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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[] = { | |
369015fb SK |
21 | * ... |
22 | * { | |
23 | * .modalias = "rtc-pcf2123", | |
24 | * .chip_select = 1, | |
25 | * .controller_data = (void *)AT91_PIN_PA10, | |
7f3923a1 CV |
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> |
5ed12f12 | 46 | #include <linux/sysfs.h> |
7f3923a1 | 47 | |
f3d2570a | 48 | #define DRV_VERSION "0.6" |
7f3923a1 CV |
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 { | |
f3d2570a | 67 | struct device_attribute attr; |
7f3923a1 CV |
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); | |
f3d2570a | 90 | struct pcf2123_sysfs_reg *r; |
7f3923a1 | 91 | u8 txbuf[1], rxbuf[1]; |
f3d2570a | 92 | unsigned long reg; |
7f3923a1 CV |
93 | int ret; |
94 | ||
f3d2570a CV |
95 | r = container_of(attr, struct pcf2123_sysfs_reg, attr); |
96 | ||
4c5591c1 JH |
97 | ret = kstrtoul(r->name, 16, ®); |
98 | if (ret) | |
99 | return ret; | |
f3d2570a CV |
100 | |
101 | txbuf[0] = PCF2123_READ | reg; | |
7f3923a1 CV |
102 | ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1); |
103 | if (ret < 0) | |
f3d2570a | 104 | return -EIO; |
7f3923a1 | 105 | pcf2123_delay_trec(); |
f3d2570a | 106 | return sprintf(buffer, "0x%x\n", rxbuf[0]); |
7f3923a1 CV |
107 | } |
108 | ||
109 | static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr, | |
110 | const char *buffer, size_t count) { | |
111 | struct spi_device *spi = to_spi_device(dev); | |
f3d2570a | 112 | struct pcf2123_sysfs_reg *r; |
7f3923a1 | 113 | u8 txbuf[2]; |
f3d2570a CV |
114 | unsigned long reg; |
115 | unsigned long val; | |
116 | ||
7f3923a1 CV |
117 | int ret; |
118 | ||
f3d2570a CV |
119 | r = container_of(attr, struct pcf2123_sysfs_reg, attr); |
120 | ||
4c5591c1 JH |
121 | ret = kstrtoul(r->name, 16, ®); |
122 | if (ret) | |
123 | return ret; | |
124 | ||
125 | ret = kstrtoul(buffer, 10, &val); | |
126 | if (ret) | |
127 | return ret; | |
f3d2570a CV |
128 | |
129 | txbuf[0] = PCF2123_WRITE | reg; | |
130 | txbuf[1] = val; | |
7f3923a1 CV |
131 | ret = spi_write(spi, txbuf, sizeof(txbuf)); |
132 | if (ret < 0) | |
133 | return -EIO; | |
134 | pcf2123_delay_trec(); | |
135 | return count; | |
136 | } | |
137 | ||
138 | static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
139 | { | |
140 | struct spi_device *spi = to_spi_device(dev); | |
141 | u8 txbuf[1], rxbuf[7]; | |
142 | int ret; | |
143 | ||
144 | txbuf[0] = PCF2123_READ | PCF2123_REG_SC; | |
145 | ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), | |
146 | rxbuf, sizeof(rxbuf)); | |
147 | if (ret < 0) | |
148 | return ret; | |
149 | pcf2123_delay_trec(); | |
150 | ||
151 | tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F); | |
152 | tm->tm_min = bcd2bin(rxbuf[1] & 0x7F); | |
153 | tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */ | |
154 | tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F); | |
155 | tm->tm_wday = rxbuf[4] & 0x07; | |
156 | tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */ | |
157 | tm->tm_year = bcd2bin(rxbuf[6]); | |
158 | if (tm->tm_year < 70) | |
159 | tm->tm_year += 100; /* assume we are in 1970...2069 */ | |
160 | ||
161 | dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
162 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
163 | __func__, | |
164 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
165 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
