1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
4
5 #include <linux/io.h>
6 #include <linux/rtc.h>
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_wakeirq.h>
12 #include <linux/clk.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15
16 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
17 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
18 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
19
20 #define RTC_SW_BIT (1 << 0)
21 #define RTC_ALM_BIT (1 << 2)
22 #define RTC_1HZ_BIT (1 << 4)
23 #define RTC_2HZ_BIT (1 << 7)
24 #define RTC_SAM0_BIT (1 << 8)
25 #define RTC_SAM1_BIT (1 << 9)
26 #define RTC_SAM2_BIT (1 << 10)
27 #define RTC_SAM3_BIT (1 << 11)
28 #define RTC_SAM4_BIT (1 << 12)
29 #define RTC_SAM5_BIT (1 << 13)
30 #define RTC_SAM6_BIT (1 << 14)
31 #define RTC_SAM7_BIT (1 << 15)
32 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
33 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
34 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
35
36 #define RTC_ENABLE_BIT (1 << 7)
37
38 #define MAX_PIE_NUM 9
39 #define MAX_PIE_FREQ 512
40
41 #define MXC_RTC_TIME 0
42 #define MXC_RTC_ALARM 1
43
44 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
45 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
46 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
47 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
48 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
49 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
50 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
51 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
52 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
53 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
54 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
55 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
56 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
57
58 enum imx_rtc_type {
59 IMX1_RTC,
60 IMX21_RTC,
61 };
62
63 struct rtc_plat_data {
64 struct rtc_device *rtc;
65 void __iomem *ioaddr;
66 int irq;
67 struct clk *clk_ref;
68 struct clk *clk_ipg;
69 struct rtc_time g_rtc_alarm;
70 enum imx_rtc_type devtype;
71 };
72
73 static const struct of_device_id imx_rtc_dt_ids[] = {
74 { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC },
75 { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC },
76 {}
77 };
78 MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids);
79
is_imx1_rtc(struct rtc_plat_data * data)80 static inline int is_imx1_rtc(struct rtc_plat_data *data)
81 {
82 return data->devtype == IMX1_RTC;
83 }
84
85 /*
86 * This function is used to obtain the RTC time or the alarm value in
87 * second.
88 */
get_alarm_or_time(struct device * dev,int time_alarm)89 static time64_t get_alarm_or_time(struct device *dev, int time_alarm)
90 {
91 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
92 void __iomem *ioaddr = pdata->ioaddr;
93 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
94
95 switch (time_alarm) {
96 case MXC_RTC_TIME:
97 day = readw(ioaddr + RTC_DAYR);
98 hr_min = readw(ioaddr + RTC_HOURMIN);
99 sec = readw(ioaddr + RTC_SECOND);
100 break;
101 case MXC_RTC_ALARM:
102 day = readw(ioaddr + RTC_DAYALARM);
103 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
104 sec = readw(ioaddr + RTC_ALRM_SEC);
105 break;
106 }
107
108 hr = hr_min >> 8;
109 min = hr_min & 0xff;
110
111 return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec;
112 }
113
114 /*
115 * This function sets the RTC alarm value or the time value.
116 */
set_alarm_or_time(struct device * dev,int time_alarm,time64_t time)117 static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time)
118 {
119 u32 tod, day, hr, min, sec, temp;
120 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
121 void __iomem *ioaddr = pdata->ioaddr;
122
123 day = div_s64_rem(time, 86400, &tod);
124
125 /* time is within a day now */
126 hr = tod / 3600;
127 tod -= hr * 3600;
128
129 /* time is within an hour now */
130 min = tod / 60;
131 sec = tod - min * 60;
132
133 temp = (hr << 8) + min;
134
135 switch (time_alarm) {
136 case MXC_RTC_TIME:
137 writew(day, ioaddr + RTC_DAYR);
138 writew(sec, ioaddr + RTC_SECOND);
139 writew(temp, ioaddr + RTC_HOURMIN);
140 break;
141 case MXC_RTC_ALARM:
142 writew(day, ioaddr + RTC_DAYALARM);
143 writew(sec, ioaddr + RTC_ALRM_SEC);
144 writew(temp, ioaddr + RTC_ALRM_HM);
145 break;
146 }
147 }
148
149 /*
150 * This function updates the RTC alarm registers and then clears all the
151 * interrupt status bits.
