summaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-rp5c01.c
blob: 026035373ae65a446122c6ebf39df9364b58718a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/*
 *  Ricoh RP5C01 RTC Driver
 *
 *  Copyright 2009 Geert Uytterhoeven
 *
 *  Based on the A3000 TOD code in arch/m68k/amiga/config.c
 *  Copyright (C) 1993 Hamish Macdonald
 */

#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>


enum {
	RP5C01_1_SECOND		= 0x0,	/* MODE 00 */
	RP5C01_10_SECOND	= 0x1,	/* MODE 00 */
	RP5C01_1_MINUTE		= 0x2,	/* MODE 00 and MODE 01 */
	RP5C01_10_MINUTE	= 0x3,	/* MODE 00 and MODE 01 */
	RP5C01_1_HOUR		= 0x4,	/* MODE 00 and MODE 01 */
	RP5C01_10_HOUR		= 0x5,	/* MODE 00 and MODE 01 */
	RP5C01_DAY_OF_WEEK	= 0x6,	/* MODE 00 and MODE 01 */
	RP5C01_1_DAY		= 0x7,	/* MODE 00 and MODE 01 */
	RP5C01_10_DAY		= 0x8,	/* MODE 00 and MODE 01 */
	RP5C01_1_MONTH		= 0x9,	/* MODE 00 */
	RP5C01_10_MONTH		= 0xa,	/* MODE 00 */
	RP5C01_1_YEAR		= 0xb,	/* MODE 00 */
	RP5C01_10_YEAR		= 0xc,	/* MODE 00 */

	RP5C01_12_24_SELECT	= 0xa,	/* MODE 01 */
	RP5C01_LEAP_YEAR	= 0xb,	/* MODE 01 */

	RP5C01_MODE		= 0xd,	/* all modes */
	RP5C01_TEST		= 0xe,	/* all modes */
	RP5C01_RESET		= 0xf,	/* all modes */
};

#define RP5C01_12_24_SELECT_12	(0 << 0)
#define RP5C01_12_24_SELECT_24	(1 << 0)

#define RP5C01_10_HOUR_AM	(0 << 1)
#define RP5C01_10_HOUR_PM	(1 << 1)

#define RP5C01_MODE_TIMER_EN	(1 << 3)	/* timer enable */
#define RP5C01_MODE_ALARM_EN	(1 << 2)	/* alarm enable */

#define RP5C01_MODE_MODE_MASK	(3 << 0)
#define RP5C01_MODE_MODE00	(0 << 0)	/* time */
#define RP5C01_MODE_MODE01	(1 << 0)	/* alarm, 12h/24h, leap year */
#define RP5C01_MODE_RAM_BLOCK10	(2 << 0)	/* RAM 4 bits x 13 */
#define RP5C01_MODE_RAM_BLOCK11	(3 << 0)	/* RAM 4 bits x 13 */

#define RP5C01_RESET_1HZ_PULSE	(1 << 3)
#define RP5C01_RESET_16HZ_PULSE	(1 << 2)
#define RP5C01_RESET_SECOND	(1 << 1)	/* reset divider stages for */
						/* seconds or smaller units */
#define RP5C01_RESET_ALARM	(1 << 0)	/* reset all alarm registers */


struct rp5c01_priv {
	u32 __iomem *regs;
	struct rtc_device *rtc;
	spinlock_t lock;	/* against concurrent RTC/NVRAM access */
	struct bin_attribute nvram_attr;
};

static inline unsigned int rp5c01_read(struct rp5c01_priv *priv,
				       unsigned int reg)
{
	return __raw_readl(&priv->regs[reg]) & 0xf;
}

static inline void rp5c01_write(struct rp5c01_priv *priv, unsigned int val,
				unsigned int reg)
{
	__raw_writel(val, &priv->regs[reg]);
}

static void rp5c01_lock(struct rp5c01_priv *priv)
{
	rp5c01_write(priv, RP5C01_MODE_MODE00, RP5C01_MODE);
}

static void rp5c01_unlock(struct rp5c01_priv *priv)
{
	rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
		     RP5C01_MODE);
}

static int rp5c01_read_time(struct device *dev, struct rtc_time *tm)
{
	struct rp5c01_priv *priv = dev_get_drvdata(dev);

	spin_lock_irq(&priv->lock);
	rp5c01_lock(priv);

	tm->tm_sec  = rp5c01_read(priv, RP5C01_10_SECOND) * 10 +
		      rp5c01_read(priv, RP5C01_1_SECOND);
	tm->tm_min  = rp5c01_read(priv, RP5C01_10_MINUTE) * 10 +
		      rp5c01_read(priv, RP5C01_1_MINUTE);
	tm->tm_hour = rp5c01_read(priv, RP5C01_10_HOUR) * 10 +
		      rp5c01_read(priv, RP5C01_1_HOUR);
	tm->tm_mday = rp5c01_read(priv, RP5C01_10_DAY) * 10 +
		      rp5c01_read(priv, RP5C01_1_DAY);
	tm->tm_wday = rp5c01_read(priv, RP5C01_DAY_OF_WEEK);
	tm->tm_mon  = rp5c01_read(priv, RP5C01_10_MONTH) * 10 +
		      rp5c01_read(priv, RP5C01_1_MONTH) - 1;
	tm->tm_year = rp5c01_read(priv, RP5C01_10_YEAR) * 10 +
		      rp5c01_read(priv, RP5C01_1_YEAR);
	if (tm->tm_year <= 69)
		tm->tm_year += 100;

