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1802d0be | 1 | // SPDX-License-Identifier: GPL-2.0-only |
dd3bf50b SR |
2 | /* |
3 | * Motorola CPCAP PMIC RTC driver | |
4 | * | |
5 | * Based on cpcap-regulator.c from Motorola Linux kernel tree | |
6 | * Copyright (C) 2009 Motorola, Inc. | |
7 | * | |
8 | * Rewritten for mainline kernel | |
9 | * - use DT | |
10 | * - use regmap | |
11 | * - use standard interrupt framework | |
12 | * - use managed device resources | |
13 | * - remove custom "secure clock daemon" helpers | |
14 | * | |
15 | * Copyright (C) 2017 Sebastian Reichel <sre@kernel.org> | |
dd3bf50b SR |
16 | */ |
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
ac316725 | 19 | #include <linux/mod_devicetable.h> |
dd3bf50b SR |
20 | #include <linux/init.h> |
21 | #include <linux/device.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/rtc.h> | |
24 | #include <linux/err.h> | |
25 | #include <linux/regmap.h> | |
26 | #include <linux/mfd/motorola-cpcap.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/sched.h> | |
29 | ||
30 | #define SECS_PER_DAY 86400 | |
31 | #define DAY_MASK 0x7FFF | |
32 | #define TOD1_MASK 0x00FF | |
33 | #define TOD2_MASK 0x01FF | |
34 | ||
35 | struct cpcap_time { | |
36 | int day; | |
37 | int tod1; | |
38 | int tod2; | |
39 | }; | |
40 | ||
41 | struct cpcap_rtc { | |
42 | struct regmap *regmap; | |
43 | struct rtc_device *rtc_dev; | |
44 | u16 vendor; | |
45 | int alarm_irq; | |
46 | bool alarm_enabled; | |
47 | int update_irq; | |
48 | bool update_enabled; | |
49 | }; | |
50 | ||
51 | static void cpcap2rtc_time(struct rtc_time *rtc, struct cpcap_time *cpcap) | |
52 | { | |
53 | unsigned long int tod; | |
54 | unsigned long int time; | |
55 | ||
56 | tod = (cpcap->tod1 & TOD1_MASK) | ((cpcap->tod2 & TOD2_MASK) << 8); | |
57 | time = tod + ((cpcap->day & DAY_MASK) * SECS_PER_DAY); | |
58 | ||
d238df15 | 59 | rtc_time64_to_tm(time, rtc); |
dd3bf50b SR |
60 | } |
61 | ||
62 | static void rtc2cpcap_time(struct cpcap_time *cpcap, struct rtc_time *rtc) | |
63 | { | |
64 | unsigned long time; | |
65 | ||
d238df15 | 66 | time = rtc_tm_to_time64(rtc); |
dd3bf50b SR |
67 | |
68 | cpcap->day = time / SECS_PER_DAY; | |
69 | time %= SECS_PER_DAY; | |
70 | cpcap->tod2 = (time >> 8) & TOD2_MASK; | |
71 | cpcap->tod1 = time & TOD1_MASK; | |
72 | } | |
73 | ||
74 | static int cpcap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) | |
75 | { | |
76 | struct cpcap_rtc *rtc = dev_get_drvdata(dev); | |
77 | ||
78 | if (rtc->alarm_enabled == enabled) | |
79 | return 0; | |
80 | ||
81 | if (enabled) | |
82 | enable_irq(rtc->alarm_irq); | |
83 | else | |
84 | disable_irq(rtc->alarm_irq); | |
85 | ||
86 | rtc->alarm_enabled = !!enabled; | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | static int cpcap_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
92 | { | |
93 | struct cpcap_rtc *rtc; | |
94 | struct cpcap_time cpcap_tm; | |
95 | int temp_tod2; | |
96 | int ret; | |
97 | ||
98 | rtc = dev_get_drvdata(dev); | |
99 | ||
100 | ret = regmap_read(rtc->regmap, CPCAP_REG_TOD2, &temp_tod2); | |
101 | ret |= regmap_read(rtc->regmap, CPCAP_REG_DAY, &cpcap_tm.day); | |
102 | ret |= regmap_read(rtc->regmap, CPCAP_REG_TOD1, &cpcap_tm.tod1); | |
103 | ret |= regmap_read(rtc->regmap, CPCAP_REG_TOD2, &cpcap_tm.tod2); | |
104 | ||
105 | if (temp_tod2 > cpcap_tm.tod2) | |
106 | ret |= regmap_read(rtc->regmap, CPCAP_REG_DAY, &cpcap_tm.day); | |
107 | ||
108 | if (ret) { | |
109 | dev_err(dev, "Failed to read time\n"); | |
110 | return -EIO; | |
111 | } | |
112 | ||
113 | cpcap2rtc_time(tm, &cpcap_tm); | |
114 | ||
35a21123 | 115 | return 0; |
dd3bf50b SR |
116 | } |
117 | ||
118 | static int cpcap_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
