Merge tag 'amd-drm-next-5.9-2020-07-01' of git://people.freedesktop.org/~agd5f/linux...
[linux-2.6-microblaze.git] / drivers / rtc / rtc-88pm860x.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Real Time Clock driver for Marvell 88PM860x PMIC
4  *
5  * Copyright (c) 2010 Marvell International Ltd.
6  * Author:      Haojian Zhuang <haojian.zhuang@marvell.com>
7  */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/platform_device.h>
13 #include <linux/slab.h>
14 #include <linux/mutex.h>
15 #include <linux/rtc.h>
16 #include <linux/delay.h>
17 #include <linux/mfd/core.h>
18 #include <linux/mfd/88pm860x.h>
19
20 #define VRTC_CALIBRATION
21
22 struct pm860x_rtc_info {
23         struct pm860x_chip      *chip;
24         struct i2c_client       *i2c;
25         struct rtc_device       *rtc_dev;
26         struct device           *dev;
27         struct delayed_work     calib_work;
28
29         int                     irq;
30         int                     vrtc;
31 };
32
33 #define REG_VRTC_MEAS1          0x7D
34
35 #define REG0_ADDR               0xB0
36 #define REG1_ADDR               0xB2
37 #define REG2_ADDR               0xB4
38 #define REG3_ADDR               0xB6
39
40 #define REG0_DATA               0xB1
41 #define REG1_DATA               0xB3
42 #define REG2_DATA               0xB5
43 #define REG3_DATA               0xB7
44
45 /* bit definitions of Measurement Enable Register 2 (0x51) */
46 #define MEAS2_VRTC              (1 << 0)
47
48 /* bit definitions of RTC Register 1 (0xA0) */
49 #define ALARM_EN                (1 << 3)
50 #define ALARM_WAKEUP            (1 << 4)
51 #define ALARM                   (1 << 5)
52 #define RTC1_USE_XO             (1 << 7)
53
54 #define VRTC_CALIB_INTERVAL     (HZ * 60 * 10)          /* 10 minutes */
55
56 static irqreturn_t rtc_update_handler(int irq, void *data)
57 {
58         struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
59         int mask;
60
61         mask = ALARM | ALARM_WAKEUP;
62         pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
63         rtc_update_irq(info->rtc_dev, 1, RTC_AF);
64         return IRQ_HANDLED;
65 }
66
67 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
68 {
69         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
70
71         if (enabled)
72                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
73         else
74                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
75         return 0;
76 }
77
78 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
79 {
80         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
81         unsigned char buf[8];
82         unsigned long ticks, base, data;
83
84         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
85         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
86                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
87         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
88                 (buf[5] << 8) | buf[7];
89
90         /* load 32-bit read-only counter */
91         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
92         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
93                 (buf[1] << 8) | buf[0];
94         ticks = base + data;
95         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
96                 base, data, ticks);
97
98         rtc_time64_to_tm(ticks, tm);
99
100         return 0;
101 }
102
103 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
104 {
105         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
106         unsigned char buf[4];
107         unsigned long ticks, base, data;
108
109         ticks = rtc_tm_to_time64(tm);
110
111         /* load 32-bit read-only counter */
112         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
113         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
114                 (buf[1] << 8) | buf[0];
115         base = ticks - data;
116         dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
117                 base, data, ticks);
118
119         pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
120         pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
121         pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
122         pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
123
124         return 0;
125 }
126
127 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
128 {
129         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
130         unsigned char buf[8];
131         unsigned long ticks, base, data;
132         int ret;
133
134         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
135         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
136                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
137         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
138                 (buf[5] << 8) | buf[7];
139
140         pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
141         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
142                 (buf[1] << 8) | buf[0];
143         ticks = base + data;
144         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
145                 base, data, ticks);
146
147         rtc_time64_to_tm(ticks, &alrm->time);
148         ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
149         alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
150         alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
151         return 0;
152 }
153
154 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
155 {
156         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
157         unsigned long ticks, base, data;
158         unsigned char buf[8];
159         int mask;
160
161         pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
162
163         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
164         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
165                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
166         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
167                 (buf[5] << 8) | buf[7];
168
169         ticks = rtc_tm_to_time64(&alrm->time);
170         data = ticks - base;
171
172         buf[0] = data & 0xff;
173         buf[1] = (data >> 8) & 0xff;
174         buf[2] = (data >> 16) & 0xff;
175         buf[3] = (data >> 24) & 0xff;
176         pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
177         if (alrm->enabled) {
178                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
179                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
180         } else {
181                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
182                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
183                                 ALARM | ALARM_WAKEUP);
184         }
185         return 0;
186 }
187
188 static const struct rtc_class_ops pm860x_rtc_ops = {
189         .read_time      = pm860x_rtc_read_time,
190         .set_time       = pm860x_rtc_set_time,
191         .read_alarm     = pm860x_rtc_read_alarm,