	rp5c01_unlock(priv);
	spin_unlock_irq(&priv->lock);

	return rtc_valid_tm(tm);
}

static int rp5c01_set_time(struct device *dev, struct rtc_time *tm)
{
	struct rp5c01_priv *priv = dev_get_drvdata(dev);

	spin_lock_irq(&priv->lock);
	rp5c01_lock(priv);

	rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND);
	rp5c01_write(priv, tm->tm_sec % 10, RP5C01_1_SECOND);
	rp5c01_write(priv, tm->tm_min / 10, RP5C01_10_MINUTE);
	rp5c01_write(priv, tm->tm_min % 10, RP5C01_1_MINUTE);
	rp5c01_write(priv, tm->tm_hour / 10, RP5C01_10_HOUR);
	rp5c01_write(priv, tm->tm_hour % 10, RP5C01_1_HOUR);
	rp5c01_write(priv, tm->tm_mday / 10, RP5C01_10_DAY);
	rp5c01_write(priv, tm->tm_mday % 10, RP5C01_1_DAY);
	if (tm->tm_wday != -1)
		rp5c01_write(priv, tm->tm_wday, RP5C01_DAY_OF_WEEK);
	rp5c01_write(priv, (tm->tm_mon + 1) / 10, RP5C01_10_MONTH);
	rp5c01_write(priv, (tm->tm_mon + 1) % 10, RP5C01_1_MONTH);
	if (tm->tm_year >= 100)
		tm->tm_year -= 100;
	rp5c01_write(priv, tm->tm_year / 10, RP5C01_10_YEAR);
	rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR);

	rp5c01_unlock(priv);
	spin_unlock_irq(&priv->lock);
	return 0;
}

static const struct rtc_class_ops rp5c01_rtc_ops = {
	.read_time	= rp5c01_read_time,
	.set_time	= rp5c01_set_time,
};


/*
 * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits.
 * We provide access to them like AmigaOS does: the high nibble of each 8-bit
 * byte is stored in BLOCK10, the low nibble in BLOCK11.
 */

static ssize_t rp5c01_nvram_read(struct file *filp, struct kobject *kobj,
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct rp5c01_priv *priv = dev_get_drvdata(dev);
	ssize_t count;

	spin_lock_irq(&priv->lock);

	for (count = 0; count < size; count++) {
		u8 data;

		rp5c01_write(priv,
			     RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10,
			     RP5C01_MODE);
		data = rp5c01_read(priv, pos) << 4;
		rp5c01_write(priv,
			     RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11,
			     RP5C01_MODE);
		data |= rp5c01_read(priv, pos++);
		rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
			     RP5C01_MODE);
		*buf++ = data;
	}

	spin_unlock_irq(&priv->lock);
	return count;
}

static ssize_t rp5c01_nvram_write(struct file *filp, struct kobject *kobj,
				  struct bin_attribute *bin_attr,
				  char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct rp5c01_priv *priv = dev_get_drvdata(dev);
	ssize_t count;

	spin_lock_irq(&priv->lock);

	for (count = 0; count < size; count++) {
		u8 data = *buf++;

		rp5c01_write(priv,
			     RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10,
			     RP5C01_MODE);
		rp5c01_write(priv, data >> 4, pos);
		rp5c01_write(priv,
			     RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11,
			     RP5C01_MODE);
		rp5c01_write(priv, data & 0xf, pos++);
		rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
			     RP5C01_MODE);
	}

	spin_unlock_irq(&priv->lock);
	return count;
}

static int __init rp5c01_rtc_probe(struct platform_device *dev)
{
	struct resource *res;
	struct rp5c01_priv *priv;
	struct rtc_device *rtc;
	int error;

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->regs = devm_ioremap(&dev->dev, res->start, resource_size(res));
	if (!priv->regs)
		return -ENOMEM;

	sysfs_bin_attr_init(&priv->nvram_attr);
	priv->nvram_attr.attr.name = "nvram";
	priv->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
	priv->nvram_attr.read = rp5c01_nvram_read;
	priv->nvram_attr.write = rp5c01_nvram_write;
	priv->nvram_attr.size = RP5C01_MODE;

	spin_lock_init(&priv->lock);

	platform_set_drvdata(dev, priv);

	rtc = devm_rtc_device_register(&dev->dev, "rtc-rp5c01", &rp5c01_rtc_ops,
				  THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);
	priv->rtc = rtc;

	error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr);
	if (error)
		return error;

	return 0;
}

static int __exit rp5c01_rtc_remove(struct platform_device *dev)
{
	struct rp5c01_priv *priv = platform_get_drvdata(dev);

	sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr);
	return 0;
}

static struct platform_driver rp5c01_rtc_driver = {
	.driver	= {
		.name	= "rtc-rp5c01",
	},
	.remove	= __exit_p(rp5c01_rtc_remove),
};

module_platform_driver_probe(rp5c01_rtc_driver, rp5c01_rtc_probe);

MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Ricoh RP5C01 RTC driver");
MODULE_ALIAS("platform:rtc-rp5c01");