119 | { | |
120 | struct cpcap_rtc *rtc; | |
121 | struct cpcap_time cpcap_tm; | |
122 | int ret = 0; | |
123 | ||
124 | rtc = dev_get_drvdata(dev); | |
125 | ||
126 | rtc2cpcap_time(&cpcap_tm, tm); | |
127 | ||
128 | if (rtc->alarm_enabled) | |
129 | disable_irq(rtc->alarm_irq); | |
130 | if (rtc->update_enabled) | |
131 | disable_irq(rtc->update_irq); | |
132 | ||
133 | if (rtc->vendor == CPCAP_VENDOR_ST) { | |
134 | /* The TOD1 and TOD2 registers MUST be written in this order | |
135 | * for the change to properly set. | |
136 | */ | |
137 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1, | |
138 | TOD1_MASK, cpcap_tm.tod1); | |
139 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD2, | |
140 | TOD2_MASK, cpcap_tm.tod2); | |
141 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_DAY, | |
142 | DAY_MASK, cpcap_tm.day); | |
143 | } else { | |
144 | /* Clearing the upper lower 8 bits of the TOD guarantees that | |
145 | * the upper half of TOD (TOD2) will not increment for 0xFF RTC | |
146 | * ticks (255 seconds). During this time we can safely write | |
147 | * to DAY, TOD2, then TOD1 (in that order) and expect RTC to be | |
148 | * synchronized to the exact time requested upon the final write | |
149 | * to TOD1. | |
150 | */ | |
151 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1, | |
152 | TOD1_MASK, 0); | |
153 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_DAY, | |
154 | DAY_MASK, cpcap_tm.day); | |
155 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD2, | |
156 | TOD2_MASK, cpcap_tm.tod2); | |
157 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1, | |
158 | TOD1_MASK, cpcap_tm.tod1); | |
159 | } | |
160 | ||
161 | if (rtc->update_enabled) | |
162 | enable_irq(rtc->update_irq); | |
163 | if (rtc->alarm_enabled) | |
164 | enable_irq(rtc->alarm_irq); | |
165 | ||
166 | return ret; | |
167 | } | |
168 | ||
169 | static int cpcap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) | |
170 | { | |
171 | struct cpcap_rtc *rtc; | |
172 | struct cpcap_time cpcap_tm; | |
173 | int ret; | |
174 | ||
175 | rtc = dev_get_drvdata(dev); | |
176 | ||
177 | alrm->enabled = rtc->alarm_enabled; | |
178 | ||
179 | ret = regmap_read(rtc->regmap, CPCAP_REG_DAYA, &cpcap_tm.day); | |
180 | ret |= regmap_read(rtc->regmap, CPCAP_REG_TODA2, &cpcap_tm.tod2); | |
181 | ret |= regmap_read(rtc->regmap, CPCAP_REG_TODA1, &cpcap_tm.tod1); | |
182 | ||
183 | if (ret) { | |
184 | dev_err(dev, "Failed to read time\n"); | |
185 | return -EIO; | |
186 | } | |
187 | ||
188 | cpcap2rtc_time(&alrm->time, &cpcap_tm); | |
189 | return rtc_valid_tm(&alrm->time); | |
190 | } | |
191 | ||
192 | static int cpcap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) | |
193 | { | |
194 | struct cpcap_rtc *rtc; | |
195 | struct cpcap_time cpcap_tm; | |
196 | int ret; | |
197 | ||
198 | rtc = dev_get_drvdata(dev); | |
199 | ||
200 | rtc2cpcap_time(&cpcap_tm, &alrm->time); | |
201 | ||
202 | if (rtc->alarm_enabled) | |
203 | disable_irq(rtc->alarm_irq); | |
204 | ||
205 | ret = regmap_update_bits(rtc->regmap, CPCAP_REG_DAYA, DAY_MASK, | |
206 | cpcap_tm.day); | |
207 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TODA2, TOD2_MASK, | |
208 | cpcap_tm.tod2); | |
209 | ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TODA1, TOD1_MASK, | |
210 | cpcap_tm.tod1); | |
211 | ||
212 | if (!ret) { | |
213 | enable_irq(rtc->alarm_irq); | |
214 | rtc->alarm_enabled = true; | |
215 | } | |
216 | ||
217 | return ret; | |
218 | } | |
219 | ||
220 | static const struct rtc_class_ops cpcap_rtc_ops = { | |
221 | .read_time = cpcap_rtc_read_time, | |
222 | .set_time = cpcap_rtc_set_time, | |
223 | .read_alarm = cpcap_rtc_read_alarm, | |
224 | .set_alarm = cpcap_rtc_set_alarm, | |
