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Linux 4.16.11
[linux/fpc-iii.git] / drivers / rtc / rtc-pic32.c
blob5cfb6df5c43032e294ccc5a610637ba6e049b27f
1 /*
2 * PIC32 RTC driver
3 *
4 * Joshua Henderson <joshua.henderson@microchip.com>
5 * Copyright (C) 2016 Microchip Technology Inc. All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 */
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23 #include <linux/clk.h>
24 #include <linux/rtc.h>
25 #include <linux/bcd.h>
26
27 #include <asm/mach-pic32/pic32.h>
28
29 #define PIC32_RTCCON 0x00
30 #define PIC32_RTCCON_ON BIT(15)
31 #define PIC32_RTCCON_SIDL BIT(13)
32 #define PIC32_RTCCON_RTCCLKSEL (3 << 9)
33 #define PIC32_RTCCON_RTCCLKON BIT(6)
34 #define PIC32_RTCCON_RTCWREN BIT(3)
35 #define PIC32_RTCCON_RTCSYNC BIT(2)
36 #define PIC32_RTCCON_HALFSEC BIT(1)
37 #define PIC32_RTCCON_RTCOE BIT(0)
38
39 #define PIC32_RTCALRM 0x10
40 #define PIC32_RTCALRM_ALRMEN BIT(15)
41 #define PIC32_RTCALRM_CHIME BIT(14)
42 #define PIC32_RTCALRM_PIV BIT(13)
43 #define PIC32_RTCALRM_ALARMSYNC BIT(12)
44 #define PIC32_RTCALRM_AMASK 0x0F00
45 #define PIC32_RTCALRM_ARPT 0xFF
46
47 #define PIC32_RTCHOUR 0x23
48 #define PIC32_RTCMIN 0x22
49 #define PIC32_RTCSEC 0x21
50 #define PIC32_RTCYEAR 0x33
51 #define PIC32_RTCMON 0x32
52 #define PIC32_RTCDAY 0x31
53
54 #define PIC32_ALRMTIME 0x40
55 #define PIC32_ALRMDATE 0x50
56
57 #define PIC32_ALRMHOUR 0x43
58 #define PIC32_ALRMMIN 0x42
59 #define PIC32_ALRMSEC 0x41
60 #define PIC32_ALRMYEAR 0x53
61 #define PIC32_ALRMMON 0x52
62 #define PIC32_ALRMDAY 0x51
63
64 struct pic32_rtc_dev {
65 struct rtc_device *rtc;
66 void __iomem *reg_base;
67 struct clk *clk;
68 spinlock_t alarm_lock;
69 int alarm_irq;
70 bool alarm_clk_enabled;
71 };
72
73 static void pic32_rtc_alarm_clk_enable(struct pic32_rtc_dev *pdata,
74 bool enable)
75 {
76 unsigned long flags;
77
78 spin_lock_irqsave(&pdata->alarm_lock, flags);
79 if (enable) {
80 if (!pdata->alarm_clk_enabled) {
81 clk_enable(pdata->clk);
82 pdata->alarm_clk_enabled = true;
83 }
84 } else {
85 if (pdata->alarm_clk_enabled) {
86 clk_disable(pdata->clk);
87 pdata->alarm_clk_enabled = false;
88 }
89 }
90 spin_unlock_irqrestore(&pdata->alarm_lock, flags);
91 }
92
93 static irqreturn_t pic32_rtc_alarmirq(int irq, void *id)
94 {
95 struct pic32_rtc_dev *pdata = (struct pic32_rtc_dev *)id;
96
97 clk_enable(pdata->clk);
98 rtc_update_irq(pdata->rtc, 1, RTC_AF | RTC_IRQF);
99 clk_disable(pdata->clk);
100
101 pic32_rtc_alarm_clk_enable(pdata, false);
102
103 return IRQ_HANDLED;
104 }
105
106 static int pic32_rtc_setaie(struct device *dev, unsigned int enabled)
107 {
108 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
109 void __iomem *base = pdata->reg_base;
110
111 clk_enable(pdata->clk);
112
113 writel(PIC32_RTCALRM_ALRMEN,
114 base + (enabled ? PIC32_SET(PIC32_RTCALRM) :
115 PIC32_CLR(PIC32_RTCALRM)));
116
117 clk_disable(pdata->clk);
118
119 pic32_rtc_alarm_clk_enable(pdata, enabled);
120
121 return 0;
122 }
123
124 static int pic32_rtc_setfreq(struct device *dev, int freq)
125 {
126 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
127 void __iomem *base = pdata->reg_base;
128
129 clk_enable(pdata->clk);
130
131 writel(PIC32_RTCALRM_AMASK, base + PIC32_CLR(PIC32_RTCALRM));
132 writel(freq << 8, base + PIC32_SET(PIC32_RTCALRM));
133 writel(PIC32_RTCALRM_CHIME, base + PIC32_SET(PIC32_RTCALRM));
134
135 clk_disable(pdata->clk);
136
137 return 0;
138 }
139
140 static int pic32_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
141 {
142 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
143 void __iomem *base = pdata->reg_base;
144 unsigned int tries = 0;
145
146 clk_enable(pdata->clk);
147
148 do {
149 rtc_tm->tm_hour = readb(base + PIC32_RTCHOUR);
150 rtc_tm->tm_min = readb(base + PIC32_RTCMIN);
151 rtc_tm->tm_mon = readb(base + PIC32_RTCMON);
152 rtc_tm->tm_mday = readb(base + PIC32_RTCDAY);
153 rtc_tm->tm_year = readb(base + PIC32_RTCYEAR);
154 rtc_tm->tm_sec = readb(base + PIC32_RTCSEC);
155
156 /*
157 * The only way to work out whether the system was mid-update
158 * when we read it is to check the second counter, and if it
159 * is zero, then we re-try the entire read.
