1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2017, Linaro Ltd. All rights reserved. 4 * 5 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> 6 */ 7 #include <linux/clk.h> 8 #include <linux/interrupt.h> 9 #include <linux/of.h> 10 #include <linux/of_address.h> 11 #include <linux/of_irq.h> 12 #include <linux/slab.h> 13 14 #include "timer-of.h" 15 16 /** 17 * timer_of_irq_exit - Release the interrupt 18 * @of_irq: an of_timer_irq structure pointer 19 * 20 * Free the irq resource 21 */ 22 static __init void timer_of_irq_exit(struct of_timer_irq *of_irq) 23 { 24 struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); 25 26 struct clock_event_device *clkevt = &to->clkevt; 27 28 free_irq(of_irq->irq, clkevt); 29 } 30 31 /** 32 * timer_of_irq_init - Request the interrupt 33 * @np: a device tree node pointer 34 * @of_irq: an of_timer_irq structure pointer 35 * 36 * Get the interrupt number from the DT from its definition and 37 * request it. The interrupt is gotten by falling back the following way: 38 * 39 * - Get interrupt number by name 40 * - Get interrupt number by index 41 * 42 * Returns 0 on success, < 0 otherwise 43 */ 44 static __init int timer_of_irq_init(struct device_node *np, 45 struct of_timer_irq *of_irq) 46 { 47 int ret; 48 struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); 49 struct clock_event_device *clkevt = &to->clkevt; 50 51 if (of_irq->name) { 52 of_irq->irq = ret = of_irq_get_byname(np, of_irq->name); 53 if (ret < 0) { 54 pr_err("Failed to get interrupt %s for %pOF\n", 55 of_irq->name, np); 56 return ret; 57 } 58 } else { 59 of_irq->irq = irq_of_parse_and_map(np, of_irq->index); 60 } 61 if (!of_irq->irq) { 62 pr_err("Failed to map interrupt for %pOF\n", np); 63 return -EINVAL; 64 } 65 66 ret = request_irq(of_irq->irq, of_irq->handler, 67 of_irq->flags ? of_irq->flags : IRQF_TIMER, 68 np->full_name, clkevt); 69 if (ret) { 70 pr_err("Failed to request irq %d for %pOF\n", of_irq->irq, np); 71 return ret; 72 } 73 74 clkevt->irq = of_irq->irq; 75 76 return 0; 77 } 78 79 /** 80 * timer_of_clk_exit - Release the clock resources 81 * @of_clk: a of_timer_clk structure pointer 82 * 83 * Disables and releases the refcount on the clk 84 */ 85 static __init void timer_of_clk_exit(struct of_timer_clk *of_clk) 86 { 87 of_clk->rate = 0; 88 clk_disable_unprepare(of_clk->clk); 89 clk_put(of_clk->clk); 90 } 91 92 /** 93 * timer_of_clk_init - Initialize the clock resources 94 * @np: a device tree node pointer 95 * @of_clk: a of_timer_clk structure pointer 96 * 97 * Get the clock by name or by index, enable it and get the rate 98 * 99 * Returns 0 on success, < 0 otherwise 100 */ 101 static __init int timer_of_clk_init(struct device_node *np, 102 struct of_timer_clk *of_clk) 103 { 104 int ret; 105 106 of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) : 107 of_clk_get(np, of_clk->index); 108 if (IS_ERR(of_clk->clk)) { 109 ret = PTR_ERR(of_clk->clk); 110 if (ret != -EPROBE_DEFER) 111 pr_err("Failed to get clock for %pOF\n", np); 112 goto out; 113 } 114 115 ret = clk_prepare_enable(of_clk->clk); 116 if (ret) { 117 pr_err("Failed for enable clock for %pOF\n", np); 118 goto out_clk_put; 119 } 120 121 of_clk->rate = clk_get_rate(of_clk->clk); 122 if (!of_clk->rate) { 123 ret = -EINVAL; 124 pr_err("Failed to get clock rate for %pOF\n", np); 125 goto out_clk_disable; 126 } 127 128 of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ); 129 out: 130 return ret; 131 132 out_clk_disable: 133 clk_disable_unprepare(of_clk->clk); 134 out_clk_put: 135 clk_put(of_clk->clk); 136 137 goto out; 138 } 139 140 static __init void timer_of_base_exit(struct of_timer_base *of_base) 141 { 142 iounmap(of_base->base); 143 } 144 145 static __init int timer_of_base_init(struct device_node *np, 146 struct of_timer_base *of_base) 147 { 148 of_base->base = of_base->name ? 149 of_io_request_and_map(np, of_base->index, of_base->name) : 150 of_iomap(np, of_base->index); 151 if (IS_ERR_OR_NULL(of_base->base)) { 152 pr_err("Failed to iomap (%s:%s)\n", np->name, of_base->name); 153 return of_base->base ? PTR_ERR(of_base->base) : -ENOMEM; 154 } 155 156 return 0; 157 } 158 159 int __init timer_of_init(struct device_node *np, struct timer_of *to) 160 { 161 int ret = -EINVAL; 162 int flags = 0; 163 164 if (to->flags & TIMER_OF_BASE) { 165 ret = timer_of_base_init(np, &to->of_base); 166 if (ret) 167 goto out_fail; 168 flags |= TIMER_OF_BASE; 169 } 170 171 if (to->flags & TIMER_OF_CLOCK) { 172 ret = timer_of_clk_init(np, &to->of_clk); 173 if (ret) 174 goto out_fail; 175 flags |= TIMER_OF_CLOCK; 176 } 177 178 if (to->flags & TIMER_OF_IRQ) { 179 ret = timer_of_irq_init(np, &to->of_irq); 180 if (ret) 181 goto out_fail; 182 flags |= TIMER_OF_IRQ; 183 } 184 185 if (!to->clkevt.name) 186 to->clkevt.name = np->full_name; 187 188 to->np = np; 189 190 return ret; 191 192 out_fail: 193 if (flags & TIMER_OF_IRQ) 194 timer_of_irq_exit(&to->of_irq); 195 196 if (flags & TIMER_OF_CLOCK) 197 timer_of_clk_exit(&to->of_clk); 198 199 if (flags & TIMER_OF_BASE) 200 timer_of_base_exit(&to->of_base); 201 return ret; 202 } 203 204 /** 205 * timer_of_cleanup - release timer_of resources 206 * @to: timer_of structure 207 * 208 * Release the resources that has been used in timer_of_init(). 209 * This function should be called in init error cases 210 */ 211 void __init timer_of_cleanup(struct timer_of *to) 212 { 213 if (to->flags & TIMER_OF_IRQ) 214 timer_of_irq_exit(&to->of_irq); 215 216 if (to->flags & TIMER_OF_CLOCK) 217 timer_of_clk_exit(&to->of_clk); 218 219 if (to->flags & TIMER_OF_BASE) 220 timer_of_base_exit(&to->of_base); 221 } 222