Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 Altera Corporation |
| 3 | * Copyright (c) 2011 Picochip Ltd., Jamie Iles |
| 4 | * |
| 5 | * Modified from mach-picoxcell/time.c |
| 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 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | */ |
| 19 | #include <linux/dw_apb_timer.h> |
| 20 | #include <linux/of.h> |
| 21 | #include <linux/of_address.h> |
| 22 | #include <linux/of_irq.h> |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame^] | 23 | #include <linux/clk.h> |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 24 | |
| 25 | #include <asm/mach/time.h> |
| 26 | #include <asm/sched_clock.h> |
| 27 | |
| 28 | static void timer_get_base_and_rate(struct device_node *np, |
| 29 | void __iomem **base, u32 *rate) |
| 30 | { |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame^] | 31 | struct clk *timer_clk; |
| 32 | struct clk *pclk; |
| 33 | |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 34 | *base = of_iomap(np, 0); |
| 35 | |
| 36 | if (!*base) |
| 37 | panic("Unable to map regs for %s", np->name); |
| 38 | |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame^] | 39 | /* |
| 40 | * Not all implementations use a periphal clock, so don't panic |
| 41 | * if it's not present |
| 42 | */ |
| 43 | pclk = of_clk_get_by_name(np, "pclk"); |
| 44 | if (!IS_ERR(pclk)) |
| 45 | if (clk_prepare_enable(pclk)) |
| 46 | pr_warn("pclk for %s is present, but could not be activated\n", |
| 47 | np->name); |
| 48 | |
| 49 | timer_clk = of_clk_get_by_name(np, "timer"); |
| 50 | if (IS_ERR(timer_clk)) |
| 51 | goto try_clock_freq; |
| 52 | |
| 53 | if (!clk_prepare_enable(timer_clk)) { |
| 54 | *rate = clk_get_rate(timer_clk); |
| 55 | return; |
| 56 | } |
| 57 | |
| 58 | try_clock_freq: |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 59 | if (of_property_read_u32(np, "clock-freq", rate) && |
| 60 | of_property_read_u32(np, "clock-frequency", rate)) |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame^] | 61 | panic("No clock nor clock-frequency property for %s", np->name); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 62 | } |
| 63 | |
| 64 | static void add_clockevent(struct device_node *event_timer) |
| 65 | { |
| 66 | void __iomem *iobase; |
| 67 | struct dw_apb_clock_event_device *ced; |
| 68 | u32 irq, rate; |
| 69 | |
| 70 | irq = irq_of_parse_and_map(event_timer, 0); |
| 71 | if (irq == NO_IRQ) |
| 72 | panic("No IRQ for clock event timer"); |
| 73 | |
| 74 | timer_get_base_and_rate(event_timer, &iobase, &rate); |
| 75 | |
| 76 | ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq, |
| 77 | rate); |
| 78 | if (!ced) |
| 79 | panic("Unable to initialise clockevent device"); |
| 80 | |
| 81 | dw_apb_clockevent_register(ced); |
| 82 | } |
| 83 | |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 84 | static void __iomem *sched_io_base; |
| 85 | static u32 sched_rate; |
| 86 | |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 87 | static void add_clocksource(struct device_node *source_timer) |
| 88 | { |
| 89 | void __iomem *iobase; |
| 90 | struct dw_apb_clocksource *cs; |
| 91 | u32 rate; |
| 92 | |
| 93 | timer_get_base_and_rate(source_timer, &iobase, &rate); |
| 94 | |
| 95 | cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate); |
| 96 | if (!cs) |
| 97 | panic("Unable to initialise clocksource device"); |
| 98 | |
| 99 | dw_apb_clocksource_start(cs); |
| 100 | dw_apb_clocksource_register(cs); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 101 | |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 102 | /* |
| 103 | * Fallback to use the clocksource as sched_clock if no separate |
| 104 | * timer is found. sched_io_base then points to the current_value |
| 105 | * register of the clocksource timer. |
| 106 | */ |
| 107 | sched_io_base = iobase + 0x04; |
| 108 | sched_rate = rate; |
| 109 | } |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 110 | |
| 111 | static u32 read_sched_clock(void) |
| 112 | { |
| 113 | return __raw_readl(sched_io_base); |
| 114 | } |
| 115 | |
| 116 | static const struct of_device_id sptimer_ids[] __initconst = { |
| 117 | { .compatible = "picochip,pc3x2-rtc" }, |
| 118 | { .compatible = "snps,dw-apb-timer-sp" }, |
| 119 | { /* Sentinel */ }, |
| 120 | }; |
| 121 | |
| 122 | static void init_sched_clock(void) |
| 123 | { |
| 124 | struct device_node *sched_timer; |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 125 | |
| 126 | sched_timer = of_find_matching_node(NULL, sptimer_ids); |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 127 | if (sched_timer) { |
| 128 | timer_get_base_and_rate(sched_timer, &sched_io_base, |
| 129 | &sched_rate); |
| 130 | of_node_put(sched_timer); |
| 131 | } |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 132 | |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 133 | setup_sched_clock(read_sched_clock, 32, sched_rate); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 134 | } |
| 135 | |
| 136 | static const struct of_device_id osctimer_ids[] __initconst = { |
| 137 | { .compatible = "picochip,pc3x2-timer" }, |
| 138 | { .compatible = "snps,dw-apb-timer-osc" }, |
| 139 | {}, |
| 140 | }; |
| 141 | |
Stephen Warren | 6bb27d7 | 2012-11-08 12:40:59 -0700 | [diff] [blame] | 142 | void __init dw_apb_timer_init(void) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 143 | { |
| 144 | struct device_node *event_timer, *source_timer; |
| 145 | |
| 146 | event_timer = of_find_matching_node(NULL, osctimer_ids); |
| 147 | if (!event_timer) |
| 148 | panic("No timer for clockevent"); |
| 149 | add_clockevent(event_timer); |
| 150 | |
| 151 | source_timer = of_find_matching_node(event_timer, osctimer_ids); |
| 152 | if (!source_timer) |
| 153 | panic("No timer for clocksource"); |
| 154 | add_clocksource(source_timer); |
| 155 | |
| 156 | of_node_put(source_timer); |
| 157 | |
| 158 | init_sched_clock(); |
| 159 | } |