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Atsushi Nemotoe0ac4762006-06-28 04:26:47 -07001/*
2 * A SPI driver for the Ricoh RS5C348 RTC
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * The board specific init code should provide characteristics of this
11 * device:
12 * Mode 1 (High-Active, Shift-Then-Sample), High Avtive CS
13 */
14
15#include <linux/bcd.h>
16#include <linux/delay.h>
17#include <linux/device.h>
18#include <linux/errno.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/string.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/slab.h>
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070023#include <linux/rtc.h>
24#include <linux/workqueue.h>
25#include <linux/spi/spi.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040026#include <linux/module.h>
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070027
Atsushi Nemoto13c73f02006-09-29 02:01:37 -070028#define DRV_VERSION "0.2"
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070029
30#define RS5C348_REG_SECS 0
31#define RS5C348_REG_MINS 1
32#define RS5C348_REG_HOURS 2
33#define RS5C348_REG_WDAY 3
34#define RS5C348_REG_DAY 4
35#define RS5C348_REG_MONTH 5
36#define RS5C348_REG_YEAR 6
37#define RS5C348_REG_CTL1 14
38#define RS5C348_REG_CTL2 15
39
40#define RS5C348_SECS_MASK 0x7f
41#define RS5C348_MINS_MASK 0x7f
42#define RS5C348_HOURS_MASK 0x3f
43#define RS5C348_WDAY_MASK 0x03
44#define RS5C348_DAY_MASK 0x3f
45#define RS5C348_MONTH_MASK 0x1f
46
47#define RS5C348_BIT_PM 0x20 /* REG_HOURS */
48#define RS5C348_BIT_Y2K 0x80 /* REG_MONTH */
49#define RS5C348_BIT_24H 0x20 /* REG_CTL1 */
50#define RS5C348_BIT_XSTP 0x10 /* REG_CTL2 */
51#define RS5C348_BIT_VDET 0x40 /* REG_CTL2 */
52
53#define RS5C348_CMD_W(addr) (((addr) << 4) | 0x08) /* single write */
54#define RS5C348_CMD_R(addr) (((addr) << 4) | 0x0c) /* single read */
55#define RS5C348_CMD_MW(addr) (((addr) << 4) | 0x00) /* burst write */
56#define RS5C348_CMD_MR(addr) (((addr) << 4) | 0x04) /* burst read */
57
58struct rs5c348_plat_data {
59 struct rtc_device *rtc;
60 int rtc_24h;
61};
62
63static int
64rs5c348_rtc_set_time(struct device *dev, struct rtc_time *tm)
65{
66 struct spi_device *spi = to_spi_device(dev);
67 struct rs5c348_plat_data *pdata = spi->dev.platform_data;
68 u8 txbuf[5+7], *txp;
69 int ret;
70
71 /* Transfer 5 bytes before writing SEC. This gives 31us for carry. */
72 txp = txbuf;
73 txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
74 txbuf[1] = 0; /* dummy */
75 txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
76 txbuf[3] = 0; /* dummy */
77 txbuf[4] = RS5C348_CMD_MW(RS5C348_REG_SECS); /* cmd, sec, ... */
78 txp = &txbuf[5];
Adrian Bunkfe20ba72008-10-18 20:28:41 -070079 txp[RS5C348_REG_SECS] = bin2bcd(tm->tm_sec);
80 txp[RS5C348_REG_MINS] = bin2bcd(tm->tm_min);
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070081 if (pdata->rtc_24h) {
Adrian Bunkfe20ba72008-10-18 20:28:41 -070082 txp[RS5C348_REG_HOURS] = bin2bcd(tm->tm_hour);
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070083 } else {
84 /* hour 0 is AM12, noon is PM12 */
Adrian Bunkfe20ba72008-10-18 20:28:41 -070085 txp[RS5C348_REG_HOURS] = bin2bcd((tm->tm_hour + 11) % 12 + 1) |
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070086 (tm->tm_hour >= 12 ? RS5C348_BIT_PM : 0);
87 }
Adrian Bunkfe20ba72008-10-18 20:28:41 -070088 txp[RS5C348_REG_WDAY] = bin2bcd(tm->tm_wday);
89 txp[RS5C348_REG_DAY] = bin2bcd(tm->tm_mday);
90 txp[RS5C348_REG_MONTH] = bin2bcd(tm->tm_mon + 1) |
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070091 (tm->tm_year >= 100 ? RS5C348_BIT_Y2K : 0);
Adrian Bunkfe20ba72008-10-18 20:28:41 -070092 txp[RS5C348_REG_YEAR] = bin2bcd(tm->tm_year % 100);
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -070093 /* write in one transfer to avoid data inconsistency */
94 ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), NULL, 0);
95 udelay(62); /* Tcsr 62us */
96 return ret;
97}
98
99static int
100rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
101{
102 struct spi_device *spi = to_spi_device(dev);
103 struct rs5c348_plat_data *pdata = spi->dev.platform_data;
104 u8 txbuf[5], rxbuf[7];
105 int ret;
106
107 /* Transfer 5 byte befores reading SEC. This gives 31us for carry. */
108 txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
109 txbuf[1] = 0; /* dummy */
110 txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
111 txbuf[3] = 0; /* dummy */
112 txbuf[4] = RS5C348_CMD_MR(RS5C348_REG_SECS); /* cmd, sec, ... */
113
114 /* read in one transfer to avoid data inconsistency */
115 ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
