1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2016 Oleksij Rempel <linux@rempel-privat.de>
4 */
5
6 #include <linux/clk.h>
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/rtc.h>
13
14 /* Miscellaneous registers */
15 /* Interrupt Location Register */
16 #define HW_ILR 0x00
17 #define BM_RTCALF BIT(1)
18 #define BM_RTCCIF BIT(0)
19
20 /* Clock Control Register */
21 #define HW_CCR 0x08
22 /* Calibration counter disable */
23 #define BM_CCALOFF BIT(4)
24 /* Reset internal oscillator divider */
25 #define BM_CTCRST BIT(1)
26 /* Clock Enable */
27 #define BM_CLKEN BIT(0)
28
29 /* Counter Increment Interrupt Register */
30 #define HW_CIIR 0x0C
31 #define BM_CIIR_IMYEAR BIT(7)
32 #define BM_CIIR_IMMON BIT(6)
33 #define BM_CIIR_IMDOY BIT(5)
34 #define BM_CIIR_IMDOW BIT(4)
35 #define BM_CIIR_IMDOM BIT(3)
36 #define BM_CIIR_IMHOUR BIT(2)
37 #define BM_CIIR_IMMIN BIT(1)
38 #define BM_CIIR_IMSEC BIT(0)
39
40 /* Alarm Mask Register */
41 #define HW_AMR 0x10
42 #define BM_AMR_IMYEAR BIT(7)
43 #define BM_AMR_IMMON BIT(6)
44 #define BM_AMR_IMDOY BIT(5)
45 #define BM_AMR_IMDOW BIT(4)
46 #define BM_AMR_IMDOM BIT(3)
47 #define BM_AMR_IMHOUR BIT(2)
48 #define BM_AMR_IMMIN BIT(1)
49 #define BM_AMR_IMSEC BIT(0)
50 #define BM_AMR_OFF 0xff
51
52 /* Consolidated time registers */
53 #define HW_CTIME0 0x14
54 #define BM_CTIME0_DOW_S 24
55 #define BM_CTIME0_DOW_M 0x7
56 #define BM_CTIME0_HOUR_S 16
57 #define BM_CTIME0_HOUR_M 0x1f
58 #define BM_CTIME0_MIN_S 8
59 #define BM_CTIME0_MIN_M 0x3f
60 #define BM_CTIME0_SEC_S 0
61 #define BM_CTIME0_SEC_M 0x3f
62
63 #define HW_CTIME1 0x18
64 #define BM_CTIME1_YEAR_S 16
65 #define BM_CTIME1_YEAR_M 0xfff
66 #define BM_CTIME1_MON_S 8
67 #define BM_CTIME1_MON_M 0xf
68 #define BM_CTIME1_DOM_S 0
69 #define BM_CTIME1_DOM_M 0x1f
70
71 #define HW_CTIME2 0x1C
72 #define BM_CTIME2_DOY_S 0
73 #define BM_CTIME2_DOY_M 0xfff
74
75 /* Time counter registers */
76 #define HW_SEC 0x20
77 #define HW_MIN 0x24
78 #define HW_HOUR 0x28
79 #define HW_DOM 0x2C
80 #define HW_DOW 0x30
81 #define HW_DOY 0x34
82 #define HW_MONTH 0x38
83 #define HW_YEAR 0x3C
84
85 #define HW_CALIBRATION 0x40
86 #define BM_CALDIR_BACK BIT(17)
87 #define BM_CALVAL_M 0x1ffff
88
89 /* General purpose registers */
90 #define HW_GPREG0 0x44
91 #define HW_GPREG1 0x48
92 #define HW_GPREG2 0x4C
93 #define HW_GPREG3 0x50
94 #define HW_GPREG4 0x54
95
96 /* Alarm register group */
97 #define HW_ALSEC 0x60
98 #define HW_ALMIN 0x64
99 #define HW_ALHOUR 0x68
100 #define HW_ALDOM 0x6C
101 #define HW_ALDOW 0x70
102 #define HW_ALDOY 0x74
103 #define HW_ALMON 0x78
104 #define HW_ALYEAR 0x7C
105
106 struct asm9260_rtc_priv {
107 struct device *dev;
108 void __iomem *iobase;
109 struct rtc_device *rtc;
110 struct clk *clk;
111 };
112
asm9260_rtc_irq(int irq,void * dev_id)113 static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id)
114 {
115 struct asm9260_rtc_priv *priv = dev_id;
116 u32 isr;
117 unsigned long events = 0;
118
119 rtc_lock(priv->rtc);
120 isr = ioread32(priv->iobase + HW_CIIR);
121 if (!isr) {
122 rtc_unlock(priv->rtc);
123 return IRQ_NONE;
124 }
125
126 iowrite32(0, priv->iobase + HW_CIIR);
127 rtc_unlock(priv->rtc);
128
129 events |= RTC_AF | RTC_IRQF;
130
131 rtc_update_irq(priv->rtc, 1, events);
132
133 return IRQ_HANDLED;
134 }
135
asm9260_rtc_read_time(struct device * dev,struct rtc_time * tm)136 static int asm9260_rtc_read_time(struct device *dev, struct rtc_time *tm)
137 {
138 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
139 u32 ctime0, ctime1, ctime2;
140
141 ctime0 = ioread32(priv->iobase + HW_CTIME0);
142 ctime1 = ioread32(priv->iobase + HW_CTIME1);
143 ctime2 = ioread32(priv->iobase + HW_CTIME2);
144
145 if (ctime1 != ioread32(priv->iobase + HW_CTIME1)) {
146 /*
147 * woops, counter flipped right now. Now we are safe
148 * to reread.
