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1/*
2 * Copyright (C) 2007-2009 ST-Ericsson AB
3 * License terms: GNU General Public License (GPL) version 2
4 * Real Time Clock interface for ST-Ericsson AB COH 901 331 RTC.
5 * Author: Linus Walleij <linus.walleij@stericsson.com>
6 * Based on rtc-pl031.c by Deepak Saxena <dsaxena@plexity.net>
7 * Copyright 2006 (c) MontaVista Software, Inc.
8 */
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/rtc.h>
12#include <linux/clk.h>
13#include <linux/interrupt.h>
14#include <linux/pm.h>
15#include <linux/platform_device.h>
16#include <linux/io.h>
17#include <linux/slab.h>
18
19/*
20 * Registers in the COH 901 331
21 */
22/* Alarm value 32bit (R/W) */
23#define COH901331_ALARM 0x00U
24/* Used to set current time 32bit (R/W) */
25#define COH901331_SET_TIME 0x04U
26/* Indication if current time is valid 32bit (R/-) */
27#define COH901331_VALID 0x08U
28/* Read the current time 32bit (R/-) */
29#define COH901331_CUR_TIME 0x0cU
30/* Event register for the "alarm" interrupt */
31#define COH901331_IRQ_EVENT 0x10U
32/* Mask register for the "alarm" interrupt */
33#define COH901331_IRQ_MASK 0x14U
34/* Force register for the "alarm" interrupt */
35#define COH901331_IRQ_FORCE 0x18U
36
37/*
38 * Reference to RTC block clock
39 * Notice that the frequent clk_enable()/clk_disable() on this
40 * clock is mainly to be able to turn on/off other clocks in the
41 * hierarchy as needed, the RTC clock is always on anyway.
42 */
43struct coh901331_port {
44 struct rtc_device *rtc;
45 struct clk *clk;
46 u32 phybase;
47 u32 physize;
48 void __iomem *virtbase;
49 int irq;
50#ifdef CONFIG_PM
51 u32 irqmaskstore;
52#endif
53};
54
55static irqreturn_t coh901331_interrupt(int irq, void *data)
56{
57 struct coh901331_port *rtap = data;
58
59 clk_enable(rtap->clk);
60 /* Ack IRQ */
61 writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
62 /*
63 * Disable the interrupt. This is necessary because
64 * the RTC lives on a lower-clocked line and will
65 * not release the IRQ line until after a few (slower)
66 * clock cycles. The interrupt will be re-enabled when
67 * a new alarm is set anyway.
68 */
69 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
70 clk_disable(rtap->clk);
71
72 /* Set alarm flag */
73 rtc_update_irq(rtap->rtc, 1, RTC_AF);
74
75 return IRQ_HANDLED;
76}
77
78static int coh901331_read_time(struct device *dev, struct rtc_time *tm)
79{
80 struct coh901331_port *rtap = dev_get_drvdata(dev);
81
82 clk_enable(rtap->clk);
83 /* Check if the time is valid */
84 if (readl(rtap->virtbase + COH901331_VALID)) {
85 rtc_time_to_tm(readl(rtap->virtbase + COH901331_CUR_TIME), tm);
86 clk_disable(rtap->clk);
87 return rtc_valid_tm(tm);
88 }
89 clk_disable(rtap->clk);
90 return -EINVAL;
91}
92
93static int coh901331_set_mmss(struct device *dev, unsigned long secs)
94{
95 struct coh901331_port *rtap = dev_get_drvdata(dev);
96
97 clk_enable(rtap->clk);
98 writel(secs, rtap->virtbase + COH901331_SET_TIME);
99 clk_disable(rtap->clk);
100
101 return 0;
102}
103
104static int coh901331_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
105{
106 struct coh901331_port *rtap = dev_get_drvdata(dev);
107
108 clk_enable(rtap->clk);
109 rtc_time_to_tm(readl(rtap->virtbase + COH901331_ALARM), &alarm->time);
110 alarm->pending = readl(rtap->virtbase + COH901331_IRQ_EVENT) & 1U;
111 alarm->enabled = readl(rtap->virtbase + COH901331_IRQ_MASK) & 1U;
112 clk_disable(rtap->clk);
113
114 return 0;
115}
116
117static int coh901331_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
118{
119 struct coh901331_port *rtap = dev_get_drvdata(dev);