116 rxbuf, sizeof(rxbuf));
117 udelay(62); /* Tcsr 62us */
118 if (ret < 0)
119 return ret;
120
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700121 tm->tm_sec = bcd2bin(rxbuf[RS5C348_REG_SECS] & RS5C348_SECS_MASK);
122 tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
123 tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700124 if (!pdata->rtc_24h) {
125 tm->tm_hour %= 12;
126 if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM)
127 tm->tm_hour += 12;
128 }
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700129 tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
130 tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700131 tm->tm_mon =
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700132 bcd2bin(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700133 /* year is 1900 + tm->tm_year */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700134 tm->tm_year = bcd2bin(rxbuf[RS5C348_REG_YEAR]) +
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700135 ((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);
136
137 if (rtc_valid_tm(tm) < 0) {
138 dev_err(&spi->dev, "retrieved date/time is not valid.\n");
139 rtc_time_to_tm(0, tm);
140 }
141
142 return 0;
143}
144
David Brownellff8371a2006-09-30 23:28:17 -0700145static const struct rtc_class_ops rs5c348_rtc_ops = {
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700146 .read_time = rs5c348_rtc_read_time,
147 .set_time = rs5c348_rtc_set_time,
148};
149
150static struct spi_driver rs5c348_driver;
151
152static int __devinit rs5c348_probe(struct spi_device *spi)
153{
154 int ret;
155 struct rtc_device *rtc;
156 struct rs5c348_plat_data *pdata;
157
158 pdata = kzalloc(sizeof(struct rs5c348_plat_data), GFP_KERNEL);
159 if (!pdata)
160 return -ENOMEM;
161 spi->dev.platform_data = pdata;
162
163 /* Check D7 of SECOND register */
164 ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_SECS));
165 if (ret < 0 || (ret & 0x80)) {
166 dev_err(&spi->dev, "not found.\n");
167 goto kfree_exit;
168 }
169
170 dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
171 dev_info(&spi->dev, "spiclk %u KHz.\n",
172 (spi->max_speed_hz + 500) / 1000);
173
174 /* turn RTC on if it was not on */
175 ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
176 if (ret < 0)
177 goto kfree_exit;
178 if (ret & (RS5C348_BIT_XSTP | RS5C348_BIT_VDET)) {
179 u8 buf[2];
Atsushi Nemoto13c73f02006-09-29 02:01:37 -0700180 struct rtc_time tm;
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700181 if (ret & RS5C348_BIT_VDET)
182 dev_warn(&spi->dev, "voltage-low detected.\n");
Atsushi Nemoto13c73f02006-09-29 02:01:37 -0700183 if (ret & RS5C348_BIT_XSTP)
184 dev_warn(&spi->dev, "oscillator-stop detected.\n");
185 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
186 ret = rs5c348_rtc_set_time(&spi->dev, &tm);
187 if (ret < 0)
188 goto kfree_exit;
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700189 buf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
190 buf[1] = 0;
191 ret = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0);
192 if (ret < 0)
193 goto kfree_exit;
194 }
195
196 ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
197 if (ret < 0)
198 goto kfree_exit;
199 if (ret & RS5C348_BIT_24H)
200 pdata->rtc_24h = 1;
201
202 rtc = rtc_device_register(rs5c348_driver.driver.name, &spi->dev,
203 &rs5c348_rtc_ops, THIS_MODULE);
204
205 if (IS_ERR(rtc)) {
206 ret = PTR_ERR(rtc);
207 goto kfree_exit;
208 }
209
210 pdata->rtc = rtc;
211
212 return 0;
213 kfree_exit:
214 kfree(pdata);
215 return ret;
216}
217
218static int __devexit rs5c348_remove(struct spi_device *spi)
219{
220 struct rs5c348_plat_data *pdata = spi->dev.platform_data;
221 struct rtc_device *rtc = pdata->rtc;
222
223 if (rtc)
224 rtc_device_unregister(rtc);
225 kfree(pdata);
226 return 0;
227}
228
229static struct spi_driver rs5c348_driver = {
230 .driver = {
Atsushi Nemoto9f90a032007-08-19 22:32:10 +0900231 .name = "rtc-rs5c348",
Atsushi Nemotoe0ac4762006-06-28 04:26:47 -0700232 .owner = THIS_MODULE,
233 },
234 .probe = rs5c348_probe,
235 .remove = __devexit_p(rs5c348_remove),
236};
237
238static __init int rs5c348_init(void)
239{
240 return spi_register_driver(&rs5c348_driver);
241}
242
243static __exit void rs5c348_exit(void)
244{
245 spi_unregister_driver(&rs5c348_driver);
246}
247
248module_init(rs5c348_init);
249module_exit(rs5c348_exit);
250
251MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
252MODULE_DESCRIPTION("Ricoh RS5C348 RTC driver");
253MODULE_LICENSE("GPL");
254MODULE_VERSION(DRV_VERSION);
Anton Vorontsove0626e32009-09-22 16:46:08 -0700255MODULE_ALIAS("spi:rtc-rs5c348");