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Paul Mundt739d3402008-02-06 01:38:44 -08001/*
2 * Dallas DS1302 RTC Support
3 *
Alessandro Zummo2bfc3302009-08-20 12:31:49 +09004 * Copyright (C) 2002 David McCullough
5 * Copyright (C) 2003 - 2007 Paul Mundt
Paul Mundt739d3402008-02-06 01:38:44 -08006 *
7 * This file is subject to the terms and conditions of the GNU General Public
Alessandro Zummo2bfc3302009-08-20 12:31:49 +09008 * License version 2. See the file "COPYING" in the main directory of
Paul Mundt739d3402008-02-06 01:38:44 -08009 * this archive for more details.
10 */
Alessandro Zummo2bfc3302009-08-20 12:31:49 +090011
Paul Mundt739d3402008-02-06 01:38:44 -080012#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/platform_device.h>
Paul Mundt739d3402008-02-06 01:38:44 -080016#include <linux/rtc.h>
Paul Mundt739d3402008-02-06 01:38:44 -080017#include <linux/io.h>
18#include <linux/bcd.h>
Paul Mundt739d3402008-02-06 01:38:44 -080019
20#define DRV_NAME "rtc-ds1302"
Alessandro Zummo2bfc3302009-08-20 12:31:49 +090021#define DRV_VERSION "0.1.1"
Paul Mundt739d3402008-02-06 01:38:44 -080022
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
Marc Zyngier72cc8e52010-05-24 14:33:47 -070036#ifdef CONFIG_SH_SECUREEDGE5410
37#include <asm/rtc.h>
Paul Mundtf6eec8d2010-10-29 19:06:53 +090038#include <mach/secureedge5410.h>
Marc Zyngier72cc8e52010-05-24 14:33:47 -070039
Paul Mundt739d3402008-02-06 01:38:44 -080040#define RTC_RESET 0x1000
41#define RTC_IODATA 0x0800
42#define RTC_SCLK 0x0400
43
Paul Mundt739d3402008-02-06 01:38:44 -080044#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
45#define get_dp() SECUREEDGE_READ_IOPORT()
Marc Zyngier72cc8e52010-05-24 14:33:47 -070046#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
Paul Mundt739d3402008-02-06 01:38:44 -080085#else
86#error "Add support for your platform"
87#endif
88
Paul Mundt739d3402008-02-06 01:38:44 -080089static void ds1302_sendbits(unsigned int val)
90{
91 int i;
92
Marc Zyngier72cc8e52010-05-24 14:33:47 -070093 ds1302_set_tx();
94
Paul Mundt739d3402008-02-06 01:38:44 -080095 for (i = 8; (i); i--, val >>= 1) {
Marc Zyngier72cc8e52010-05-24 14:33:47 -070096 ds1302_txbit(val & 0x1);
97 ds1302_clock();
Paul Mundt739d3402008-02-06 01:38:44 -080098 }
99}
100
101static unsigned int ds1302_recvbits(void)
102{
103 unsigned int val;
104 int i;
105
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700106 ds1302_set_rx();
107
Paul Mundt739d3402008-02-06 01:38:44 -0800108 for (i = 0, val = 0; (i < 8); i++) {
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700109 val |= (ds1302_rxbit() << i);
110 ds1302_clock();
Paul Mundt739d3402008-02-06 01:38:44 -0800111 }
112
113 return val;
114}
115
116static unsigned int ds1302_readbyte(unsigned int addr)
117{
118 unsigned int val;
119
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700120 ds1302_reset();
Paul Mundt739d3402008-02-06 01:38:44 -0800121
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700122 ds1302_start();
Paul Mundt739d3402008-02-06 01:38:44 -0800123 ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
124 val = ds1302_recvbits();
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700125 ds1302_stop();
Paul Mundt739d3402008-02-06 01:38:44 -0800126
127 return val;
128}
129
130static void ds1302_writebyte(unsigned int addr, unsigned int val)
131{
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700132 ds1302_reset();
133
134 ds1302_start();
Paul Mundt739d3402008-02-06 01:38:44 -0800135 ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
136 ds1302_sendbits(val);
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700137 ds1302_stop();
Paul Mundt739d3402008-02-06 01:38:44 -0800138}
139
140static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
141{
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700142 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));
Paul Mundt739d3402008-02-06 01:38:44 -0800149
150 if (tm->tm_year < 70)