120 unsigned long time;
121
122 rtc_tm_to_time(&alarm->time, &time);
123 clk_enable(rtap->clk);
124 writel(time, rtap->virtbase + COH901331_ALARM);
125 writel(alarm->enabled, rtap->virtbase + COH901331_IRQ_MASK);
126 clk_disable(rtap->clk);
127
128 return 0;
129}
130
131static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
132{
133 struct coh901331_port *rtap = dev_get_drvdata(dev);
134
135 clk_enable(rtap->clk);
136 if (enabled)
137 writel(1, rtap->virtbase + COH901331_IRQ_MASK);
138 else
139 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
140 clk_disable(rtap->clk);
141
142 return 0;
143}
144
145static struct rtc_class_ops coh901331_ops = {
146 .read_time = coh901331_read_time,
147 .set_mmss = coh901331_set_mmss,
148 .read_alarm = coh901331_read_alarm,
149 .set_alarm = coh901331_set_alarm,
150 .alarm_irq_enable = coh901331_alarm_irq_enable,
151};
152
153static int __exit coh901331_remove(struct platform_device *pdev)
154{
155 struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
156
157 if (rtap) {
158 free_irq(rtap->irq, rtap);
159 rtc_device_unregister(rtap->rtc);
160 clk_put(rtap->clk);
161 iounmap(rtap->virtbase);
162 release_mem_region(rtap->phybase, rtap->physize);
163 platform_set_drvdata(pdev, NULL);
164 kfree(rtap);
165 }
166
167 return 0;
168}
169
170
171static int __init coh901331_probe(struct platform_device *pdev)
172{
173 int ret;
174 struct coh901331_port *rtap;
175 struct resource *res;
176
177 rtap = kzalloc(sizeof(struct coh901331_port), GFP_KERNEL);
178 if (!rtap)
179 return -ENOMEM;
180
181 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
182 if (!res) {
183 ret = -ENOENT;
184 goto out_no_resource;
185 }
186 rtap->phybase = res->start;
187 rtap->physize = resource_size(res);
188
189 if (request_mem_region(rtap->phybase, rtap->physize,
190 "rtc-coh901331") == NULL) {
191 ret = -EBUSY;
192 goto out_no_memregion;
193 }
194
195 rtap->virtbase = ioremap(rtap->phybase, rtap->physize);
196 if (!rtap->virtbase) {
197 ret = -ENOMEM;
198 goto out_no_remap;
199 }
200
201 rtap->irq = platform_get_irq(pdev, 0);
202 if (request_irq(rtap->irq, coh901331_interrupt, 0,
203 "RTC COH 901 331 Alarm", rtap)) {
204 ret = -EIO;
205 goto out_no_irq;
206 }
207
208 rtap->clk = clk_get(&pdev->dev, NULL);
209 if (IS_ERR(rtap->clk)) {
210 ret = PTR_ERR(rtap->clk);
211 dev_err(&pdev->dev, "could not get clock\n");
212 goto out_no_clk;
213 }
214
215 /* We enable/disable the clock only to assure it works */
216 ret = clk_enable(rtap->clk);
217 if (ret) {
218 dev_err(&pdev->dev, "could not enable clock\n");
219 goto out_no_clk_enable;
220 }
221 clk_disable(rtap->clk);
222
223 platform_set_drvdata(pdev, rtap);
224 rtap->rtc = rtc_device_register("coh901331", &pdev->dev, &coh901331_ops,
225 THIS_MODULE);
226 if (IS_ERR(rtap->rtc)) {
227 ret = PTR_ERR(rtap->rtc);
228 goto out_no_rtc;
229 }
230
231 return 0;
232
233 out_no_rtc:
234 platform_set_drvdata(pdev, NULL);
235 out_no_clk_enable:
236 clk_put(rtap->clk);
237 out_no_clk:
238 free_irq(rtap->irq, rtap);
239 out_no_irq:
240 iounmap(rtap->virtbase);
241 out_no_remap:
242 platform_set_drvdata(pdev, NULL);
243 out_no_memregion:
244 release_mem_region(rtap->phybase, SZ_4K);
245 out_no_resource:
246 kfree(rtap);
247 return ret;
248}
249
250#ifdef CONFIG_PM
251static int coh901331_suspend(struct platform_device *pdev, pm_message_t state)
252{
253 struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
254
255 /*
256 * If this RTC alarm will be used for waking the system up,
257 * don't disable it of course. Else we just disable the alarm
258 * and await suspension.
