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1// SPDX-License-Identifier: GPL-2.0+
2//
3// Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
4
5#include <linux/init.h>
6#include <linux/io.h>
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/platform_device.h>
11#include <linux/pm_wakeirq.h>
12#include <linux/rtc.h>
13#include <linux/clk.h>
14#include <linux/mfd/syscon.h>
15#include <linux/regmap.h>
16
17#define SNVS_LPREGISTER_OFFSET 0x34
18
19/* These register offsets are relative to LP (Low Power) range */
20#define SNVS_LPCR 0x04
21#define SNVS_LPSR 0x18
22#define SNVS_LPSRTCMR 0x1c
23#define SNVS_LPSRTCLR 0x20
24#define SNVS_LPTAR 0x24
25#define SNVS_LPPGDR 0x30
26
27#define SNVS_LPCR_SRTC_ENV (1 << 0)
28#define SNVS_LPCR_LPTA_EN (1 << 1)
29#define SNVS_LPCR_LPWUI_EN (1 << 3)
30#define SNVS_LPSR_LPTA (1 << 0)
31
32#define SNVS_LPPGDR_INIT 0x41736166
33#define CNTR_TO_SECS_SH 15
34
35/* The maximum RTC clock cycles that are allowed to pass between two
36 * consecutive clock counter register reads. If the values are corrupted a
37 * bigger difference is expected. The RTC frequency is 32kHz. With 320 cycles
38 * we end at 10ms which should be enough for most cases. If it once takes
39 * longer than expected we do a retry.
40 */
41#define MAX_RTC_READ_DIFF_CYCLES 320
42
43struct snvs_rtc_data {
44 struct rtc_device *rtc;
45 struct regmap *regmap;
46 int offset;
47 int irq;
48 struct clk *clk;
49};
50
51/* Read 64 bit timer register, which could be in inconsistent state */
52static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
53{
54 u32 msb, lsb;
55
56 regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
57 regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
58 return (u64)msb << 32 | lsb;
59}
60
61/* Read the secure real time counter, taking care to deal with the cases of the
62 * counter updating while being read.
63 */
64static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
65{
66 u64 read1, read2;
67 s64 diff;
68 unsigned int timeout = 100;
69
70 /* As expected, the registers might update between the read of the LSB
71 * reg and the MSB reg. It's also possible that one register might be
72 * in partially modified state as well.
73 */
74 read1 = rtc_read_lpsrt(data);
75 do {
76 read2 = read1;
77 read1 = rtc_read_lpsrt(data);
78 diff = read1 - read2;
79 } while (((diff < 0) || (diff > MAX_RTC_READ_DIFF_CYCLES)) && --timeout);
80 if (!timeout)
81 dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
82
83 /* Convert 47-bit counter to 32-bit raw second count */
84 return (u32) (read1 >> CNTR_TO_SECS_SH);
85}
86
87/* Just read the lsb from the counter, dealing with inconsistent state */
88static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
89{
90 u32 count1, count2;
91 s32 diff;
92 unsigned int timeout = 100;
93
94 regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
95 do {
96 count2 = count1;
97 regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
98 diff = count1 - count2;
99 } while (((diff < 0) || (diff > MAX_RTC_READ_DIFF_CYCLES)) && --timeout);
100 if (!timeout) {
101 dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
102 return -ETIMEDOUT;
103 }
104
105 *lsb = count1;
106 return 0;
107}
108
109static int rtc_write_sync_lp(struct snvs_rtc_data *data)
110{
111 u32 count1, count2;
112 u32 elapsed;
113 unsigned int timeout = 1000;
114 int ret;
115
116 ret = rtc_read_lp_counter_lsb(data, &count1);
117 if (ret)
118 return ret;
119
120 /* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
121 do {
122 ret = rtc_read_lp_counter_lsb(data, &count2);
123 if (ret)
124 return ret;
125 elapsed = count2 - count1; /* wrap around _is_ handled! */
126 } while (elapsed < 3 && --timeout);
127 if (!timeout) {
