tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2016 Oleksij Rempel <linux@rempel-privat.de>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2 of the License,
7 * or (at your option) any later version.
8 */
9
10#include <linux/clk.h>
11#include <linux/interrupt.h>
12#include <linux/io.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/rtc.h>
17
18/* Miscellaneous registers */
19/* Interrupt Location Register */
20#define HW_ILR 0x00
21#define BM_RTCALF BIT(1)
22#define BM_RTCCIF BIT(0)
23
24/* Clock Control Register */
25#define HW_CCR 0x08
26/* Calibration counter disable */
27#define BM_CCALOFF BIT(4)
28/* Reset internal oscillator divider */
29#define BM_CTCRST BIT(1)
30/* Clock Enable */
31#define BM_CLKEN BIT(0)
32
33/* Counter Increment Interrupt Register */
34#define HW_CIIR 0x0C
35#define BM_CIIR_IMYEAR BIT(7)
36#define BM_CIIR_IMMON BIT(6)
37#define BM_CIIR_IMDOY BIT(5)
38#define BM_CIIR_IMDOW BIT(4)
39#define BM_CIIR_IMDOM BIT(3)
40#define BM_CIIR_IMHOUR BIT(2)
41#define BM_CIIR_IMMIN BIT(1)
42#define BM_CIIR_IMSEC BIT(0)
43
44/* Alarm Mask Register */
45#define HW_AMR 0x10
46#define BM_AMR_IMYEAR BIT(7)
47#define BM_AMR_IMMON BIT(6)
48#define BM_AMR_IMDOY BIT(5)
49#define BM_AMR_IMDOW BIT(4)
50#define BM_AMR_IMDOM BIT(3)
51#define BM_AMR_IMHOUR BIT(2)
52#define BM_AMR_IMMIN BIT(1)
53#define BM_AMR_IMSEC BIT(0)
54#define BM_AMR_OFF 0xff
55
56/* Consolidated time registers */
57#define HW_CTIME0 0x14
58#define BM_CTIME0_DOW_S 24
59#define BM_CTIME0_DOW_M 0x7
60#define BM_CTIME0_HOUR_S 16
61#define BM_CTIME0_HOUR_M 0x1f
62#define BM_CTIME0_MIN_S 8
63#define BM_CTIME0_MIN_M 0x3f
64#define BM_CTIME0_SEC_S 0
65#define BM_CTIME0_SEC_M 0x3f
66
67#define HW_CTIME1 0x18
68#define BM_CTIME1_YEAR_S 16
69#define BM_CTIME1_YEAR_M 0xfff
70#define BM_CTIME1_MON_S 8
71#define BM_CTIME1_MON_M 0xf
72#define BM_CTIME1_DOM_S 0
73#define BM_CTIME1_DOM_M 0x1f
74
75#define HW_CTIME2 0x1C
76#define BM_CTIME2_DOY_S 0
77#define BM_CTIME2_DOY_M 0xfff
78
79/* Time counter registers */
80#define HW_SEC 0x20
81#define HW_MIN 0x24
82#define HW_HOUR 0x28
83#define HW_DOM 0x2C
84#define HW_DOW 0x30
85#define HW_DOY 0x34
86#define HW_MONTH 0x38
87#define HW_YEAR 0x3C
88
89#define HW_CALIBRATION 0x40
90#define BM_CALDIR_BACK BIT(17)
91#define BM_CALVAL_M 0x1ffff
92
93/* General purpose registers */
94#define HW_GPREG0 0x44
95#define HW_GPREG1 0x48
96#define HW_GPREG2 0x4C
97#define HW_GPREG3 0x50
98#define HW_GPREG4 0x54
99
100/* Alarm register group */
101#define HW_ALSEC 0x60
102#define HW_ALMIN 0x64
103#define HW_ALHOUR 0x68
104#define HW_ALDOM 0x6C
105#define HW_ALDOW 0x70
106#define HW_ALDOY 0x74
107#define HW_ALMON 0x78
108#define HW_ALYEAR 0x7C
109
110struct asm9260_rtc_priv {
111 struct device *dev;
112 void __iomem *iobase;
113 struct rtc_device *rtc;
114 struct clk *clk;
115};
116
117static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id)
118{
119 struct asm9260_rtc_priv *priv = dev_id;
120 u32 isr;
121 unsigned long events = 0;
122
123 mutex_lock(&priv->rtc->ops_lock);
124 isr = ioread32(priv->iobase + HW_CIIR);
125 if (!isr) {
126 mutex_unlock(&priv->rtc->ops_lock);
127 return IRQ_NONE;
128 }
129
130 iowrite32(0, priv->iobase + HW_CIIR);
131 mutex_unlock(&priv->rtc->ops_lock);
132
133 events |= RTC_AF | RTC_IRQF;
134
135 rtc_update_irq(priv->rtc, 1, events);
136
137 return IRQ_HANDLED;
138}
139
140static int asm9260_rtc_read_time(struct device *dev, struct rtc_time *tm)
141{
142 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
143 u32 ctime0, ctime1, ctime2;
144
145 ctime0 = ioread32(priv->iobase + HW_CTIME0);
146 ctime1 = ioread32(priv->iobase + HW_CTIME1);
147 ctime2 = ioread32(priv->iobase + HW_CTIME2);
148
149 if (ctime1 != ioread32(priv->iobase + HW_CTIME1)) {
150 /*
151 * woops, counter flipped right now. Now we are safe
152 * to reread.