192         .set_alarm      = pm860x_rtc_set_alarm,
193         .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
194 };
195
196 #ifdef VRTC_CALIBRATION
197 static void calibrate_vrtc_work(struct work_struct *work)
198 {
199         struct pm860x_rtc_info *info = container_of(work,
200                 struct pm860x_rtc_info, calib_work.work);
201         unsigned char buf[2];
202         unsigned int sum, data, mean, vrtc_set;
203         int i;
204
205         for (i = 0, sum = 0; i < 16; i++) {
206                 msleep(100);
207                 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
208                 data = (buf[0] << 4) | buf[1];
209                 data = (data * 5400) >> 12;     /* convert to mv */
210                 sum += data;
211         }
212         mean = sum >> 4;
213         vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
214         dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
215
216         sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
217         data = sum & 0x3;
218         if ((mean + 200) < vrtc_set) {
219                 /* try higher voltage */
220                 if (++data == 4)
221                         goto out;
222                 data = (sum & 0xf8) | (data & 0x3);
223                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
224         } else if ((mean - 200) > vrtc_set) {
225                 /* try lower voltage */
226                 if (data-- == 0)
227                         goto out;
228                 data = (sum & 0xf8) | (data & 0x3);
229                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
230         } else
231                 goto out;
232         dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
233         /* trigger next calibration since VRTC is updated */
234         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
235         return;
236 out:
237         /* disable measurement */
238         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
239         dev_dbg(info->dev, "finish VRTC calibration\n");
240         return;
241 }
242 #endif
243
244 #ifdef CONFIG_OF
245 static int pm860x_rtc_dt_init(struct platform_device *pdev,
246                               struct pm860x_rtc_info *info)
247 {
248         struct device_node *np = pdev->dev.parent->of_node;
249         int ret;
250         if (!np)
251                 return -ENODEV;
252         np = of_get_child_by_name(np, "rtc");
253         if (!np) {
254                 dev_err(&pdev->dev, "failed to find rtc node\n");
255                 return -ENODEV;
256         }
257         ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
258         if (ret)
259                 info->vrtc = 0;
260         of_node_put(np);
261         return 0;
262 }
263 #else
264 #define pm860x_rtc_dt_init(x, y)        do { } while (0)
265 #endif
266
267 static int pm860x_rtc_probe(struct platform_device *pdev)
268 {
269         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
270         struct pm860x_rtc_info *info;
271         int ret;
272
273         info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
274                             GFP_KERNEL);
275         if (!info)
276                 return -ENOMEM;
277         info->irq = platform_get_irq(pdev, 0);
278         if (info->irq < 0)
279                 return info->irq;
280
281         info->chip = chip;
282         info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
283         info->dev = &pdev->dev;
284         dev_set_drvdata(&pdev->dev, info);
285
286         info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
287         if (IS_ERR(info->rtc_dev))
288                 return PTR_ERR(info->rtc_dev);
289
290         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
291                                         rtc_update_handler, IRQF_ONESHOT, "rtc",
292                                         info);
293         if (ret < 0) {
294                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
295                         info->irq, ret);
296                 return ret;
297         }
298
299         /* set addresses of 32-bit base value for RTC time */
300         pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
301         pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
302         pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
303         pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
304
305         pm860x_rtc_dt_init(pdev, info);
306
307         info->rtc_dev->ops = &pm860x_rtc_ops;
308         info->rtc_dev->range_max = U32_MAX;
309
310         ret = rtc_register_device(info->rtc_dev);
311         if (ret)
312                 return ret;
313
314         /*
315          * enable internal XO instead of internal 3.25MHz clock since it can
316          * free running in PMIC power-down state.
317          */
318         pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
319
320 #ifdef VRTC_CALIBRATION
321         /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
322         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
323
324         /* calibrate VRTC */
325         INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
326         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
327 #endif  /* VRTC_CALIBRATION */
328
329         device_init_wakeup(&pdev->dev, 1);
330
331         return 0;
332 }
333
334 static int pm860x_rtc_remove(struct platform_device *pdev)
335 {
336         struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
337
338 #ifdef VRTC_CALIBRATION
339         cancel_delayed_work_sync(&info->calib_work);
340         /* disable measurement */
341         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
342 #endif  /* VRTC_CALIBRATION */
343
344         return 0;
345 }
346
347 #ifdef CONFIG_PM_SLEEP
348 static int pm860x_rtc_suspend(struct device *dev)
349 {
350         struct platform_device *pdev = to_platform_device(dev);
351         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
352
353         if (device_may_wakeup(dev))
354                 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
355         return 0;
356 }
357 static int pm860x_rtc_resume(struct device *dev)
358 {
359         struct platform_device *pdev = to_platform_device(dev);
360         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
361
362         if (device_may_wakeup(dev))
363                 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
364         return 0;
365 }
366 #endif
367
368 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
369
370 static struct platform_driver pm860x_rtc_driver = {
371         .driver         = {
372                 .name   = "88pm860x-rtc",
373                 .pm     = &pm860x_rtc_pm_ops,
374         },
375         .probe          = pm860x_rtc_probe,
376         .remove         = pm860x_rtc_remove,
377 };
378
379 module_platform_driver(pm860x_rtc_driver);
380
381 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
382 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
383 MODULE_LICENSE("GPL");