Lars-Peter Clausen | b200eff | 2010-06-19 04:08:10 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> |
| 3 | * JZ4740 platform time support |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by the |
| 7 | * Free Software Foundation; either version 2 of the License, or (at your |
| 8 | * option) any later version. |
| 9 | * |
| 10 | * You should have received a copy of the GNU General Public License along |
| 11 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 12 | * 675 Mass Ave, Cambridge, MA 02139, USA. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/time.h> |
| 19 | |
| 20 | #include <linux/clockchips.h> |
| 21 | |
| 22 | #include <asm/mach-jz4740/irq.h> |
| 23 | #include <asm/time.h> |
| 24 | |
| 25 | #include "clock.h" |
| 26 | #include "timer.h" |
| 27 | |
| 28 | #define TIMER_CLOCKEVENT 0 |
| 29 | #define TIMER_CLOCKSOURCE 1 |
| 30 | |
| 31 | static uint16_t jz4740_jiffies_per_tick; |
| 32 | |
| 33 | static cycle_t jz4740_clocksource_read(struct clocksource *cs) |
| 34 | { |
| 35 | return jz4740_timer_get_count(TIMER_CLOCKSOURCE); |
| 36 | } |
| 37 | |
| 38 | static struct clocksource jz4740_clocksource = { |
| 39 | .name = "jz4740-timer", |
| 40 | .rating = 200, |
| 41 | .read = jz4740_clocksource_read, |
| 42 | .mask = CLOCKSOURCE_MASK(16), |
| 43 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| 44 | }; |
| 45 | |
| 46 | static irqreturn_t jz4740_clockevent_irq(int irq, void *devid) |
| 47 | { |
| 48 | struct clock_event_device *cd = devid; |
| 49 | |
| 50 | jz4740_timer_ack_full(TIMER_CLOCKEVENT); |
| 51 | |
| 52 | if (cd->mode != CLOCK_EVT_MODE_PERIODIC) |
| 53 | jz4740_timer_disable(TIMER_CLOCKEVENT); |
| 54 | |
| 55 | cd->event_handler(cd); |
| 56 | |
| 57 | return IRQ_HANDLED; |
| 58 | } |
| 59 | |
| 60 | static void jz4740_clockevent_set_mode(enum clock_event_mode mode, |
| 61 | struct clock_event_device *cd) |
| 62 | { |
| 63 | switch (mode) { |
| 64 | case CLOCK_EVT_MODE_PERIODIC: |
| 65 | jz4740_timer_set_count(TIMER_CLOCKEVENT, 0); |
| 66 | jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick); |
| 67 | case CLOCK_EVT_MODE_RESUME: |
| 68 | jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT); |
| 69 | jz4740_timer_enable(TIMER_CLOCKEVENT); |
| 70 | break; |
| 71 | case CLOCK_EVT_MODE_ONESHOT: |
| 72 | case CLOCK_EVT_MODE_SHUTDOWN: |
| 73 | jz4740_timer_disable(TIMER_CLOCKEVENT); |
| 74 | break; |
| 75 | default: |
| 76 | break; |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | static int jz4740_clockevent_set_next(unsigned long evt, |
| 81 | struct clock_event_device *cd) |
| 82 | { |
| 83 | jz4740_timer_set_count(TIMER_CLOCKEVENT, 0); |
| 84 | jz4740_timer_set_period(TIMER_CLOCKEVENT, evt); |
| 85 | jz4740_timer_enable(TIMER_CLOCKEVENT); |
| 86 | |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | static struct clock_event_device jz4740_clockevent = { |
| 91 | .name = "jz4740-timer", |
| 92 | .features = CLOCK_EVT_FEAT_PERIODIC, |
| 93 | .set_next_event = jz4740_clockevent_set_next, |
| 94 | .set_mode = jz4740_clockevent_set_mode, |
| 95 | .rating = 200, |
| 96 | .irq = JZ4740_IRQ_TCU0, |
| 97 | }; |
| 98 | |
| 99 | static struct irqaction timer_irqaction = { |
| 100 | .handler = jz4740_clockevent_irq, |
| 101 | .flags = IRQF_PERCPU | IRQF_TIMER, |
| 102 | .name = "jz4740-timerirq", |
| 103 | .dev_id = &jz4740_clockevent, |
| 104 | }; |
| 105 | |
| 106 | void __init plat_time_init(void) |
| 107 | { |
| 108 | int ret; |
| 109 | uint32_t clk_rate; |
| 110 | uint16_t ctrl; |
| 111 | |
| 112 | jz4740_timer_init(); |
| 113 | |
| 114 | clk_rate = jz4740_clock_bdata.ext_rate >> 4; |
| 115 | jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ); |
| 116 | |
| 117 | clockevent_set_clock(&jz4740_clockevent, clk_rate); |
| 118 | jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent); |
| 119 | jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent); |
| 120 | jz4740_clockevent.cpumask = cpumask_of(0); |
| 121 | |
| 122 | clockevents_register_device(&jz4740_clockevent); |
| 123 | |
John Stultz | 75c4fd8 | 2010-04-26 20:23:11 -0700 | [diff] [blame^] | 124 | ret = clocksource_register_hz(&jz4740_clocksource, clk_rate); |
Lars-Peter Clausen | b200eff | 2010-06-19 04:08:10 +0000 | [diff] [blame] | 125 | |
| 126 | if (ret) |
| 127 | printk(KERN_ERR "Failed to register clocksource: %d\n", ret); |
| 128 | |
| 129 | setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction); |
| 130 | |
| 131 | ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT; |
| 132 | |
| 133 | jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl); |
| 134 | jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl); |
| 135 | |
| 136 | jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick); |
| 137 | jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT); |
| 138 | |
| 139 | jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff); |
| 140 | |
| 141 | jz4740_timer_enable(TIMER_CLOCKEVENT); |
| 142 | jz4740_timer_enable(TIMER_CLOCKSOURCE); |
| 143 | } |