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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_CMD_WRITE_ENABLE 0x00 /* Write enable */ | |
27 | #define RTC_CMD_WRITE_DISABLE 0x80 /* Write disable */ | |
28 | ||
29 | #define RTC_ADDR_RAM0 0x20 /* Address of RAM0 */ | |
30 | #define RTC_ADDR_TCR 0x08 /* Address of trickle charge register */ | |
31 | #define RTC_ADDR_CTRL 0x07 /* Address of control register */ | |
32 | #define RTC_ADDR_YEAR 0x06 /* Address of year register */ | |
33 | #define RTC_ADDR_DAY 0x05 /* Address of day of week register */ | |
34 | #define RTC_ADDR_MON 0x04 /* Address of month register */ | |
35 | #define RTC_ADDR_DATE 0x03 /* Address of day of month register */ | |
36 | #define RTC_ADDR_HOUR 0x02 /* Address of hour register */ | |
37 | #define RTC_ADDR_MIN 0x01 /* Address of minute register */ | |
38 | #define RTC_ADDR_SEC 0x00 /* Address of second register */ | |
39 | ||
40 | #ifdef CONFIG_SH_SECUREEDGE5410 | |
41 | #include <asm/rtc.h> | |
42 | #include <mach/secureedge5410.h> | |
43 | ||
44 | #define RTC_RESET 0x1000 | |
45 | #define RTC_IODATA 0x0800 | |
46 | #define RTC_SCLK 0x0400 | |
47 | ||
48 | #define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00) | |
49 | #define get_dp() SECUREEDGE_READ_IOPORT() | |
50 | #define ds1302_set_tx() | |
51 | #define ds1302_set_rx() | |
52 | ||
53 | static inline int ds1302_hw_init(void) | |
54 | { | |
55 | return 0; | |
56 | } | |
57 | ||
58 | static inline void ds1302_reset(void) | |
59 | { | |
60 | set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); | |
61 | } | |
62 | ||
63 | static inline void ds1302_clock(void) | |
64 | { | |
65 | set_dp(get_dp() | RTC_SCLK); /* clock high */ | |
66 | set_dp(get_dp() & ~RTC_SCLK); /* clock low */ | |
67 | } | |
68 | ||
69 | static inline void ds1302_start(void) | |
70 | { | |
71 | set_dp(get_dp() | RTC_RESET); | |
72 | } | |
73 | ||
74 | static inline void ds1302_stop(void) | |
75 | { | |
76 | set_dp(get_dp() & ~RTC_RESET); | |
77 | } | |
78 | ||
79 | static inline void ds1302_txbit(int bit) | |
80 | { | |
81 | set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0)); | |
82 | } | |
83 | ||
84 | static inline int ds1302_rxbit(void) | |
85 | { | |
86 | return !!(get_dp() & RTC_IODATA); | |
87 | } | |
88 | ||
89 | #else | |
90 | #error "Add support for your platform" | |
91 | #endif | |
92 | ||
93 | static void ds1302_sendbits(unsigned int val) | |
94 | { | |
95 | int i; | |
96 | ||
97 | ds1302_set_tx(); | |
98 | ||
99 | for (i = 8; (i); i--, val >>= 1) { | |
100 | ds1302_txbit(val & 0x1); | |
101 | ds1302_clock(); | |
102 | } | |
103 | } | |
104 | ||
105 | static unsigned int ds1302_recvbits(void) | |
106 | { | |
107 | unsigned int val; | |
108 | int i; | |
109 | ||
110 | ds1302_set_rx(); | |
111 | ||
112 | for (i = 0, val = 0; (i < 8); i++) { | |
113 | val |= (ds1302_rxbit() << i); | |
114 | ds1302_clock(); | |
115 | } | |
116 | ||
117 | return val; | |
118 | } | |
119 | ||
120 | static unsigned int ds1302_readbyte(unsigned int addr) | |
121 | { | |
122 | unsigned int val; | |
123 | ||
124 | ds1302_reset(); | |
125 | ||
126 | ds1302_start(); | |
127 | ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ); | |
128 | val = ds1302_recvbits(); | |
129 | ds1302_stop(); | |
130 | ||
131 | return val; | |
132 | } | |
133 | ||
134 | static void ds1302_writebyte(unsigned int addr, unsigned int val) | |
135 | { | |
136 | ds1302_reset(); | |
137 | ||
138 | ds1302_start(); | |
139 | ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE); | |
140 | ds1302_sendbits(val); | |
141 | ds1302_stop(); | |
142 | } | |
143 | ||
144 | static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
145 | { | |
146 | tm->tm_sec = bcd2bin(ds1302_readbyte(RTC_ADDR_SEC)); | |
