xref: /linux/drivers/rtc/rtc-rp5c01.c (revision 7f50548abb5454bd82c25aae15f0a3bf6a530f46)
1 /*
2  *  Ricoh RP5C01 RTC Driver
3  *
4  *  Copyright 2009 Geert Uytterhoeven
5  *
6  *  Based on the A3000 TOD code in arch/m68k/amiga/config.c
7  *  Copyright (C) 1993 Hamish Macdonald
8  */
9 
10 #include <linux/io.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/rtc.h>
15 
16 
17 enum {
18 	RP5C01_1_SECOND		= 0x0,	/* MODE 00 */
19 	RP5C01_10_SECOND	= 0x1,	/* MODE 00 */
20 	RP5C01_1_MINUTE		= 0x2,	/* MODE 00 and MODE 01 */
21 	RP5C01_10_MINUTE	= 0x3,	/* MODE 00 and MODE 01 */
22 	RP5C01_1_HOUR		= 0x4,	/* MODE 00 and MODE 01 */
23 	RP5C01_10_HOUR		= 0x5,	/* MODE 00 and MODE 01 */
24 	RP5C01_DAY_OF_WEEK	= 0x6,	/* MODE 00 and MODE 01 */
25 	RP5C01_1_DAY		= 0x7,	/* MODE 00 and MODE 01 */
26 	RP5C01_10_DAY		= 0x8,	/* MODE 00 and MODE 01 */
27 	RP5C01_1_MONTH		= 0x9,	/* MODE 00 */
28 	RP5C01_10_MONTH		= 0xa,	/* MODE 00 */
29 	RP5C01_1_YEAR		= 0xb,	/* MODE 00 */
30 	RP5C01_10_YEAR		= 0xc,	/* MODE 00 */
31 
32 	RP5C01_12_24_SELECT	= 0xa,	/* MODE 01 */
33 	RP5C01_LEAP_YEAR	= 0xb,	/* MODE 01 */
34 
35 	RP5C01_MODE		= 0xd,	/* all modes */
36 	RP5C01_TEST		= 0xe,	/* all modes */
37 	RP5C01_RESET		= 0xf,	/* all modes */
38 };
39 
40 #define RP5C01_12_24_SELECT_12	(0 << 0)
41 #define RP5C01_12_24_SELECT_24	(1 << 0)
42 
43 #define RP5C01_10_HOUR_AM	(0 << 1)
44 #define RP5C01_10_HOUR_PM	(1 << 1)
45 
46 #define RP5C01_MODE_TIMER_EN	(1 << 3)	/* timer enable */
47 #define RP5C01_MODE_ALARM_EN	(1 << 2)	/* alarm enable */
48 
49 #define RP5C01_MODE_MODE_MASK	(3 << 0)
50 #define RP5C01_MODE_MODE00	(0 << 0)	/* time */
51 #define RP5C01_MODE_MODE01	(1 << 0)	/* alarm, 12h/24h, leap year */
52 #define RP5C01_MODE_RAM_BLOCK10	(2 << 0)	/* RAM 4 bits x 13 */
53 #define RP5C01_MODE_RAM_BLOCK11	(3 << 0)	/* RAM 4 bits x 13 */
54 
55 #define RP5C01_RESET_1HZ_PULSE	(1 << 3)
56 #define RP5C01_RESET_16HZ_PULSE	(1 << 2)
57 #define RP5C01_RESET_SECOND	(1 << 1)	/* reset divider stages for */
58 						/* seconds or smaller units */
59 #define RP5C01_RESET_ALARM	(1 << 0)	/* reset all alarm registers */
60 
61 
62 struct rp5c01_priv {
63 	u32 __iomem *regs;
64 	struct rtc_device *rtc;
65 };
66 
67 static inline unsigned int rp5c01_read(struct rp5c01_priv *priv,
68 				       unsigned int reg)
69 {
70 	return __raw_readl(&priv->regs[reg]) & 0xf;
71 }
72 
73 static inline void rp5c01_write(struct rp5c01_priv *priv, unsigned int val,
74 				unsigned int reg)
75 {
76 	return __raw_writel(val, &priv->regs[reg]);
77 }
78 
79 static void rp5c01_lock(struct rp5c01_priv *priv)
80 {
81 	rp5c01_write(priv, RP5C01_MODE_MODE00, RP5C01_MODE);
82 }
83 
84 static void rp5c01_unlock(struct rp5c01_priv *priv)
85 {
86 	rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
87 		     RP5C01_MODE);
88 }
89 
90 static int rp5c01_read_time(struct device *dev, struct rtc_time *tm)
91 {
92 	struct rp5c01_priv *priv = dev_get_drvdata(dev);
93 
94 	rp5c01_lock(priv);
95 
96 	tm->tm_sec  = rp5c01_read(priv, RP5C01_10_SECOND) * 10 +
97 		      rp5c01_read(priv, RP5C01_1_SECOND);
98 	tm->tm_min  = rp5c01_read(priv, RP5C01_10_MINUTE) * 10 +
99 		      rp5c01_read(priv, RP5C01_1_MINUTE);
100 	tm->tm_hour = rp5c01_read(priv, RP5C01_10_HOUR) * 10 +
101 		      rp5c01_read(priv, RP5C01_1_HOUR);
102 	tm->tm_mday = rp5c01_read(priv, RP5C01_10_DAY) * 10 +
103 		      rp5c01_read(priv, RP5C01_1_DAY);
104 	tm->tm_wday = rp5c01_read(priv, RP5C01_DAY_OF_WEEK);
