1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * rtc-as3722.c - Real Time Clock driver for ams AS3722 PMICs
4 *
5 * Copyright (C) 2013 ams AG
6 * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
7 *
8 * Author: Florian Lobmaier <florian.lobmaier@ams.com>
9 * Author: Laxman Dewangan <ldewangan@nvidia.com>
10 */
11
12#include <linux/bcd.h>
13#include <linux/completion.h>
14#include <linux/delay.h>
15#include <linux/interrupt.h>
16#include <linux/ioctl.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/mfd/as3722.h>
20#include <linux/platform_device.h>
21#include <linux/rtc.h>
22#include <linux/time.h>
23
24#define AS3722_RTC_START_YEAR	  2000
25struct as3722_rtc {
26	struct rtc_device	*rtc;
27	struct device		*dev;
28	struct as3722		*as3722;
29	int			alarm_irq;
30	bool			irq_enable;
31};
32
33static void as3722_time_to_reg(u8 *rbuff, struct rtc_time *tm)
34{
35	rbuff[0] = bin2bcd(tm->tm_sec);
36	rbuff[1] = bin2bcd(tm->tm_min);
37	rbuff[2] = bin2bcd(tm->tm_hour);
38	rbuff[3] = bin2bcd(tm->tm_mday);
39	rbuff[4] = bin2bcd(tm->tm_mon + 1);
40	rbuff[5] = bin2bcd(tm->tm_year - (AS3722_RTC_START_YEAR - 1900));
41}
42
43static void as3722_reg_to_time(u8 *rbuff, struct rtc_time *tm)
44{
45	tm->tm_sec = bcd2bin(rbuff[0] & 0x7F);
46	tm->tm_min = bcd2bin(rbuff[1] & 0x7F);
47	tm->tm_hour = bcd2bin(rbuff[2] & 0x3F);
48	tm->tm_mday = bcd2bin(rbuff[3] & 0x3F);
49	tm->tm_mon = bcd2bin(rbuff[4] & 0x1F) - 1;
50	tm->tm_year = (AS3722_RTC_START_YEAR - 1900) + bcd2bin(rbuff[5] & 0x7F);
51	return;
52}
53
54static int as3722_rtc_read_time(struct device *dev, struct rtc_time *tm)
55{
56	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
57	struct as3722 *as3722 = as3722_rtc->as3722;
58	u8 as_time_array[6];
59	int ret;
60
61	ret = as3722_block_read(as3722, AS3722_RTC_SECOND_REG,
62			6, as_time_array);
63	if (ret < 0) {
64		dev_err(dev, "RTC_SECOND reg block read failed %d\n", ret);
65		return ret;
66	}
67	as3722_reg_to_time(as_time_array, tm);
68	return 0;
69}
70
71static int as3722_rtc_set_time(struct device *dev, struct rtc_time *tm)
72{
73	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
74	struct as3722 *as3722 = as3722_rtc->as3722;
75	u8 as_time_array[6];
76	int ret;
77
78	if (tm->tm_year < (AS3722_RTC_START_YEAR - 1900))
79		return -EINVAL;
80
81	as3722_time_to_reg(as_time_array, tm);
82	ret = as3722_block_write(as3722, AS3722_RTC_SECOND_REG, 6,
83			as_time_array);
84	if (ret < 0)
85		dev_err(dev, "RTC_SECOND reg block write failed %d\n", ret);
86	return ret;
87}
88
89static int as3722_rtc_alarm_irq_enable(struct device *dev,
90		unsigned int enabled)
91{
92	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
93
94	if (enabled && !as3722_rtc->irq_enable) {
95		enable_irq(as3722_rtc->alarm_irq);
96		as3722_rtc->irq_enable = true;
97	} else if (!enabled && as3722_rtc->irq_enable)  {
98		disable_irq(as3722_rtc->alarm_irq);
99		as3722_rtc->irq_enable = false;
100	}
101	return 0;
102}
103
104static int as3722_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
105{
106	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
107	struct as3722 *as3722 = as3722_rtc->as3722;
108	u8 as_time_array[6];
109	int ret;
110
111	ret = as3722_block_read(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
112			as_time_array);
113	if (ret < 0) {
114		dev_err(dev, "RTC_ALARM_SECOND block read failed %d\n", ret);
115		return ret;
116	}
117
118	as3722_reg_to_time(as_time_array, &alrm->time);
119	return 0;
120}
121
122static int as3722_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
123{
124	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
125	struct as3722 *as3722 = as3722_rtc->as3722;
126	u8 as_time_array[6];
127	int ret;
128
