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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[] = {
Sachin Kamat369015f2013-07-03 15:06:01 -070021 * ...
22 * {
23 * .modalias = "rtc-pcf2123",
24 * .chip_select = 1,
25 * .controller_data = (void *)AT91_PIN_PA10,
Chris Verges7f3923a2009-09-22 16:46:20 -070026 * .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>
Joshua Clayton3fc70072015-02-13 14:40:29 -080041#include <linux/of.h>
Chris Verges7f3923a2009-09-22 16:46:20 -070042#include <linux/string.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090043#include <linux/slab.h>
Chris Verges7f3923a2009-09-22 16:46:20 -070044#include <linux/rtc.h>
45#include <linux/spi/spi.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040046#include <linux/module.h>
Ilya Shchepetkov5ed12f12012-08-21 16:16:06 -070047#include <linux/sysfs.h>
Chris Verges7f3923a2009-09-22 16:46:20 -070048
Chris Vergesf3d2570a2009-09-22 16:46:22 -070049#define DRV_VERSION "0.6"
Chris Verges7f3923a2009-09-22 16:46:20 -070050
51#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
52#define PCF2123_REG_CTRL2 (0x01) /* Control Register 2 */
53#define PCF2123_REG_SC (0x02) /* datetime */
54#define PCF2123_REG_MN (0x03)
55#define PCF2123_REG_HR (0x04)
56#define PCF2123_REG_DM (0x05)
57#define PCF2123_REG_DW (0x06)
58#define PCF2123_REG_MO (0x07)
59#define PCF2123_REG_YR (0x08)
60
61#define PCF2123_SUBADDR (1 << 4)
62#define PCF2123_WRITE ((0 << 7) | PCF2123_SUBADDR)
63#define PCF2123_READ ((1 << 7) | PCF2123_SUBADDR)
64
65static struct spi_driver pcf2123_driver;
66
67struct pcf2123_sysfs_reg {
Chris Vergesf3d2570a2009-09-22 16:46:22 -070068 struct device_attribute attr;
Chris Verges7f3923a2009-09-22 16:46:20 -070069 char name[2];
70};
71
72struct pcf2123_plat_data {
73 struct rtc_device *rtc;
74 struct pcf2123_sysfs_reg regs[16];
75};
76
77/*
78 * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
79 * is released properly after an SPI write. This function should be
80 * called after EVERY read/write call over SPI.
81 */
82static inline void pcf2123_delay_trec(void)
83{
84 ndelay(30);
85}
86
87static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
88 char *buffer)
89{
90 struct spi_device *spi = to_spi_device(dev);
Chris Vergesf3d2570a2009-09-22 16:46:22 -070091 struct pcf2123_sysfs_reg *r;
Chris Verges7f3923a2009-09-22 16:46:20 -070092 u8 txbuf[1], rxbuf[1];
Chris Vergesf3d2570a2009-09-22 16:46:22 -070093 unsigned long reg;
Chris Verges7f3923a2009-09-22 16:46:20 -070094 int ret;
95
Chris Vergesf3d2570a2009-09-22 16:46:22 -070096 r = container_of(attr, struct pcf2123_sysfs_reg, attr);
97
Jingoo Han4c5591c2013-07-03 15:07:58 -070098 ret = kstrtoul(r->name, 16, &reg);
99 if (ret)
100 return ret;
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700101
102 txbuf[0] = PCF2123_READ | reg;
Chris Verges7f3923a2009-09-22 16:46:20 -0700103 ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
104 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700105 return -EIO;
Chris Verges7f3923a2009-09-22 16:46:20 -0700106 pcf2123_delay_trec();
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700107 return sprintf(buffer, "0x%x\n", rxbuf[0]);
Chris Verges7f3923a2009-09-22 16:46:20 -0700108}
109
110static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
111 const char *buffer, size_t count) {
112 struct spi_device *spi = to_spi_device(dev);
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700113 struct pcf2123_sysfs_reg *r;
Chris Verges7f3923a2009-09-22 16:46:20 -0700114 u8 txbuf[2];
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700115 unsigned long reg;
116 unsigned long val;
117
Chris Verges7f3923a2009-09-22 16:46:20 -0700118 int ret;
119
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700120 r = container_of(attr, struct pcf2123_sysfs_reg, attr);
121
Jingoo Han4c5591c2013-07-03 15:07:58 -0700122 ret = kstrtoul(r->name, 16, &reg);
123 if (ret)
124 return ret;
125
126 ret = kstrtoul(buffer, 10, &val);
127 if (ret)
128 return ret;
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700129
130 txbuf[0] = PCF2123_WRITE | reg;
131 txbuf[1] = val;
Chris Verges7f3923a2009-09-22 16:46:20 -0700132 ret = spi_write(spi, txbuf, sizeof(txbuf));
