Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/mach-sa1100/time.c |
| 3 | * |
| 4 | * Copyright (C) 1998 Deborah Wallach. |
Kristoffer Ericson | 9398253 | 2008-11-26 20:58:43 +0100 | [diff] [blame] | 5 | * Twiddles (C) 1999 Hugo Fiennes <hugo@empeg.com> |
| 6 | * |
Nicolas Pitre | 2f82af0 | 2009-09-14 03:25:28 -0400 | [diff] [blame] | 7 | * 2000/03/29 (C) Nicolas Pitre <nico@fluxnic.net> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * Rewritten: big cleanup, much simpler, better HZ accuracy. |
| 9 | * |
| 10 | */ |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/errno.h> |
| 13 | #include <linux/interrupt.h> |
Thomas Gleixner | 119c641 | 2006-07-01 22:32:38 +0100 | [diff] [blame] | 14 | #include <linux/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/timex.h> |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 16 | #include <linux/clockchips.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | |
| 18 | #include <asm/mach/time.h> |
Russell King | 5094b92 | 2010-12-15 21:49:06 +0000 | [diff] [blame] | 19 | #include <asm/sched_clock.h> |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 20 | #include <mach/hardware.h> |
Rob Herring | f314f33 | 2012-02-24 00:06:51 +0100 | [diff] [blame] | 21 | #include <mach/irqs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
Linus Walleij | ef3a0bf | 2012-01-04 11:42:19 +0100 | [diff] [blame] | 23 | static u32 notrace sa1100_read_sched_clock(void) |
Russell King | 5094b92 | 2010-12-15 21:49:06 +0000 | [diff] [blame] | 24 | { |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 25 | return readl_relaxed(OSCR); |
Russell King | 5094b92 | 2010-12-15 21:49:06 +0000 | [diff] [blame] | 26 | } |
| 27 | |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 28 | #define MIN_OSCR_DELTA 2 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 30 | static irqreturn_t sa1100_ost0_interrupt(int irq, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | { |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 32 | struct clock_event_device *c = dev_id; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 34 | /* Disarm the compare/match, signal the event. */ |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 35 | writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER); |
| 36 | writel_relaxed(OSSR_M0, OSSR); |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 37 | c->event_handler(c); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | return IRQ_HANDLED; |
| 40 | } |
| 41 | |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 42 | static int |
| 43 | sa1100_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c) |
| 44 | { |
Uwe Kleine-König | a602f0f | 2009-12-17 12:43:29 +0100 | [diff] [blame] | 45 | unsigned long next, oscr; |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 46 | |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 47 | writel_relaxed(readl_relaxed(OIER) | OIER_E0, OIER); |
| 48 | next = readl_relaxed(OSCR) + delta; |
| 49 | writel_relaxed(next, OSMR0); |
| 50 | oscr = readl_relaxed(OSCR); |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 51 | |
| 52 | return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0; |
| 53 | } |
| 54 | |
| 55 | static void |
| 56 | sa1100_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *c) |
| 57 | { |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 58 | switch (mode) { |
| 59 | case CLOCK_EVT_MODE_ONESHOT: |
| 60 | case CLOCK_EVT_MODE_UNUSED: |
| 61 | case CLOCK_EVT_MODE_SHUTDOWN: |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 62 | writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER); |
| 63 | writel_relaxed(OSSR_M0, OSSR); |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 64 | break; |
| 65 | |
| 66 | case CLOCK_EVT_MODE_RESUME: |
| 67 | case CLOCK_EVT_MODE_PERIODIC: |
| 68 | break; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | static struct clock_event_device ckevt_sa1100_osmr0 = { |
