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Tony Lindgren1dbae812005-11-10 14:26:51 +00001/*
2 * linux/arch/arm/mach-omap2/timer-gp.c
3 *
4 * OMAP2 GP timer support.
5 *
Paul Walmsleyf2480762009-04-23 21:11:10 -06006 * Copyright (C) 2009 Nokia Corporation
7 *
Kevin Hilman5a3a3882007-11-12 23:24:02 -08008 * 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:
Tony Lindgren1dbae812005-11-10 14:26:51 +000013 * Copyright (C) 2005 Nokia Corporation
14 * Author: Paul Mundt <paul.mundt@nokia.com>
Jan Engelhardt96de0e22007-10-19 23:21:04 +020015 * Juha Yrjölä <juha.yrjola@nokia.com>
Timo Teras77900a22006-06-26 16:16:12 -070016 * OMAP Dual-mode timer framework support by Timo Teras
Tony Lindgren1dbae812005-11-10 14:26:51 +000017 *
18 * Some parts based off of TI's 24xx code:
19 *
Santosh Shilimkar44169072009-05-28 14:16:04 -070020 * Copyright (C) 2004-2009 Texas Instruments, Inc.
Tony Lindgren1dbae812005-11-10 14:26:51 +000021 *
22 * Roughly modelled after the OMAP1 MPU timer code.
Santosh Shilimkar44169072009-05-28 14:16:04 -070023 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
Tony Lindgren1dbae812005-11-10 14:26:51 +000024 *
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>
Russell Kingf8ce2542006-01-07 16:15:52 +000033#include <linux/clk.h>
Timo Teras77900a22006-06-26 16:16:12 -070034#include <linux/delay.h>
Dirk Behmee6687292006-12-06 17:14:00 -080035#include <linux/irq.h>
Kevin Hilman5a3a3882007-11-12 23:24:02 -080036#include <linux/clocksource.h>
37#include <linux/clockchips.h>
Russell Kingf8ce2542006-01-07 16:15:52 +000038
Tony Lindgren1dbae812005-11-10 14:26:51 +000039#include <asm/mach/time.h>
Tony Lindgrence491cf2009-10-20 09:40:47 -070040#include <plat/dmtimer.h>
Santosh Shilimkar39e1d4c2009-04-28 20:52:00 +053041#include <asm/localtimer.h>
Tony Lindgren1dbae812005-11-10 14:26:51 +000042
Paul Walmsleyf2480762009-04-23 21:11:10 -060043/* MAX_GPTIMER_ID: number of GPTIMERs on the chip */
44#define MAX_GPTIMER_ID 12
45
Timo Teras77900a22006-06-26 16:16:12 -070046static struct omap_dm_timer *gptimer;
Kevin Hilman5a3a3882007-11-12 23:24:02 -080047static struct clock_event_device clockevent_gpt;
Paul Walmsleyf2480762009-04-23 21:11:10 -060048static u8 __initdata gptimer_id = 1;
49static u8 __initdata inited;
Kevin Hilmand7814e42009-10-06 14:30:23 -070050struct omap_dm_timer *gptimer_wakeup;
Tony Lindgren1dbae812005-11-10 14:26:51 +000051
Linus Torvalds0cd61b62006-10-06 10:53:39 -070052static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
Tony Lindgren1dbae812005-11-10 14:26:51 +000053{
Kevin Hilman5a3a3882007-11-12 23:24:02 -080054 struct omap_dm_timer *gpt = (struct omap_dm_timer *)dev_id;
55 struct clock_event_device *evt = &clockevent_gpt;
Tony Lindgren1dbae812005-11-10 14:26:51 +000056
Kevin Hilman5a3a3882007-11-12 23:24:02 -080057 omap_dm_timer_write_status(gpt, OMAP_TIMER_INT_OVERFLOW);
58
59 evt->event_handler(evt);
Tony Lindgren1dbae812005-11-10 14:26:51 +000060 return IRQ_HANDLED;
61}
62
63static struct irqaction omap2_gp_timer_irq = {
64 .name = "gp timer",
Bernhard Walleb30faba2007-05-08 00:35:39 -070065 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
Tony Lindgren1dbae812005-11-10 14:26:51 +000066 .handler = omap2_gp_timer_interrupt,
67};
68
Kevin Hilman5a3a3882007-11-12 23:24:02 -080069static int omap2_gp_timer_set_next_event(unsigned long cycles,
70 struct clock_event_device *evt)
Tony Lindgren1dbae812005-11-10 14:26:51 +000071{
