blob: 836118795c0bdb4f0ad5874a3b3dc50dee5ffd69 [file] [log] [blame]
Chris Verges7f3923a2009-09-22 16:46:20 -07001/*
2 * An SPI driver for the Philips PCF2123 RTC
3 * Copyright 2009 Cyber Switching, Inc.
4 *
5 * Author: Chris Verges <chrisv@cyberswitching.com>
6 * Maintainers: http://www.cyberswitching.com
7 *
8 * based on the RS5C348 driver in this same directory.
9 *
10 * Thanks to Christian Pellegrin <chripell@fsfe.org> for
11 * the sysfs contributions to this driver.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
16 *
17 * Please note that the CS is active high, so platform data
18 * should look something like:
19 *
20 * static struct spi_board_info ek_spi_devices[] = {
21 * ...
22 * {
23 * .modalias = "rtc-pcf2123",
24 * .chip_select = 1,
25 * .controller_data = (void *)AT91_PIN_PA10,
26 * .max_speed_hz = 1000 * 1000,
27 * .mode = SPI_CS_HIGH,
28 * .bus_num = 0,
29 * },
30 * ...
31 *};
32 *
33 */
34
35#include <linux/bcd.h>
36#include <linux/delay.h>
37#include <linux/device.h>
38#include <linux/errno.h>
39#include <linux/init.h>
40#include <linux/kernel.h>
41#include <linux/string.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090042#include <linux/slab.h>
Chris Verges7f3923a2009-09-22 16:46:20 -070043#include <linux/rtc.h>
44#include <linux/spi/spi.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040045#include <linux/module.h>
Chris Verges7f3923a2009-09-22 16:46:20 -070046
Chris Vergesf3d2570a2009-09-22 16:46:22 -070047#define DRV_VERSION "0.6"
Chris Verges7f3923a2009-09-22 16:46:20 -070048
49#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
50#define PCF2123_REG_CTRL2 (0x01) /* Control Register 2 */
51#define PCF2123_REG_SC (0x02) /* datetime */
52#define PCF2123_REG_MN (0x03)
53#define PCF2123_REG_HR (0x04)
54#define PCF2123_REG_DM (0x05)
55#define PCF2123_REG_DW (0x06)
56#define PCF2123_REG_MO (0x07)
57#define PCF2123_REG_YR (0x08)
58
59#define PCF2123_SUBADDR (1 << 4)
60#define PCF2123_WRITE ((0 << 7) | PCF2123_SUBADDR)
61#define PCF2123_READ ((1 << 7) | PCF2123_SUBADDR)
62
63static struct spi_driver pcf2123_driver;
64
65struct pcf2123_sysfs_reg {
Chris Vergesf3d2570a2009-09-22 16:46:22 -070066 struct device_attribute attr;
Chris Verges7f3923a2009-09-22 16:46:20 -070067 char name[2];
68};
69
70struct pcf2123_plat_data {
71 struct rtc_device *rtc;
72 struct pcf2123_sysfs_reg regs[16];
73};
74
75/*
76 * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
77 * is released properly after an SPI write. This function should be
78 * called after EVERY read/write call over SPI.