166 | ||
167 | /* the clock can give out invalid datetime, but we cannot return | |
168 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. | |
169 | */ | |
170 | if (rtc_valid_tm(tm) < 0) | |
171 | dev_err(dev, "retrieved date/time is not valid.\n"); | |
172 | ||
173 | return 0; | |
174 | } | |
175 | ||
176 | static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
177 | { | |
178 | struct spi_device *spi = to_spi_device(dev); | |
179 | u8 txbuf[8]; | |
180 | int ret; | |
181 | ||
182 | dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
183 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
184 | __func__, | |
185 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
186 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
187 | ||
188 | /* Stop the counter first */ | |
189 | txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1; | |
190 | txbuf[1] = 0x20; | |
191 | ret = spi_write(spi, txbuf, 2); | |
192 | if (ret < 0) | |
193 | return ret; | |
194 | pcf2123_delay_trec(); | |
195 | ||
196 | /* Set the new time */ | |
197 | txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC; | |
198 | txbuf[1] = bin2bcd(tm->tm_sec & 0x7F); | |
199 | txbuf[2] = bin2bcd(tm->tm_min & 0x7F); | |
200 | txbuf[3] = bin2bcd(tm->tm_hour & 0x3F); | |
201 | txbuf[4] = bin2bcd(tm->tm_mday & 0x3F); | |
202 | txbuf[5] = tm->tm_wday & 0x07; | |
203 | txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */ | |
204 | txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100); | |
205 | ||
206 | ret = spi_write(spi, txbuf, sizeof(txbuf)); | |
207 | if (ret < 0) | |
208 | return ret; | |
209 | pcf2123_delay_trec(); | |
210 | ||
211 | /* Start the counter */ | |
212 | txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1; | |
213 | txbuf[1] = 0x00; | |
214 | ret = spi_write(spi, txbuf, 2); | |
215 | if (ret < 0) | |
216 | return ret; | |
217 | pcf2123_delay_trec(); | |
218 | ||
219 | return 0; | |
220 | } | |
221 | ||
222 | static const struct rtc_class_ops pcf2123_rtc_ops = { | |
223 | .read_time = pcf2123_rtc_read_time, | |
224 | .set_time = pcf2123_rtc_set_time, | |
225 | }; | |
226 | ||
5a167f45 | 227 | static int pcf2123_probe(struct spi_device *spi) |
7f3923a1 CV |
228 | { |
229 | struct rtc_device *rtc; | |
230 | struct pcf2123_plat_data *pdata; | |
231 | u8 txbuf[2], rxbuf[2]; | |
232 | int ret, i; | |
233 | ||
dd48ccc4 JH |
234 | pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data), |
235 | GFP_KERNEL); | |
7f3923a1 CV |
236 | if (!pdata) |
237 | return -ENOMEM; | |
238 | spi->dev.platform_data = pdata; | |
239 | ||
240 | /* Send a software reset command */ | |
241 | txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1; | |
242 | txbuf[1] = 0x58; | |
243 | dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n", | |
244 | txbuf[0], txbuf[1]); | |
245 | ret = spi_write(spi, txbuf, 2 * sizeof(u8)); | |
246 | if (ret < 0) | |
f3d2570a | 247 | goto kfree_exit; |
7f3923a1 CV |
248 | pcf2123_delay_trec(); |
249 | ||
250 | /* Stop the counter */ | |
251 | txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1; | |
252 | txbuf[1] = 0x20; | |
253 | dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n", | |
254 | txbuf[0], txbuf[1]); | |
255 | ret = spi_write(spi, txbuf, 2 * sizeof(u8)); | |
256 | if (ret < 0) | |
f3d2570a | 257 | goto kfree_exit; |
7f3923a1 CV |
258 | pcf2123_delay_trec(); |
259 | ||
260 | /* See if the counter was actually stopped */ | |