225 | .alarm_irq_enable = cpcap_rtc_alarm_irq_enable, | |
226 | }; | |
227 | ||
228 | static irqreturn_t cpcap_rtc_alarm_irq(int irq, void *data) | |
229 | { | |
230 | struct cpcap_rtc *rtc = data; | |
231 | ||
232 | rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF); | |
233 | return IRQ_HANDLED; | |
234 | } | |
235 | ||
236 | static irqreturn_t cpcap_rtc_update_irq(int irq, void *data) | |
237 | { | |
238 | struct cpcap_rtc *rtc = data; | |
239 | ||
240 | rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF); | |
241 | return IRQ_HANDLED; | |
242 | } | |
243 | ||
244 | static int cpcap_rtc_probe(struct platform_device *pdev) | |
245 | { | |
246 | struct device *dev = &pdev->dev; | |
247 | struct cpcap_rtc *rtc; | |
248 | int err; | |
249 | ||
250 | rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL); | |
251 | if (!rtc) | |
252 | return -ENOMEM; | |
253 | ||
254 | rtc->regmap = dev_get_regmap(dev->parent, NULL); | |
255 | if (!rtc->regmap) | |
256 | return -ENODEV; | |
257 | ||
258 | platform_set_drvdata(pdev, rtc); | |
05b38d18 | 259 | rtc->rtc_dev = devm_rtc_allocate_device(dev); |
65e9e65c | 260 | if (IS_ERR(rtc->rtc_dev)) |
dd3bf50b | 261 | return PTR_ERR(rtc->rtc_dev); |
dd3bf50b | 262 | |
05b38d18 | 263 | rtc->rtc_dev->ops = &cpcap_rtc_ops; |
3180cfab | 264 | rtc->rtc_dev->range_max = (timeu64_t) (DAY_MASK + 1) * SECS_PER_DAY - 1; |
05b38d18 | 265 | |
dd3bf50b SR |
266 | err = cpcap_get_vendor(dev, rtc->regmap, &rtc->vendor); |
267 | if (err) | |
268 | return err; | |
269 | ||
270 | rtc->alarm_irq = platform_get_irq(pdev, 0); | |
271 | err = devm_request_threaded_irq(dev, rtc->alarm_irq, NULL, | |
bc06cfc1 TT |
272 | cpcap_rtc_alarm_irq, |
273 | IRQF_TRIGGER_NONE | IRQF_ONESHOT, | |
dd3bf50b SR |
274 | "rtc_alarm", rtc); |
275 | if (err) { | |
276 | dev_err(dev, "Could not request alarm irq: %d\n", err); | |
277 | return err; | |
278 | } | |
279 | disable_irq(rtc->alarm_irq); | |
280 | ||
281 | /* Stock Android uses the 1 Hz interrupt for "secure clock daemon", | |
282 | * which is not supported by the mainline kernel. The mainline kernel | |
283 | * does not use the irq at the moment, but we explicitly request and | |
284 | * disable it, so that its masked and does not wake up the processor | |
285 | * every second. | |
286 | */ | |
287 | rtc->update_irq = platform_get_irq(pdev, 1); | |
288 | err = devm_request_threaded_irq(dev, rtc->update_irq, NULL, | |
bc06cfc1 TT |
289 | cpcap_rtc_update_irq, |
290 | IRQF_TRIGGER_NONE | IRQF_ONESHOT, | |
dd3bf50b SR |
291 | "rtc_1hz", rtc); |
292 | if (err) { | |
293 | dev_err(dev, "Could not request update irq: %d\n", err); | |
294 | return err; | |
295 | } | |
296 | disable_irq(rtc->update_irq); | |
297 | ||
298 | err = device_init_wakeup(dev, 1); | |
299 | if (err) { | |
300 | dev_err(dev, "wakeup initialization failed (%d)\n", err); | |
301 | /* ignore error and continue without wakeup support */ | |
302 | } | |
303 | ||
fdcfd854 | 304 | return devm_rtc_register_device(rtc->rtc_dev); |
dd3bf50b SR |
305 | } |
306 | ||
307 | static const struct of_device_id cpcap_rtc_of_match[] = { | |
308 | { .compatible = "motorola,cpcap-rtc", }, | |
309 | {}, | |
310 | }; | |
311 | MODULE_DEVICE_TABLE(of, cpcap_rtc_of_match); | |
312 | ||
313 | static struct platform_driver cpcap_rtc_driver = { | |
314 | .probe = cpcap_rtc_probe, | |
315 | .driver = { | |
316 | .name = "cpcap-rtc", | |
317 | .of_match_table = cpcap_rtc_of_match, | |
318 | }, | |
319 | }; | |
320 | ||
321 | module_platform_driver(cpcap_rtc_driver); | |
322 | ||
323 | MODULE_ALIAS("platform:cpcap-rtc"); | |
324 | MODULE_DESCRIPTION("CPCAP RTC driver"); | |
325 | MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>"); | |
326 | MODULE_LICENSE("GPL"); |