128 dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
129 return -ETIMEDOUT;
130 }
131 return 0;
132}
133
134static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
135{
136 int timeout = 1000;
137 u32 lpcr;
138
139 regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
140 enable ? SNVS_LPCR_SRTC_ENV : 0);
141
142 while (--timeout) {
143 regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);
144
145 if (enable) {
146 if (lpcr & SNVS_LPCR_SRTC_ENV)
147 break;
148 } else {
149 if (!(lpcr & SNVS_LPCR_SRTC_ENV))
150 break;
151 }
152 }
153
154 if (!timeout)
155 return -ETIMEDOUT;
156
157 return 0;
158}
159
160static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
161{
162 struct snvs_rtc_data *data = dev_get_drvdata(dev);
163 unsigned long time;
164 int ret;
165
166 ret = clk_enable(data->clk);
167 if (ret)
168 return ret;
169
170 time = rtc_read_lp_counter(data);
171 rtc_time64_to_tm(time, tm);
172
173 clk_disable(data->clk);
174
175 return 0;
176}
177
178static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
179{
180 struct snvs_rtc_data *data = dev_get_drvdata(dev);
181 unsigned long time = rtc_tm_to_time64(tm);
182 int ret;
183
184 ret = clk_enable(data->clk);
185 if (ret)
186 return ret;
187
188 /* Disable RTC first */
189 ret = snvs_rtc_enable(data, false);
190 if (ret)
191 return ret;
192
193 /* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
194 regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
195 regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
196
197 /* Enable RTC again */
198 ret = snvs_rtc_enable(data, true);
199
200 clk_disable(data->clk);
201
202 return ret;
203}
204
205static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
206{
207 struct snvs_rtc_data *data = dev_get_drvdata(dev);
208 u32 lptar, lpsr;
209 int ret;
210
211 ret = clk_enable(data->clk);
212 if (ret)
213 return ret;
214
215 regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
216 rtc_time64_to_tm(lptar, &alrm->time);
217
218 regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
219 alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
220
221 clk_disable(data->clk);
222
223 return 0;
224}
225
226static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
227{
228 struct snvs_rtc_data *data = dev_get_drvdata(dev);
229 int ret;
230
231 ret = clk_enable(data->clk);
232 if (ret)
233 return ret;
234
235 regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
236 (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
237 enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);
238
239 ret = rtc_write_sync_lp(data);
240
241 clk_disable(data->clk);
242
243 return ret;
244}
245
246static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
247{
248 struct snvs_rtc_data *data = dev_get_drvdata(dev);
249 unsigned long time = rtc_tm_to_time64(&alrm->time);
250 int ret;
251
252 ret = clk_enable(data->clk);
253 if (ret)
254 return ret;
255
256 regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
257 ret = rtc_write_sync_lp(data);
258 if (ret)
259 return ret;
260 regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
261
262 /* Clear alarm interrupt status bit */
263 regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);
264
265 clk_disable(data->clk);
266
267 return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
268}
269
270static const struct rtc_class_ops snvs_rtc_ops = {
271 .read_time = snvs_rtc_read_time,
272 .set_time = snvs_rtc_set_time,
273 .read_alarm = snvs_rtc_read_alarm,
274 .set_alarm = snvs_rtc_set_alarm,
275 .alarm_irq_enable = snvs_rtc_alarm_irq_enable,
276};
277
278static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
279{
280 struct device *dev = dev_id;
281 struct snvs_rtc_data *data = dev_get_drvdata(dev);
282 u32 lpsr;