261 | txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1; | |
262 | dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n", | |
263 | txbuf[0]); | |
264 | ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8), | |
265 | rxbuf, 2 * sizeof(u8)); | |
266 | dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n", | |
267 | rxbuf[0], rxbuf[1]); | |
268 | if (ret < 0) | |
269 | goto kfree_exit; | |
270 | pcf2123_delay_trec(); | |
271 | ||
272 | if (!(rxbuf[0] & 0x20)) { | |
273 | dev_err(&spi->dev, "chip not found\n"); | |
35623715 | 274 | ret = -ENODEV; |
7f3923a1 CV |
275 | goto kfree_exit; |
276 | } | |
277 | ||
278 | dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n"); | |
279 | dev_info(&spi->dev, "spiclk %u KHz.\n", | |
280 | (spi->max_speed_hz + 500) / 1000); | |
281 | ||
282 | /* Start the counter */ | |
283 | txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1; | |
284 | txbuf[1] = 0x00; | |
285 | ret = spi_write(spi, txbuf, sizeof(txbuf)); | |
286 | if (ret < 0) | |
287 | goto kfree_exit; | |
288 | pcf2123_delay_trec(); | |
289 | ||
290 | /* Finalize the initialization */ | |
dd48ccc4 | 291 | rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name, |
7f3923a1 CV |
292 | &pcf2123_rtc_ops, THIS_MODULE); |
293 | ||
294 | if (IS_ERR(rtc)) { | |
295 | dev_err(&spi->dev, "failed to register.\n"); | |
296 | ret = PTR_ERR(rtc); | |
297 | goto kfree_exit; | |
298 | } | |
299 | ||
300 | pdata->rtc = rtc; | |
301 | ||
302 | for (i = 0; i < 16; i++) { | |
5ed12f12 | 303 | sysfs_attr_init(&pdata->regs[i].attr.attr); |
7f3923a1 CV |
304 | sprintf(pdata->regs[i].name, "%1x", i); |
305 | pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR; | |
306 | pdata->regs[i].attr.attr.name = pdata->regs[i].name; | |
307 | pdata->regs[i].attr.show = pcf2123_show; | |
308 | pdata->regs[i].attr.store = pcf2123_store; | |
309 | ret = device_create_file(&spi->dev, &pdata->regs[i].attr); | |
310 | if (ret) { | |
311 | dev_err(&spi->dev, "Unable to create sysfs %s\n", | |
312 | pdata->regs[i].name); | |
f3d2570a | 313 | goto sysfs_exit; |
7f3923a1 CV |
314 | } |
315 | } | |
316 | ||
317 | return 0; | |
f3d2570a CV |
318 | |
319 | sysfs_exit: | |
320 | for (i--; i >= 0; i--) | |
321 | device_remove_file(&spi->dev, &pdata->regs[i].attr); | |
322 | ||
7f3923a1 | 323 | kfree_exit: |
7f3923a1 CV |
324 | spi->dev.platform_data = NULL; |
325 | return ret; | |
326 | } | |
327 | ||
5a167f45 | 328 | static int pcf2123_remove(struct spi_device *spi) |
7f3923a1 CV |
329 | { |
330 | struct pcf2123_plat_data *pdata = spi->dev.platform_data; | |
331 | int i; | |
332 | ||
333 | if (pdata) { | |
7f3923a1 CV |
334 | for (i = 0; i < 16; i++) |
335 | if (pdata->regs[i].name[0]) | |
336 | device_remove_file(&spi->dev, | |
337 | &pdata->regs[i].attr); | |
7f3923a1 CV |
338 | } |
339 | ||
340 | return 0; | |
341 | } | |
342 | ||
343 | static struct spi_driver pcf2123_driver = { | |
344 | .driver = { | |
345 | .name = "rtc-pcf2123", | |
7f3923a1 CV |
346 | .owner = THIS_MODULE, |
347 | }, | |
348 | .probe = pcf2123_probe, | |
5a167f45 | 349 | .remove = pcf2123_remove, |
7f3923a1 CV |
350 | }; |
351 | ||
109e9418 | 352 | module_spi_driver(pcf2123_driver); |
7f3923a1 CV |
353 | |
354 | MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>"); | |
355 | MODULE_DESCRIPTION("NXP PCF2123 RTC driver"); | |
356 | MODULE_LICENSE("GPL"); | |
357 | MODULE_VERSION(DRV_VERSION); |