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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
Andrea Scian821f51c2015-06-16 11:35:19 +0200168 return rtc_valid_tm(tm);
Chris Verges7f3923a2009-09-22 16:46:20 -0700169}
170
171static 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
217static const struct rtc_class_ops pcf2123_rtc_ops = {
218 .read_time = pcf2123_rtc_read_time,
219 .set_time = pcf2123_rtc_set_time,
220};
221
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800222static int pcf2123_probe(struct spi_device *spi)
Chris Verges7f3923a2009-09-22 16:46:20 -0700223{
224 struct rtc_device *rtc;
225 struct pcf2123_plat_data *pdata;
226 u8 txbuf[2], rxbuf[2];
227 int ret, i;
228
Jingoo Handd48ccc2013-04-29 16:20:47 -0700229 pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data),
230 GFP_KERNEL);
Chris Verges7f3923a2009-09-22 16:46:20 -0700231 if (!pdata)
232 return -ENOMEM;
233 spi->dev.platform_data = pdata;
234
235 /* Send a software reset command */
236 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
237 txbuf[1] = 0x58;
238 dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
239 txbuf[0], txbuf[1]);
240 ret = spi_write(spi, txbuf, 2 * sizeof(u8));
241 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700242 goto kfree_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700243 pcf2123_delay_trec();
244
245 /* Stop the counter */
246 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
247 txbuf[1] = 0x20;
248 dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
249 txbuf[0], txbuf[1]);
250 ret = spi_write(spi, txbuf, 2 * sizeof(u8));
251 if (ret < 0)
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700252 goto kfree_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700253 pcf2123_delay_trec();
254
255 /* See if the counter was actually stopped */
256 txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1;
257 dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
258 txbuf[0]);
259 ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
260 rxbuf, 2 * sizeof(u8));
261 dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
262 rxbuf[0], rxbuf[1]);
263 if (ret < 0)
264 goto kfree_exit;
265 pcf2123_delay_trec();
266
267 if (!(rxbuf[0] & 0x20)) {
268 dev_err(&spi->dev, "chip not found\n");
Wei Yongjun35623712013-04-29 16:21:07 -0700269 ret = -ENODEV;
Chris Verges7f3923a2009-09-22 16:46:20 -0700270 goto kfree_exit;
271 }
272
273 dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
274 dev_info(&spi->dev, "spiclk %u KHz.\n",
275 (spi->max_speed_hz + 500) / 1000);
276
277 /* Start the counter */
278 txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
279 txbuf[1] = 0x00;
280 ret = spi_write(spi, txbuf, sizeof(txbuf));
281 if (ret < 0)
282 goto kfree_exit;
283 pcf2123_delay_trec();
284
285 /* Finalize the initialization */
Jingoo Handd48ccc2013-04-29 16:20:47 -0700286 rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name,
Chris Verges7f3923a2009-09-22 16:46:20 -0700287 &pcf2123_rtc_ops, THIS_MODULE);
288
289 if (IS_ERR(rtc)) {
290 dev_err(&spi->dev, "failed to register.\n");
291 ret = PTR_ERR(rtc);
292 goto kfree_exit;
293 }
294
295 pdata->rtc = rtc;
296
297 for (i = 0; i < 16; i++) {
Ilya Shchepetkov5ed12f12012-08-21 16:16:06 -0700298 sysfs_attr_init(&pdata->regs[i].attr.attr);
Chris Verges7f3923a2009-09-22 16:46:20 -0700299 sprintf(pdata->regs[i].name, "%1x", i);
300 pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
301 pdata->regs[i].attr.attr.name = pdata->regs[i].name;
302 pdata->regs[i].attr.show = pcf2123_show;
303 pdata->regs[i].attr.store = pcf2123_store;
304 ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
305 if (ret) {
306 dev_err(&spi->dev, "Unable to create sysfs %s\n",
307 pdata->regs[i].name);
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700308 goto sysfs_exit;
Chris Verges7f3923a2009-09-22 16:46:20 -0700309 }
310 }
311
312 return 0;
Chris Vergesf3d2570a2009-09-22 16:46:22 -0700313
314sysfs_exit:
315 for (i--; i >= 0; i--)
316 device_remove_file(&spi->dev, &pdata->regs[i].attr);
317
Chris Verges7f3923a2009-09-22 16:46:20 -0700318kfree_exit:
Chris Verges7f3923a2009-09-22 16:46:20 -0700319 spi->dev.platform_data = NULL;
320 return ret;
321}
322
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800323static int pcf2123_remove(struct spi_device *spi)
Chris Verges7f3923a2009-09-22 16:46:20 -0700324{
Jingoo Hanffc75bb2013-11-12 15:10:50 -0800325 struct pcf2123_plat_data *pdata = dev_get_platdata(&spi->dev);
Chris Verges7f3923a2009-09-22 16:46:20 -0700326 int i;
327
328 if (pdata) {
Chris Verges7f3923a2009-09-22 16:46:20 -0700329 for (i = 0; i < 16; i++)
330 if (pdata->regs[i].name[0])
331 device_remove_file(&spi->dev,
332 &pdata->regs[i].attr);
Chris Verges7f3923a2009-09-22 16:46:20 -0700333 }
334
335 return 0;
336}
337
Joshua Clayton3fc70072015-02-13 14:40:29 -0800338#ifdef CONFIG_OF
339static const struct of_device_id pcf2123_dt_ids[] = {
340 { .compatible = "nxp,rtc-pcf2123", },
341 { /* sentinel */ }
342};
343MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);
344#endif
345
Chris Verges7f3923a2009-09-22 16:46:20 -0700346static struct spi_driver pcf2123_driver = {
347 .driver = {
348 .name = "rtc-pcf2123",
Joshua Clayton3fc70072015-02-13 14:40:29 -0800349 .of_match_table = of_match_ptr(pcf2123_dt_ids),
Chris Verges7f3923a2009-09-22 16:46:20 -0700350 },
351 .probe = pcf2123_probe,
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800352 .remove = pcf2123_remove,
Chris Verges7f3923a2009-09-22 16:46:20 -0700353};
354
Axel Lin109e9412012-03-23 15:02:30 -0700355module_spi_driver(pcf2123_driver);
Chris Verges7f3923a2009-09-22 16:46:20 -0700356
357MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
358MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
359MODULE_LICENSE("GPL");
360MODULE_VERSION(DRV_VERSION);