1 /* 2 * Copyright (c) 2017, Linaro Ltd. All rights reserved. 3 * 4 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 #include <linux/clk.h> 19 #include <linux/interrupt.h> 20 #include <linux/of.h> 21 #include <linux/of_address.h> 22 #include <linux/of_irq.h> 23 #include <linux/slab.h> 24 25 #include "timer-of.h" 26 27 static __init void timer_irq_exit(struct of_timer_irq *of_irq) 28 { 29 struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); 30 31 struct clock_event_device *clkevt = &to->clkevt; 32 33 of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) : 34 free_irq(of_irq->irq, clkevt); 35 } 36 37 static __init int timer_irq_init(struct device_node *np, 38 struct of_timer_irq *of_irq) 39 { 40 int ret; 41 struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); 42 struct clock_event_device *clkevt = &to->clkevt; 43 44 of_irq->irq = of_irq->name ? of_irq_get_byname(np, of_irq->name): 45 irq_of_parse_and_map(np, of_irq->index); 46 if (!of_irq->irq) { 47 pr_err("Failed to map interrupt for %s\n", np->full_name); 48 return -EINVAL; 49 } 50 51 ret = of_irq->percpu ? 52 request_percpu_irq(of_irq->irq, of_irq->handler, 53 np->full_name, clkevt) : 54 request_irq(of_irq->irq, of_irq->handler, 55 of_irq->flags ? of_irq->flags : IRQF_TIMER, 56 np->full_name, clkevt); 57 if (ret) { 58 pr_err("Failed to request irq %d for %s\n", of_irq->irq, 59 np->full_name); 60 return ret; 61 } 62 63 clkevt->irq = of_irq->irq; 64 65 return 0; 66 } 67 68 static __init void timer_clk_exit(struct of_timer_clk *of_clk) 69 { 70 of_clk->rate = 0; 71 clk_disable_unprepare(of_clk->clk); 72 clk_put(of_clk->clk); 73 } 74 75 static __init int timer_clk_init(struct device_node *np, 76 struct of_timer_clk *of_clk) 77 { 78 int ret; 79 80 of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) : 81 of_clk_get(np, of_clk->index); 82 if (IS_ERR(of_clk->clk)) { 83 pr_err("Failed to get clock for %s\n", np->full_name); 84 return PTR_ERR(of_clk->clk); 85 } 86 87 ret = clk_prepare_enable(of_clk->clk); 88 if (ret) { 89 pr_err("Failed for enable clock for %s\n", np->full_name); 90 goto out_clk_put; 91 } 92 93 of_clk->rate = clk_get_rate(of_clk->clk); 94 if (!of_clk->rate) { 95 ret = -EINVAL; 96 pr_err("Failed to get clock rate for %s\n", np->full_name); 97 goto out_clk_disable; 98 } 99 100 of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ); 101 out: 102 return ret; 103 104 out_clk_disable: 105 clk_disable_unprepare(of_clk->clk); 106 out_clk_put: 107 clk_put(of_clk->clk); 108 109 goto out; 110 } 111 112 static __init void timer_base_exit(struct of_timer_base *of_base) 113 { 114 iounmap(of_base->base); 115 } 116 117 static __init int timer_base_init(struct device_node *np, 118 struct of_timer_base *of_base) 119 { 120 const char *name = of_base->name ? of_base->name : np->full_name; 121 122 of_base->base = of_io_request_and_map(np, of_base->index, name); 123 if (!of_base->base) { 124 pr_err("Failed to iomap (%s)\n", name); 125 return -ENXIO; 126 } 127 128 return 0; 129 } 130 131 int __init timer_of_init(struct device_node *np, struct timer_of *to) 132 { 133 int ret = -EINVAL; 134 int flags = 0; 135 136 if (to->flags & TIMER_OF_BASE) { 137 ret = timer_base_init(np, &to->of_base); 138 if (ret) 139 goto out_fail; 140 flags |= TIMER_OF_BASE; 141 } 142 143 if (to->flags & TIMER_OF_CLOCK) { 144 ret = timer_clk_init(np, &to->of_clk); 145 if (ret) 146 goto out_fail; 147 flags |= TIMER_OF_CLOCK; 148 } 149 150 if (to->flags & TIMER_OF_IRQ) { 151 ret = timer_irq_init(np, &to->of_irq); 152 if (ret) 153 goto out_fail; 154 flags |= TIMER_OF_IRQ; 155 } 156 157 if (!to->clkevt.name) 158 to->clkevt.name = np->name; 159 return ret; 160 161 out_fail: 162 if (flags & TIMER_OF_IRQ) 163 timer_irq_exit(&to->of_irq); 164 165 if (flags & TIMER_OF_CLOCK) 166 timer_clk_exit(&to->of_clk); 167 168 if (flags & TIMER_OF_BASE) 169 timer_base_exit(&to->of_base); 170 return ret; 171 } 172