database for
541 * given class name and then build and register the timer device.
542 */
543static int __init omap2_dm_timer_init(void)
544{
545 int ret;
546
547 ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
548 if (unlikely(ret)) {
549 pr_err("%s: device registration failed.\n", __func__);
550 return -EINVAL;
551 }
552
553 return 0;
554}
555arch_initcall(omap2_dm_timer_init);
556
557/**
558 * omap2_override_clocksource - clocksource override with user configuration
559 *
560 * Allows user to override default clocksource, using kernel parameter
561 * clocksource="gp_timer" (For all OMAP2PLUS architectures)
562 *
563 * Note that, here we are using same standard kernel parameter "clocksource=",
564 * and not introducing any OMAP specific interface.
565 */
566static int __init omap2_override_clocksource(char *str)
567{
568 if (!str)
569 return 0;
570 /*
571 * For OMAP architecture, we only have two options
572 * - sync_32k (default)
573 * - gp_timer (sys_clk based)
574 */
575 if (!strcmp(str, "gp_timer"))
576 use_gptimer_clksrc = true;
577
578 return 0;
579}
580early_param("clocksource", omap2_override_clocksource);