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 %pOF\n", np); 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 %pOF\n", of_irq->irq, np); 67 return ret; 68 } 69 70 clkevt->irq = of_irq->irq; 71 72 return 0; 73 } 74 75 static __init void timer_clk_exit(struct of_timer_clk *of_clk) 76 { 77 of_clk->rate = 0; 78 clk_disable_unprepare(of_clk->clk); 79 clk_put(of_clk->clk); 80 } 81 82 static __init int timer_clk_init(struct device_node *np, 83 struct of_timer_clk *of_clk) 84 { 85 int ret; 86 87 of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) : 88 of_clk_get(np, of_clk->index); 89 if (IS_ERR(of_clk->clk)) { 90 pr_err("Failed to get clock for %pOF\n", np); 91 return PTR_ERR(of_clk->clk); 92 } 93 94 ret = clk_prepare_enable(of_clk->clk); 95 if (ret) { 96 pr_err("Failed for enable clock for %pOF\n", np); 97 goto out_clk_put; 98 } 99 100 of_clk->rate = clk_get_rate(of_clk->clk); 101 if (!of_clk->rate) { 102 ret = -EINVAL; 103 pr_err("Failed to get clock rate for %pOF\n", np); 104 goto out_clk_disable; 105 } 106 107 of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ); 108 out: 109 return ret; 110 111 out_clk_disable: 112 clk_disable_unprepare(of_clk->clk); 113 out_clk_put: 114 clk_put(of_clk->clk); 115 116 goto out; 117 } 118 119 static __init void timer_base_exit(struct of_timer_base *of_base) 120 { 121 iounmap(of_base->base); 122 } 123 124 static __init int timer_base_init(struct device_node *np, 125 struct of_timer_base *of_base) 126 { 127 const char *name = of_base->name ? of_base->name : np->full_name; 128 129 of_base->base = of_io_request_and_map(np, of_base->index, name); 130 if (IS_ERR(of_base->base)) { 131 pr_err("Failed to iomap (%s)\n", name); 132 return PTR_ERR(of_base->base); 133 } 134 135 return 0; 136 } 137 138 int __init timer_of_init(struct device_node *np, struct timer_of *to) 139 { 140 int ret = -EINVAL; 141 int flags = 0; 142 143 if (to->flags & TIMER_OF_BASE) { 144 ret = timer_base_init(np, &to->of_base); 145 if (ret) 146 goto out_fail; 147 flags |= TIMER_OF_BASE; 148 } 149 150 if (to->flags & TIMER_OF_CLOCK) { 151 ret = timer_clk_init(np, &to->of_clk); 152 if (ret) 153 goto out_fail; 154 flags |= TIMER_OF_CLOCK; 155 } 156 157 if (to->flags & TIMER_OF_IRQ) { 158 ret = timer_irq_init(np, &to->of_irq); 159 if (ret) 160 goto out_fail; 161 flags |= TIMER_OF_IRQ; 162 } 163 164 if (!to->clkevt.name) 165 to->clkevt.name = np->name; 166 return ret; 167 168 out_fail: 169 if (flags & TIMER_OF_IRQ) 170 timer_irq_exit(&to->of_irq); 171 172 if (flags & TIMER_OF_CLOCK) 173 timer_clk_exit(&to->of_clk); 174 175 if (flags & TIMER_OF_BASE) 176 timer_base_exit(&to->of_base); 177 return ret; 178 } 179 180 /** 181 * timer_of_cleanup - release timer_of ressources 182 * @to: timer_of structure 183 * 184 * Release the ressources that has been used in timer_of_init(). 185 * This function should be called in init error cases 186 */ 187 void __init timer_of_cleanup(struct timer_of *to) 188 { 189 if (to->flags & TIMER_OF_IRQ) 190 timer_irq_exit(&to->of_irq); 191 192 if (to->flags & TIMER_OF_CLOCK) 193 timer_clk_exit(&to->of_clk); 194 195 if (to->flags & TIMER_OF_BASE) 196 timer_base_exit(&to->of_base); 197 } 198