152 */
rtc_update_alarm(struct device * dev,struct rtc_time * alrm)153 static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
154 {
155 time64_t time;
156 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
157 void __iomem *ioaddr = pdata->ioaddr;
158
159 time = rtc_tm_to_time64(alrm);
160
161 /* clear all the interrupt status bits */
162 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
163 set_alarm_or_time(dev, MXC_RTC_ALARM, time);
164 }
165
mxc_rtc_irq_enable(struct device * dev,unsigned int bit,unsigned int enabled)166 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
167 unsigned int enabled)
168 {
169 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
170 void __iomem *ioaddr = pdata->ioaddr;
171 u32 reg;
172 unsigned long flags;
173
174 spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
175 reg = readw(ioaddr + RTC_RTCIENR);
176
177 if (enabled)
178 reg |= bit;
179 else
180 reg &= ~bit;
181
182 writew(reg, ioaddr + RTC_RTCIENR);
183 spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
184 }
185
186 /* This function is the RTC interrupt service routine. */
mxc_rtc_interrupt(int irq,void * dev_id)187 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
188 {
189 struct platform_device *pdev = dev_id;
190 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
191 void __iomem *ioaddr = pdata->ioaddr;
192 u32 status;
193 u32 events = 0;
194
195 spin_lock(&pdata->rtc->irq_lock);
196 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
197 /* clear interrupt sources */
198 writew(status, ioaddr + RTC_RTCISR);
199
200 /* update irq data & counter */
201 if (status & RTC_ALM_BIT) {
202 events |= (RTC_AF | RTC_IRQF);
203 /* RTC alarm should be one-shot */
204 mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0);
205 }
206
207 if (status & PIT_ALL_ON)
208 events |= (RTC_PF | RTC_IRQF);
209
210 rtc_update_irq(pdata->rtc, 1, events);
211 spin_unlock(&pdata->rtc->irq_lock);
212
213 return IRQ_HANDLED;
214 }
215
mxc_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)216 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
217 {
218 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
219 return 0;
220 }
221
222 /*
223 * This function reads the current RTC time into tm in Gregorian date.
224 */
mxc_rtc_read_time(struct device * dev,struct rtc_time * tm)225 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
226 {
227 time64_t val;
228
229 /* Avoid roll-over from reading the different registers */
230 do {
231 val = get_alarm_or_time(dev, MXC_RTC_TIME);
232 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
233
234 rtc_time64_to_tm(val, tm);
235
236 return 0;
237 }
238
239 /*
240 * This function sets the internal RTC time based on tm in Gregorian date.
241 */
mxc_rtc_set_time(struct device * dev,struct rtc_time * tm)242 static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
243 {
244 time64_t time = rtc_tm_to_time64(tm);
245
246 /* Avoid roll-over from reading the different registers */
247 do {
248 set_alarm_or_time(dev, MXC_RTC_TIME, time);
249 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
250
251 return 0;
252 }
253
254 /*
255 * This function reads the current alarm value into the passed in 'alrm'
256 * argument. It updates the alrm's pending field value based on the whether
257 * an alarm interrupt occurs or not.
258 */
mxc_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)259 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
260 {
261 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
262 void __iomem *ioaddr = pdata->ioaddr;
263
264 rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
265 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
266
267 return 0;
268 }
269
270 /*
271 * This function sets the RTC alarm based on passed in alrm.