259 */
260 if (device_may_wakeup(&pdev->dev)) {
261 enable_irq_wake(rtap->irq);
262 } else {
263 clk_enable(rtap->clk);
264 rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK);
265 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
266 clk_disable(rtap->clk);
267 }
268 return 0;
269}
270
271static int coh901331_resume(struct platform_device *pdev)
272{
273 struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
274
275 if (device_may_wakeup(&pdev->dev)) {
276 disable_irq_wake(rtap->irq);
277 } else {
278 clk_enable(rtap->clk);
279 writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK);
280 clk_disable(rtap->clk);
281 }
282 return 0;
283}
284#else
285#define coh901331_suspend NULL
286#define coh901331_resume NULL
287#endif
288
289static void coh901331_shutdown(struct platform_device *pdev)
290{
291 struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
292
293 clk_enable(rtap->clk);
294 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
295 clk_disable(rtap->clk);
296}
297
298static struct platform_driver coh901331_driver = {
299 .driver = {
300 .name = "rtc-coh901331",
301 .owner = THIS_MODULE,
302 },
303 .remove = __exit_p(coh901331_remove),
304 .suspend = coh901331_suspend,
305 .resume = coh901331_resume,
306 .shutdown = coh901331_shutdown,
307};
308
309static int __init coh901331_init(void)
310{
311 return platform_driver_probe(&coh901331_driver, coh901331_probe);
312}
313
314static void __exit coh901331_exit(void)
315{
316 platform_driver_unregister(&coh901331_driver);
317}
318
319module_init(coh901331_init);
320module_exit(coh901331_exit);
321
322MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
323MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver");
324MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007-2009 ST-Ericsson AB
4 * Real Time Clock interface for ST-Ericsson AB COH 901 331 RTC.
5 * Author: Linus Walleij <linus.walleij@stericsson.com>
6 * Based on rtc-pl031.c by Deepak Saxena <dsaxena@plexity.net>
7 * Copyright 2006 (c) MontaVista Software, Inc.
8 */
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/mod_devicetable.h>
12#include <linux/rtc.h>
13#include <linux/clk.h>
14#include <linux/interrupt.h>
15#include <linux/pm.h>
16#include <linux/platform_device.h>
17#include <linux/io.h>
18#include <linux/slab.h>
19
20/*
21 * Registers in the COH 901 331
22 */
23/* Alarm value 32bit (R/W) */
24#define COH901331_ALARM 0x00U
25/* Used to set current time 32bit (R/W) */
26#define COH901331_SET_TIME 0x04U
27/* Indication if current time is valid 32bit (R/-) */
28#define COH901331_VALID 0x08U
29/* Read the current time 32bit (R/-) */
30#define COH901331_CUR_TIME 0x0cU
31/* Event register for the "alarm" interrupt */
32#define COH901331_IRQ_EVENT 0x10U
33/* Mask register for the "alarm" interrupt */
34#define COH901331_IRQ_MASK 0x14U
35/* Force register for the "alarm" interrupt */
36#define COH901331_IRQ_FORCE 0x18U
37
38/*
39 * Reference to RTC block clock
40 * Notice that the frequent clk_enable()/clk_disable() on this
41 * clock is mainly to be able to turn on/off other clocks in the
42 * hierarchy as needed, the RTC clock is always on anyway.