79 */
80static inline void pcf2123_delay_trec(void)
81{
82 ndelay(30);
83}
84
85static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
86 char *buffer)
87{
88 struct spi_device *spi = to_spi_device(dev);
Chris Vergesf3d2570a2009-09-22 16:46:22 -070089 struct pcf2123_sysfs_reg *r;
Chris Verges7f3923a2009-09-22 16:46:20 -070090 u8 txbuf[1], rxbuf[1];
Chris Vergesf3d2570a2009-09-22 16:46:22 -070091 unsigned long reg;
Chris Verges7f3923a2009-09-22 16:46:20 -070092 int ret;
93
Chris Vergesf3d2570a2009-09-22 16:46:22 -070094 r = container_of(attr, struct pcf2123_sysfs_reg, attr);
95
96 if (strict_strtoul(r->name, 16, &reg))
97 return -EINVAL;
98
99 txbuf[0] = PCF2123_READ | reg;
Chris Verges7f3923a2009-09-22 16:46:20 -0700100 ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
101 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700102 return -EIO;
Chris Verges7f3923a2009-09-22 16:46:20 -0700103 pcf2123_delay_trec();
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700104 return sprintf(buffer, "0x%x\n", rxbuf[0]);
Chris Verges7f3923a2009-09-22 16:46:20 -0700105}
106
107static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
108 const char *buffer, size_t count) {
109 struct spi_device *spi = to_spi_device(dev);
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700110 struct pcf2123_sysfs_reg *r;
Chris Verges7f3923a2009-09-22 16:46:20 -0700111 u8 txbuf[2];
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700112 unsigned long reg;
113 unsigned long val;
114
Chris Verges7f3923a2009-09-22 16:46:20 -0700115 int ret;
116
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700117 r = container_of(attr, struct pcf2123_sysfs_reg, attr);
118
119 if (strict_strtoul(r->name, 16, &reg)
120 || strict_strtoul(buffer, 10, &val))
121 return -EINVAL;
122
123 txbuf[0] = PCF2123_WRITE | reg;
124 txbuf[1] = val;
Chris Verges7f3923a2009-09-22 16:46:20 -0700125 ret = spi_write(spi, txbuf, sizeof(txbuf));
126 if (ret < 0)
127 return -EIO;
128 pcf2123_delay_trec();
129 return count;
130}
131
132static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
133{
134 struct spi_device *spi = to_spi_device(dev);
135 u8 txbuf[1], rxbuf[7];
136 int ret;
137
138 txbuf[0] = PCF2123_READ | PCF2123_REG_SC;
139 ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
140 rxbuf, sizeof(rxbuf));
141 if (ret < 0)
142 return ret;
143 pcf2123_delay_trec();
144
145 tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
146 tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
147 tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
148 tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
149 tm->tm_wday = rxbuf[4] & 0x07;
150 tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
151 tm->tm_year = bcd2bin(rxbuf[6]);
152 if (tm->tm_year < 70)
153 tm->tm_year += 100; /* assume we are in 1970...2069 */
154
155 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
156 "mday=%d, mon=%d, year=%d, wday=%d\n",
157 __func__,
158 tm->tm_sec, tm->tm_min, tm->tm_hour,
159 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
160
161 /* the clock can give out invalid datetime, but we cannot return
162 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
163 */
164 if (rtc_valid_tm(tm) < 0)
165 dev_err(dev, "retrieved date/time is not valid.\n");
166
167 return 0;
168}
169
170static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
171{
172 struct spi_device *spi = to_spi_device(dev);
173 u8 txbuf[8];
174 int ret;
175
176 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
177 "mday=%d, mon=%d, year=%d, wday=%d\n",
178 __func__,
179 tm->tm_sec, tm->tm_min, tm->tm_hour,
180 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
181
182 /* Stop the counter first */
183 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
184 txbuf[1] = 0x20;
185 ret = spi_write(spi, txbuf, 2);
186 if (ret < 0)
187 return ret;
188 pcf2123_delay_trec();
189
190 /* Set the new time */
191 txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC;
192 txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
193 txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
194 txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
195 txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
196 txbuf[5] = tm->tm_wday & 0x07;
197 txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
198 txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
199
200 ret = spi_write(spi, txbuf, sizeof(txbuf));
201 if (ret < 0)
202 return ret;
203 pcf2123_delay_trec();
204
205 /* Start the counter */
206 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
