xref: /openbmc/linux/drivers/rtc/rtc-rc5t583.c (revision ade527dd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * rtc-rc5t583.c -- RICOH RC5T583 Real Time Clock
4  *
5  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
6  * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
16 #include <linux/platform_device.h>
17 #include <linux/interrupt.h>
18 #include <linux/mfd/rc5t583.h>
19 
20 struct rc5t583_rtc {
21 	struct rtc_device	*rtc;
22 	/* To store the list of enabled interrupts, during system suspend */
23 	u32 irqen;
24 };
25 
26 /* Total number of RTC registers needed to set time*/
27 #define NUM_TIME_REGS	(RC5T583_RTC_YEAR - RC5T583_RTC_SEC + 1)
28 
29 /* Total number of RTC registers needed to set Y-Alarm*/
30 #define NUM_YAL_REGS	(RC5T583_RTC_AY_YEAR - RC5T583_RTC_AY_MIN + 1)
31 
32 /* Set Y-Alarm interrupt */
33 #define SET_YAL BIT(5)
34 
35 /* Get Y-Alarm interrupt status*/
36 #define GET_YAL_STATUS BIT(3)
37 
rc5t583_rtc_alarm_irq_enable(struct device * dev,unsigned enabled)38 static int rc5t583_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
39 {
40 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
41 	u8 val;
42 
43 	/* Set Y-Alarm, based on 'enabled' */
44 	val = enabled ? SET_YAL : 0;
45 
46 	return regmap_update_bits(rc5t583->regmap, RC5T583_RTC_CTL1, SET_YAL,
47 		val);
48 }
49 
50 /*
51  * Gets current rc5t583 RTC time and date parameters.
52  *
53  * The RTC's time/alarm representation is not what gmtime(3) requires
54  * Linux to use:
55  *
56  *  - Months are 1..12 vs Linux 0-11
57  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
58  */
rc5t583_rtc_read_time(struct device * dev,struct rtc_time * tm)59 static int rc5t583_rtc_read_time(struct device *dev, struct rtc_time *tm)
60 {
61 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
62 	u8 rtc_data[NUM_TIME_REGS];
63 	int ret;
64 
65 	ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
66 		NUM_TIME_REGS);
67 	if (ret < 0) {
68 		dev_err(dev, "RTC read time failed with err:%d\n", ret);
69 		return ret;
70 	}
71 
72 	tm->tm_sec = bcd2bin(rtc_data[0]);
73 	tm->tm_min = bcd2bin(rtc_data[1]);
74 	tm->tm_hour = bcd2bin(rtc_data[2]);
75 	tm->tm_wday = bcd2bin(rtc_data[3]);
76 	tm->tm_mday = bcd2bin(rtc_data[4]);
77 	tm->tm_mon = bcd2bin(rtc_data[5]) - 1;
78 	tm->tm_year = bcd2bin(rtc_data[6]) + 100;
79 
80 	return ret;
81 }
82 
rc5t583_rtc_set_time(struct device * dev,struct rtc_time * tm)83 static int rc5t583_rtc_set_time(struct device *dev, struct rtc_time *tm)
84 {
85 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
86 	unsigned char rtc_data[NUM_TIME_REGS];
87 	int ret;
88 
89 	rtc_data[0] = bin2bcd(tm->tm_sec);
90 	rtc_data[1] = bin2bcd(tm->tm_min);
91 	rtc_data[2] = bin2bcd(tm->tm_hour);
92 	rtc_data[3] = bin2bcd(tm->tm_wday);
93 	rtc_data[4] = bin2bcd(tm->tm_mday);
94 	rtc_data[5] = bin2bcd(tm->tm_mon + 1);
95 	rtc_data[6] = bin2bcd(tm->tm_year - 100);
96 
97 	ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
98 		NUM_TIME_REGS);
99 	if (ret < 0) {
100 		dev_err(dev, "RTC set time failed with error %d\n", ret);
101 		return ret;
102 	}
103 
104 	return ret;
105 }
106 