283 u32 events = 0;
284
285 clk_enable(data->clk);
286
287 regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
288
289 if (lpsr & SNVS_LPSR_LPTA) {
290 events |= (RTC_AF | RTC_IRQF);
291
292 /* RTC alarm should be one-shot */
293 snvs_rtc_alarm_irq_enable(dev, 0);
294
295 rtc_update_irq(data->rtc, 1, events);
296 }
297
298 /* clear interrupt status */
299 regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
300
301 clk_disable(data->clk);
302
303 return events ? IRQ_HANDLED : IRQ_NONE;
304}
305
306static const struct regmap_config snvs_rtc_config = {
307 .reg_bits = 32,
308 .val_bits = 32,
309 .reg_stride = 4,
310};
311
312static void snvs_rtc_action(void *data)
313{
314 clk_disable_unprepare(data);
315}
316
317static int snvs_rtc_probe(struct platform_device *pdev)
318{
319 struct snvs_rtc_data *data;
320 int ret;
321 void __iomem *mmio;
322
323 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
324 if (!data)
325 return -ENOMEM;
326
327 data->rtc = devm_rtc_allocate_device(&pdev->dev);
328 if (IS_ERR(data->rtc))
329 return PTR_ERR(data->rtc);
330
331 data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
332
333 if (IS_ERR(data->regmap)) {
334 dev_warn(&pdev->dev, "snvs rtc: you use old dts file, please update it\n");
335
336 mmio = devm_platform_ioremap_resource(pdev, 0);
337 if (IS_ERR(mmio))
338 return PTR_ERR(mmio);
339
340 data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
341 } else {
342 data->offset = SNVS_LPREGISTER_OFFSET;
343 of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
344 }
345
346 if (IS_ERR(data->regmap)) {
347 dev_err(&pdev->dev, "Can't find snvs syscon\n");
348 return -ENODEV;
349 }
350
351 data->irq = platform_get_irq(pdev, 0);
352 if (data->irq < 0)
353 return data->irq;
354
355 data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
356 if (IS_ERR(data->clk)) {
357 data->clk = NULL;
358 } else {
359 ret = clk_prepare_enable(data->clk);
360 if (ret) {
361 dev_err(&pdev->dev,
362 "Could not prepare or enable the snvs clock\n");
363 return ret;
364 }
365 }
366
367 ret = devm_add_action_or_reset(&pdev->dev, snvs_rtc_action, data->clk);
368 if (ret)
369 return ret;
370
371 platform_set_drvdata(pdev, data);
372
373 /* Initialize glitch detect */
374 regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);
375
376 /* Clear interrupt status */
377 regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
378
379 /* Enable RTC */
380 ret = snvs_rtc_enable(data, true);
381 if (ret) {
382 dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
383 return ret;
384 }
385
386 device_init_wakeup(&pdev->dev, true);
387 ret = dev_pm_set_wake_irq(&pdev->dev, data->irq);
388 if (ret)
389 dev_err(&pdev->dev, "failed to enable irq wake\n");
390
391 ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
392 IRQF_SHARED, "rtc alarm", &pdev->dev);
393 if (ret) {
394 dev_err(&pdev->dev, "failed to request irq %d: %d\n",
395 data->irq, ret);
396 return ret;
397 }
398
399 data->rtc->ops = &snvs_rtc_ops;
400 data->rtc->range_max = U32_MAX;
401
402 return devm_rtc_register_device(data->rtc);
403}
404
405static int __maybe_unused snvs_rtc_suspend_noirq(struct device *dev)
406{
407 struct snvs_rtc_data *data = dev_get_drvdata(dev);
408
409 clk_disable(data->clk);
410
411 return 0;
412}
413
414static int __maybe_unused snvs_rtc_resume_noirq(struct device *dev)
415{
416 struct snvs_rtc_data *data = dev_get_drvdata(dev);
417
418 if (data->clk)
419 return clk_enable(data->clk);
420
421 return 0;
422}
423
424static const struct dev_pm_ops snvs_rtc_pm_ops = {
425 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(snvs_rtc_suspend_noirq, snvs_rtc_resume_noirq)
426};
427
428static const struct of_device_id snvs_dt_ids[] = {
