1/*
2 * rtc-as3722.c - Real Time Clock driver for ams AS3722 PMICs
3 *
4 * Copyright (C) 2013 ams AG
5 * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
6 *
7 * Author: Florian Lobmaier <florian.lobmaier@ams.com>
8 * Author: Laxman Dewangan <ldewangan@nvidia.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 */
20
21#include <linux/bcd.h>
22#include <linux/completion.h>
23#include <linux/delay.h>
24#include <linux/interrupt.h>
25#include <linux/ioctl.h>
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/mfd/as3722.h>
29#include <linux/platform_device.h>
30#include <linux/rtc.h>
31#include <linux/time.h>
32
33#define AS3722_RTC_START_YEAR	  2000
34struct as3722_rtc {
35	struct rtc_device	*rtc;
36	struct device		*dev;
37	struct as3722		*as3722;
38	int			alarm_irq;
39	bool			irq_enable;
40};
41
42static void as3722_time_to_reg(u8 *rbuff, struct rtc_time *tm)
43{
44	rbuff[0] = bin2bcd(tm->tm_sec);
45	rbuff[1] = bin2bcd(tm->tm_min);
46	rbuff[2] = bin2bcd(tm->tm_hour);
47	rbuff[3] = bin2bcd(tm->tm_mday);
48	rbuff[4] = bin2bcd(tm->tm_mon);
49	rbuff[5] = bin2bcd(tm->tm_year - (AS3722_RTC_START_YEAR - 1900));
50}
51
52static void as3722_reg_to_time(u8 *rbuff, struct rtc_time *tm)
53{
54	tm->tm_sec = bcd2bin(rbuff[0] & 0x7F);
55	tm->tm_min = bcd2bin(rbuff[1] & 0x7F);
56	tm->tm_hour = bcd2bin(rbuff[2] & 0x3F);
57	tm->tm_mday = bcd2bin(rbuff[3] & 0x3F);
58	tm->tm_mon = bcd2bin(rbuff[4] & 0x1F);
59	tm->tm_year = (AS3722_RTC_START_YEAR - 1900) + bcd2bin(rbuff[5] & 0x7F);
60	return;
61}
62
63static int as3722_rtc_read_time(struct device *dev, struct rtc_time *tm)
64{
65	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
66	struct as3722 *as3722 = as3722_rtc->as3722;
67	u8 as_time_array[6];
68	int ret;
69
70	ret = as3722_block_read(as3722, AS3722_RTC_SECOND_REG,
71			6, as_time_array);
72	if (ret < 0) {
73		dev_err(dev, "RTC_SECOND reg block read failed %d\n", ret);
74		return ret;
75	}
76	as3722_reg_to_time(as_time_array, tm);
77	return 0;
78}
79
80static int as3722_rtc_set_time(struct device *dev, struct rtc_time *tm)
81{
82	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
83	struct as3722 *as3722 = as3722_rtc->as3722;
84	u8 as_time_array[6];
85	int ret;
86
87	if (tm->tm_year < (AS3722_RTC_START_YEAR - 1900))
88		return -EINVAL;
89
90	as3722_time_to_reg(as_time_array, tm);
91	ret = as3722_block_write(as3722, AS3722_RTC_SECOND_REG, 6,
92			as_time_array);
93	if (ret < 0)
94		dev_err(dev, "RTC_SECOND reg block write failed %d\n", ret);
95	return ret;
96}
97
98static int as3722_rtc_alarm_irq_enable(struct device *dev,
99		unsigned int enabled)
100{
101	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
102
103	if (enabled && !as3722_rtc->irq_enable) {
104		enable_irq(as3722_rtc->alarm_irq);
105		as3722_rtc->irq_enable = true;
106	} else if (!enabled && as3722_rtc->irq_enable)  {
107		disable_irq(as3722_rtc->alarm_irq);
108		as3722_rtc->irq_enable = false;
109	}
110	return 0;
111}
112
113static int as3722_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
114{
115	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
116	struct as3722 *as3722 = as3722_rtc->as3722;
117	u8 as_time_array[6];
118	int ret;
119
120	ret = as3722_block_read(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
121			as_time_array);
122	if (ret < 0) {
123		dev_err(dev, "RTC_ALARM_SECOND block read failed %d\n", ret);
124		return ret;
125	}
126
127	as3722_reg_to_time(as_time_array, &alrm->time);
128	return 0;
129}
130
131static int as3722_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
132{
133	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
134	struct as3722 *as3722 = as3722_rtc->as3722;
135	u8 as_time_array[6];
136	int ret;
137
