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(rtc: info->rtc_dev, num: 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(time: 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(time: ticks, tm: &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(tm: &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(msecs: 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(dwork: &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(node: np, name: "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, propname: "marvell,88pm860x-vrtc" , out_value: &info->vrtc); |
258 | if (ret) |
259 | info->vrtc = 0; |
260 | of_node_put(node: 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(dev: pdev->dev.parent); |
270 | struct pm860x_rtc_info *info; |
271 | int ret; |
272 | |
273 | info = devm_kzalloc(dev: &pdev->dev, size: 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(dev: &pdev->dev, data: info); |
285 | |
286 | info->rtc_dev = devm_rtc_allocate_device(dev: &pdev->dev); |
287 | if (IS_ERR(ptr: info->rtc_dev)) |
288 | return PTR_ERR(ptr: info->rtc_dev); |
289 | |
290 | ret = devm_request_threaded_irq(dev: &pdev->dev, irq: info->irq, NULL, |
291 | thread_fn: rtc_update_handler, IRQF_ONESHOT, devname: "rtc" , |
292 | dev_id: 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 = devm_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(dwork: &info->calib_work, VRTC_CALIB_INTERVAL); |
327 | #endif /* VRTC_CALIBRATION */ |
328 | |
329 | device_init_wakeup(dev: &pdev->dev, enable: 1); |
330 | |
331 | return 0; |
332 | } |
333 | |
334 | static void 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(dwork: &info->calib_work); |
340 | /* disable measurement */ |
341 | pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); |
342 | #endif /* VRTC_CALIBRATION */ |
343 | } |
344 | |
345 | #ifdef CONFIG_PM_SLEEP |
346 | static int pm860x_rtc_suspend(struct device *dev) |
347 | { |
348 | struct platform_device *pdev = to_platform_device(dev); |
349 | struct pm860x_chip *chip = dev_get_drvdata(dev: pdev->dev.parent); |
350 | |
351 | if (device_may_wakeup(dev)) |
352 | chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; |
353 | return 0; |
354 | } |
355 | static int pm860x_rtc_resume(struct device *dev) |
356 | { |
357 | struct platform_device *pdev = to_platform_device(dev); |
358 | struct pm860x_chip *chip = dev_get_drvdata(dev: pdev->dev.parent); |
359 | |
360 | if (device_may_wakeup(dev)) |
361 | chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); |
362 | return 0; |
363 | } |
364 | #endif |
365 | |
366 | static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); |
367 | |
368 | static struct platform_driver pm860x_rtc_driver = { |
369 | .driver = { |
370 | .name = "88pm860x-rtc" , |
371 | .pm = &pm860x_rtc_pm_ops, |
372 | }, |
373 | .probe = pm860x_rtc_probe, |
374 | .remove_new = pm860x_rtc_remove, |
375 | }; |
376 | |
377 | module_platform_driver(pm860x_rtc_driver); |
378 | |
379 | MODULE_DESCRIPTION("Marvell 88PM860x RTC driver" ); |
380 | MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>" ); |
381 | MODULE_LICENSE("GPL" ); |
382 | |