153 */
154 ctime0 = ioread32(priv->iobase + HW_CTIME0);
155 ctime1 = ioread32(priv->iobase + HW_CTIME1);
156 ctime2 = ioread32(priv->iobase + HW_CTIME2);
157 }
158
159 tm->tm_sec = (ctime0 >> BM_CTIME0_SEC_S) & BM_CTIME0_SEC_M;
160 tm->tm_min = (ctime0 >> BM_CTIME0_MIN_S) & BM_CTIME0_MIN_M;
161 tm->tm_hour = (ctime0 >> BM_CTIME0_HOUR_S) & BM_CTIME0_HOUR_M;
162 tm->tm_wday = (ctime0 >> BM_CTIME0_DOW_S) & BM_CTIME0_DOW_M;
163
164 tm->tm_mday = (ctime1 >> BM_CTIME1_DOM_S) & BM_CTIME1_DOM_M;
165 tm->tm_mon = (ctime1 >> BM_CTIME1_MON_S) & BM_CTIME1_MON_M;
166 tm->tm_year = (ctime1 >> BM_CTIME1_YEAR_S) & BM_CTIME1_YEAR_M;
167
168 tm->tm_yday = (ctime2 >> BM_CTIME2_DOY_S) & BM_CTIME2_DOY_M;
169
170 return 0;
171}
172
173static int asm9260_rtc_set_time(struct device *dev, struct rtc_time *tm)
174{
175 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
176
177 /*
178 * make sure SEC counter will not flip other counter on write time,
179 * real value will be written at the enf of sequence.
180 */
181 iowrite32(0, priv->iobase + HW_SEC);
182
183 iowrite32(tm->tm_year, priv->iobase + HW_YEAR);
184 iowrite32(tm->tm_mon, priv->iobase + HW_MONTH);
185 iowrite32(tm->tm_mday, priv->iobase + HW_DOM);
186 iowrite32(tm->tm_wday, priv->iobase + HW_DOW);
187 iowrite32(tm->tm_yday, priv->iobase + HW_DOY);
188 iowrite32(tm->tm_hour, priv->iobase + HW_HOUR);
189 iowrite32(tm->tm_min, priv->iobase + HW_MIN);
190 iowrite32(tm->tm_sec, priv->iobase + HW_SEC);
191
192 return 0;
193}
194
195static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
196{
197 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
198
199 alrm->time.tm_year = ioread32(priv->iobase + HW_ALYEAR);
200 alrm->time.tm_mon = ioread32(priv->iobase + HW_ALMON);
201 alrm->time.tm_mday = ioread32(priv->iobase + HW_ALDOM);
202 alrm->time.tm_wday = ioread32(priv->iobase + HW_ALDOW);
203 alrm->time.tm_yday = ioread32(priv->iobase + HW_ALDOY);
204 alrm->time.tm_hour = ioread32(priv->iobase + HW_ALHOUR);
205 alrm->time.tm_min = ioread32(priv->iobase + HW_ALMIN);
206 alrm->time.tm_sec = ioread32(priv->iobase + HW_ALSEC);
207
208 alrm->enabled = ioread32(priv->iobase + HW_AMR) ? 1 : 0;
209 alrm->pending = ioread32(priv->iobase + HW_CIIR) ? 1 : 0;
210
211 return rtc_valid_tm(&alrm->time);
212}
213
214static int asm9260_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
215{
216 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
217
218 iowrite32(alrm->time.tm_year, priv->iobase + HW_ALYEAR);
219 iowrite32(alrm->time.tm_mon, priv->iobase + HW_ALMON);
220 iowrite32(alrm->time.tm_mday, priv->iobase + HW_ALDOM);
221 iowrite32(alrm->time.tm_wday, priv->iobase + HW_ALDOW);
222 iowrite32(alrm->time.tm_yday, priv->iobase + HW_ALDOY);
223 iowrite32(alrm->time.tm_hour, priv->iobase + HW_ALHOUR);
224 iowrite32(alrm->time.tm_min, priv->iobase + HW_ALMIN);
225 iowrite32(alrm->time.tm_sec, priv->iobase + HW_ALSEC);
226
227 iowrite32(alrm->enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR);
228
229 return 0;
230}
231
232static int asm9260_alarm_irq_enable(struct device *dev, unsigned int enabled)
233{
234 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
