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
25 struct 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 
as3722_time_to_reg(u8 * rbuff,struct rtc_time * tm)33 static 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 
as3722_reg_to_time(u8 * rbuff,struct rtc_time * tm)43 static 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 
as3722_rtc_read_time(struct device * dev,struct rtc_time * tm)54 static 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 
as3722_rtc_set_time(struct device * dev,struct rtc_time * tm)71 static 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 
as3722_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)89 static 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 
as3722_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)104 static 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 
as3722_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)122 static 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 
as3722_alarm_irq(int irq,void * data)151 static 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 
159 static 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 
as3722_rtc_probe(struct platform_device * pdev)167 static 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
as3722_rtc_suspend(struct device * dev)216 static 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 
as3722_rtc_resume(struct device * dev)226 static 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 
236 static SIMPLE_DEV_PM_OPS(as3722_rtc_pm_ops, as3722_rtc_suspend,
237 			 as3722_rtc_resume);
238 
239 static 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 };
246 module_platform_driver(as3722_rtc_driver);
247 
248 MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");
249 MODULE_ALIAS("platform:as3722-rtc");
250 MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
251 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
252 MODULE_LICENSE("GPL");
253