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1// SPDX-License-Identifier: GPL-2.0-only2/*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 interrupt18 * @of_irq: an of_timer_irq structure pointer19 *20 * Free the irq resource21 */22static __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 interrupt33 * @np: a device tree node pointer34 * @of_irq: an of_timer_irq structure pointer35 *36 * Get the interrupt number from the DT from its definition and37 * request it. The interrupt is gotten by falling back the following way:38 *39 * - Get interrupt number by name40 * - Get interrupt number by index41 *42 * Returns 0 on success, < 0 otherwise43 */44static __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 resources81 * @of_clk: a of_timer_clk structure pointer82 *83 * Disables and releases the refcount on the clk84 */85static __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 resources94 * @np: a device tree node pointer95 * @of_clk: a of_timer_clk structure pointer96 *97 * Get the clock by name or by index, enable it and get the rate98 *99 * Returns 0 on success, < 0 otherwise100 */101static __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);129out:130 return ret;131 132out_clk_disable:133 clk_disable_unprepare(of_clk->clk);134out_clk_put:135 clk_put(of_clk->clk);136 137 goto out;138}139 140static __init void timer_of_base_exit(struct of_timer_base *of_base)141{142 iounmap(of_base->base);143}144 145static __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 159int __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 192out_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 resources206 * @to: timer_of structure207 *208 * Release the resources that has been used in timer_of_init().209 * This function should be called in init error cases210 */211void __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