Richard Woodruff3fddd092008-07-03 12:24:30 +030072 omap_dm_timer_set_load_start(gptimer, 0, 0xffffffff - cycles);
Tony Lindgren1dbae812005-11-10 14:26:51 +000073
Kevin Hilman5a3a3882007-11-12 23:24:02 -080074 return 0;
75}
76
77static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
78 struct clock_event_device *evt)
79{
80 u32 period;
81
82 omap_dm_timer_stop(gptimer);
83
84 switch (mode) {
85 case CLOCK_EVT_MODE_PERIODIC:
86 period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ;
87 period -= 1;
Richard Woodruff3fddd092008-07-03 12:24:30 +030088 omap_dm_timer_set_load_start(gptimer, 1, 0xffffffff - period);
Kevin Hilman5a3a3882007-11-12 23:24:02 -080089 break;
90 case CLOCK_EVT_MODE_ONESHOT:
91 break;
92 case CLOCK_EVT_MODE_UNUSED:
93 case CLOCK_EVT_MODE_SHUTDOWN:
94 case CLOCK_EVT_MODE_RESUME:
95 break;
96 }
97}
98
99static struct clock_event_device clockevent_gpt = {
100 .name = "gp timer",
101 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
102 .shift = 32,
103 .set_next_event = omap2_gp_timer_set_next_event,
104 .set_mode = omap2_gp_timer_set_mode,
105};
106
Paul Walmsleyf2480762009-04-23 21:11:10 -0600107/**
108 * omap2_gp_clockevent_set_gptimer - set which GPTIMER is used for clockevents
109 * @id: GPTIMER to use (1..MAX_GPTIMER_ID)
110 *
111 * Define the GPTIMER that the system should use for the tick timer.
112 * Meant to be called from board-*.c files in the event that GPTIMER1, the
113 * default, is unsuitable. Returns -EINVAL on error or 0 on success.
114 */
115int __init omap2_gp_clockevent_set_gptimer(u8 id)
116{
117 if (id < 1 || id > MAX_GPTIMER_ID)
118 return -EINVAL;
119
120 BUG_ON(inited);
121
122 gptimer_id = id;
123
124 return 0;
125}
126
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800127static void __init omap2_gp_clockevent_init(void)
128{
129 u32 tick_rate;
Paul Walmsleyf2480762009-04-23 21:11:10 -0600130 int src;
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800131
Paul Walmsleyf2480762009-04-23 21:11:10 -0600132 inited = 1;
133
134 gptimer = omap_dm_timer_request_specific(gptimer_id);
Timo Teras77900a22006-06-26 16:16:12 -0700135 BUG_ON(gptimer == NULL);
Kevin Hilmand7814e42009-10-06 14:30:23 -0700136 gptimer_wakeup = gptimer;
Tony Lindgren1dbae812005-11-10 14:26:51 +0000137
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800138#if defined(CONFIG_OMAP_32K_TIMER)
Paul Walmsleyf2480762009-04-23 21:11:10 -0600139 src = OMAP_TIMER_SRC_32_KHZ;
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800140#else
Paul Walmsleyf2480762009-04-23 21:11:10 -0600141 src = OMAP_TIMER_SRC_SYS_CLK;
142 WARN(gptimer_id == 12, "WARNING: GPTIMER12 can only use the "
143 "secure 32KiHz clock source\n");
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800144#endif
Paul Walmsleyf2480762009-04-23 21:11:10 -0600145
146 if (gptimer_id != 12)
147 WARN(IS_ERR_VALUE(omap_dm_timer_set_source(gptimer, src)),
148 "timer-gp: omap_dm_timer_set_source() failed\n");
149
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800150 tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gptimer));
Tony Lindgren1dbae812005-11-10 14:26:51 +0000151
Paul Walmsleyf2480762009-04-23 21:11:10 -0600152 pr_info("OMAP clockevent source: GPTIMER%d at %u Hz\n",
153 gptimer_id, tick_rate);
154
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800155 omap2_gp_timer_irq.dev_id = (void *)gptimer;
