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7f3923a1 CV |
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> | |
5a0e3ad6 | 42 | #include <linux/slab.h> |
7f3923a1 CV |
43 | #include <linux/rtc.h> |
44 | #include <linux/spi/spi.h> | |
2113852b | 45 | #include <linux/module.h> |
7f3923a1 | 46 | |
f3d2570a | 47 | #define DRV_VERSION "0.6" |
7f3923a1 CV |
48 | |
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 | ||
63 | static struct spi_driver pcf2123_driver; | |
64 | ||
65 | struct pcf2123_sysfs_reg { | |
f3d2570a | 66 | struct device_attribute attr; |
7f3923a1 CV |
67 | char name[2]; |
68 | }; | |
69 | ||
70 | struct 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 | */ | |
80 | static inline void pcf2123_delay_trec(void) | |
81 | { | |
82 | ndelay(30); | |
83 | } | |
84 | ||
85 | static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr, | |
86 | char *buffer) | |
87 | { | |
88 | struct spi_device *spi = to_spi_device(dev); | |
f3d2570a | 89 | struct pcf2123_sysfs_reg *r; |
7f3923a1 | 90 | u8 txbuf[1], rxbuf[1]; |
f3d2570a | 91 | unsigned long reg; |
7f3923a1 CV |
92 | int ret; |
93 | ||
f3d2570a CV |
94 | r = container_of(attr, struct pcf2123_sysfs_reg, attr); |
95 | ||
96 | if (strict_strtoul(r->name, 16, ®)) | |
97 | return -EINVAL; | |
98 | ||
99 | txbuf[0] = PCF2123_READ | reg; | |
7f3923a1 CV |
100 | ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1); |
101 | if (ret < 0) | |
f3d2570a | 102 | return -EIO; |
7f3923a1 | 103 | pcf2123_delay_trec(); |
f3d2570a | 104 | return sprintf(buffer, "0x%x\n", rxbuf[0]); |
7f3923a1 CV |
105 | } |
106 | ||
107 | static 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); | |
f3d2570a | 110 | struct pcf2123_sysfs_reg *r; |
7f3923a1 | 111 | u8 txbuf[2]; |
f3d2570a CV |
112 | unsigned long reg; |
113 | unsigned long val; | |
114 | ||
7f3923a1 CV |
115 | int ret; |
116 | ||
f3d2570a CV |
117 | r = container_of(attr, struct pcf2123_sysfs_reg, attr); |
118 | ||
119 | if (strict_strtoul(r->name, 16, ®) | |
120 | || strict_strtoul(buffer, 10, &val)) | |
121 | return -EINVAL; | |
122 | ||
123 | txbuf[0] = PCF2123_WRITE | reg; | |
124 | txbuf[1] = val; | |
7f3923a1 CV |
125 | ret = spi_write(spi, txbuf, sizeof(txbuf)); |
126 | if (ret < 0) | |
127 | return -EIO; | |
128 | pcf2123_delay_trec(); | |
129 | return count; | |
130 | } | |
131 | ||
132 | static 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 | ||
170 | static 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 | ||
216 | static const struct rtc_class_ops pcf2123_rtc_ops = { | |
217 | .read_time = pcf2123_rtc_read_time, | |
218 | .set_time = pcf2123_rtc_set_time, | |
219 | }; | |
220 | ||
221 | static 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) | |
f3d2570a | 240 | goto kfree_exit; |
7f3923a1 CV |
241 | 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) | |
f3d2570a | 250 | goto kfree_exit; |
7f3923a1 CV |
251 | 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); | |
f3d2570a | 304 | goto sysfs_exit; |
7f3923a1 CV |
305 | } |
306 | } | |
307 | ||
308 | return 0; | |
f3d2570a CV |
309 | |
310 | sysfs_exit: | |
311 | for (i--; i >= 0; i--) | |
312 | device_remove_file(&spi->dev, &pdata->regs[i].attr); | |
313 | ||
7f3923a1 CV |
314 | kfree_exit: |
315 | kfree(pdata); | |
316 | spi->dev.platform_data = NULL; | |
317 | return ret; | |
318 | } | |
319 | ||
b51e8293 | 320 | static int __devexit pcf2123_remove(struct spi_device *spi) |
7f3923a1 CV |
321 | { |
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 | ||
340 | static struct spi_driver pcf2123_driver = { | |
341 | .driver = { | |
342 | .name = "rtc-pcf2123", | |
7f3923a1 CV |
343 | .owner = THIS_MODULE, |
344 | }, | |
345 | .probe = pcf2123_probe, | |
346 | .remove = __devexit_p(pcf2123_remove), | |
347 | }; | |
348 | ||
109e9418 | 349 | module_spi_driver(pcf2123_driver); |
7f3923a1 CV |
350 | |
351 | MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>"); | |
352 | MODULE_DESCRIPTION("NXP PCF2123 RTC driver"); | |
353 | MODULE_LICENSE("GPL"); | |
354 | MODULE_VERSION(DRV_VERSION); |