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 | 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 | */ |
50 | static __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(dev: np, name: 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(node: np, index: 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(irq: of_irq->irq, handler: of_irq->handler, |
74 | devname: np->full_name, percpu_dev_id: clkevt) : |
75 | request_irq(irq: of_irq->irq, handler: of_irq->handler, |
76 | flags: of_irq->flags ? of_irq->flags : IRQF_TIMER, |
77 | name: np->full_name, dev: 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 | */ |
94 | static __init void timer_of_clk_exit(struct of_timer_clk *of_clk) |
95 | { |
96 | of_clk->rate = 0; |
97 | clk_disable_unprepare(clk: of_clk->clk); |
98 | clk_put(clk: 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 | */ |
110 | static __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, name: of_clk->name) : |
116 | of_clk_get(np, index: of_clk->index); |
117 | if (IS_ERR(ptr: of_clk->clk)) { |
118 | ret = PTR_ERR(ptr: 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(clk: 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(clk: 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); |
138 | out: |
139 | return ret; |
140 | |
141 | out_clk_disable: |
142 | clk_disable_unprepare(clk: of_clk->clk); |
143 | out_clk_put: |
144 | clk_put(clk: of_clk->clk); |
145 | |
146 | goto out; |
147 | } |
148 | |
149 | static __init void timer_of_base_exit(struct of_timer_base *of_base) |
150 | { |
151 | iounmap(addr: of_base->base); |
152 | } |
153 | |
154 | static __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(device: np, index: of_base->index, name: of_base->name) : |
159 | of_iomap(node: np, index: of_base->index); |
160 | if (IS_ERR_OR_NULL(ptr: of_base->base)) { |
161 | pr_err("Failed to iomap (%s:%s)\n" , np->name, of_base->name); |
162 | return of_base->base ? PTR_ERR(ptr: of_base->base) : -ENOMEM; |
163 | } |
164 | |
165 | return 0; |
166 | } |
167 | |
168 | int __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, of_base: &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, of_clk: &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, of_irq: &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 | |
201 | out_fail: |
202 | if (flags & TIMER_OF_IRQ) |
203 | timer_of_irq_exit(of_irq: &to->of_irq); |
204 | |
205 | if (flags & TIMER_OF_CLOCK) |
206 | timer_of_clk_exit(of_clk: &to->of_clk); |
207 | |
208 | if (flags & TIMER_OF_BASE) |
209 | timer_of_base_exit(of_base: &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 | */ |
220 | void __init timer_of_cleanup(struct timer_of *to) |
221 | { |
222 | if (to->flags & TIMER_OF_IRQ) |
223 | timer_of_irq_exit(of_irq: &to->of_irq); |
224 | |
225 | if (to->flags & TIMER_OF_CLOCK) |
226 | timer_of_clk_exit(of_clk: &to->of_clk); |
227 | |
228 | if (to->flags & TIMER_OF_BASE) |
229 | timer_of_base_exit(of_base: &to->of_base); |
230 | } |
231 | |