133 if (ret < 0)
134 return -EIO;
135 pcf2123_delay_trec();
136 return count;
137}
138
139static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
140{
141 struct spi_device *spi = to_spi_device(dev);
142 u8 txbuf[1], rxbuf[7];
143 int ret;
144
145 txbuf[0] = PCF2123_READ | PCF2123_REG_SC;
146 ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
147 rxbuf, sizeof(rxbuf));
148 if (ret < 0)
149 return ret;
150 pcf2123_delay_trec();
151
152 tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
153 tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
154 tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
155 tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
156 tm->tm_wday = rxbuf[4] & 0x07;
157 tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
158 tm->tm_year = bcd2bin(rxbuf[6]);
159 if (tm->tm_year < 70)
160 tm->tm_year += 100; /* assume we are in 1970...2069 */
161
162 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
163 "mday=%d, mon=%d, year=%d, wday=%d\n",
164 __func__,
165 tm->tm_sec, tm->tm_min, tm->tm_hour,
166 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
167
168 /* the clock can give out invalid datetime, but we cannot return
169 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
170 */
171 if (rtc_valid_tm(tm) < 0)
172 dev_err(dev, "retrieved date/time is not valid.\n");
173
174 return 0;
175}
176
177static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
178{
179 struct spi_device *spi = to_spi_device(dev);
180 u8 txbuf[8];
181 int ret;
182
183 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
184 "mday=%d, mon=%d, year=%d, wday=%d\n",
185 __func__,
186 tm->tm_sec, tm->tm_min, tm->tm_hour,
187 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
188
189 /* Stop the counter first */
190 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
191 txbuf[1] = 0x20;
192 ret = spi_write(spi, txbuf, 2);
193 if (ret < 0)
194 return ret;
195 pcf2123_delay_trec();
196
197 /* Set the new time */
198 txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC;
199 txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
200 txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
201 txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
202 txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
203 txbuf[5] = tm->tm_wday & 0x07;
204 txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
205 txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
206
207 ret = spi_write(spi, txbuf, sizeof(txbuf));
208 if (ret < 0)
209 return ret;
210 pcf2123_delay_trec();
211
212 /* Start the counter */
213 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
214 txbuf[1] = 0x00;
215 ret = spi_write(spi, txbuf, 2);
216 if (ret < 0)
217 return ret;
218 pcf2123_delay_trec();
219
220 return 0;
221}
222
223static const struct rtc_class_ops pcf2123_rtc_ops = {
224 .read_time = pcf2123_rtc_read_time,
225 .set_time = pcf2123_rtc_set_time,
226};
227
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800228static int pcf2123_probe(struct spi_device *spi)
Chris Verges7f3923a2009-09-22 16:46:20 -0700229{
230 struct rtc_device *rtc;
231 struct pcf2123_plat_data *pdata;
232 u8 txbuf[2], rxbuf[2];
233 int ret, i;
234
Jingoo Handd48ccc2013-04-29 16:20:47 -0700235 pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data),
236 GFP_KERNEL);
Chris Verges7f3923a2009-09-22 16:46:20 -0700237 if (!pdata)
238 return -ENOMEM;
239 spi->dev.platform_data = pdata;
240
241 /* Send a software reset command */
242 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
243 txbuf[1] = 0x58;
244 dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
245 txbuf[0], txbuf[1]);
246 ret = spi_write(spi, txbuf, 2 * sizeof(u8));
247 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700248 goto kfree_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700249 pcf2123_delay_trec();
250
251 /* Stop the counter */
252 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
253 txbuf[1] = 0x20;
254 dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
255 txbuf[0], txbuf[1]);
256 ret = spi_write(spi, txbuf, 2 * sizeof(u8));
257 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700258 goto kfree_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700259 pcf2123_delay_trec();