Timo Teras77900a22006-06-26 16:16:12 -0700156 setup_irq(omap_dm_timer_get_irq(gptimer), &omap2_gp_timer_irq);
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800157 omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW);
158
159 clockevent_gpt.mult = div_sc(tick_rate, NSEC_PER_SEC,
160 clockevent_gpt.shift);
161 clockevent_gpt.max_delta_ns =
162 clockevent_delta2ns(0xffffffff, &clockevent_gpt);
163 clockevent_gpt.min_delta_ns =
Aaro Koskinendf88acb2009-01-29 08:57:17 -0800164 clockevent_delta2ns(3, &clockevent_gpt);
165 /* Timer internal resynch latency. */
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800166
Rusty Russell320ab2b2008-12-13 21:20:26 +1030167 clockevent_gpt.cpumask = cpumask_of(0);
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800168 clockevents_register_device(&clockevent_gpt);
169}
170
Paul Walmsleyf2480762009-04-23 21:11:10 -0600171/* Clocksource code */
172
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800173#ifdef CONFIG_OMAP_32K_TIMER
174/*
175 * When 32k-timer is enabled, don't use GPTimer for clocksource
176 * instead, just leave default clocksource which uses the 32k
177 * sync counter. See clocksource setup in see plat-omap/common.c.
178 */
179
180static inline void __init omap2_gp_clocksource_init(void) {}
181#else
182/*
183 * clocksource
184 */
185static struct omap_dm_timer *gpt_clocksource;
Magnus Damm8e196082009-04-21 12:24:00 -0700186static cycle_t clocksource_read_cycles(struct clocksource *cs)
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800187{
188 return (cycle_t)omap_dm_timer_read_counter(gpt_clocksource);
189}
190
191static struct clocksource clocksource_gpt = {
192 .name = "gp timer",
193 .rating = 300,
194 .read = clocksource_read_cycles,
195 .mask = CLOCKSOURCE_MASK(32),
196 .shift = 24,
197 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
198};
199
200/* Setup free-running counter for clocksource */
201static void __init omap2_gp_clocksource_init(void)
202{
203 static struct omap_dm_timer *gpt;
204 u32 tick_rate, tick_period;
205 static char err1[] __initdata = KERN_ERR
206 "%s: failed to request dm-timer\n";
207 static char err2[] __initdata = KERN_ERR
208 "%s: can't register clocksource!\n";
209
210 gpt = omap_dm_timer_request();
211 if (!gpt)
212 printk(err1, clocksource_gpt.name);
213 gpt_clocksource = gpt;
214
215 omap_dm_timer_set_source(gpt, OMAP_TIMER_SRC_SYS_CLK);
216 tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gpt));
217 tick_period = (tick_rate / HZ) - 1;
218
Richard Woodruff3fddd092008-07-03 12:24:30 +0300219 omap_dm_timer_set_load_start(gpt, 1, 0);
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800220
221 clocksource_gpt.mult =
222 clocksource_khz2mult(tick_rate/1000, clocksource_gpt.shift);
223 if (clocksource_register(&clocksource_gpt))
224 printk(err2, clocksource_gpt.name);
225}
226#endif
227
228static void __init omap2_gp_timer_init(void)
229{
Santosh Shilimkar39e1d4c2009-04-28 20:52:00 +0530230#ifdef CONFIG_LOCAL_TIMERS
Tony Lindgrene4e7a132009-10-19 15:25:26 -0700231 twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_256);
232 BUG_ON(!twd_base);
Santosh Shilimkar39e1d4c2009-04-28 20:52:00 +0530233#endif
Kevin Hilman5a3a3882007-11-12 23:24:02 -0800234 omap_dm_timer_init();
235
236 omap2_gp_clockevent_init();
237 omap2_gp_clocksource_init();
Tony Lindgren1dbae812005-11-10 14:26:51 +0000238}
239
240struct sys_timer omap_timer = {
241 .init = omap2_gp_timer_init,
242};