272 */
mxc_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)273 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
274 {
275 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
276
277 rtc_update_alarm(dev, &alrm->time);
278
279 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
280 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
281
282 return 0;
283 }
284
285 /* RTC layer */
286 static const struct rtc_class_ops mxc_rtc_ops = {
287 .read_time = mxc_rtc_read_time,
288 .set_time = mxc_rtc_set_time,
289 .read_alarm = mxc_rtc_read_alarm,
290 .set_alarm = mxc_rtc_set_alarm,
291 .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
292 };
293
mxc_rtc_probe(struct platform_device * pdev)294 static int mxc_rtc_probe(struct platform_device *pdev)
295 {
296 struct rtc_device *rtc;
297 struct rtc_plat_data *pdata = NULL;
298 u32 reg;
299 unsigned long rate;
300 int ret;
301
302 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
303 if (!pdata)
304 return -ENOMEM;
305
306 pdata->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
307
308 pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
309 if (IS_ERR(pdata->ioaddr))
310 return PTR_ERR(pdata->ioaddr);
311
312 rtc = devm_rtc_allocate_device(&pdev->dev);
313 if (IS_ERR(rtc))
314 return PTR_ERR(rtc);
315
316 pdata->rtc = rtc;
317 rtc->ops = &mxc_rtc_ops;
318 if (is_imx1_rtc(pdata)) {
319 struct rtc_time tm;
320
321 /* 9bit days + hours minutes seconds */
322 rtc->range_max = (1 << 9) * 86400 - 1;
323
324 /*
325 * Set the start date as beginning of the current year. This can
326 * be overridden using device tree.
327 */
328 rtc_time64_to_tm(ktime_get_real_seconds(), &tm);
329 rtc->start_secs = mktime64(tm.tm_year, 1, 1, 0, 0, 0);
330 rtc->set_start_time = true;
331 } else {
332 /* 16bit days + hours minutes seconds */
333 rtc->range_max = (1 << 16) * 86400ULL - 1;
334 }
335
336 pdata->clk_ipg = devm_clk_get_enabled(&pdev->dev, "ipg");
337 if (IS_ERR(pdata->clk_ipg)) {
338 dev_err(&pdev->dev, "unable to get ipg clock!\n");
339 return PTR_ERR(pdata->clk_ipg);
340 }
341
342 pdata->clk_ref = devm_clk_get_enabled(&pdev->dev, "ref");
343 if (IS_ERR(pdata->clk_ref)) {
344 dev_err(&pdev->dev, "unable to get ref clock!\n");
345 return PTR_ERR(pdata->clk_ref);
346 }
347
348 rate = clk_get_rate(pdata->clk_ref);
349
350 if (rate == 32768)
351 reg = RTC_INPUT_CLK_32768HZ;
352 else if (rate == 32000)
353 reg = RTC_INPUT_CLK_32000HZ;
354 else if (rate == 38400)
355 reg = RTC_INPUT_CLK_38400HZ;
356 else {
357 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
358 return -EINVAL;
359 }
360
361 reg |= RTC_ENABLE_BIT;
362 writew(reg, (pdata->ioaddr + RTC_RTCCTL));
363 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
364 dev_err(&pdev->dev, "hardware module can't be enabled!\n");
365 return -EIO;
366 }
367
368 platform_set_drvdata(pdev, pdata);
369
370 /* Configure and enable the RTC */
371 pdata->irq = platform_get_irq(pdev, 0);
372
373 if (pdata->irq >= 0 &&
374 devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
375 IRQF_SHARED, pdev->name, pdev) < 0) {
376 dev_warn(&pdev->dev, "interrupt not available.\n");
377 pdata->irq = -1;
378 }
379
380 if (pdata->irq >= 0) {
381 device_init_wakeup(&pdev->dev, 1);
382 ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
383 if (ret)
384 dev_err(&pdev->dev, "failed to enable irq wake\n");
385 }
386
387 ret = devm_rtc_register_device(rtc);
388
389 return ret;
390 }
391
392 static struct platform_driver mxc_rtc_driver = {
393 .driver = {
394 .name = "mxc_rtc",
395 .of_match_table = imx_rtc_dt_ids,
396 },
397 .probe = mxc_rtc_probe,
398 };
399
400 module_platform_driver(mxc_rtc_driver)
401
402 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
403 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
404 MODULE_LICENSE("GPL");
405
406