149 */
150 ctime0 = ioread32(priv->iobase + HW_CTIME0);
151 ctime1 = ioread32(priv->iobase + HW_CTIME1);
152 ctime2 = ioread32(priv->iobase + HW_CTIME2);
153 }
154
155 tm->tm_sec = (ctime0 >> BM_CTIME0_SEC_S) & BM_CTIME0_SEC_M;
156 tm->tm_min = (ctime0 >> BM_CTIME0_MIN_S) & BM_CTIME0_MIN_M;
157 tm->tm_hour = (ctime0 >> BM_CTIME0_HOUR_S) & BM_CTIME0_HOUR_M;
158 tm->tm_wday = (ctime0 >> BM_CTIME0_DOW_S) & BM_CTIME0_DOW_M;
159
160 tm->tm_mday = (ctime1 >> BM_CTIME1_DOM_S) & BM_CTIME1_DOM_M;
161 tm->tm_mon = (ctime1 >> BM_CTIME1_MON_S) & BM_CTIME1_MON_M;
162 tm->tm_year = (ctime1 >> BM_CTIME1_YEAR_S) & BM_CTIME1_YEAR_M;
163
164 tm->tm_yday = (ctime2 >> BM_CTIME2_DOY_S) & BM_CTIME2_DOY_M;
165
166 return 0;
167 }
168
asm9260_rtc_set_time(struct device * dev,struct rtc_time * tm)169 static int asm9260_rtc_set_time(struct device *dev, struct rtc_time *tm)
170 {
171 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
172
173 /*
174 * make sure SEC counter will not flip other counter on write time,
175 * real value will be written at the enf of sequence.
176 */
177 iowrite32(0, priv->iobase + HW_SEC);
178
179 iowrite32(tm->tm_year, priv->iobase + HW_YEAR);
180 iowrite32(tm->tm_mon, priv->iobase + HW_MONTH);
181 iowrite32(tm->tm_mday, priv->iobase + HW_DOM);
182 iowrite32(tm->tm_wday, priv->iobase + HW_DOW);
183 iowrite32(tm->tm_yday, priv->iobase + HW_DOY);
184 iowrite32(tm->tm_hour, priv->iobase + HW_HOUR);
185 iowrite32(tm->tm_min, priv->iobase + HW_MIN);
186 iowrite32(tm->tm_sec, priv->iobase + HW_SEC);
187
188 return 0;
189 }
190
asm9260_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)191 static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
192 {
193 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
194
195 alrm->time.tm_year = ioread32(priv->iobase + HW_ALYEAR);
196 alrm->time.tm_mon = ioread32(priv->iobase + HW_ALMON);
197 alrm->time.tm_mday = ioread32(priv->iobase + HW_ALDOM);
198 alrm->time.tm_wday = ioread32(priv->iobase + HW_ALDOW);
199 alrm->time.tm_yday = ioread32(priv->iobase + HW_ALDOY);
200 alrm->time.tm_hour = ioread32(priv->iobase + HW_ALHOUR);
201 alrm->time.tm_min = ioread32(priv->iobase + HW_ALMIN);
202 alrm->time.tm_sec = ioread32(priv->iobase + HW_ALSEC);
203
204 alrm->enabled = ioread32(priv->iobase + HW_AMR) ? 1 : 0;
205 alrm->pending = ioread32(priv->iobase + HW_CIIR) ? 1 : 0;
206
207 return rtc_valid_tm(&alrm->time);
208 }
209
asm9260_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)210 static int asm9260_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
211 {
212 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
213
214 iowrite32(alrm->time.tm_year, priv->iobase + HW_ALYEAR);
215 iowrite32(alrm->time.tm_mon, priv->iobase + HW_ALMON);
216 iowrite32(alrm->time.tm_mday, priv->iobase + HW_ALDOM);
217 iowrite32(alrm->time.tm_wday, priv->iobase + HW_ALDOW);
218 iowrite32(alrm->time.tm_yday, priv->iobase + HW_ALDOY);
219 iowrite32(alrm->time.tm_hour, priv->iobase + HW_ALHOUR);
220 iowrite32(alrm->time.tm_min, priv->iobase + HW_ALMIN);
221 iowrite32(alrm->time.tm_sec, priv->iobase + HW_ALSEC);
222
223 iowrite32(alrm->enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR);
224
225 return 0;
226 }
227
asm9260_alarm_irq_enable(struct device * dev,unsigned int enabled)228 static int asm9260_alarm_irq_enable(struct device *dev, unsigned int enabled)
