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> |
Stephen Boyd | 38ff87f | 2013-06-01 23:39:40 -0700 | [diff] [blame] | 24 | #include <linux/sched_clock.h> |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 25 | |
Uwe Kleine-König | 1cf0203 | 2013-10-01 10:38:12 +0200 | [diff] [blame] | 26 | static void __init timer_get_base_and_rate(struct device_node *np, |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 27 | void __iomem **base, u32 *rate) |
| 28 | { |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame] | 29 | struct clk *timer_clk; |
| 30 | struct clk *pclk; |
| 31 | |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 32 | *base = of_iomap(np, 0); |
| 33 | |
| 34 | if (!*base) |
| 35 | panic("Unable to map regs for %s", np->name); |
| 36 | |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame] | 37 | /* |
| 38 | * Not all implementations use a periphal clock, so don't panic |
| 39 | * if it's not present |
| 40 | */ |
| 41 | pclk = of_clk_get_by_name(np, "pclk"); |
| 42 | if (!IS_ERR(pclk)) |
| 43 | if (clk_prepare_enable(pclk)) |
| 44 | pr_warn("pclk for %s is present, but could not be activated\n", |
| 45 | np->name); |
| 46 | |
| 47 | timer_clk = of_clk_get_by_name(np, "timer"); |
| 48 | if (IS_ERR(timer_clk)) |
| 49 | goto try_clock_freq; |
| 50 | |
| 51 | if (!clk_prepare_enable(timer_clk)) { |
| 52 | *rate = clk_get_rate(timer_clk); |
| 53 | return; |
| 54 | } |
| 55 | |
| 56 | try_clock_freq: |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 57 | if (of_property_read_u32(np, "clock-freq", rate) && |
Uwe Kleine-König | 1cf0203 | 2013-10-01 10:38:12 +0200 | [diff] [blame] | 58 | of_property_read_u32(np, "clock-frequency", rate)) |
Heiko Stuebner | a8b447f | 2013-06-04 11:37:36 +0200 | [diff] [blame] | 59 | panic("No clock nor clock-frequency property for %s", np->name); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 60 | } |
| 61 | |
Uwe Kleine-König | 1cf0203 | 2013-10-01 10:38:12 +0200 | [diff] [blame] | 62 | static void __init add_clockevent(struct device_node *event_timer) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 63 | { |
| 64 | void __iomem *iobase; |
| 65 | struct dw_apb_clock_event_device *ced; |
| 66 | u32 irq, rate; |
| 67 | |
| 68 | irq = irq_of_parse_and_map(event_timer, 0); |
Baruch Siach | 1a33bd2 | 2013-05-29 10:11:17 +0200 | [diff] [blame] | 69 | if (irq == 0) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 70 | panic("No IRQ for clock event timer"); |
| 71 | |
| 72 | timer_get_base_and_rate(event_timer, &iobase, &rate); |
| 73 | |
| 74 | ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq, |
| 75 | rate); |
| 76 | if (!ced) |
| 77 | panic("Unable to initialise clockevent device"); |
| 78 | |
| 79 | dw_apb_clockevent_register(ced); |
| 80 | } |
| 81 | |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 82 | static void __iomem *sched_io_base; |
| 83 | static u32 sched_rate; |
| 84 | |
Uwe Kleine-König | 1cf0203 | 2013-10-01 10:38:12 +0200 | [diff] [blame] | 85 | static void __init add_clocksource(struct device_node *source_timer) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 86 | { |
| 87 | void __iomem *iobase; |
| 88 | struct dw_apb_clocksource *cs; |
| 89 | u32 rate; |
| 90 | |
| 91 | timer_get_base_and_rate(source_timer, &iobase, &rate); |
| 92 | |
| 93 | cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate); |
| 94 | if (!cs) |
| 95 | panic("Unable to initialise clocksource device"); |
| 96 | |
| 97 | dw_apb_clocksource_start(cs); |
