]> git.kernelconcepts.de Git - karo-tx-linux.git/blob - drivers/rtc/rtc-pcf2123.c
regulator: max8997: Convert max8997_safeout_ops to set_voltage_sel and list_voltage_table
[karo-tx-linux.git] / drivers / rtc / rtc-pcf2123.c
1 /*
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>
42 #include <linux/slab.h>
43 #include <linux/rtc.h>
44 #include <linux/spi/spi.h>
45 #include <linux/module.h>
46 #include <linux/sysfs.h>
47
48 #define DRV_VERSION "0.6"
49
50 #define PCF2123_REG_CTRL1       (0x00)  /* Control Register 1 */
51 #define PCF2123_REG_CTRL2       (0x01)  /* Control Register 2 */
52 #define PCF2123_REG_SC          (0x02)  /* datetime */
53 #define PCF2123_REG_MN          (0x03)
54 #define PCF2123_REG_HR          (0x04)
55 #define PCF2123_REG_DM          (0x05)
56 #define PCF2123_REG_DW          (0x06)
57 #define PCF2123_REG_MO          (0x07)
58 #define PCF2123_REG_YR          (0x08)
59
60 #define PCF2123_SUBADDR         (1 << 4)
61 #define PCF2123_WRITE           ((0 << 7) | PCF2123_SUBADDR)
62 #define PCF2123_READ            ((1 << 7) | PCF2123_SUBADDR)
63
64 static struct spi_driver pcf2123_driver;
65
66 struct pcf2123_sysfs_reg {
67         struct device_attribute attr;
68         char name[2];
69 };
70
71 struct pcf2123_plat_data {
72         struct rtc_device *rtc;
73         struct pcf2123_sysfs_reg regs[16];
74 };
75
76 /*
77  * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
78  * is released properly after an SPI write.  This function should be
79  * called after EVERY read/write call over SPI.
80  */
81 static inline void pcf2123_delay_trec(void)
82 {
83         ndelay(30);
84 }
85
86 static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
87                             char *buffer)
88 {
89         struct spi_device *spi = to_spi_device(dev);
90         struct pcf2123_sysfs_reg *r;
91         u8 txbuf[1], rxbuf[1];
92         unsigned long reg;
93         int ret;
94
95         r = container_of(attr, struct pcf2123_sysfs_reg, attr);
96
97         if (strict_strtoul(r->name, 16, &reg))
98                 return -EINVAL;
99
100         txbuf[0] = PCF2123_READ | reg;
101         ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
102         if (ret < 0)
103                 return -EIO;
104         pcf2123_delay_trec();
105         return sprintf(buffer, "0x%x\n", rxbuf[0]);
106 }
107
108 static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
109                              const char *buffer, size_t count) {
110         struct spi_device *spi = to_spi_device(dev);
111         struct pcf2123_sysfs_reg *r;
112         u8 txbuf[2];
113         unsigned long reg;
114         unsigned long val;
115
116         int ret;
117
118         r = container_of(attr, struct pcf2123_sysfs_reg, attr);
119
120         if (strict_strtoul(r->name, 16, &reg)
121                 || strict_strtoul(buffer, 10, &val))
122                 return -EINVAL;
123
124         txbuf[0] = PCF2123_WRITE | reg;
125         txbuf[1] = val;
126         ret = spi_write(spi, txbuf, sizeof(txbuf));
127         if (ret < 0)
128                 return -EIO;
129         pcf2123_delay_trec();
130         return count;
131 }
132
133 static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
134 {
135         struct spi_device *spi = to_spi_device(dev);
136         u8 txbuf[1], rxbuf[7];
137         int ret;
138
139         txbuf[0] = PCF2123_READ | PCF2123_REG_SC;
140         ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
141                         rxbuf, sizeof(rxbuf));
142         if (ret < 0)
143                 return ret;
144         pcf2123_delay_trec();
145
146         tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
147         tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
148         tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
149         tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
150         tm->tm_wday = rxbuf[4] & 0x07;
151         tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
152         tm->tm_year = bcd2bin(rxbuf[6]);
153         if (tm->tm_year < 70)
154                 tm->tm_year += 100;     /* assume we are in 1970...2069 */
155
156         dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
157                         "mday=%d, mon=%d, year=%d, wday=%d\n",
158                         __func__,
159                         tm->tm_sec, tm->tm_min, tm->tm_hour,
160                         tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
161
162         /* the clock can give out invalid datetime, but we cannot return
163          * -EINVAL otherwise hwclock will refuse to set the time on bootup.