151 tm->tm_year += 100;
152
Paul Mundt739d3402008-02-06 01:38:44 -0800153 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
154 "mday=%d, mon=%d, year=%d, wday=%d\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700155 __func__,
Paul Mundt739d3402008-02-06 01:38:44 -0800156 tm->tm_sec, tm->tm_min, tm->tm_hour,
157 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
158
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900159 return rtc_valid_tm(tm);
Paul Mundt739d3402008-02-06 01:38:44 -0800160}
161
162static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
163{
Paul Mundt739d3402008-02-06 01:38:44 -0800164 /* Stop RTC */
165 ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
166
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700167 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));
Paul Mundt739d3402008-02-06 01:38:44 -0800174
175 /* Start RTC */
176 ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
177
Paul Mundt739d3402008-02-06 01:38:44 -0800178 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 {
Paul Mundt739d3402008-02-06 01:38:44 -0800188 int tcs_val;
189
190 if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
191 return -EFAULT;
192
Paul Mundt739d3402008-02-06 01:38:44 -0800193 ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf));
Paul Mundt739d3402008-02-06 01:38:44 -0800194 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
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900208static int __init ds1302_rtc_probe(struct platform_device *pdev)
Paul Mundt739d3402008-02-06 01:38:44 -0800209{
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900210 struct rtc_device *rtc;
Paul Mundt739d3402008-02-06 01:38:44 -0800211
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700212 if (ds1302_hw_init()) {
213 dev_err(&pdev->dev, "Failed to init communication channel");
214 return -EINVAL;
215 }
216
Paul Mundt739d3402008-02-06 01:38:44 -0800217 /* Reset */
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700218 ds1302_reset();
Paul Mundt739d3402008-02-06 01:38:44 -0800219
220 /* Write a magic value to the DS1302 RAM, and see if it sticks. */
221 ds1302_writebyte(RTC_ADDR_RAM0, 0x42);
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700222 if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) {
223 dev_err(&pdev->dev, "Failed to probe");
Paul Mundt739d3402008-02-06 01:38:44 -0800224 return -ENODEV;
Marc Zyngier72cc8e52010-05-24 14:33:47 -0700225 }
Paul Mundt739d3402008-02-06 01:38:44 -0800226
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900227 rtc = rtc_device_register("ds1302", &pdev->dev,
Paul Mundt739d3402008-02-06 01:38:44 -0800228 &ds1302_rtc_ops, THIS_MODULE);
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900229 if (IS_ERR(rtc))
230 return PTR_ERR(rtc);
Paul Mundt739d3402008-02-06 01:38:44 -0800231
232 platform_set_drvdata(pdev, rtc);
233
234 return 0;
Paul Mundt739d3402008-02-06 01:38:44 -0800235}
236
237static int __devexit ds1302_rtc_remove(struct platform_device *pdev)
238{
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900239 struct rtc_device *rtc = platform_get_drvdata(pdev);
Paul Mundt739d3402008-02-06 01:38:44 -0800240
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900241 rtc_device_unregister(rtc);
Paul Mundt739d3402008-02-06 01:38:44 -0800242 platform_set_drvdata(pdev, NULL);
243
Paul Mundt739d3402008-02-06 01:38:44 -0800244 return 0;
245}
246
247static struct platform_driver ds1302_platform_driver = {
248 .driver = {
249 .name = DRV_NAME,
250 .owner = THIS_MODULE,
251 },
Uwe Kleine-Königb9e05c62009-11-24 22:07:23 +0100252 .remove = __devexit_p(ds1302_rtc_remove),
Paul Mundt739d3402008-02-06 01:38:44 -0800253};
254
255static int __init ds1302_rtc_init(void)
256{
Alessandro Zummo2bfc3302009-08-20 12:31:49 +0900257 return platform_driver_probe(&ds1302_platform_driver, ds1302_rtc_probe);
Paul Mundt739d3402008-02-06 01:38:44 -0800258}
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");