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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * rtc-palmas.c -- Palmas Real Time Clock driver.
4
5 * RTC driver for TI Palma series devices like TPS65913,
6 * TPS65914 power management IC.
7 *
8 * Copyright (c) 2012, NVIDIA Corporation.
9 *
10 * Author: Laxman Dewangan <[email protected]>
11 */
12
13#include <linux/bcd.h>
14#include <linux/errno.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/kernel.h>
18#include <linux/mfd/palmas.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/rtc.h>
22#include <linux/types.h>
23#include <linux/platform_device.h>
24#include <linux/pm.h>
25
26struct palmas_rtc {
27 struct rtc_device *rtc;
28 struct device *dev;
29 unsigned int irq;
30};
31
32/* Total number of RTC registers needed to set time*/
33#define PALMAS_NUM_TIME_REGS (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
34
35static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
36{
37 unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
38 struct palmas *palmas = dev_get_drvdata(dev->parent);
39 int ret;
40
41 /* Copy RTC counting registers to static registers or latches */
42 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
43 PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
44 if (ret < 0) {
45 dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
46 return ret;
47 }
48
49 ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
50 rtc_data, PALMAS_NUM_TIME_REGS);
51 if (ret < 0) {
52 dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
53 return ret;
54 }
55
56 tm->tm_sec = bcd2bin(rtc_data[0]);
57 tm->tm_min = bcd2bin(rtc_data[1]);
58 tm->tm_hour = bcd2bin(rtc_data[2]);
59 tm->tm_mday = bcd2bin(rtc_data[3]);
60 tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
61 tm->tm_year = bcd2bin(rtc_data[5]) + 100;
62
63 return ret;
64}
65
66static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
67{
68 unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
69 struct palmas *palmas = dev_get_drvdata(dev->parent);
70 int ret;
71
72 rtc_data[0] = bin2bcd(tm->tm_sec);
73 rtc_data[1] = bin2bcd(tm->tm_min);
74 rtc_data[2] = bin2bcd(tm->tm_hour);
75 rtc_data[3] = bin2bcd(tm->tm_mday);
76 rtc_data[4] = bin2bcd(tm->tm_mon + 1);
77 rtc_data[5] = bin2bcd(tm->tm_year - 100);
78
79 /* Stop RTC while updating the RTC time registers */
80 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
81 PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
82 if (ret < 0) {
83 dev_err(dev, "RTC stop failed, err = %d\n", ret);
84 return ret;
85 }
86
87 ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
88 rtc_data, PALMAS_NUM_TIME_REGS);
89 if (ret < 0) {
90 dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
91 return ret;
92 }
93
94 /* Start back RTC */
95 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
96 PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
97 if (ret < 0)
98 dev_err(dev, "RTC start failed, err = %d\n", ret);
99 return ret;
100}
101
102static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
103{
104 struct palmas *palmas = dev_get_drvdata(dev->parent);
105 u8 val;
106
107 val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
108 return palmas_write(palmas, PALMAS_RTC_BASE,
109 PALMAS_RTC_INTERRUPTS_REG, val);
110}
111
112static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
113{
114 unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
115 u32 int_val;
116 struct palmas *palmas = dev_get_drvdata(dev->parent);
117 int ret;
118
119 ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
120 PALMAS_ALARM_SECONDS_REG,
121 alarm_data, PALMAS_NUM_TIME_REGS);
122 if (ret < 0) {
123 dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
124 return ret;
125 }
126
127 alm->time.tm_sec = bcd2bin(alarm_data[0]);
128 alm->time.tm_min = bcd2bin(alarm_data[1]);
129 alm->time.tm_hour = bcd2bin(alarm_data[2]);
130 alm->time.tm_mday = bcd2bin(alarm_data[3]);
131 alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
132 alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
133
134 ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
135 &int_val);
136 if (ret < 0) {
137 dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
138 return ret;
139 }
140
141 if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
142 alm->enabled = 1;
143 return ret;
144}
145
146static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
147{
148 unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
149 struct palmas *palmas = dev_get_drvdata(dev->parent);
150 int ret;
151
152 ret = palmas_rtc_alarm_irq_enable(dev, 0);
153 if (ret < 0) {
154 dev_err(dev, "Disable RTC alarm failed\n");
155 return ret;
156 }
157
158 alarm_data[0] = bin2bcd(alm->time.tm_sec);
159 alarm_data[1] = bin2bcd(alm->time.tm_min);
160 alarm_data[2] = bin2bcd(alm->time.tm_hour);
161 alarm_data[3] = bin2bcd(alm->time.tm_mday);
162 alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
163 alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
164
165 ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
166 PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
167 if (ret < 0) {
168 dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
169 return ret;
170 }
171
172 if (alm->enabled)