147 | tm->tm_min = bcd2bin(ds1302_readbyte(RTC_ADDR_MIN)); | |
148 | tm->tm_hour = bcd2bin(ds1302_readbyte(RTC_ADDR_HOUR)); | |
149 | tm->tm_wday = bcd2bin(ds1302_readbyte(RTC_ADDR_DAY)); | |
150 | tm->tm_mday = bcd2bin(ds1302_readbyte(RTC_ADDR_DATE)); | |
151 | tm->tm_mon = bcd2bin(ds1302_readbyte(RTC_ADDR_MON)) - 1; | |
152 | tm->tm_year = bcd2bin(ds1302_readbyte(RTC_ADDR_YEAR)); | |
153 | ||
154 | if (tm->tm_year < 70) | |
155 | tm->tm_year += 100; | |
156 | ||
157 | dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
158 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
159 | __func__, | |
160 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
161 | tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday); | |
162 | ||
163 | return rtc_valid_tm(tm); | |
164 | } | |
165 | ||
166 | static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
167 | { | |
168 | ds1302_writebyte(RTC_ADDR_CTRL, RTC_CMD_WRITE_ENABLE); | |
169 | /* Stop RTC */ | |
170 | ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80); | |
171 | ||
172 | ds1302_writebyte(RTC_ADDR_SEC, bin2bcd(tm->tm_sec)); | |
173 | ds1302_writebyte(RTC_ADDR_MIN, bin2bcd(tm->tm_min)); | |
174 | ds1302_writebyte(RTC_ADDR_HOUR, bin2bcd(tm->tm_hour)); | |
175 | ds1302_writebyte(RTC_ADDR_DAY, bin2bcd(tm->tm_wday)); | |
176 | ds1302_writebyte(RTC_ADDR_DATE, bin2bcd(tm->tm_mday)); | |
177 | ds1302_writebyte(RTC_ADDR_MON, bin2bcd(tm->tm_mon + 1)); | |
178 | ds1302_writebyte(RTC_ADDR_YEAR, bin2bcd(tm->tm_year % 100)); | |
179 | ||
180 | /* Start RTC */ | |
181 | ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80); | |
182 | ||
183 | ds1302_writebyte(RTC_ADDR_CTRL, RTC_CMD_WRITE_DISABLE); | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd, | |
189 | unsigned long arg) | |
190 | { | |
191 | switch (cmd) { | |
192 | #ifdef RTC_SET_CHARGE | |
193 | case RTC_SET_CHARGE: | |
194 | { | |
195 | int tcs_val; | |
196 | ||
197 | if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int))) | |
198 | return -EFAULT; | |
199 | ||
200 | ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf)); | |
201 | return 0; | |
202 | } | |
203 | #endif | |
204 | } | |
205 | ||
206 | return -ENOIOCTLCMD; | |
207 | } | |
208 | ||
209 | static struct rtc_class_ops ds1302_rtc_ops = { | |
210 | .read_time = ds1302_rtc_read_time, | |
211 | .set_time = ds1302_rtc_set_time, | |
212 | .ioctl = ds1302_rtc_ioctl, | |
213 | }; | |
214 | ||
215 | static int __init ds1302_rtc_probe(struct platform_device *pdev) | |
216 | { | |
217 | struct rtc_device *rtc; | |
218 | ||
219 | if (ds1302_hw_init()) { | |
220 | dev_err(&pdev->dev, "Failed to init communication channel"); | |
221 | return -EINVAL; | |
222 | } | |
223 | ||
224 | /* Reset */ | |
225 | ds1302_reset(); | |
226 | ||
227 | /* Write a magic value to the DS1302 RAM, and see if it sticks. */ | |
228 | ds1302_writebyte(RTC_ADDR_RAM0, 0x42); | |
229 | if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) { | |
230 | dev_err(&pdev->dev, "Failed to probe"); | |
231 | return -ENODEV; | |
232 | } | |
233 | ||
234 | rtc = devm_rtc_device_register(&pdev->dev, "ds1302", | |
235 | &ds1302_rtc_ops, THIS_MODULE); | |
236 | if (IS_ERR(rtc)) | |
237 | return PTR_ERR(rtc); | |
238 | ||
239 | platform_set_drvdata(pdev, rtc); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static struct platform_driver ds1302_platform_driver = { | |
245 | .driver = { | |
246 | .name = DRV_NAME, | |
247 | }, | |
248 | }; | |
249 | ||
250 | module_platform_driver_probe(ds1302_platform_driver, ds1302_rtc_probe); | |
251 | ||
252 | MODULE_DESCRIPTION("Dallas DS1302 RTC driver"); | |
253 | MODULE_VERSION(DRV_VERSION); | |
254 | MODULE_AUTHOR("Paul Mundt, David McCullough"); | |
255 | MODULE_LICENSE("GPL v2"); |