[SCSI] bxn2i: Added support for other TMFs besides ABORT_TASK
[linux-2.6.git] / drivers / rtc / rtc-ds1302.c
1 /*
2  * Dallas DS1302 RTC Support
3  *
4  *  Copyright (C) 2002 David McCullough
5  *  Copyright (C) 2003 - 2007 Paul Mundt
6  *
7  * This file is subject to the terms and conditions of the GNU General Public
8  * License version 2. See the file "COPYING" in the main directory of
9  * this archive for more details.
10  */
11
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/platform_device.h>
16 #include <linux/rtc.h>
17 #include <linux/io.h>
18 #include <linux/bcd.h>
19
20 #define DRV_NAME        "rtc-ds1302"
21 #define DRV_VERSION     "0.1.1"
22
23 #define RTC_CMD_READ    0x81            /* Read command */
24 #define RTC_CMD_WRITE   0x80            /* Write command */
25
26 #define RTC_ADDR_RAM0   0x20            /* Address of RAM0 */
27 #define RTC_ADDR_TCR    0x08            /* Address of trickle charge register */
28 #define RTC_ADDR_YEAR   0x06            /* Address of year register */
29 #define RTC_ADDR_DAY    0x05            /* Address of day of week register */
30 #define RTC_ADDR_MON    0x04            /* Address of month register */
31 #define RTC_ADDR_DATE   0x03            /* Address of day of month register */
32 #define RTC_ADDR_HOUR   0x02            /* Address of hour register */
33 #define RTC_ADDR_MIN    0x01            /* Address of minute register */
34 #define RTC_ADDR_SEC    0x00            /* Address of second register */
35
36 #ifdef CONFIG_SH_SECUREEDGE5410
37 #include <asm/rtc.h>
38 #include <mach/snapgear.h>
39
40 #define RTC_RESET       0x1000
41 #define RTC_IODATA      0x0800
42 #define RTC_SCLK        0x0400
43
44 #define set_dp(x)       SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
45 #define get_dp()        SECUREEDGE_READ_IOPORT()
46 #define ds1302_set_tx()
47 #define ds1302_set_rx()
48
49 static inline int ds1302_hw_init(void)
50 {
51         return 0;
52 }
53
54 static inline void ds1302_reset(void)
55 {
56         set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
57 }
58
59 static inline void ds1302_clock(void)
60 {
61         set_dp(get_dp() | RTC_SCLK);    /* clock high */
62         set_dp(get_dp() & ~RTC_SCLK);   /* clock low */
63 }
64
65 static inline void ds1302_start(void)
66 {
67         set_dp(get_dp() | RTC_RESET);
68 }
69
70 static inline void ds1302_stop(void)
71 {
72         set_dp(get_dp() & ~RTC_RESET);
73 }
74
75 static inline void ds1302_txbit(int bit)
76 {
77         set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0));
78 }
79
80 static inline int ds1302_rxbit(void)
81 {
82         return !!(get_dp() & RTC_IODATA);
83 }
84
85 #else
86 #error "Add support for your platform"
87 #endif
88
89 static void ds1302_sendbits(unsigned int val)
90 {
91         int i;
92
93         ds1302_set_tx();
94
95         for (i = 8; (i); i--, val >>= 1) {
96                 ds1302_txbit(val & 0x1);
97                 ds1302_clock();
98         }
99 }
100
101 static unsigned int ds1302_recvbits(void)
102 {
103         unsigned int val;
104         int i;
105
106         ds1302_set_rx();
107
108         for (i = 0, val = 0; (i < 8); i++) {
109                 val |= (ds1302_rxbit() << i);
110                 ds1302_clock();
111         }
112
113         return val;
114 }
115
116 static unsigned int ds1302_readbyte(unsigned int addr)
117 {
118         unsigned int val;
119
120         ds1302_reset();
121
122         ds1302_start();
123         ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
124         val = ds1302_recvbits();
125         ds1302_stop();
126
127         return val;
128 }
129
130 static void ds1302_writebyte(unsigned int addr, unsigned int val)
131 {
132         ds1302_reset();
133
134         ds1302_start();
135         ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
136         ds1302_sendbits(val);
137         ds1302_stop();
138 }
139
140 static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
141 {
142         tm->tm_sec      = bcd2bin(ds1302_readbyte(RTC_ADDR_SEC));
143         tm->tm_min      = bcd2bin(ds1302_readbyte(RTC_ADDR_MIN));
144         tm->tm_hour     = bcd2bin(ds1302_readbyte(RTC_ADDR_HOUR));
145         tm->tm_wday     = bcd2bin(ds1302_readbyte(RTC_ADDR_DAY));
