Merge tag 'pstore-v4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees...
[linux-2.6-microblaze.git] / drivers / clocksource / timer-of.c
1 /*
2  * Copyright (c) 2017, Linaro Ltd.  All rights reserved.
3  *
4  * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 #include <linux/clk.h>
19 #include <linux/interrupt.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 #include <linux/slab.h>
24
25 #include "timer-of.h"
26
27 /**
28  * timer_of_irq_exit - Release the interrupt
29  * @of_irq: an of_timer_irq structure pointer
30  *
31  * Free the irq resource
32  */
33 static __init void timer_of_irq_exit(struct of_timer_irq *of_irq)
34 {
35         struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
36
37         struct clock_event_device *clkevt = &to->clkevt;
38
39         of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) :
40                 free_irq(of_irq->irq, clkevt);
41 }
42
43 /**
44  * timer_of_irq_init - Request the interrupt
45  * @np: a device tree node pointer
46  * @of_irq: an of_timer_irq structure pointer
47  *
48  * Get the interrupt number from the DT from its definition and
49  * request it. The interrupt is gotten by falling back the following way:
50  *
51  * - Get interrupt number by name
52  * - Get interrupt number by index
53  *
54  * When the interrupt is per CPU, 'request_percpu_irq()' is called,
55  * otherwise 'request_irq()' is used.
56  *
57  * Returns 0 on success, < 0 otherwise
58  */
59 static __init int timer_of_irq_init(struct device_node *np,
60                                     struct of_timer_irq *of_irq)
61 {
62         int ret;
63         struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
64         struct clock_event_device *clkevt = &to->clkevt;
65
66         if (of_irq->name) {
67                 of_irq->irq = ret = of_irq_get_byname(np, of_irq->name);
68                 if (ret < 0) {
69                         pr_err("Failed to get interrupt %s for %s\n",
70                                of_irq->name, np->full_name);
71                         return ret;
72                 }
73         } else  {
74                 of_irq->irq = irq_of_parse_and_map(np, of_irq->index);
75         }
76         if (!of_irq->irq) {
77                 pr_err("Failed to map interrupt for %pOF\n", np);
78                 return -EINVAL;
79         }
80
81         ret = of_irq->percpu ?
82                 request_percpu_irq(of_irq->irq, of_irq->handler,
83                                    np->full_name, clkevt) :
84                 request_irq(of_irq->irq, of_irq->handler,
85                             of_irq->flags ? of_irq->flags : IRQF_TIMER,
86                             np->full_name, clkevt);
87         if (ret) {
88                 pr_err("Failed to request irq %d for %pOF\n", of_irq->irq, np);
89                 return ret;
90         }
91
92         clkevt->irq = of_irq->irq;
93
94         return 0;
95 }
96
97 /**
98  * timer_of_clk_exit - Release the clock resources
99  * @of_clk: a of_timer_clk structure pointer
100  *
101  * Disables and releases the refcount on the clk
102  */
103 static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
104 {
105         of_clk->rate = 0;
106         clk_disable_unprepare(of_clk->clk);
107         clk_put(of_clk->clk);
108 }
109
110 /**
111  * timer_of_clk_init - Initialize the clock resources
112  * @np: a device tree node pointer
113  * @of_clk: a of_timer_clk structure pointer
114  *
115  * Get the clock by name or by index, enable it and get the rate
116  *
117  * Returns 0 on success, < 0 otherwise
118  */
119 static __init int timer_of_clk_init(struct device_node *np,
120                                     struct of_timer_clk *of_clk)
121 {
122         int ret;
123
124         of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) :
125                 of_clk_get(np, of_clk->index);
126         if (IS_ERR(of_clk->clk)) {
127                 pr_err("Failed to get clock for %pOF\n", np);
128                 return PTR_ERR(of_clk->clk);
129         }
130
131         ret = clk_prepare_enable(of_clk->clk);
132         if (ret) {
133                 pr_err("Failed for enable clock for %pOF\n", np);
134                 goto out_clk_put;
135         }
136
137         of_clk->rate = clk_get_rate(of_clk->clk);
138         if (!of_clk->rate) {
139                 ret = -EINVAL;
140                 pr_err("Failed to get clock rate for %pOF\n", np);
141                 goto out_clk_disable;
142         }
143
144         of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ);
145 out:
146         return ret;
147
148 out_clk_disable:
149         clk_disable_unprepare(of_clk->clk);
150 out_clk_put:
151         clk_put(of_clk->clk);
152
153         goto out;
154 }
155
156 static __init void timer_of_base_exit(struct of_timer_base *of_base)
157 {
158         iounmap(of_base->base);
159 }
160
161 static __init int timer_of_base_init(struct device_node *np,
162                                      struct of_timer_base *of_base)
163 {
164         of_base->base = of_base->name ?
165                 of_io_request_and_map(np, of_base->index, of_base->name) :
166                 of_iomap(np, of_base->index);
167         if (IS_ERR(of_base->base)) {
168                 pr_err("Failed to iomap (%s)\n", of_base->name);
169                 return PTR_ERR(of_base->base);
170         }
171
172         return 0;
173 }
174
175 int __init timer_of_init(struct device_node *np, struct timer_of *to)
176 {
177         int ret = -EINVAL;
178         int flags = 0;
179
180         if (to->flags & TIMER_OF_BASE) {
181                 ret = timer_of_base_init(np, &to->of_base);
182                 if (ret)
183                         goto out_fail;
184                 flags |= TIMER_OF_BASE;
185         }
186
187         if (to->flags & TIMER_OF_CLOCK) {
188                 ret = timer_of_clk_init(np, &to->of_clk);
189                 if (ret)
190                         goto out_fail;
191                 flags |= TIMER_OF_CLOCK;
192         }
193
194         if (to->flags & TIMER_OF_IRQ) {
195                 ret = timer_of_irq_init(np, &to->of_irq);
196                 if (ret)
197                         goto out_fail;
198                 flags |= TIMER_OF_IRQ;
199         }
200
201         if (!to->clkevt.name)
202                 to->clkevt.name = np->name;
203
204         to->np = np;
205
206         return ret;
207
208 out_fail:
209         if (flags & TIMER_OF_IRQ)
210                 timer_of_irq_exit(&to->of_irq);
211
212         if (flags & TIMER_OF_CLOCK)
213                 timer_of_clk_exit(&to->of_clk);
214
215         if (flags & TIMER_OF_BASE)
216                 timer_of_base_exit(&to->of_base);
217         return ret;
218 }
219
220 /**
221  * timer_of_cleanup - release timer_of ressources
222  * @to: timer_of structure
223  *
224  * Release the ressources that has been used in timer_of_init().
225  * This function should be called in init error cases
226  */
227 void __init timer_of_cleanup(struct timer_of *to)
228 {
229         if (to->flags & TIMER_OF_IRQ)
230                 timer_of_irq_exit(&to->of_irq);
231
232         if (to->flags & TIMER_OF_CLOCK)
233                 timer_of_clk_exit(&to->of_clk);
234
235         if (to->flags & TIMER_OF_BASE)
236                 timer_of_base_exit(&to->of_base);
237 }