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 if (of_irq->name) { 45 of_irq->irq = ret = of_irq_get_byname(np, of_irq->name); 46 if (ret < 0) { 47 pr_err("Failed to get interrupt %s for %s\n", 48 of_irq->name, np->full_name); 49 return ret; 50 } 51 } else { 52 of_irq->irq = irq_of_parse_and_map(np, of_irq->index); 53 } 54 if (!of_irq->irq) { 55 pr_err("Failed to map interrupt for %s\n", np->full_name); 56 return -EINVAL; 57 } 58 59 ret = of_irq->percpu ? 60 request_percpu_irq(of_irq->irq, of_irq->handler, 61 np->full_name, clkevt) : 62 request_irq(of_irq->irq, of_irq->handler, 63 of_irq->flags ? of_irq->flags : IRQF_TIMER, 64 np->full_name, clkevt); 65 if (ret) { 66 pr_err("Failed to request irq %d for %s\n", of_irq->irq, 67 np->full_name); 68 return ret; 69 } 70 71 clkevt->irq = of_irq->irq; 72 73 return 0; 74 } 75 76 static __init void timer_clk_exit(struct of_timer_clk *of_clk) 77 { 78 of_clk->rate = 0; 79 clk_disable_unprepare(of_clk->clk); 80 clk_put(of_clk->clk); 81 } 82 83 static __init int timer_clk_init(struct device_node *np, 84 struct of_timer_clk *of_clk) 85 { 86 int ret; 87 88 of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) : 89 of_clk_get(np, of_clk->index); 90 if (IS_ERR(of_clk->clk)) { 91 pr_err("Failed to get clock for %s\n", np->full_name); 92 return PTR_ERR(of_clk->clk); 93 } 94 95 ret = clk_prepare_enable(of_clk->clk); 96 if (ret) { 97 pr_err("Failed for enable clock for %s\n", np->full_name); 98 goto out_clk_put; 99 } 100 101 of_clk->rate = clk_get_rate(of_clk->clk); 102 if (!of_clk->rate) { 103 ret = -EINVAL; 104 pr_err("Failed to get clock rate for %s\n", np->full_name); 105 goto out_clk_disable; 106 } 107 108 of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ); 109 out: 110 return ret; 111 112 out_clk_disable: 113 clk_disable_unprepare(of_clk->clk); 114 out_clk_put: 115 clk_put(of_clk->clk); 116 117 goto out; 118 } 119 120 static __init void timer_base_exit(struct of_timer_base *of_base) 121 { 122 iounmap(of_base->base); 123 } 124 125 static __init int timer_base_init(struct device_node *np, 126 struct of_timer_base *of_base) 127 { 128 const char *name = of_base->name ? of_base->name : np->full_name; 129 130 of_base->base = of_io_request_and_map(np, of_base->index, name); 131 if (!of_base->base) { 132 pr_err("Failed to iomap (%s)\n", name); 133 return -ENXIO; 134 } 135 136 return 0; 137 } 138 139 int __init timer_of_init(struct device_node *np, struct timer_of *to) 140 { 141 int ret = -EINVAL; 142 int flags = 0; 143 144 if (to->flags & TIMER_OF_BASE) { 145 ret = timer_base_init(np, &to->of_base); 146 if (ret) 147 goto out_fail; 148 flags |= TIMER_OF_BASE; 149 } 150 151 if (to->flags & TIMER_OF_CLOCK) { 152 ret = timer_clk_init(np, &to->of_clk); 153 if (ret) 154 goto out_fail; 155 flags |= TIMER_OF_CLOCK; 156 } 157 158 if (to->flags & TIMER_OF_IRQ) { 159 ret = timer_irq_init(np, &to->of_irq); 160 if (ret) 161 goto out_fail; 162 flags |= TIMER_OF_IRQ; 163 } 164 165 if (!to->clkevt.name) 166 to->clkevt.name = np->name; 167 return ret; 168 169 out_fail: 170 if (flags & TIMER_OF_IRQ) 171 timer_irq_exit(&to->of_irq); 172 173 if (flags & TIMER_OF_CLOCK) 174 timer_clk_exit(&to->of_clk); 175 176 if (flags & TIMER_OF_BASE) 177 timer_base_exit(&to->of_base); 178 return ret; 179 } 180