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739d340d PM |
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 | #include <linux/init.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/platform_device.h> | |
15 | #include <linux/time.h> | |
16 | #include <linux/rtc.h> | |
17 | #include <linux/spinlock.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/bcd.h> | |
20 | #include <asm/rtc.h> | |
21 | ||
22 | #define DRV_NAME "rtc-ds1302" | |
23 | #define DRV_VERSION "0.1.0" | |
24 | ||
25 | #define RTC_CMD_READ 0x81 /* Read command */ | |
26 | #define RTC_CMD_WRITE 0x80 /* Write command */ | |
27 | ||
28 | #define RTC_ADDR_RAM0 0x20 /* Address of RAM0 */ | |
29 | #define RTC_ADDR_TCR 0x08 /* Address of trickle charge register */ | |
30 | #define RTC_ADDR_YEAR 0x06 /* Address of year register */ | |
31 | #define RTC_ADDR_DAY 0x05 /* Address of day of week register */ | |
32 | #define RTC_ADDR_MON 0x04 /* Address of month register */ | |
33 | #define RTC_ADDR_DATE 0x03 /* Address of day of month register */ | |
34 | #define RTC_ADDR_HOUR 0x02 /* Address of hour register */ | |
35 | #define RTC_ADDR_MIN 0x01 /* Address of minute register */ | |
36 | #define RTC_ADDR_SEC 0x00 /* Address of second register */ | |
37 | ||
38 | #define RTC_RESET 0x1000 | |
39 | #define RTC_IODATA 0x0800 | |
40 | #define RTC_SCLK 0x0400 | |
41 | ||
42 | #ifdef CONFIG_SH_SECUREEDGE5410 | |
7639a454 | 43 | #include <mach/snapgear.h> |
739d340d PM |
44 | #define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00) |
45 | #define get_dp() SECUREEDGE_READ_IOPORT() | |
46 | #else | |
47 | #error "Add support for your platform" | |
48 | #endif | |
49 | ||
50 | struct ds1302_rtc { | |
51 | struct rtc_device *rtc_dev; | |
52 | spinlock_t lock; | |
53 | }; | |
54 | ||
55 | static void ds1302_sendbits(unsigned int val) | |
56 | { | |
57 | int i; | |
58 | ||
59 | for (i = 8; (i); i--, val >>= 1) { | |
60 | set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ? | |
61 | RTC_IODATA : 0)); | |
62 | set_dp(get_dp() | RTC_SCLK); /* clock high */ | |
63 | set_dp(get_dp() & ~RTC_SCLK); /* clock low */ | |
64 | } | |
65 | } | |
66 | ||
67 | static unsigned int ds1302_recvbits(void) | |
68 | { | |
69 | unsigned int val; | |
70 | int i; | |
71 | ||
72 | for (i = 0, val = 0; (i < 8); i++) { | |
73 | val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i); | |
74 | set_dp(get_dp() | RTC_SCLK); /* clock high */ | |
75 | set_dp(get_dp() & ~RTC_SCLK); /* clock low */ | |
76 | } | |
77 | ||
78 | return val; | |
79 | } | |
80 | ||
81 | static unsigned int ds1302_readbyte(unsigned int addr) | |
82 | { | |
83 | unsigned int val; | |
84 | ||
85 | set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); | |
86 | ||
87 | set_dp(get_dp() | RTC_RESET); | |
88 | ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ); | |
89 | val = ds1302_recvbits(); | |
90 | set_dp(get_dp() & ~RTC_RESET); | |
91 | ||
92 | return val; | |
93 | } | |
94 | ||
95 | static void ds1302_writebyte(unsigned int addr, unsigned int val) | |
96 | { | |
97 | set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); | |
98 | set_dp(get_dp() | RTC_RESET); | |
99 | ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE); | |
100 | ds1302_sendbits(val); | |
101 | set_dp(get_dp() & ~RTC_RESET); | |
102 | } | |
103 | ||
104 | static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
105 | { | |
106 | struct ds1302_rtc *rtc = dev_get_drvdata(dev); | |
107 | ||
108 | spin_lock_irq(&rtc->lock); | |
109 | ||
fe20ba70 AB |
110 | tm->tm_sec = bcd2bin(ds1302_readbyte(RTC_ADDR_SEC)); |
111 | tm->tm_min = bcd2bin(ds1302_readbyte(RTC_ADDR_MIN)); | |
112 | tm->tm_hour = bcd2bin(ds1302_readbyte(RTC_ADDR_HOUR)); | |
113 | tm->tm_wday = bcd2bin(ds1302_readbyte(RTC_ADDR_DAY)); | |
114 | tm->tm_mday = bcd2bin(ds1302_readbyte(RTC_ADDR_DATE)); | |
115 | tm->tm_mon = bcd2bin(ds1302_readbyte(RTC_ADDR_MON)) - 1; | |
116 | tm->tm_year = bcd2bin(ds1302_readbyte(RTC_ADDR_YEAR)); | |
739d340d PM |
117 | |
118 | if (tm->tm_year < 70) | |
119 | tm->tm_year += 100; | |
120 | ||
121 | spin_unlock_irq(&rtc->lock); | |
122 | ||
123 | dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
124 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 125 | __func__, |
739d340d PM |