146         tm->tm_mday     = bcd2bin(ds1302_readbyte(RTC_ADDR_DATE));
147         tm->tm_mon      = bcd2bin(ds1302_readbyte(RTC_ADDR_MON)) - 1;
148         tm->tm_year     = bcd2bin(ds1302_readbyte(RTC_ADDR_YEAR));
149
150         if (tm->tm_year < 70)
151                 tm->tm_year += 100;
152
153         dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
154                 "mday=%d, mon=%d, year=%d, wday=%d\n",
155                 __func__,
156                 tm->tm_sec, tm->tm_min, tm->tm_hour,
157                 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
158
159         return rtc_valid_tm(tm);
160 }
161
162 static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
163 {
164         /* Stop RTC */
165         ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
166
167         ds1302_writebyte(RTC_ADDR_SEC, bin2bcd(tm->tm_sec));
168         ds1302_writebyte(RTC_ADDR_MIN, bin2bcd(tm->tm_min));
169         ds1302_writebyte(RTC_ADDR_HOUR, bin2bcd(tm->tm_hour));
170         ds1302_writebyte(RTC_ADDR_DAY, bin2bcd(tm->tm_wday));
171         ds1302_writebyte(RTC_ADDR_DATE, bin2bcd(tm->tm_mday));
172         ds1302_writebyte(RTC_ADDR_MON, bin2bcd(tm->tm_mon + 1));
173         ds1302_writebyte(RTC_ADDR_YEAR, bin2bcd(tm->tm_year % 100));
174
175         /* Start RTC */
176         ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
177
178         return 0;
179 }
180
181 static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd,
182                             unsigned long arg)
183 {
184         switch (cmd) {
185 #ifdef RTC_SET_CHARGE
186         case RTC_SET_CHARGE:
187         {
188                 int tcs_val;
189
190                 if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
191                         return -EFAULT;
192
193                 ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf));
194                 return 0;
195         }
196 #endif
197         }
198
199         return -ENOIOCTLCMD;
200 }
201
202 static struct rtc_class_ops ds1302_rtc_ops = {
203         .read_time      = ds1302_rtc_read_time,
204         .set_time       = ds1302_rtc_set_time,
205         .ioctl          = ds1302_rtc_ioctl,
206 };
207
208 static int __init ds1302_rtc_probe(struct platform_device *pdev)
209 {
210         struct rtc_device *rtc;
211
212         if (ds1302_hw_init()) {
213                 dev_err(&pdev->dev, "Failed to init communication channel");
214                 return -EINVAL;
215         }
216
217         /* Reset */
218         ds1302_reset();
219
220         /* Write a magic value to the DS1302 RAM, and see if it sticks. */
221         ds1302_writebyte(RTC_ADDR_RAM0, 0x42);
222         if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) {
223                 dev_err(&pdev->dev, "Failed to probe");
224                 return -ENODEV;
225         }
226
227         rtc = rtc_device_register("ds1302", &pdev->dev,
228                                            &ds1302_rtc_ops, THIS_MODULE);
229         if (IS_ERR(rtc))
230                 return PTR_ERR(rtc);
231
232         platform_set_drvdata(pdev, rtc);
233
234         return 0;
235 }
236
237 static int __devexit ds1302_rtc_remove(struct platform_device *pdev)
238 {
239         struct rtc_device *rtc = platform_get_drvdata(pdev);
240
241         rtc_device_unregister(rtc);
242         platform_set_drvdata(pdev, NULL);
243
244         return 0;
245 }
246
247 static struct platform_driver ds1302_platform_driver = {
248         .driver         = {
249                 .name   = DRV_NAME,
250                 .owner  = THIS_MODULE,
251         },
252         .remove         = __devexit_p(ds1302_rtc_remove),
253 };
254
255 static int __init ds1302_rtc_init(void)
256 {
257         return platform_driver_probe(&ds1302_platform_driver, ds1302_rtc_probe);
258 }
259
260 static void __exit ds1302_rtc_exit(void)
261 {
262         platform_driver_unregister(&ds1302_platform_driver);
263 }
264
265 module_init(ds1302_rtc_init);
266 module_exit(ds1302_rtc_exit);
267
268 MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
269 MODULE_VERSION(DRV_VERSION);
270 MODULE_AUTHOR("Paul Mundt, David McCullough");
271 MODULE_LICENSE("GPL v2");