160 */
161 tries += 1;
162 } while (rtc_tm->tm_sec == 0 && tries < 2);
163
164 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
165 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
166 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
167 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
168 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon) - 1;
169 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
170
171 rtc_tm->tm_year += 100;
172
173 dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d\n",
174 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
175 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
176
177 clk_disable(pdata->clk);
178 return rtc_valid_tm(rtc_tm);
179 }
180
181 static int pic32_rtc_settime(struct device *dev, struct rtc_time *tm)
182 {
183 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
184 void __iomem *base = pdata->reg_base;
185 int year = tm->tm_year - 100;
186
187 dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d\n",
188 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
189 tm->tm_hour, tm->tm_min, tm->tm_sec);
190
191 if (year < 0 || year >= 100) {
192 dev_err(dev, "rtc only supports 100 years\n");
193 return -EINVAL;
194 }
195
196 clk_enable(pdata->clk);
197 writeb(bin2bcd(tm->tm_sec), base + PIC32_RTCSEC);
198 writeb(bin2bcd(tm->tm_min), base + PIC32_RTCMIN);
199 writeb(bin2bcd(tm->tm_hour), base + PIC32_RTCHOUR);
200 writeb(bin2bcd(tm->tm_mday), base + PIC32_RTCDAY);
201 writeb(bin2bcd(tm->tm_mon + 1), base + PIC32_RTCMON);
202 writeb(bin2bcd(year), base + PIC32_RTCYEAR);
203 clk_disable(pdata->clk);
204
205 return 0;
206 }
207
208 static int pic32_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
209 {
210 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
211 struct rtc_time *alm_tm = &alrm->time;
212 void __iomem *base = pdata->reg_base;
213 unsigned int alm_en;
214
215 clk_enable(pdata->clk);
216 alm_tm->tm_sec = readb(base + PIC32_ALRMSEC);
217 alm_tm->tm_min = readb(base + PIC32_ALRMMIN);
218 alm_tm->tm_hour = readb(base + PIC32_ALRMHOUR);
219 alm_tm->tm_mon = readb(base + PIC32_ALRMMON);
220 alm_tm->tm_mday = readb(base + PIC32_ALRMDAY);
221 alm_tm->tm_year = readb(base + PIC32_ALRMYEAR);
222
223 alm_en = readb(base + PIC32_RTCALRM);
224
225 alrm->enabled = (alm_en & PIC32_RTCALRM_ALRMEN) ? 1 : 0;
226
227 dev_dbg(dev, "getalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
228 alm_en,
229 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
230 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
231
232 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
233 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
234 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
235 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
236 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon) - 1;
237 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
238
239 clk_disable(pdata->clk);
240 return 0;
241 }
242
243 static int pic32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
244 {
245 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
246 struct rtc_time *tm = &alrm->time;
247 void __iomem *base = pdata->reg_base;
248
249 clk_enable(pdata->clk);
250 dev_dbg(dev, "setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
251 alrm->enabled,
252 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
253 tm->tm_hour, tm->tm_min, tm->tm_sec);
254
255 writel(0x00, base + PIC32_ALRMTIME);
256 writel(0x00, base + PIC32_ALRMDATE);
257
258 pic32_rtc_setaie(dev, alrm->enabled);
259
260 clk_disable(pdata->clk);
261 return 0;
262 }
263
264 static int pic32_rtc_proc(struct device *dev, struct seq_file *seq)
265 {
266 struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