164          */
165         if (rtc_valid_tm(tm) < 0)
166                 dev_err(dev, "retrieved date/time is not valid.\n");
167
168         return 0;
169 }
170
171 static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
172 {
173         struct spi_device *spi = to_spi_device(dev);
174         u8 txbuf[8];
175         int ret;
176
177         dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
178                         "mday=%d, mon=%d, year=%d, wday=%d\n",
179                         __func__,
180                         tm->tm_sec, tm->tm_min, tm->tm_hour,
181                         tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
182
183         /* Stop the counter first */
184         txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
185         txbuf[1] = 0x20;
186         ret = spi_write(spi, txbuf, 2);
187         if (ret < 0)
188                 return ret;
189         pcf2123_delay_trec();
190
191         /* Set the new time */
192         txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC;
193         txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
194         txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
195         txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
196         txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
197         txbuf[5] = tm->tm_wday & 0x07;
198         txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
199         txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
200
201         ret = spi_write(spi, txbuf, sizeof(txbuf));
202         if (ret < 0)
203                 return ret;
204         pcf2123_delay_trec();
205
206         /* Start the counter */
207         txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
208         txbuf[1] = 0x00;
209         ret = spi_write(spi, txbuf, 2);
210         if (ret < 0)
211                 return ret;
212         pcf2123_delay_trec();
213
214         return 0;
215 }
216
217 static const struct rtc_class_ops pcf2123_rtc_ops = {
218         .read_time      = pcf2123_rtc_read_time,
219         .set_time       = pcf2123_rtc_set_time,
220 };
221
222 static int __devinit pcf2123_probe(struct spi_device *spi)
223 {
224         struct rtc_device *rtc;
225         struct pcf2123_plat_data *pdata;
226         u8 txbuf[2], rxbuf[2];
227         int ret, i;
228
229         pdata = kzalloc(sizeof(struct pcf2123_plat_data), GFP_KERNEL);
230         if (!pdata)
231                 return -ENOMEM;
232         spi->dev.platform_data = pdata;
233
234         /* Send a software reset command */
235         txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
236         txbuf[1] = 0x58;
237         dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
238                         txbuf[0], txbuf[1]);
239         ret = spi_write(spi, txbuf, 2 * sizeof(u8));
240         if (ret < 0)
241                 goto kfree_exit;
242         pcf2123_delay_trec();
243
244         /* Stop the counter */
245         txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
246         txbuf[1] = 0x20;
247         dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
248                         txbuf[0], txbuf[1]);
249         ret = spi_write(spi, txbuf, 2 * sizeof(u8));
250         if (ret < 0)
251                 goto kfree_exit;
252         pcf2123_delay_trec();
253
254         /* See if the counter was actually stopped */
255         txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1;
256         dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
257                         txbuf[0]);
258         ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
259                                         rxbuf, 2 * sizeof(u8));
260         dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
261                         rxbuf[0], rxbuf[1]);
262         if (ret < 0)
263                 goto kfree_exit;
264         pcf2123_delay_trec();
265
266         if (!(rxbuf[0] & 0x20)) {
267                 dev_err(&spi->dev, "chip not found\n");
268                 goto kfree_exit;
269         }
270
271         dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
272         dev_info(&spi->dev, "spiclk %u KHz.\n",
273                         (spi->max_speed_hz + 500) / 1000);
274
275         /* Start the counter */
276         txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
277         txbuf[1] = 0x00;
278         ret = spi_write(spi, txbuf, sizeof(txbuf));
279         if (ret < 0)
280                 goto kfree_exit;
281         pcf2123_delay_trec();
282
283         /* Finalize the initialization */
284         rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,
285                         &pcf2123_rtc_ops, THIS_MODULE);
286
287         if (IS_ERR(rtc)) {
288                 dev_err(&spi->dev, "failed to register.\n");
289                 ret = PTR_ERR(rtc);
290                 goto kfree_exit;
291         }
292
293         pdata->rtc = rtc;
294
295         for (i = 0; i < 16; i++) {
296                 sysfs_attr_init(&pdata->regs[i].attr.attr);
297                 sprintf(pdata->regs[i].name, "%1x", i);
298                 pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
299                 pdata->regs[i].attr.attr.name = pdata->regs[i].name;
300                 pdata->regs[i].attr.show = pcf2123_show;
301                 pdata->regs[i].attr.store = pcf2123_store;
302                 ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
303                 if (ret) {
304                         dev_err(&spi->dev, "Unable to create sysfs %s\n",
305                                 pdata->regs[i].name);
306                         goto sysfs_exit;
307                 }
308         }
309
310         return 0;
311
312 sysfs_exit:
313         for (i--; i >= 0; i--)
314                 device_remove_file(&spi->dev, &pdata->regs[i].attr);
315
316 kfree_exit:
317         kfree(pdata);
318         spi->dev.platform_data = NULL;
319         return ret;
320 }
321
322 static int __devexit pcf2123_remove(struct spi_device *spi)
323 {
324         struct pcf2123_plat_data *pdata = spi->dev.platform_data;
325         int i;
326
327         if (pdata) {
328                 struct rtc_device *rtc = pdata->rtc;
329
330                 if (rtc)
331                         rtc_device_unregister(rtc);
332                 for (i = 0; i < 16; i++)
333                         if (pdata->regs[i].name[0])
334                                 device_remove_file(&spi->dev,
335                                                    &pdata->regs[i].attr);
336                 kfree(pdata);
337         }
338
339         return 0;
340 }
341
342 static struct spi_driver pcf2123_driver = {
343         .driver = {
344                         .name   = "rtc-pcf2123",
345                         .owner  = THIS_MODULE,
346         },
347         .probe  = pcf2123_probe,
348         .remove = __devexit_p(pcf2123_remove),
349 };
350
351 module_spi_driver(pcf2123_driver);
352
353 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
354 MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
355 MODULE_LICENSE("GPL");
356 MODULE_VERSION(DRV_VERSION);