| 98 | dw_apb_clocksource_register(cs); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 99 | |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 100 | /* |
| 101 | * Fallback to use the clocksource as sched_clock if no separate |
| 102 | * timer is found. sched_io_base then points to the current_value |
| 103 | * register of the clocksource timer. |
| 104 | */ |
| 105 | sched_io_base = iobase + 0x04; |
| 106 | sched_rate = rate; |
| 107 | } |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 108 | |
Yang Wei | 0d24d1f | 2014-05-13 11:10:08 +0800 | [diff] [blame^] | 109 | static u64 notrace read_sched_clock(void) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 110 | { |
Dinh Nguyen | 85dc6ee | 2013-12-10 19:49:18 +0100 | [diff] [blame] | 111 | return ~__raw_readl(sched_io_base); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 112 | } |
| 113 | |
| 114 | static const struct of_device_id sptimer_ids[] __initconst = { |
| 115 | { .compatible = "picochip,pc3x2-rtc" }, |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 116 | { /* Sentinel */ }, |
| 117 | }; |
| 118 | |
Uwe Kleine-König | 1cf0203 | 2013-10-01 10:38:12 +0200 | [diff] [blame] | 119 | static void __init init_sched_clock(void) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 120 | { |
| 121 | struct device_node *sched_timer; |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 122 | |
| 123 | sched_timer = of_find_matching_node(NULL, sptimer_ids); |
Heiko Stuebner | a1198f8 | 2013-06-04 11:37:02 +0200 | [diff] [blame] | 124 | if (sched_timer) { |
| 125 | timer_get_base_and_rate(sched_timer, &sched_io_base, |
| 126 | &sched_rate); |
| 127 | of_node_put(sched_timer); |
| 128 | } |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 129 | |
Stephen Boyd | fa8296a | 2013-07-18 16:21:22 -0700 | [diff] [blame] | 130 | sched_clock_register(read_sched_clock, 32, sched_rate); |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 131 | } |
| 132 | |
Heiko Stuebner | 1002148 | 2013-06-04 11:38:42 +0200 | [diff] [blame] | 133 | static int num_called; |
| 134 | static void __init dw_apb_timer_init(struct device_node *timer) |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 135 | { |
Heiko Stuebner | 1002148 | 2013-06-04 11:38:42 +0200 | [diff] [blame] | 136 | switch (num_called) { |
| 137 | case 0: |
| 138 | pr_debug("%s: found clockevent timer\n", __func__); |
| 139 | add_clockevent(timer); |
Heiko Stuebner | 1002148 | 2013-06-04 11:38:42 +0200 | [diff] [blame] | 140 | break; |
| 141 | case 1: |
| 142 | pr_debug("%s: found clocksource timer\n", __func__); |
| 143 | add_clocksource(timer); |
Heiko Stuebner | 1002148 | 2013-06-04 11:38:42 +0200 | [diff] [blame] | 144 | init_sched_clock(); |
| 145 | break; |
| 146 | default: |
| 147 | break; |
| 148 | } |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 149 | |
Heiko Stuebner | 1002148 | 2013-06-04 11:38:42 +0200 | [diff] [blame] | 150 | num_called++; |
Dinh Nguyen | cfda590 | 2012-07-11 15:13:16 -0500 | [diff] [blame] | 151 | } |
Heiko Stuebner | 1002148 | 2013-06-04 11:38:42 +0200 | [diff] [blame] | 152 | CLOCKSOURCE_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init); |
Dinh Nguyen | 9ab4727 | 2013-12-10 19:49:18 +0100 | [diff] [blame] | 153 | CLOCKSOURCE_OF_DECLARE(apb_timer_osc, "snps,dw-apb-timer-osc", dw_apb_timer_init); |
| 154 | CLOCKSOURCE_OF_DECLARE(apb_timer_sp, "snps,dw-apb-timer-sp", dw_apb_timer_init); |
| 155 | CLOCKSOURCE_OF_DECLARE(apb_timer, "snps,dw-apb-timer", dw_apb_timer_init); |