173 ret = palmas_rtc_alarm_irq_enable(dev, 1);
174 return ret;
175}
176
177static int palmas_clear_interrupts(struct device *dev)
178{
179 struct palmas *palmas = dev_get_drvdata(dev->parent);
180 unsigned int rtc_reg;
181 int ret;
182
183 ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
184 &rtc_reg);
185 if (ret < 0) {
186 dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
187 return ret;
188 }
189
190 ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
191 rtc_reg);
192 if (ret < 0) {
193 dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
194 return ret;
195 }
196 return 0;
197}
198
199static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
200{
201 struct palmas_rtc *palmas_rtc = context;
202 struct device *dev = palmas_rtc->dev;
203 int ret;
204
205 ret = palmas_clear_interrupts(dev);
206 if (ret < 0) {
207 dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
208 return IRQ_NONE;
209 }
210
211 rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
212 return IRQ_HANDLED;
213}
214
215static const struct rtc_class_ops palmas_rtc_ops = {
216 .read_time = palmas_rtc_read_time,
217 .set_time = palmas_rtc_set_time,
218 .read_alarm = palmas_rtc_read_alarm,
219 .set_alarm = palmas_rtc_set_alarm,
220 .alarm_irq_enable = palmas_rtc_alarm_irq_enable,
221};
222
223static int palmas_rtc_probe(struct platform_device *pdev)
224{
225 struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
226 struct palmas_rtc *palmas_rtc = NULL;
227 int ret;
228 bool enable_bb_charging = false;
229 bool high_bb_charging = false;
230
231 if (pdev->dev.of_node) {
232 enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
233 "ti,backup-battery-chargeable");
234 high_bb_charging = of_property_read_bool(pdev->dev.of_node,
235 "ti,backup-battery-charge-high-current");
236 }
237
238 palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
239 GFP_KERNEL);
240 if (!palmas_rtc)
241 return -ENOMEM;
242
243 /* Clear pending interrupts */
244 ret = palmas_clear_interrupts(&pdev->dev);
245 if (ret < 0) {
246 dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
247 return ret;
248 }
249
250 palmas_rtc->dev = &pdev->dev;
251 platform_set_drvdata(pdev, palmas_rtc);
252
253 if (enable_bb_charging) {
254 unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
255
256 if (high_bb_charging)
257 reg = 0;
258
259 ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
260 PALMAS_BACKUP_BATTERY_CTRL,
261 PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
262 if (ret < 0) {
263 dev_err(&pdev->dev,
264 "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
265 return ret;
266 }
267
268 ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
269 PALMAS_BACKUP_BATTERY_CTRL,
270 PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
271 PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
272 if (ret < 0) {
273 dev_err(&pdev->dev,
274 "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
275 return ret;
276 }
277 }
278
279 /* Start RTC */
280 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
281 PALMAS_RTC_CTRL_REG_STOP_RTC,
282 PALMAS_RTC_CTRL_REG_STOP_RTC);
283 if (ret < 0) {
284 dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
285 return ret;
286 }
287
288 palmas_rtc->irq = platform_get_irq(pdev, 0);
289
290 device_init_wakeup(&pdev->dev, true);
291 palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
292 &palmas_rtc_ops, THIS_MODULE);
293 if (IS_ERR(palmas_rtc->rtc)) {
294 ret = PTR_ERR(palmas_rtc->rtc);
295 dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
296 return ret;
297 }
298
299 ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
300 palmas_rtc_interrupt,
301 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
302 dev_name(&pdev->dev), palmas_rtc);
303 if (ret < 0) {
304 dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
305 return ret;
306 }
307
308 return 0;
309}
310
311static void palmas_rtc_remove(struct platform_device *pdev)
312{
313 palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
314}
315
316#ifdef CONFIG_PM_SLEEP
317static int palmas_rtc_suspend(struct device *dev)
318{
319 struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
320
321 if (device_may_wakeup(dev))
322 enable_irq_wake(palmas_rtc->irq);
323 return 0;
324}
325
326static int palmas_rtc_resume(struct device *dev)
327{
328 struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
329
330 if (device_may_wakeup(dev))
331 disable_irq_wake(palmas_rtc->irq);
332 return 0;
333}
334#endif
335
336static SIMPLE_DEV_PM_OPS(palmas_rtc_pm_ops, palmas_rtc_suspend,
337 palmas_rtc_resume);
338
339#ifdef CONFIG_OF
340static const struct of_device_id of_palmas_rtc_match[] = {
341 { .compatible = "ti,palmas-rtc"},
342 { },
343};
344MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
345#endif
346
347static struct platform_driver palmas_rtc_driver = {
348 .probe = palmas_rtc_probe,
349 .remove = palmas_rtc_remove,
350 .driver = {
351 .name = "palmas-rtc",
352 .pm = &palmas_rtc_pm_ops,
353 .of_match_table = of_match_ptr(of_palmas_rtc_match),
354 },
355};
356
357module_platform_driver(palmas_rtc_driver);
358
359MODULE_ALIAS("platform:palmas_rtc");
360MODULE_DESCRIPTION("TI PALMAS series RTC driver");
361MODULE_AUTHOR("Laxman Dewangan <[email protected]>");
362MODULE_LICENSE("GPL v2");