rc5t583_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)107 static int rc5t583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
108 {
109 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
110 	unsigned char alarm_data[NUM_YAL_REGS];
111 	u32 interrupt_enable;
112 	int ret;
113 
114 	ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data,
115 		NUM_YAL_REGS);
116 	if (ret < 0) {
117 		dev_err(dev, "rtc_read_alarm error %d\n", ret);
118 		return ret;
119 	}
120 
121 	alm->time.tm_sec = 0;
122 	alm->time.tm_min = bcd2bin(alarm_data[0]);
123 	alm->time.tm_hour = bcd2bin(alarm_data[1]);
124 	alm->time.tm_mday = bcd2bin(alarm_data[2]);
125 	alm->time.tm_mon = bcd2bin(alarm_data[3]) - 1;
126 	alm->time.tm_year = bcd2bin(alarm_data[4]) + 100;
127 
128 	ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1, &interrupt_enable);
129 	if (ret < 0)
130 		return ret;
131 
132 	/* check if YALE is set */
133 	if (interrupt_enable & SET_YAL)
134 		alm->enabled = 1;
135 
136 	return ret;
137 }
138 
rc5t583_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)139 static int rc5t583_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
140 {
141 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
142 	unsigned char alarm_data[NUM_YAL_REGS];
143 	int ret;
144 
145 	ret = rc5t583_rtc_alarm_irq_enable(dev, 0);
146 	if (ret)
147 		return ret;
148 
149 	alarm_data[0] = bin2bcd(alm->time.tm_min);
150 	alarm_data[1] = bin2bcd(alm->time.tm_hour);
151 	alarm_data[2] = bin2bcd(alm->time.tm_mday);
152 	alarm_data[3] = bin2bcd(alm->time.tm_mon + 1);
153 	alarm_data[4] = bin2bcd(alm->time.tm_year - 100);
154 
155 	ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data,
156 		NUM_YAL_REGS);
157 	if (ret) {
158 		dev_err(dev, "rtc_set_alarm error %d\n", ret);
159 		return ret;
160 	}
161 
162 	if (alm->enabled)
163 		ret = rc5t583_rtc_alarm_irq_enable(dev, 1);
164 
165 	return ret;
166 }
167 
rc5t583_rtc_interrupt(int irq,void * rtc)168 static irqreturn_t rc5t583_rtc_interrupt(int irq, void *rtc)
169 {
170 	struct device *dev = rtc;
171 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
172 	struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
173 	unsigned long events = 0;
174 	int ret;
175 	u32 rtc_reg;
176 
177 	ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL2, &rtc_reg);
178 	if (ret < 0)
179 		return IRQ_NONE;
180 
181 	if (rtc_reg & GET_YAL_STATUS) {
182 		events = RTC_IRQF | RTC_AF;
183 		/* clear pending Y-alarm interrupt bit */
184 		rtc_reg &= ~GET_YAL_STATUS;
185 	}
186 
187 	ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, rtc_reg);
188 	if (ret)
189 		return IRQ_NONE;
190 
191 	/* Notify RTC core on event */
192 	rtc_update_irq(rc5t583_rtc->rtc, 1, events);
193 
194 	return IRQ_HANDLED;
195 }
196 
197 static const struct rtc_class_ops rc5t583_rtc_ops = {
198 	.read_time	= rc5t583_rtc_read_time,
199 	.set_time	= rc5t583_rtc_set_time,
200 	.read_alarm	= rc5t583_rtc_read_alarm,
201 	.set_alarm	= rc5t583_rtc_set_alarm,
202 	.alarm_irq_enable = rc5t583_rtc_alarm_irq_enable,
203 };
204 
rc5t583_rtc_probe(struct platform_device * pdev)205 static int rc5t583_rtc_probe(struct platform_device *pdev)
206 {
207 	struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent);
