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223 lines · 5.0 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2017, Linaro Ltd. All rights reserved.
4 *
5 * Author: Daniel Lezcano <[email protected]>
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 */
22static 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 */
44static 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 */
85static 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 */
101static 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 void timer_of_base_exit(struct of_timer_base *of_base)
141{
142 iounmap(of_base->base);
143}
144
145static 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 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}
203EXPORT_SYMBOL_GPL(timer_of_init);
204
205/**
206 * timer_of_cleanup - release timer_of resources
207 * @to: timer_of structure
208 *
209 * Release the resources that has been used in timer_of_init().
210 * This function should be called in init error cases
211 */
212void timer_of_cleanup(struct timer_of *to)
213{
214 if (to->flags & TIMER_OF_IRQ)
215 timer_of_irq_exit(&to->of_irq);
216
217 if (to->flags & TIMER_OF_CLOCK)
218 timer_of_clk_exit(&to->of_clk);
219
220 if (to->flags & TIMER_OF_BASE)
221 timer_of_base_exit(&to->of_base);
222}
223EXPORT_SYMBOL_GPL(timer_of_cleanup);