43 */
44struct coh901331_port {
45 struct rtc_device *rtc;
46 struct clk *clk;
47 void __iomem *virtbase;
48 int irq;
49#ifdef CONFIG_PM_SLEEP
50 u32 irqmaskstore;
51#endif
52};
53
54static irqreturn_t coh901331_interrupt(int irq, void *data)
55{
56 struct coh901331_port *rtap = data;
57
58 clk_enable(rtap->clk);
59 /* Ack IRQ */
60 writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
61 /*
62 * Disable the interrupt. This is necessary because
63 * the RTC lives on a lower-clocked line and will
64 * not release the IRQ line until after a few (slower)
65 * clock cycles. The interrupt will be re-enabled when
66 * a new alarm is set anyway.
67 */
68 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
69 clk_disable(rtap->clk);
70
71 /* Set alarm flag */
72 rtc_update_irq(rtap->rtc, 1, RTC_AF);
73
74 return IRQ_HANDLED;
75}
76
77static int coh901331_read_time(struct device *dev, struct rtc_time *tm)
78{
79 struct coh901331_port *rtap = dev_get_drvdata(dev);
80
81 clk_enable(rtap->clk);
82 /* Check if the time is valid */
83 if (!readl(rtap->virtbase + COH901331_VALID)) {
84 clk_disable(rtap->clk);
85 return -EINVAL;
86 }
87
88 rtc_time64_to_tm(readl(rtap->virtbase + COH901331_CUR_TIME), tm);
89 clk_disable(rtap->clk);
90 return 0;
91}
92
93static int coh901331_set_time(struct device *dev, struct rtc_time *tm)
94{
95 struct coh901331_port *rtap = dev_get_drvdata(dev);
96
97 clk_enable(rtap->clk);
98 writel(rtc_tm_to_time64(tm), rtap->virtbase + COH901331_SET_TIME);
99 clk_disable(rtap->clk);
100
101 return 0;
102}
103
104static int coh901331_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
105{
106 struct coh901331_port *rtap = dev_get_drvdata(dev);
107
108 clk_enable(rtap->clk);
109 rtc_time64_to_tm(readl(rtap->virtbase + COH901331_ALARM), &alarm->time);
110 alarm->pending = readl(rtap->virtbase + COH901331_IRQ_EVENT) & 1U;
111 alarm->enabled = readl(rtap->virtbase + COH901331_IRQ_MASK) & 1U;
112 clk_disable(rtap->clk);
113
114 return 0;
115}
116
117static int coh901331_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
118{
119 struct coh901331_port *rtap = dev_get_drvdata(dev);
120 unsigned long time = rtc_tm_to_time64(&alarm->time);
121
122 clk_enable(rtap->clk);
123 writel(time, rtap->virtbase + COH901331_ALARM);
124 writel(alarm->enabled, rtap->virtbase + COH901331_IRQ_MASK);
125 clk_disable(rtap->clk);
126
127 return 0;
128}
129
130static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
131{
132 struct coh901331_port *rtap = dev_get_drvdata(dev);
133
134 clk_enable(rtap->clk);
135 if (enabled)
136 writel(1, rtap->virtbase + COH901331_IRQ_MASK);
137 else
138 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
139 clk_disable(rtap->clk);
140
141 return 0;
142}
143
144static const struct rtc_class_ops coh901331_ops = {
145 .read_time = coh901331_read_time,
146 .set_time = coh901331_set_time,
147 .read_alarm = coh901331_read_alarm,
148 .set_alarm = coh901331_set_alarm,
149 .alarm_irq_enable = coh901331_alarm_irq_enable,
150};
151
152static int __exit coh901331_remove(struct platform_device *pdev)
153{
154 struct coh901331_port *rtap = platform_get_drvdata(pdev);
155
156 if (rtap)
157 clk_unprepare(rtap->clk);
158
159 return 0;
160}
161
162
163static int __init coh901331_probe(struct platform_device *pdev)
164{
165 int ret;
166 struct coh901331_port *rtap;