429 { .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
430 { /* sentinel */ }
431};
432MODULE_DEVICE_TABLE(of, snvs_dt_ids);
433
434static struct platform_driver snvs_rtc_driver = {
435 .driver = {
436 .name = "snvs_rtc",
437 .pm = &snvs_rtc_pm_ops,
438 .of_match_table = snvs_dt_ids,
439 },
440 .probe = snvs_rtc_probe,
441};
442module_platform_driver(snvs_rtc_driver);
443
444MODULE_AUTHOR("Freescale Semiconductor, Inc.");
445MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
446MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2//
3// Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
4
5#include <linux/init.h>
6#include <linux/io.h>
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/of_device.h>
11#include <linux/platform_device.h>
12#include <linux/pm_wakeirq.h>
13#include <linux/rtc.h>
14#include <linux/clk.h>
15#include <linux/mfd/syscon.h>
16#include <linux/regmap.h>
17
18#define SNVS_LPREGISTER_OFFSET 0x34
19
20/* These register offsets are relative to LP (Low Power) range */
21#define SNVS_LPCR 0x04
22#define SNVS_LPSR 0x18
23#define SNVS_LPSRTCMR 0x1c
24#define SNVS_LPSRTCLR 0x20
25#define SNVS_LPTAR 0x24
26#define SNVS_LPPGDR 0x30
27
28#define SNVS_LPCR_SRTC_ENV (1 << 0)
29#define SNVS_LPCR_LPTA_EN (1 << 1)
30#define SNVS_LPCR_LPWUI_EN (1 << 3)
31#define SNVS_LPSR_LPTA (1 << 0)
32
33#define SNVS_LPPGDR_INIT 0x41736166
34#define CNTR_TO_SECS_SH 15
35
36struct snvs_rtc_data {
37 struct rtc_device *rtc;
38 struct regmap *regmap;
39 int offset;
40 int irq;
41 struct clk *clk;
42};
43
44/* Read 64 bit timer register, which could be in inconsistent state */
45static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
46{
47 u32 msb, lsb;
48
49 regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
50 regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
51 return (u64)msb << 32 | lsb;
52}
53
54/* Read the secure real time counter, taking care to deal with the cases of the
55 * counter updating while being read.
56 */
57static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
58{
59 u64 read1, read2;
60 unsigned int timeout = 100;
61
62 /* As expected, the registers might update between the read of the LSB
63 * reg and the MSB reg. It's also possible that one register might be
64 * in partially modified state as well.
65 */
66 read1 = rtc_read_lpsrt(data);
67 do {
68 read2 = read1;
69 read1 = rtc_read_lpsrt(data);
70 } while (read1 != read2 && --timeout);
71 if (!timeout)
72 dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
73
74 /* Convert 47-bit counter to 32-bit raw second count */
75 return (u32) (read1 >> CNTR_TO_SECS_SH);
76}
77
78/* Just read the lsb from the counter, dealing with inconsistent state */
79static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
80{
81 u32 count1, count2;
82 unsigned int timeout = 100;
83
84 regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
85 do {
86 count2 = count1;
87 regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
88 } while (count1 != count2 && --timeout);
89 if (!timeout) {
90 dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
91 return -ETIMEDOUT;
92 }
93
94 *lsb = count1;
95 return 0;
96}
97
98static int rtc_write_sync_lp(struct snvs_rtc_data *data)
99{
100 u32 count1, count2;
101 u32 elapsed;
102 unsigned int timeout = 1000;
103 int ret;
104
105 ret = rtc_read_lp_counter_lsb(data, &count1);
106 if (ret)
107 return ret;
108
109 /* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
110 do {
111 ret = rtc_read_lp_counter_lsb(data, &count2);
112 if (ret)
113 return ret;
114 elapsed = count2 - count1; /* wrap around _is_ handled! */
115 } while (elapsed < 3 && --timeout);
116 if (!timeout) {
117 dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
118 return -ETIMEDOUT;
119 }
120 return 0;
