xref: /openbmc/linux/drivers/rtc/rtc-pcap.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  pcap rtc code for Motorola EZX phones
4  *
5  *  Copyright (c) 2008 guiming zhuo <gmzhuo@gmail.com>
6  *  Copyright (c) 2009 Daniel Ribeiro <drwyrm@gmail.com>
7  *
8  *  Based on Motorola's rtc.c Copyright (c) 2003-2005 Motorola
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/mfd/ezx-pcap.h>
15 #include <linux/rtc.h>
16 #include <linux/slab.h>
17 #include <linux/platform_device.h>
18 
19 struct pcap_rtc {
20 	struct pcap_chip *pcap;
21 	struct rtc_device *rtc;
22 };
23 
24 static irqreturn_t pcap_rtc_irq(int irq, void *_pcap_rtc)
25 {
26 	struct pcap_rtc *pcap_rtc = _pcap_rtc;
27 	unsigned long rtc_events;
28 
29 	if (irq == pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ))
30 		rtc_events = RTC_IRQF | RTC_UF;
31 	else if (irq == pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA))
32 		rtc_events = RTC_IRQF | RTC_AF;
33 	else
34 		rtc_events = 0;
35 
36 	rtc_update_irq(pcap_rtc->rtc, 1, rtc_events);
37 	return IRQ_HANDLED;
38 }
39 
40 static int pcap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
41 {
42 	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
43 	struct rtc_time *tm = &alrm->time;
44 	unsigned long secs;
45 	u32 tod;	/* time of day, seconds since midnight */
46 	u32 days;	/* days since 1/1/1970 */
47 
48 	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_TODA, &tod);
49 	secs = tod & PCAP_RTC_TOD_MASK;
50 
51 	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_DAYA, &days);
52 	secs += (days & PCAP_RTC_DAY_MASK) * SEC_PER_DAY;
53 
54 	rtc_time64_to_tm(secs, tm);
55 
56 	return 0;
57 }
58 
59 static int pcap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
60 {
61 	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
62 	unsigned long secs = rtc_tm_to_time64(&alrm->time);
63 	u32 tod, days;
64 
65 	tod = secs % SEC_PER_DAY;
66 	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_TODA, tod);
67 
68 	days = secs / SEC_PER_DAY;
69 	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_DAYA, days);
70 
71 	return 0;
72 }
73 
74 static int pcap_rtc_read_time(struct device *dev, struct rtc_time *tm)
75 {
76 	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
77 	unsigned long secs;
78 	u32 tod, days;
79 
80 	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_TOD, &tod);
81 	secs = tod & PCAP_RTC_TOD_MASK;
82 
83 	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_DAY, &days);
84 	secs += (days & PCAP_RTC_DAY_MASK) * SEC_PER_DAY;
85 
86 	rtc_time64_to_tm(secs, tm);
87 
88 	return 0;
89 }
90 
91 static int pcap_rtc_set_time(struct device *dev, struct rtc_time *tm)
92 {
93 	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
94 	unsigned long secs = rtc_tm_to_time64(tm);
95 	u32 tod, days;
96 
97 	tod = secs % SEC_PER_DAY;
98 	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_TOD, tod);
99 
100 	days = secs / SEC_PER_DAY;
101 	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_DAY, days);
102 
103 	return 0;
104 }
105 
106 static int pcap_rtc_irq_enable(struct device *dev, int pirq, unsigned int en)
107 {
108 	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
109 
110 	if (en)
111 		enable_irq(pcap_to_irq(pcap_rtc->pcap, pirq));
112 	else
113 		disable_irq(pcap_to_irq(pcap_rtc->pcap, pirq));
114 
115 	return 0;
116 }
117 
118 static int pcap_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
119 {
120 	return pcap_rtc_irq_enable(dev, PCAP_IRQ_TODA, en);
121 }
122 
123 static const struct rtc_class_ops pcap_rtc_ops = {
124 	.read_time = pcap_rtc_read_time,
125 	.set_time = pcap_rtc_set_time,
126 	.read_alarm = pcap_rtc_read_alarm,
127 	.set_alarm = pcap_rtc_set_alarm,
128 	.alarm_irq_enable = pcap_rtc_alarm_irq_enable,
129 };
130 
131 static int __init pcap_rtc_probe(struct platform_device *pdev)
132 {
133 	struct pcap_rtc *pcap_rtc;
134 	int timer_irq, alarm_irq;
135 	int err = -ENOMEM;
136 
137 	pcap_rtc = devm_kzalloc(&pdev->dev, sizeof(struct pcap_rtc),
138 				GFP_KERNEL);
139 	if (!pcap_rtc)
140 		return err;
141 
142 	pcap_rtc->pcap = dev_get_drvdata(pdev->dev.parent);
143 
144 	platform_set_drvdata(pdev, pcap_rtc);
145 
146 	pcap_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
147 	if (IS_ERR(pcap_rtc->rtc))
148 		return PTR_ERR(pcap_rtc->rtc);
149 
150 	pcap_rtc->rtc->ops = &pcap_rtc_ops;
151 	pcap_rtc->rtc->range_max = (1 << 14) * 86400ULL - 1;
152 
153 	timer_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ);
154 	alarm_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA);
155 
156 	err = devm_request_irq(&pdev->dev, timer_irq, pcap_rtc_irq, 0,
157 				"RTC Timer", pcap_rtc);
158 	if (err)
159 		return err;
160 
161 	err = devm_request_irq(&pdev->dev, alarm_irq, pcap_rtc_irq, 0,
162 				"RTC Alarm", pcap_rtc);
163 	if (err)
164 		return err;
165 
166 	return devm_rtc_register_device(pcap_rtc->rtc);
167 }
168 
169 static int __exit pcap_rtc_remove(struct platform_device *pdev)
170 {
171 	return 0;
172 }
173 
174 static struct platform_driver pcap_rtc_driver = {
175 	.remove = __exit_p(pcap_rtc_remove),
176 	.driver = {
177 		.name  = "pcap-rtc",
178 	},
179 };
180 
181 module_platform_driver_probe(pcap_rtc_driver, pcap_rtc_probe);
182 
183 MODULE_DESCRIPTION("Motorola pcap rtc driver");
184 MODULE_AUTHOR("guiming zhuo <gmzhuo@gmail.com>");
185 MODULE_LICENSE("GPL");
186