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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_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/secureedge5410.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
49static inline int ds1302_hw_init(void)
50{
51 return 0;
52}
53
54static inline void ds1302_reset(void)
55{
56 set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
57}
58
59static 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
65static inline void ds1302_start(void)
66{
67 set_dp(get_dp() | RTC_RESET);
68}
69
70static inline void ds1302_stop(void)
71{
72 set_dp(get_dp() & ~RTC_RESET);
73}
74
75static inline void ds1302_txbit(int bit)
76{
77 set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0));
78}
79
80static 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
89static 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
101static 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
116static 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
130static 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
140static 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
162static 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
181static 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
202static 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
208static 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
237static 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
247static 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
255static int __init ds1302_rtc_init(void)
256{
257 return platform_driver_probe(&ds1302_platform_driver, ds1302_rtc_probe);
258}
259
260static void __exit ds1302_rtc_exit(void)
261{
262 platform_driver_unregister(&ds1302_platform_driver);
263}
264
265module_init(ds1302_rtc_init);
266module_exit(ds1302_rtc_exit);
267
268MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
269MODULE_VERSION(DRV_VERSION);
270MODULE_AUTHOR("Paul Mundt, David McCullough");
271MODULE_LICENSE("GPL v2");
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
53static inline int ds1302_hw_init(void)
54{
55 return 0;
56}
57
58static inline void ds1302_reset(void)
59{
60 set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
61}
62
63static 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
69static inline void ds1302_start(void)
70{
71 set_dp(get_dp() | RTC_RESET);
72}
73
74static inline void ds1302_stop(void)
75{
76 set_dp(get_dp() & ~RTC_RESET);
77}
78
79static inline void ds1302_txbit(int bit)
80{
81 set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0));
82}
83
84static 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
93static 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
105static 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
120static 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
134static 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
144static 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
166static 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
188static 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
209static 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
215static 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
244static struct platform_driver ds1302_platform_driver = {
245 .driver = {
246 .name = DRV_NAME,
247 },
248};
249
250module_platform_driver_probe(ds1302_platform_driver, ds1302_rtc_probe);
251
252MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
253MODULE_VERSION(DRV_VERSION);
254MODULE_AUTHOR("Paul Mundt, David McCullough");
255MODULE_LICENSE("GPL v2");