207 txbuf[1] = 0x00;
208 ret = spi_write(spi, txbuf, 2);
209 if (ret < 0)
210 return ret;
211 pcf2123_delay_trec();
212
213 return 0;
214}
215
216static const struct rtc_class_ops pcf2123_rtc_ops = {
217 .read_time = pcf2123_rtc_read_time,
218 .set_time = pcf2123_rtc_set_time,
219};
220
221static int __devinit pcf2123_probe(struct spi_device *spi)
222{
223 struct rtc_device *rtc;
224 struct pcf2123_plat_data *pdata;
225 u8 txbuf[2], rxbuf[2];
226 int ret, i;
227
228 pdata = kzalloc(sizeof(struct pcf2123_plat_data), GFP_KERNEL);
229 if (!pdata)
230 return -ENOMEM;
231 spi->dev.platform_data = pdata;
232
233 /* Send a software reset command */
234 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
235 txbuf[1] = 0x58;
236 dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
237 txbuf[0], txbuf[1]);
238 ret = spi_write(spi, txbuf, 2 * sizeof(u8));
239 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700240 goto kfree_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700241 pcf2123_delay_trec();
242
243 /* Stop the counter */
244 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
245 txbuf[1] = 0x20;
246 dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
247 txbuf[0], txbuf[1]);
248 ret = spi_write(spi, txbuf, 2 * sizeof(u8));
249 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700250 goto kfree_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700251 pcf2123_delay_trec();
252
253 /* See if the counter was actually stopped */
254 txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1;
255 dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
256 txbuf[0]);
257 ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
258 rxbuf, 2 * sizeof(u8));
259 dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
260 rxbuf[0], rxbuf[1]);
261 if (ret < 0)
262 goto kfree_exit;
263 pcf2123_delay_trec();
264
265 if (!(rxbuf[0] & 0x20)) {
266 dev_err(&spi->dev, "chip not found\n");
267 goto kfree_exit;
268 }
269
270 dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
271 dev_info(&spi->dev, "spiclk %u KHz.\n",
272 (spi->max_speed_hz + 500) / 1000);
273
274 /* Start the counter */
275 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
276 txbuf[1] = 0x00;
277 ret = spi_write(spi, txbuf, sizeof(txbuf));
278 if (ret < 0)
279 goto kfree_exit;
280 pcf2123_delay_trec();
281
282 /* Finalize the initialization */
283 rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,
284 &pcf2123_rtc_ops, THIS_MODULE);
285
286 if (IS_ERR(rtc)) {
287 dev_err(&spi->dev, "failed to register.\n");
288 ret = PTR_ERR(rtc);
289 goto kfree_exit;
290 }
291
292 pdata->rtc = rtc;
293
294 for (i = 0; i < 16; i++) {
295 sprintf(pdata->regs[i].name, "%1x", i);
296 pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
297 pdata->regs[i].attr.attr.name = pdata->regs[i].name;
298 pdata->regs[i].attr.show = pcf2123_show;
299 pdata->regs[i].attr.store = pcf2123_store;
300 ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
301 if (ret) {
302 dev_err(&spi->dev, "Unable to create sysfs %s\n",
303 pdata->regs[i].name);
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700304 goto sysfs_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700305 }
306 }
307
308 return 0;
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700309
310sysfs_exit:
311 for (i--; i >= 0; i--)
312 device_remove_file(&spi->dev, &pdata->regs[i].attr);
313
Chris Verges7f3923a2009-09-22 16:46:20 -0700314kfree_exit:
315 kfree(pdata);
316 spi->dev.platform_data = NULL;
317 return ret;
318}
319
Uwe Kleine-Königb51e8292010-03-05 13:44:21 -0800320static int __devexit pcf2123_remove(struct spi_device *spi)
Chris Verges7f3923a2009-09-22 16:46:20 -0700321{
322 struct pcf2123_plat_data *pdata = spi->dev.platform_data;
323 int i;
324
325 if (pdata) {
326 struct rtc_device *rtc = pdata->rtc;
327
328 if (rtc)
329 rtc_device_unregister(rtc);
330 for (i = 0; i < 16; i++)
331 if (pdata->regs[i].name[0])
332 device_remove_file(&spi->dev,
333 &pdata->regs[i].attr);
334 kfree(pdata);
335 }
336
337 return 0;
338}
339
340static struct spi_driver pcf2123_driver = {
341 .driver = {
342 .name = "rtc-pcf2123",
Chris Verges7f3923a2009-09-22 16:46:20 -0700343 .owner = THIS_MODULE,
344 },
345 .probe = pcf2123_probe,
346 .remove = __devexit_p(pcf2123_remove),
347};
348
Axel Lin109e9412012-03-23 15:02:30 -0700349module_spi_driver(pcf2123_driver);
Chris Verges7f3923a2009-09-22 16:46:20 -0700350
351MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
352MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
353MODULE_LICENSE("GPL");
354MODULE_VERSION(DRV_VERSION);