235
236 iowrite32(enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR);
237 return 0;
238}
239
240static const struct rtc_class_ops asm9260_rtc_ops = {
241 .read_time = asm9260_rtc_read_time,
242 .set_time = asm9260_rtc_set_time,
243 .read_alarm = asm9260_rtc_read_alarm,
244 .set_alarm = asm9260_rtc_set_alarm,
245 .alarm_irq_enable = asm9260_alarm_irq_enable,
246};
247
248static int asm9260_rtc_probe(struct platform_device *pdev)
249{
250 struct asm9260_rtc_priv *priv;
251 struct device *dev = &pdev->dev;
252 struct resource *res;
253 int irq_alarm, ret;
254 u32 ccr;
255
256 priv = devm_kzalloc(dev, sizeof(struct asm9260_rtc_priv), GFP_KERNEL);
257 if (!priv)
258 return -ENOMEM;
259
260 priv->dev = &pdev->dev;
261 platform_set_drvdata(pdev, priv);
262
263 irq_alarm = platform_get_irq(pdev, 0);
264 if (irq_alarm < 0) {
265 dev_err(dev, "No alarm IRQ resource defined\n");
266 return irq_alarm;
267 }
268
269 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
270 priv->iobase = devm_ioremap_resource(dev, res);
271 if (IS_ERR(priv->iobase))
272 return PTR_ERR(priv->iobase);
273
274 priv->clk = devm_clk_get(dev, "ahb");
275 ret = clk_prepare_enable(priv->clk);
276 if (ret) {
277 dev_err(dev, "Failed to enable clk!\n");
278 return ret;
279 }
280
281 ccr = ioread32(priv->iobase + HW_CCR);
282 /* if dev is not enabled, reset it */
283 if ((ccr & (BM_CLKEN | BM_CTCRST)) != BM_CLKEN) {
284 iowrite32(BM_CTCRST, priv->iobase + HW_CCR);
285 ccr = 0;
286 }
287
288 iowrite32(BM_CLKEN | ccr, priv->iobase + HW_CCR);
289 iowrite32(0, priv->iobase + HW_CIIR);
290 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR);
291
292 priv->rtc = devm_rtc_device_register(dev, dev_name(dev),
293 &asm9260_rtc_ops, THIS_MODULE);
294 if (IS_ERR(priv->rtc)) {
295 ret = PTR_ERR(priv->rtc);
296 dev_err(dev, "Failed to register RTC device: %d\n", ret);
297 goto err_return;
298 }
299
300 ret = devm_request_threaded_irq(dev, irq_alarm, NULL,
301 asm9260_rtc_irq, IRQF_ONESHOT,
302 dev_name(dev), priv);
303 if (ret < 0) {
304 dev_err(dev, "can't get irq %i, err %d\n",
305 irq_alarm, ret);
306 goto err_return;
307 }
308
309 return 0;
310
311err_return:
312 clk_disable_unprepare(priv->clk);
313 return ret;
314}
315
316static int asm9260_rtc_remove(struct platform_device *pdev)
317{
318 struct asm9260_rtc_priv *priv = platform_get_drvdata(pdev);
319
320 /* Disable alarm matching */
321 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR);
322 clk_disable_unprepare(priv->clk);
323 return 0;
324}
325
326static const struct of_device_id asm9260_dt_ids[] = {
327 { .compatible = "alphascale,asm9260-rtc", },
328 {}
329};
330MODULE_DEVICE_TABLE(of, asm9260_dt_ids);
331
332static struct platform_driver asm9260_rtc_driver = {
333 .probe = asm9260_rtc_probe,
334 .remove = asm9260_rtc_remove,
335 .driver = {
336 .name = "asm9260-rtc",
337 .of_match_table = asm9260_dt_ids,
338 },
339};
340
341module_platform_driver(asm9260_rtc_driver);
342
343MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");
344MODULE_DESCRIPTION("Alphascale asm9260 SoC Realtime Clock Driver (RTC)");
345MODULE_LICENSE("GPL");