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 <ldewangan@nvidia.com>
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, 1);
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_new	= 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 <ldewangan@nvidia.com>");
362MODULE_LICENSE("GPL v2");
363