| 73 | .name = "osmr0", |
| 74 | .features = CLOCK_EVT_FEAT_ONESHOT, |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 75 | .rating = 200, |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 76 | .set_next_event = sa1100_osmr0_set_next_event, |
| 77 | .set_mode = sa1100_osmr0_set_mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | }; |
| 79 | |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 80 | static struct irqaction sa1100_timer_irq = { |
| 81 | .name = "ost0", |
| 82 | .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, |
| 83 | .handler = sa1100_ost0_interrupt, |
| 84 | .dev_id = &ckevt_sa1100_osmr0, |
| 85 | }; |
| 86 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | static void __init sa1100_timer_init(void) |
| 88 | { |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 89 | writel_relaxed(0, OIER); |
| 90 | writel_relaxed(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR); |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 91 | |
Marc Zyngier | 2f0778af | 2011-12-15 12:19:23 +0100 | [diff] [blame] | 92 | setup_sched_clock(sa1100_read_sched_clock, 32, 3686400); |
Russell King | 5094b92 | 2010-12-15 21:49:06 +0000 | [diff] [blame] | 93 | |
Russell King | 1ba4c3c | 2011-05-08 16:14:40 +0100 | [diff] [blame] | 94 | clockevents_calc_mult_shift(&ckevt_sa1100_osmr0, 3686400, 4); |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 95 | ckevt_sa1100_osmr0.max_delta_ns = |
| 96 | clockevent_delta2ns(0x7fffffff, &ckevt_sa1100_osmr0); |
| 97 | ckevt_sa1100_osmr0.min_delta_ns = |
| 98 | clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_sa1100_osmr0) + 1; |
Rusty Russell | 320ab2b | 2008-12-13 21:20:26 +1030 | [diff] [blame] | 99 | ckevt_sa1100_osmr0.cpumask = cpumask_of(0); |
Russell King | d142b6e | 2007-11-12 21:55:12 +0000 | [diff] [blame] | 100 | |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 101 | setup_irq(IRQ_OST0, &sa1100_timer_irq); |
| 102 | |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 103 | clocksource_mmio_init(OSCR, "oscr", CLOCK_TICK_RATE, 200, 32, |
Russell King | 234b6ced | 2011-05-08 14:09:47 +0100 | [diff] [blame] | 104 | clocksource_mmio_readl_up); |
Russell King | 3e238be | 2008-04-14 23:03:10 +0100 | [diff] [blame] | 105 | clockevents_register_device(&ckevt_sa1100_osmr0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | } |
| 107 | |
| 108 | #ifdef CONFIG_PM |
| 109 | unsigned long osmr[4], oier; |
| 110 | |
| 111 | static void sa1100_timer_suspend(void) |
| 112 | { |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 113 | osmr[0] = readl_relaxed(OSMR0); |
| 114 | osmr[1] = readl_relaxed(OSMR1); |
| 115 | osmr[2] = readl_relaxed(OSMR2); |
| 116 | osmr[3] = readl_relaxed(OSMR3); |
| 117 | oier = readl_relaxed(OIER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | static void sa1100_timer_resume(void) |
| 121 | { |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 122 | writel_relaxed(0x0f, OSSR); |
| 123 | writel_relaxed(osmr[0], OSMR0); |
| 124 | writel_relaxed(osmr[1], OSMR1); |
| 125 | writel_relaxed(osmr[2], OSMR2); |
| 126 | writel_relaxed(osmr[3], OSMR3); |
| 127 | writel_relaxed(oier, OIER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | /* |
| 130 | * OSMR0 is the system timer: make sure OSCR is sufficiently behind |
| 131 | */ |
Russell King | 3169663 | 2012-06-06 11:42:36 +0100 | [diff] [blame^] | 132 | writel_relaxed(OSMR0 - LATCH, OSCR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | } |
| 134 | #else |
| 135 | #define sa1100_timer_suspend NULL |
| 136 | #define sa1100_timer_resume NULL |
| 137 | #endif |
| 138 | |
| 139 | struct sys_timer sa1100_timer = { |
| 140 | .init = sa1100_timer_init, |
| 141 | .suspend = sa1100_timer_suspend, |
| 142 | .resume = sa1100_timer_resume, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | }; |