121}
122
123static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
124{
125 int timeout = 1000;
126 u32 lpcr;
127
128 regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
129 enable ? SNVS_LPCR_SRTC_ENV : 0);
130
131 while (--timeout) {
132 regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);
133
134 if (enable) {
135 if (lpcr & SNVS_LPCR_SRTC_ENV)
136 break;
137 } else {
138 if (!(lpcr & SNVS_LPCR_SRTC_ENV))
139 break;
140 }
141 }
142
143 if (!timeout)
144 return -ETIMEDOUT;
145
146 return 0;
147}
148
149static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
150{
151 struct snvs_rtc_data *data = dev_get_drvdata(dev);
152 unsigned long time = rtc_read_lp_counter(data);
153
154 rtc_time64_to_tm(time, tm);
155
156 return 0;
157}
158
159static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
160{
161 struct snvs_rtc_data *data = dev_get_drvdata(dev);
162 unsigned long time = rtc_tm_to_time64(tm);
163 int ret;
164
165 /* Disable RTC first */
166 ret = snvs_rtc_enable(data, false);
167 if (ret)
168 return ret;
169
170 /* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
171 regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
172 regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
173
174 /* Enable RTC again */
175 ret = snvs_rtc_enable(data, true);
176
177 return ret;
178}
179
180static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
181{
182 struct snvs_rtc_data *data = dev_get_drvdata(dev);
183 u32 lptar, lpsr;
184
185 regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
186 rtc_time64_to_tm(lptar, &alrm->time);
187
188 regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
189 alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
190
191 return 0;
192}
193
194static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
195{
196 struct snvs_rtc_data *data = dev_get_drvdata(dev);
197
198 regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
199 (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
200 enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);
201
202 return rtc_write_sync_lp(data);
203}
204
205static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
206{
207 struct snvs_rtc_data *data = dev_get_drvdata(dev);
208 unsigned long time = rtc_tm_to_time64(&alrm->time);
209 int ret;
210
211 regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
212 ret = rtc_write_sync_lp(data);
213 if (ret)
214 return ret;
215 regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
216
217 /* Clear alarm interrupt status bit */
218 regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);
219
220 return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
221}
222
223static const struct rtc_class_ops snvs_rtc_ops = {
224 .read_time = snvs_rtc_read_time,
225 .set_time = snvs_rtc_set_time,
226 .read_alarm = snvs_rtc_read_alarm,
227 .set_alarm = snvs_rtc_set_alarm,
228 .alarm_irq_enable = snvs_rtc_alarm_irq_enable,
229};
230
231static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
232{
233 struct device *dev = dev_id;
234 struct snvs_rtc_data *data = dev_get_drvdata(dev);
235 u32 lpsr;
236 u32 events = 0;
237
238 if (data->clk)
239 clk_enable(data->clk);
240
241 regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
242
243 if (lpsr & SNVS_LPSR_LPTA) {
244 events |= (RTC_AF | RTC_IRQF);
245
246 /* RTC alarm should be one-shot */
247 snvs_rtc_alarm_irq_enable(dev, 0);
248
249 rtc_update_irq(data->rtc, 1, events);
250 }
251
252 /* clear interrupt status */
253 regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
254
255 if (data->clk)
256 clk_disable(data->clk);
257
258 return events ? IRQ_HANDLED : IRQ_NONE;
259}
260
261static const struct regmap_config snvs_rtc_config = {
262 .reg_bits = 32,
263 .val_bits = 32,