129	if (alrm->time.tm_year < (AS3722_RTC_START_YEAR - 1900))
130		return -EINVAL;
131
132	ret = as3722_rtc_alarm_irq_enable(dev, 0);
133	if (ret < 0) {
134		dev_err(dev, "Disable RTC alarm failed\n");
135		return ret;
136	}
137
138	as3722_time_to_reg(as_time_array, &alrm->time);
139	ret = as3722_block_write(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
140			as_time_array);
141	if (ret < 0) {
142		dev_err(dev, "RTC_ALARM_SECOND block write failed %d\n", ret);
143		return ret;
144	}
145
146	if (alrm->enabled)
147		ret = as3722_rtc_alarm_irq_enable(dev, alrm->enabled);
148	return ret;
149}
150
151static irqreturn_t as3722_alarm_irq(int irq, void *data)
152{
153	struct as3722_rtc *as3722_rtc = data;
154
155	rtc_update_irq(as3722_rtc->rtc, 1, RTC_IRQF | RTC_AF);
156	return IRQ_HANDLED;
157}
158
159static const struct rtc_class_ops as3722_rtc_ops = {
160	.read_time = as3722_rtc_read_time,
161	.set_time = as3722_rtc_set_time,
162	.read_alarm = as3722_rtc_read_alarm,
163	.set_alarm = as3722_rtc_set_alarm,
164	.alarm_irq_enable = as3722_rtc_alarm_irq_enable,
165};
166
167static int as3722_rtc_probe(struct platform_device *pdev)
168{
169	struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
170	struct as3722_rtc *as3722_rtc;
171	int ret;
172
173	as3722_rtc = devm_kzalloc(&pdev->dev, sizeof(*as3722_rtc), GFP_KERNEL);
174	if (!as3722_rtc)
175		return -ENOMEM;
176
177	as3722_rtc->as3722 = as3722;
178	as3722_rtc->dev = &pdev->dev;
179	platform_set_drvdata(pdev, as3722_rtc);
180
181	/* Enable the RTC to make sure it is running. */
182	ret = as3722_update_bits(as3722, AS3722_RTC_CONTROL_REG,
183			AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN,
184			AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN);
185	if (ret < 0) {
186		dev_err(&pdev->dev, "RTC_CONTROL reg write failed: %d\n", ret);
187		return ret;
188	}
189
190	device_init_wakeup(&pdev->dev, 1);
191
192	as3722_rtc->rtc = devm_rtc_device_register(&pdev->dev, "as3722-rtc",
193				&as3722_rtc_ops, THIS_MODULE);
194	if (IS_ERR(as3722_rtc->rtc)) {
195		ret = PTR_ERR(as3722_rtc->rtc);
196		dev_err(&pdev->dev, "RTC register failed: %d\n", ret);
197		return ret;
198	}
199
200	as3722_rtc->alarm_irq = platform_get_irq(pdev, 0);
201	dev_info(&pdev->dev, "RTC interrupt %d\n", as3722_rtc->alarm_irq);
202
203	ret = devm_request_threaded_irq(&pdev->dev, as3722_rtc->alarm_irq, NULL,
204			as3722_alarm_irq, IRQF_ONESHOT,
205			"rtc-alarm", as3722_rtc);
206	if (ret < 0) {
207		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
208				as3722_rtc->alarm_irq, ret);
209		return ret;
210	}
211	disable_irq(as3722_rtc->alarm_irq);
212	return 0;
213}
214
215#ifdef CONFIG_PM_SLEEP
216static int as3722_rtc_suspend(struct device *dev)
217{
218	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
219
220	if (device_may_wakeup(dev))
221		enable_irq_wake(as3722_rtc->alarm_irq);
222
223	return 0;
224}
225
226static int as3722_rtc_resume(struct device *dev)
227{
228	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
229
230	if (device_may_wakeup(dev))
231		disable_irq_wake(as3722_rtc->alarm_irq);
232	return 0;
233}
234#endif
235
236static SIMPLE_DEV_PM_OPS(as3722_rtc_pm_ops, as3722_rtc_suspend,
237			 as3722_rtc_resume);
238
239static struct platform_driver as3722_rtc_driver = {
240	.probe = as3722_rtc_probe,
241	.driver = {
242		.name = "as3722-rtc",
243		.pm = &as3722_rtc_pm_ops,
244	},
245};
246module_platform_driver(as3722_rtc_driver);
247
248MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");
249MODULE_ALIAS("platform:as3722-rtc");
250MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
251MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
252MODULE_LICENSE("GPL");
253