208 	struct rc5t583_rtc *ricoh_rtc;
209 	struct rc5t583_platform_data *pmic_plat_data;
210 	int ret;
211 	int irq;
212 
213 	ricoh_rtc = devm_kzalloc(&pdev->dev, sizeof(struct rc5t583_rtc),
214 			GFP_KERNEL);
215 	if (!ricoh_rtc)
216 		return -ENOMEM;
217 
218 	platform_set_drvdata(pdev, ricoh_rtc);
219 
220 	/* Clear pending interrupts */
221 	ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, 0);
222 	if (ret < 0)
223 		return ret;
224 
225 	/* clear RTC Adjust register */
226 	ret = regmap_write(rc5t583->regmap, RC5T583_RTC_ADJ, 0);
227 	if (ret < 0) {
228 		dev_err(&pdev->dev, "unable to program rtc_adjust reg\n");
229 		return -EBUSY;
230 	}
231 
232 	pmic_plat_data = dev_get_platdata(rc5t583->dev);
233 	irq = pmic_plat_data->irq_base;
234 	if (irq <= 0) {
235 		dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
236 			irq);
237 		return ret;
238 	}
239 
240 	irq += RC5T583_IRQ_YALE;
241 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
242 		rc5t583_rtc_interrupt, IRQF_TRIGGER_LOW,
243 		"rtc-rc5t583", &pdev->dev);
244 	if (ret < 0) {
245 		dev_err(&pdev->dev, "IRQ is not free.\n");
246 		return ret;
247 	}
248 	device_init_wakeup(&pdev->dev, 1);
249 
250 	ricoh_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
251 		&rc5t583_rtc_ops, THIS_MODULE);
252 	if (IS_ERR(ricoh_rtc->rtc)) {
253 		ret = PTR_ERR(ricoh_rtc->rtc);
254 		dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
255 		return ret;
256 	}
257 
258 	return 0;
259 }
260 
261 /*
262  * Disable rc5t583 RTC interrupts.
263  * Sets status flag to free.
264  */
rc5t583_rtc_remove(struct platform_device * pdev)265 static void rc5t583_rtc_remove(struct platform_device *pdev)
266 {
267 	struct rc5t583_rtc *rc5t583_rtc = platform_get_drvdata(pdev);
268 
269 	rc5t583_rtc_alarm_irq_enable(&rc5t583_rtc->rtc->dev, 0);
270 }
271 
272 #ifdef CONFIG_PM_SLEEP
rc5t583_rtc_suspend(struct device * dev)273 static int rc5t583_rtc_suspend(struct device *dev)
274 {
275 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
276 	struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
277 	int ret;
278 
279 	/* Store current list of enabled interrupts*/
280 	ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1,
281 		&rc5t583_rtc->irqen);
282 	return ret;
283 }
284 
rc5t583_rtc_resume(struct device * dev)285 static int rc5t583_rtc_resume(struct device *dev)
286 {
287 	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
288 	struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
289 
290 	/* Restore list of enabled interrupts before suspend */
291 	return regmap_write(rc5t583->regmap, RC5T583_RTC_CTL1,
292 		rc5t583_rtc->irqen);
293 }
294 #endif
295 
296 static SIMPLE_DEV_PM_OPS(rc5t583_rtc_pm_ops, rc5t583_rtc_suspend,
297 			rc5t583_rtc_resume);
298 
299 static struct platform_driver rc5t583_rtc_driver = {
300 	.probe		= rc5t583_rtc_probe,
301 	.remove_new	= rc5t583_rtc_remove,
302 	.driver		= {
303 		.name	= "rtc-rc5t583",
304 		.pm	= &rc5t583_rtc_pm_ops,
305 	},
306 };
307 
308 module_platform_driver(rc5t583_rtc_driver);
309 MODULE_ALIAS("platform:rtc-rc5t583");
310 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
311 MODULE_LICENSE("GPL v2");
312