229 {
230 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
231
232 iowrite32(enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR);
233 return 0;
234 }
235
236 static const struct rtc_class_ops asm9260_rtc_ops = {
237 .read_time = asm9260_rtc_read_time,
238 .set_time = asm9260_rtc_set_time,
239 .read_alarm = asm9260_rtc_read_alarm,
240 .set_alarm = asm9260_rtc_set_alarm,
241 .alarm_irq_enable = asm9260_alarm_irq_enable,
242 };
243
asm9260_rtc_probe(struct platform_device * pdev)244 static int asm9260_rtc_probe(struct platform_device *pdev)
245 {
246 struct asm9260_rtc_priv *priv;
247 struct device *dev = &pdev->dev;
248 int irq_alarm, ret;
249 u32 ccr;
250
251 priv = devm_kzalloc(dev, sizeof(struct asm9260_rtc_priv), GFP_KERNEL);
252 if (!priv)
253 return -ENOMEM;
254
255 priv->dev = &pdev->dev;
256 platform_set_drvdata(pdev, priv);
257
258 irq_alarm = platform_get_irq(pdev, 0);
259 if (irq_alarm < 0)
260 return irq_alarm;
261
262 priv->iobase = devm_platform_ioremap_resource(pdev, 0);
263 if (IS_ERR(priv->iobase))
264 return PTR_ERR(priv->iobase);
265
266 priv->clk = devm_clk_get(dev, "ahb");
267 if (IS_ERR(priv->clk))
268 return PTR_ERR(priv->clk);
269
270 ret = clk_prepare_enable(priv->clk);
271 if (ret) {
272 dev_err(dev, "Failed to enable clk!\n");
273 return ret;
274 }
275
276 ccr = ioread32(priv->iobase + HW_CCR);
277 /* if dev is not enabled, reset it */
278 if ((ccr & (BM_CLKEN | BM_CTCRST)) != BM_CLKEN) {
279 iowrite32(BM_CTCRST, priv->iobase + HW_CCR);
280 ccr = 0;
281 }
282
283 iowrite32(BM_CLKEN | ccr, priv->iobase + HW_CCR);
284 iowrite32(0, priv->iobase + HW_CIIR);
285 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR);
286
287 priv->rtc = devm_rtc_device_register(dev, dev_name(dev),
288 &asm9260_rtc_ops, THIS_MODULE);
289 if (IS_ERR(priv->rtc)) {
290 ret = PTR_ERR(priv->rtc);
291 dev_err(dev, "Failed to register RTC device: %d\n", ret);
292 goto err_return;
293 }
294
295 ret = devm_request_threaded_irq(dev, irq_alarm, NULL,
296 asm9260_rtc_irq, IRQF_ONESHOT,
297 dev_name(dev), priv);
298 if (ret < 0) {
299 dev_err(dev, "can't get irq %i, err %d\n",
300 irq_alarm, ret);
301 goto err_return;
302 }
303
304 return 0;
305
306 err_return:
307 clk_disable_unprepare(priv->clk);
308 return ret;
309 }
310
asm9260_rtc_remove(struct platform_device * pdev)311 static void asm9260_rtc_remove(struct platform_device *pdev)
312 {
313 struct asm9260_rtc_priv *priv = platform_get_drvdata(pdev);
314
315 /* Disable alarm matching */
316 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR);
317 clk_disable_unprepare(priv->clk);
318 }
319
320 static const struct of_device_id asm9260_dt_ids[] = {
321 { .compatible = "alphascale,asm9260-rtc", },
322 {}
323 };
324 MODULE_DEVICE_TABLE(of, asm9260_dt_ids);
325
326 static struct platform_driver asm9260_rtc_driver = {
327 .probe = asm9260_rtc_probe,
328 .remove_new = asm9260_rtc_remove,
329 .driver = {
330 .name = "asm9260-rtc",
331 .of_match_table = asm9260_dt_ids,
332 },
333 };
334
335 module_platform_driver(asm9260_rtc_driver);
336
337 MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");
338 MODULE_DESCRIPTION("Alphascale asm9260 SoC Realtime Clock Driver (RTC)");
339 MODULE_LICENSE("GPL");
340