260
261 /* See if the counter was actually stopped */
262 txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1;
263 dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
264 txbuf[0]);
265 ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
266 rxbuf, 2 * sizeof(u8));
267 dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
268 rxbuf[0], rxbuf[1]);
269 if (ret < 0)
270 goto kfree_exit;
271 pcf2123_delay_trec();
272
273 if (!(rxbuf[0] & 0x20)) {
274 dev_err(&spi->dev, "chip not found\n");
Wei Yongjun35623712013-04-29 16:21:07 -0700275 ret = -ENODEV;
Chris Verges7f3923a2009-09-22 16:46:20 -0700276 goto kfree_exit;
277 }
278
279 dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
280 dev_info(&spi->dev, "spiclk %u KHz.\n",
281 (spi->max_speed_hz + 500) / 1000);
282
283 /* Start the counter */
284 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
285 txbuf[1] = 0x00;
286 ret = spi_write(spi, txbuf, sizeof(txbuf));
287 if (ret < 0)
288 goto kfree_exit;
289 pcf2123_delay_trec();
290
291 /* Finalize the initialization */
Jingoo Handd48ccc2013-04-29 16:20:47 -0700292 rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name,
Chris Verges7f3923a2009-09-22 16:46:20 -0700293 &pcf2123_rtc_ops, THIS_MODULE);
294
295 if (IS_ERR(rtc)) {
296 dev_err(&spi->dev, "failed to register.\n");
297 ret = PTR_ERR(rtc);
298 goto kfree_exit;
299 }
300
301 pdata->rtc = rtc;
302
303 for (i = 0; i < 16; i++) {
Ilya Shchepetkov5ed12f12012-08-21 16:16:06 -0700304 sysfs_attr_init(&pdata->regs[i].attr.attr);
Chris Verges7f3923a2009-09-22 16:46:20 -0700305 sprintf(pdata->regs[i].name, "%1x", i);
306 pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
307 pdata->regs[i].attr.attr.name = pdata->regs[i].name;
308 pdata->regs[i].attr.show = pcf2123_show;
309 pdata->regs[i].attr.store = pcf2123_store;
310 ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
311 if (ret) {
312 dev_err(&spi->dev, "Unable to create sysfs %s\n",
313 pdata->regs[i].name);
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700314 goto sysfs_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700315 }
316 }
317
318 return 0;
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700319
320sysfs_exit:
321 for (i--; i >= 0; i--)
322 device_remove_file(&spi->dev, &pdata->regs[i].attr);
323
Chris Verges7f3923a2009-09-22 16:46:20 -0700324kfree_exit:
Chris Verges7f3923a2009-09-22 16:46:20 -0700325 spi->dev.platform_data = NULL;
326 return ret;
327}
328
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800329static int pcf2123_remove(struct spi_device *spi)
Chris Verges7f3923a2009-09-22 16:46:20 -0700330{
Jingoo Hanffc75bb2013-11-12 15:10:50 -0800331 struct pcf2123_plat_data *pdata = dev_get_platdata(&spi->dev);
Chris Verges7f3923a2009-09-22 16:46:20 -0700332 int i;
333
334 if (pdata) {
Chris Verges7f3923a2009-09-22 16:46:20 -0700335 for (i = 0; i < 16; i++)
336 if (pdata->regs[i].name[0])
337 device_remove_file(&spi->dev,
338 &pdata->regs[i].attr);
Chris Verges7f3923a2009-09-22 16:46:20 -0700339 }
340
341 return 0;
342}
343
Joshua Clayton3fc70072015-02-13 14:40:29 -0800344#ifdef CONFIG_OF
345static const struct of_device_id pcf2123_dt_ids[] = {
346 { .compatible = "nxp,rtc-pcf2123", },
347 { /* sentinel */ }
348};
349MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);
350#endif
351
Chris Verges7f3923a2009-09-22 16:46:20 -0700352static struct spi_driver pcf2123_driver = {
353 .driver = {
354 .name = "rtc-pcf2123",
Chris Verges7f3923a2009-09-22 16:46:20 -0700355 .owner = THIS_MODULE,
Joshua Clayton3fc70072015-02-13 14:40:29 -0800356 .of_match_table = of_match_ptr(pcf2123_dt_ids),
Chris Verges7f3923a2009-09-22 16:46:20 -0700357 },
358 .probe = pcf2123_probe,
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800359 .remove = pcf2123_remove,
Chris Verges7f3923a2009-09-22 16:46:20 -0700360};
361
Axel Lin109e9412012-03-23 15:02:30 -0700362module_spi_driver(pcf2123_driver);
Chris Verges7f3923a2009-09-22 16:46:20 -0700363
364MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
365MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
366MODULE_LICENSE("GPL");
367MODULE_VERSION(DRV_VERSION);