267 void __iomem *base = pdata->reg_base;
268 unsigned int repeat;
269
270 clk_enable(pdata->clk);
271
272 repeat = readw(base + PIC32_RTCALRM);
273 repeat &= PIC32_RTCALRM_ARPT;
274 seq_printf(seq, "periodic_IRQ\t: %s\n", repeat ? "yes" : "no");
275
276 clk_disable(pdata->clk);
277 return 0;
278 }
279
280 static const struct rtc_class_ops pic32_rtcops = {
281 .read_time = pic32_rtc_gettime,
282 .set_time = pic32_rtc_settime,
283 .read_alarm = pic32_rtc_getalarm,
284 .set_alarm = pic32_rtc_setalarm,
285 .proc = pic32_rtc_proc,
286 .alarm_irq_enable = pic32_rtc_setaie,
287 };
288
289 static void pic32_rtc_enable(struct pic32_rtc_dev *pdata, int en)
290 {
291 void __iomem *base = pdata->reg_base;
292
293 if (!base)
294 return;
295
296 clk_enable(pdata->clk);
297 if (!en) {
298 writel(PIC32_RTCCON_ON, base + PIC32_CLR(PIC32_RTCCON));
299 } else {
300 pic32_syskey_unlock();
301
302 writel(PIC32_RTCCON_RTCWREN, base + PIC32_SET(PIC32_RTCCON));
303 writel(3 << 9, base + PIC32_CLR(PIC32_RTCCON));
304
305 if (!(readl(base + PIC32_RTCCON) & PIC32_RTCCON_ON))
306 writel(PIC32_RTCCON_ON, base + PIC32_SET(PIC32_RTCCON));
307 }
308 clk_disable(pdata->clk);
309 }
310
311 static int pic32_rtc_remove(struct platform_device *pdev)
312 {
313 struct pic32_rtc_dev *pdata = platform_get_drvdata(pdev);
314
315 pic32_rtc_setaie(&pdev->dev, 0);
316 clk_unprepare(pdata->clk);
317 pdata->clk = NULL;
318
319 return 0;
320 }
321
322 static int pic32_rtc_probe(struct platform_device *pdev)
323 {
324 struct pic32_rtc_dev *pdata;
325 struct resource *res;
326 int ret;
327
328 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
329 if (!pdata)
330 return -ENOMEM;
331
332 platform_set_drvdata(pdev, pdata);
333
334 pdata->alarm_irq = platform_get_irq(pdev, 0);
335 if (pdata->alarm_irq < 0) {
336 dev_err(&pdev->dev, "no irq for alarm\n");
337 return pdata->alarm_irq;
338 }
339
340 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
341 pdata->reg_base = devm_ioremap_resource(&pdev->dev, res);
342 if (IS_ERR(pdata->reg_base))
343 return PTR_ERR(pdata->reg_base);
344
345 pdata->clk = devm_clk_get(&pdev->dev, NULL);
346 if (IS_ERR(pdata->clk)) {
347 dev_err(&pdev->dev, "failed to find rtc clock source\n");
348 ret = PTR_ERR(pdata->clk);
349 pdata->clk = NULL;
350 return ret;
351 }
352
353 spin_lock_init(&pdata->alarm_lock);
354
355 clk_prepare_enable(pdata->clk);
356
357 pic32_rtc_enable(pdata, 1);
358
359 device_init_wakeup(&pdev->dev, 1);
360
361 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
362 &pic32_rtcops,
363 THIS_MODULE);
364 if (IS_ERR(pdata->rtc)) {
365 ret = PTR_ERR(pdata->rtc);
366 goto err_nortc;
367 }
368
369 pdata->rtc->max_user_freq = 128;
370
371 pic32_rtc_setfreq(&pdev->dev, 1);
372 ret = devm_request_irq(&pdev->dev, pdata->alarm_irq,
373 pic32_rtc_alarmirq, 0,
374 dev_name(&pdev->dev), pdata);
375 if (ret) {
376 dev_err(&pdev->dev,
377 "IRQ %d error %d\n", pdata->alarm_irq, ret);
378 goto err_nortc;
379 }
380
381 clk_disable(pdata->clk);
382
383 return 0;
384
385 err_nortc:
386 pic32_rtc_enable(pdata, 0);
387 clk_disable_unprepare(pdata->clk);
388
389 return ret;
390 }
391
392 static const struct of_device_id pic32_rtc_dt_ids[] = {
393 { .compatible = "microchip,pic32mzda-rtc" },
394 { /* sentinel */ }
395 };
396 MODULE_DEVICE_TABLE(of, pic32_rtc_dt_ids);
397
398 static struct platform_driver pic32_rtc_driver = {
399 .probe = pic32_rtc_probe,
400 .remove = pic32_rtc_remove,
401 .driver = {
402 .name = "pic32-rtc",
403 .of_match_table = of_match_ptr(pic32_rtc_dt_ids),
404 },
405 };
406 module_platform_driver(pic32_rtc_driver);
407
408 MODULE_DESCRIPTION("Microchip PIC32 RTC Driver");
409 MODULE_AUTHOR("Joshua Henderson <joshua.henderson@microchip.com>");
410 MODULE_LICENSE("GPL");
Linux with added FPC-III support