105 	tm->tm_mon  = rp5c01_read(priv, RP5C01_10_MONTH) * 10 +
106 		      rp5c01_read(priv, RP5C01_1_MONTH) - 1;
107 	tm->tm_year = rp5c01_read(priv, RP5C01_10_YEAR) * 10 +
108 		      rp5c01_read(priv, RP5C01_1_YEAR);
109 	if (tm->tm_year <= 69)
110 		tm->tm_year += 100;
111 
112 	rp5c01_unlock(priv);
113 
114 	return rtc_valid_tm(tm);
115 }
116 
117 static int rp5c01_set_time(struct device *dev, struct rtc_time *tm)
118 {
119 	struct rp5c01_priv *priv = dev_get_drvdata(dev);
120 
121 	rp5c01_lock(priv);
122 
123 	rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND);
124 	rp5c01_write(priv, tm->tm_sec % 10, RP5C01_1_SECOND);
125 	rp5c01_write(priv, tm->tm_min / 10, RP5C01_10_MINUTE);
126 	rp5c01_write(priv, tm->tm_min % 10, RP5C01_1_MINUTE);
127 	rp5c01_write(priv, tm->tm_hour / 10, RP5C01_10_HOUR);
128 	rp5c01_write(priv, tm->tm_hour % 10, RP5C01_1_HOUR);
129 	rp5c01_write(priv, tm->tm_mday / 10, RP5C01_10_DAY);
130 	rp5c01_write(priv, tm->tm_mday % 10, RP5C01_1_DAY);
131 	if (tm->tm_wday != -1)
132 		rp5c01_write(priv, tm->tm_wday, RP5C01_DAY_OF_WEEK);
133 	rp5c01_write(priv, (tm->tm_mon + 1) / 10, RP5C01_10_MONTH);
134 	rp5c01_write(priv, (tm->tm_mon + 1) % 10, RP5C01_1_MONTH);
135 	if (tm->tm_year >= 100)
136 		tm->tm_year -= 100;
137 	rp5c01_write(priv, tm->tm_year / 10, RP5C01_10_YEAR);
138 	rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR);
139 
140 	rp5c01_unlock(priv);
141 	return 0;
142 }
143 
144 static const struct rtc_class_ops rp5c01_rtc_ops = {
145 	.read_time	= rp5c01_read_time,
146 	.set_time	= rp5c01_set_time,
147 };
148 
149 static int __init rp5c01_rtc_probe(struct platform_device *dev)
150 {
151 	struct resource *res;
152 	struct rp5c01_priv *priv;
153 	struct rtc_device *rtc;
154 	int error;
155 
156 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
157 	if (!res)
158 		return -ENODEV;
159 
160 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
161 	if (!priv)
162 		return -ENOMEM;
163 
164 	priv->regs = ioremap(res->start, resource_size(res));
165 	if (!priv->regs) {
166 		error = -ENOMEM;
167 		goto out_free_priv;
168 	}
169 
170 	rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops,
171 				  THIS_MODULE);
172 	if (IS_ERR(rtc)) {
173 		error = PTR_ERR(rtc);
174 		goto out_unmap;
175 	}
176 
177 	priv->rtc = rtc;
178 	platform_set_drvdata(dev, priv);
179 	return 0;
180 
181 out_unmap:
182 	iounmap(priv->regs);
183 out_free_priv:
184 	kfree(priv);
185 	return error;
186 }
187 
188 static int __exit rp5c01_rtc_remove(struct platform_device *dev)
189 {
190 	struct rp5c01_priv *priv = platform_get_drvdata(dev);
191 
192 	rtc_device_unregister(priv->rtc);
193 	iounmap(priv->regs);
194 	kfree(priv);
195 	return 0;
196 }
197 
198 static struct platform_driver rp5c01_rtc_driver = {
199 	.driver	= {
200 		.name	= "rtc-rp5c01",
201 		.owner	= THIS_MODULE,
202 	},
203 	.remove	= __exit_p(rp5c01_rtc_remove),
204 };
205 
206 static int __init rp5c01_rtc_init(void)
207 {
208 	return platform_driver_probe(&rp5c01_rtc_driver, rp5c01_rtc_probe);
209 }
210 
211 static void __exit rp5c01_rtc_fini(void)
212 {
213 	platform_driver_unregister(&rp5c01_rtc_driver);
214 }
215 
216 module_init(rp5c01_rtc_init);
217 module_exit(rp5c01_rtc_fini);
218 
219 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
220 MODULE_LICENSE("GPL");
221 MODULE_DESCRIPTION("Ricoh RP5C01 RTC driver");
222 MODULE_ALIAS("platform:rtc-rp5c01");
223