167
168 rtap = devm_kzalloc(&pdev->dev,
169 sizeof(struct coh901331_port), GFP_KERNEL);
170 if (!rtap)
171 return -ENOMEM;
172
173 rtap->virtbase = devm_platform_ioremap_resource(pdev, 0);
174 if (IS_ERR(rtap->virtbase))
175 return PTR_ERR(rtap->virtbase);
176
177 rtap->irq = platform_get_irq(pdev, 0);
178 if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0,
179 "RTC COH 901 331 Alarm", rtap))
180 return -EIO;
181
182 rtap->clk = devm_clk_get(&pdev->dev, NULL);
183 if (IS_ERR(rtap->clk)) {
184 ret = PTR_ERR(rtap->clk);
185 dev_err(&pdev->dev, "could not get clock\n");
186 return ret;
187 }
188
189 rtap->rtc = devm_rtc_allocate_device(&pdev->dev);
190 if (IS_ERR(rtap->rtc))
191 return PTR_ERR(rtap->rtc);
192
193 rtap->rtc->ops = &coh901331_ops;
194 rtap->rtc->range_max = U32_MAX;
195
196 /* We enable/disable the clock only to assure it works */
197 ret = clk_prepare_enable(rtap->clk);
198 if (ret) {
199 dev_err(&pdev->dev, "could not enable clock\n");
200 return ret;
201 }
202 clk_disable(rtap->clk);
203
204 platform_set_drvdata(pdev, rtap);
205
206 ret = rtc_register_device(rtap->rtc);
207 if (ret)
208 goto out_no_rtc;
209
210 return 0;
211
212 out_no_rtc:
213 clk_unprepare(rtap->clk);
214 return ret;
215}
216
217#ifdef CONFIG_PM_SLEEP
218static int coh901331_suspend(struct device *dev)
219{
220 struct coh901331_port *rtap = dev_get_drvdata(dev);
221
222 /*
223 * If this RTC alarm will be used for waking the system up,
224 * don't disable it of course. Else we just disable the alarm
225 * and await suspension.
226 */
227 if (device_may_wakeup(dev)) {
228 enable_irq_wake(rtap->irq);
229 } else {
230 clk_enable(rtap->clk);
231 rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK);
232 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
233 clk_disable(rtap->clk);
234 }
235 clk_unprepare(rtap->clk);
236 return 0;
237}
238
239static int coh901331_resume(struct device *dev)
240{
241 int ret;
242 struct coh901331_port *rtap = dev_get_drvdata(dev);
243
244 ret = clk_prepare(rtap->clk);
245 if (ret)
246 return ret;
247
248 if (device_may_wakeup(dev)) {
249 disable_irq_wake(rtap->irq);
250 } else {
251 clk_enable(rtap->clk);
252 writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK);
253 clk_disable(rtap->clk);
254 }
255 return 0;
256}
257#endif
258
259static SIMPLE_DEV_PM_OPS(coh901331_pm_ops, coh901331_suspend, coh901331_resume);
260
261static void coh901331_shutdown(struct platform_device *pdev)
262{
263 struct coh901331_port *rtap = platform_get_drvdata(pdev);
264
265 clk_enable(rtap->clk);
266 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
267 clk_disable_unprepare(rtap->clk);
268}
269
270static const struct of_device_id coh901331_dt_match[] = {
271 { .compatible = "stericsson,coh901331" },
272 {},
273};
274MODULE_DEVICE_TABLE(of, coh901331_dt_match);
275
276static struct platform_driver coh901331_driver = {
277 .driver = {
278 .name = "rtc-coh901331",
279 .pm = &coh901331_pm_ops,
280 .of_match_table = coh901331_dt_match,
281 },
282 .remove = __exit_p(coh901331_remove),
283 .shutdown = coh901331_shutdown,
284};
285
286module_platform_driver_probe(coh901331_driver, coh901331_probe);
287
288MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
289MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver");
290MODULE_LICENSE("GPL");