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 */
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	if (of_irq->percpu)
29		free_percpu_irq(of_irq->irq, clkevt);
30	else
31		free_irq(of_irq->irq, clkevt);
32}
33
34/**
35 * timer_of_irq_init - Request the interrupt
36 * @np: a device tree node pointer
37 * @of_irq: an of_timer_irq structure pointer
38 *
39 * Get the interrupt number from the DT from its definition and
40 * request it. The interrupt is gotten by falling back the following way:
41 *
42 * - Get interrupt number by name
43 * - Get interrupt number by index
44 *
45 * When the interrupt is per CPU, 'request_percpu_irq()' is called,
46 * otherwise 'request_irq()' is used.
47 *
48 * Returns 0 on success, < 0 otherwise
49 */
50static __init int timer_of_irq_init(struct device_node *np,
51				    struct of_timer_irq *of_irq)
52{
53	int ret;
54	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
55	struct clock_event_device *clkevt = &to->clkevt;
56
57	if (of_irq->name) {
58		of_irq->irq = ret = of_irq_get_byname(np, of_irq->name);
59		if (ret < 0) {
60			pr_err("Failed to get interrupt %s for %pOF\n",
61			       of_irq->name, np);
62			return ret;
63		}
64	} else	{
65		of_irq->irq = irq_of_parse_and_map(np, of_irq->index);
66	}
67	if (!of_irq->irq) {
68		pr_err("Failed to map interrupt for %pOF\n", np);
69		return -EINVAL;
70	}
71
72	ret = of_irq->percpu ?
73		request_percpu_irq(of_irq->irq, of_irq->handler,
74				   np->full_name, clkevt) :
75		request_irq(of_irq->irq, of_irq->handler,
76			    of_irq->flags ? of_irq->flags : IRQF_TIMER,
77			    np->full_name, clkevt);
78	if (ret) {
79		pr_err("Failed to request irq %d for %pOF\n", of_irq->irq, np);
80		return ret;
81	}
82
83	clkevt->irq = of_irq->irq;
84
85	return 0;
86}
87
88/**
89 * timer_of_clk_exit - Release the clock resources
90 * @of_clk: a of_timer_clk structure pointer
91 *
92 * Disables and releases the refcount on the clk
93 */
94static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
95{
96	of_clk->rate = 0;
97	clk_disable_unprepare(of_clk->clk);
98	clk_put(of_clk->clk);
99}
100
101/**
102 * timer_of_clk_init - Initialize the clock resources
103 * @np: a device tree node pointer
104 * @of_clk: a of_timer_clk structure pointer
105 *
106 * Get the clock by name or by index, enable it and get the rate
107 *
108 * Returns 0 on success, < 0 otherwise
109 */
110static __init int timer_of_clk_init(struct device_node *np,
111				    struct of_timer_clk *of_clk)
112{
113	int ret;
114
115	of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) :
116		of_clk_get(np, of_clk->index);
117	if (IS_ERR(of_clk->clk)) {
118		ret = PTR_ERR(of_clk->clk);
119		if (ret != -EPROBE_DEFER)
120			pr_err("Failed to get clock for %pOF\n", np);
121		goto out;
122	}
123
124	ret = clk_prepare_enable(of_clk->clk);
125	if (ret) {
126		pr_err("Failed for enable clock for %pOF\n", np);
127		goto out_clk_put;
128	}
129
130	of_clk->rate = clk_get_rate(of_clk->clk);
131	if (!of_clk->rate) {
132		ret = -EINVAL;
133		pr_err("Failed to get clock rate for %pOF\n", np);
134		goto out_clk_disable;
135	}
136
137	of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ);
138out:
139	return ret;
140
141out_clk_disable:
142	clk_disable_unprepare(of_clk->clk);
143out_clk_put:
144	clk_put(of_clk->clk);
145
146	goto out;
147}
148
149static __init void timer_of_base_exit(struct of_timer_base *of_base)
150{
151	iounmap(of_base->base);
152}
153
154static __init int timer_of_base_init(struct device_node *np,
155				     struct of_timer_base *of_base)
156{
157	of_base->base = of_base->name ?
158		of_io_request_and_map(np, of_base->index, of_base->name) :
159		of_iomap(np, of_base->index);
160	if (IS_ERR_OR_NULL(of_base->base)) {
161		pr_err("Failed to iomap (%s:%s)\n", np->name, of_base->name);
162		return of_base->base ? PTR_ERR(of_base->base) : -ENOMEM;
163	}
164
165	return 0;
166}
167
168int __init timer_of_init(struct device_node *np, struct timer_of *to)
169{
170	int ret = -EINVAL;
171	int flags = 0;
172
173	if (to->flags & TIMER_OF_BASE) {
174		ret = timer_of_base_init(np, &to->of_base);
175		if (ret)
176			goto out_fail;
177		flags |= TIMER_OF_BASE;
178	}
179
180	if (to->flags & TIMER_OF_CLOCK) {
181		ret = timer_of_clk_init(np, &to->of_clk);
182		if (ret)
183			goto out_fail;
184		flags |= TIMER_OF_CLOCK;
185	}
186
187	if (to->flags & TIMER_OF_IRQ) {
188		ret = timer_of_irq_init(np, &to->of_irq);
189		if (ret)
190			goto out_fail;
191		flags |= TIMER_OF_IRQ;
192	}
193
194	if (!to->clkevt.name)
195		to->clkevt.name = np->full_name;
196
197	to->np = np;
198
199	return ret;
200
201out_fail:
202	if (flags & TIMER_OF_IRQ)
203		timer_of_irq_exit(&to->of_irq);
204
205	if (flags & TIMER_OF_CLOCK)
206		timer_of_clk_exit(&to->of_clk);
207
208	if (flags & TIMER_OF_BASE)
209		timer_of_base_exit(&to->of_base);
210	return ret;
211}
212
213/**
214 * timer_of_cleanup - release timer_of resources
215 * @to: timer_of structure
216 *
217 * Release the resources that has been used in timer_of_init().
218 * This function should be called in init error cases
219 */
220void __init timer_of_cleanup(struct timer_of *to)
221{
222	if (to->flags & TIMER_OF_IRQ)
223		timer_of_irq_exit(&to->of_irq);
224
225	if (to->flags & TIMER_OF_CLOCK)
226		timer_of_clk_exit(&to->of_clk);
227
228	if (to->flags & TIMER_OF_BASE)
229		timer_of_base_exit(&to->of_base);
230}
231