264 .reg_stride = 4,
265};
266
267static int snvs_rtc_probe(struct platform_device *pdev)
268{
269 struct snvs_rtc_data *data;
270 int ret;
271 void __iomem *mmio;
272
273 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
274 if (!data)
275 return -ENOMEM;
276
277 data->rtc = devm_rtc_allocate_device(&pdev->dev);
278 if (IS_ERR(data->rtc))
279 return PTR_ERR(data->rtc);
280
281 data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
282
283 if (IS_ERR(data->regmap)) {
284 dev_warn(&pdev->dev, "snvs rtc: you use old dts file, please update it\n");
285
286 mmio = devm_platform_ioremap_resource(pdev, 0);
287 if (IS_ERR(mmio))
288 return PTR_ERR(mmio);
289
290 data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
291 } else {
292 data->offset = SNVS_LPREGISTER_OFFSET;
293 of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
294 }
295
296 if (IS_ERR(data->regmap)) {
297 dev_err(&pdev->dev, "Can't find snvs syscon\n");
298 return -ENODEV;
299 }
300
301 data->irq = platform_get_irq(pdev, 0);
302 if (data->irq < 0)
303 return data->irq;
304
305 data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
306 if (IS_ERR(data->clk)) {
307 data->clk = NULL;
308 } else {
309 ret = clk_prepare_enable(data->clk);
310 if (ret) {
311 dev_err(&pdev->dev,
312 "Could not prepare or enable the snvs clock\n");
313 return ret;
314 }
315 }
316
317 platform_set_drvdata(pdev, data);
318
319 /* Initialize glitch detect */
320 regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);
321
322 /* Clear interrupt status */
323 regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
324
325 /* Enable RTC */
326 ret = snvs_rtc_enable(data, true);
327 if (ret) {
328 dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
329 goto error_rtc_device_register;
330 }
331
332 device_init_wakeup(&pdev->dev, true);
333 ret = dev_pm_set_wake_irq(&pdev->dev, data->irq);
334 if (ret)
335 dev_err(&pdev->dev, "failed to enable irq wake\n");
336
337 ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
338 IRQF_SHARED, "rtc alarm", &pdev->dev);
339 if (ret) {
340 dev_err(&pdev->dev, "failed to request irq %d: %d\n",
341 data->irq, ret);
342 goto error_rtc_device_register;
343 }
344
345 data->rtc->ops = &snvs_rtc_ops;
346 data->rtc->range_max = U32_MAX;
347 ret = rtc_register_device(data->rtc);
348 if (ret) {
349 dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
350 goto error_rtc_device_register;
351 }
352
353 return 0;
354
355error_rtc_device_register:
356 if (data->clk)
357 clk_disable_unprepare(data->clk);
358
359 return ret;
360}
361
362static int __maybe_unused snvs_rtc_suspend_noirq(struct device *dev)
363{
364 struct snvs_rtc_data *data = dev_get_drvdata(dev);
365
366 if (data->clk)
367 clk_disable_unprepare(data->clk);
368
369 return 0;
370}
371
372static int __maybe_unused snvs_rtc_resume_noirq(struct device *dev)
373{
374 struct snvs_rtc_data *data = dev_get_drvdata(dev);
375
376 if (data->clk)
377 return clk_prepare_enable(data->clk);
378
379 return 0;
380}
381
382static const struct dev_pm_ops snvs_rtc_pm_ops = {
383 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(snvs_rtc_suspend_noirq, snvs_rtc_resume_noirq)
384};
385
386static const struct of_device_id snvs_dt_ids[] = {
387 { .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
388 { /* sentinel */ }
389};
390MODULE_DEVICE_TABLE(of, snvs_dt_ids);
391
392static struct platform_driver snvs_rtc_driver = {
393 .driver = {
394 .name = "snvs_rtc",
395 .pm = &snvs_rtc_pm_ops,
396 .of_match_table = snvs_dt_ids,
397 },
398 .probe = snvs_rtc_probe,
399};
400module_platform_driver(snvs_rtc_driver);
401
402MODULE_AUTHOR("Freescale Semiconductor, Inc.");
403MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
404MODULE_LICENSE("GPL");