138	if (alrm->time.tm_year < (AS3722_RTC_START_YEAR - 1900))
139		return -EINVAL;
140
141	ret = as3722_rtc_alarm_irq_enable(dev, 0);
142	if (ret < 0) {
143		dev_err(dev, "Disable RTC alarm failed\n");
144		return ret;
145	}
146
147	as3722_time_to_reg(as_time_array, &alrm->time);
148	ret = as3722_block_write(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
149			as_time_array);
150	if (ret < 0) {
151		dev_err(dev, "RTC_ALARM_SECOND block write failed %d\n", ret);
152		return ret;
153	}
154
155	if (alrm->enabled)
156		ret = as3722_rtc_alarm_irq_enable(dev, alrm->enabled);
157	return ret;
158}
159
160static irqreturn_t as3722_alarm_irq(int irq, void *data)
161{
162	struct as3722_rtc *as3722_rtc = data;
163
164	rtc_update_irq(as3722_rtc->rtc, 1, RTC_IRQF | RTC_AF);
165	return IRQ_HANDLED;
166}
167
168static const struct rtc_class_ops as3722_rtc_ops = {
169	.read_time = as3722_rtc_read_time,
170	.set_time = as3722_rtc_set_time,
171	.read_alarm = as3722_rtc_read_alarm,
172	.set_alarm = as3722_rtc_set_alarm,
173	.alarm_irq_enable = as3722_rtc_alarm_irq_enable,
174};
175
176static int as3722_rtc_probe(struct platform_device *pdev)
177{
178	struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
179	struct as3722_rtc *as3722_rtc;
180	int ret;
181
182	as3722_rtc = devm_kzalloc(&pdev->dev, sizeof(*as3722_rtc), GFP_KERNEL);
183	if (!as3722_rtc)
184		return -ENOMEM;
185
186	as3722_rtc->as3722 = as3722;
187	as3722_rtc->dev = &pdev->dev;
188	platform_set_drvdata(pdev, as3722_rtc);
189
190	/* Enable the RTC to make sure it is running. */
191	ret = as3722_update_bits(as3722, AS3722_RTC_CONTROL_REG,
192			AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN,
193			AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN);
194	if (ret < 0) {
195		dev_err(&pdev->dev, "RTC_CONTROL reg write failed: %d\n", ret);
196		return ret;
197	}
198
199	device_init_wakeup(&pdev->dev, 1);
200
201	as3722_rtc->rtc = devm_rtc_device_register(&pdev->dev, "as3722-rtc",
202				&as3722_rtc_ops, THIS_MODULE);
203	if (IS_ERR(as3722_rtc->rtc)) {
204		ret = PTR_ERR(as3722_rtc->rtc);
205		dev_err(&pdev->dev, "RTC register failed: %d\n", ret);
206		return ret;
207	}
208
209	as3722_rtc->alarm_irq = platform_get_irq(pdev, 0);
210	dev_info(&pdev->dev, "RTC interrupt %d\n", as3722_rtc->alarm_irq);
211
212	ret = devm_request_threaded_irq(&pdev->dev, as3722_rtc->alarm_irq, NULL,
213			as3722_alarm_irq, IRQF_ONESHOT | IRQF_EARLY_RESUME,
214			"rtc-alarm", as3722_rtc);
215	if (ret < 0) {
216		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
217				as3722_rtc->alarm_irq, ret);
218		return ret;
219	}
220	disable_irq(as3722_rtc->alarm_irq);
221	return 0;
222}
223
224#ifdef CONFIG_PM_SLEEP
225static int as3722_rtc_suspend(struct device *dev)
226{
227	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
228
229	if (device_may_wakeup(dev))
230		enable_irq_wake(as3722_rtc->alarm_irq);
231
232	return 0;
233}
234
235static int as3722_rtc_resume(struct device *dev)
236{
237	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
238
239	if (device_may_wakeup(dev))
240		disable_irq_wake(as3722_rtc->alarm_irq);
241	return 0;
242}
243#endif
244
245static SIMPLE_DEV_PM_OPS(as3722_rtc_pm_ops, as3722_rtc_suspend,
246			 as3722_rtc_resume);
247
248static struct platform_driver as3722_rtc_driver = {
249	.probe = as3722_rtc_probe,
250	.driver = {
251		.name = "as3722-rtc",
252		.pm = &as3722_rtc_pm_ops,
253	},
254};
255module_platform_driver(as3722_rtc_driver);
256
257MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");
258MODULE_ALIAS("platform:as3722-rtc");
259MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
260MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
261MODULE_LICENSE("GPL");
262