126 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
127 | tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday); | |
128 | ||
129 | if (rtc_valid_tm(tm) < 0) | |
130 | dev_err(dev, "invalid date\n"); | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
136 | { | |
137 | struct ds1302_rtc *rtc = dev_get_drvdata(dev); | |
138 | ||
139 | spin_lock_irq(&rtc->lock); | |
140 | ||
141 | /* Stop RTC */ | |
142 | ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80); | |
143 | ||
fe20ba70 AB |
144 | ds1302_writebyte(RTC_ADDR_SEC, bin2bcd(tm->tm_sec)); |
145 | ds1302_writebyte(RTC_ADDR_MIN, bin2bcd(tm->tm_min)); | |
146 | ds1302_writebyte(RTC_ADDR_HOUR, bin2bcd(tm->tm_hour)); | |
147 | ds1302_writebyte(RTC_ADDR_DAY, bin2bcd(tm->tm_wday)); | |
148 | ds1302_writebyte(RTC_ADDR_DATE, bin2bcd(tm->tm_mday)); | |
149 | ds1302_writebyte(RTC_ADDR_MON, bin2bcd(tm->tm_mon + 1)); | |
150 | ds1302_writebyte(RTC_ADDR_YEAR, bin2bcd(tm->tm_year % 100)); | |
739d340d PM |
151 | |
152 | /* Start RTC */ | |
153 | ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80); | |
154 | ||
155 | spin_unlock_irq(&rtc->lock); | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd, | |
161 | unsigned long arg) | |
162 | { | |
163 | switch (cmd) { | |
164 | #ifdef RTC_SET_CHARGE | |
165 | case RTC_SET_CHARGE: | |
166 | { | |
167 | struct ds1302_rtc *rtc = dev_get_drvdata(dev); | |
168 | int tcs_val; | |
169 | ||
170 | if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int))) | |
171 | return -EFAULT; | |
172 | ||
173 | spin_lock_irq(&rtc->lock); | |
174 | ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf)); | |
175 | spin_unlock_irq(&rtc->lock); | |
176 | return 0; | |
177 | } | |
178 | #endif | |
179 | } | |
180 | ||
181 | return -ENOIOCTLCMD; | |
182 | } | |
183 | ||
184 | static struct rtc_class_ops ds1302_rtc_ops = { | |
185 | .read_time = ds1302_rtc_read_time, | |
186 | .set_time = ds1302_rtc_set_time, | |
187 | .ioctl = ds1302_rtc_ioctl, | |
188 | }; | |
189 | ||
190 | static int __devinit ds1302_rtc_probe(struct platform_device *pdev) | |
191 | { | |
192 | struct ds1302_rtc *rtc; | |
193 | int ret; | |
194 | ||
195 | /* Reset */ | |
196 | set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); | |
197 | ||
198 | /* Write a magic value to the DS1302 RAM, and see if it sticks. */ | |
199 | ds1302_writebyte(RTC_ADDR_RAM0, 0x42); | |
200 | if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) | |
201 | return -ENODEV; | |
202 | ||
203 | rtc = kzalloc(sizeof(struct ds1302_rtc), GFP_KERNEL); | |
204 | if (unlikely(!rtc)) | |
205 | return -ENOMEM; | |
206 | ||
207 | spin_lock_init(&rtc->lock); | |
208 | rtc->rtc_dev = rtc_device_register("ds1302", &pdev->dev, | |
209 | &ds1302_rtc_ops, THIS_MODULE); | |
210 | if (IS_ERR(rtc->rtc_dev)) { | |
211 | ret = PTR_ERR(rtc->rtc_dev); | |
212 | goto out; | |
213 | } | |
214 | ||
215 | platform_set_drvdata(pdev, rtc); | |
216 | ||
217 | return 0; | |
218 | out: | |
219 | kfree(rtc); | |
220 | return ret; | |
221 | } | |
222 | ||
223 | static int __devexit ds1302_rtc_remove(struct platform_device *pdev) | |
224 | { | |
225 | struct ds1302_rtc *rtc = platform_get_drvdata(pdev); | |
226 | ||
227 | if (likely(rtc->rtc_dev)) | |
228 | rtc_device_unregister(rtc->rtc_dev); | |
229 | ||
230 | platform_set_drvdata(pdev, NULL); | |
231 | ||
232 | kfree(rtc); | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
237 | static struct platform_driver ds1302_platform_driver = { | |
238 | .driver = { | |
239 | .name = DRV_NAME, | |
240 | .owner = THIS_MODULE, | |
241 | }, | |
242 | .probe = ds1302_rtc_probe, | |
243 | .remove = __devexit_p(ds1302_rtc_remove), | |
244 | }; | |
245 | ||
246 | static int __init ds1302_rtc_init(void) | |
247 | { | |
248 | return platform_driver_register(&ds1302_platform_driver); | |
249 | } | |
250 | ||
251 | static void __exit ds1302_rtc_exit(void) | |
252 | { | |
253 | platform_driver_unregister(&ds1302_platform_driver); | |
254 | } | |
255 | ||
256 | module_init(ds1302_rtc_init); | |
257 | module_exit(ds1302_rtc_exit); | |
258 | ||
259 | MODULE_DESCRIPTION("Dallas DS1302 RTC driver"); | |
260 | MODULE_VERSION(DRV_VERSION); | |
261 | MODULE_AUTHOR("Paul Mundt, David McCullough"); | |
262 | MODULE_LICENSE("GPL v2"); |