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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> | |
3fc70077 | 41 | #include <linux/of.h> |
7f3923a1 | 42 | #include <linux/string.h> |
5a0e3ad6 | 43 | #include <linux/slab.h> |
7f3923a1 CV |
44 | #include <linux/rtc.h> |
45 | #include <linux/spi/spi.h> | |
2113852b | 46 | #include <linux/module.h> |
5ed12f12 | 47 | #include <linux/sysfs.h> |
7f3923a1 | 48 | |
f3d2570a | 49 | #define DRV_VERSION "0.6" |
7f3923a1 CV |
50 | |
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 | ||
65 | static struct spi_driver pcf2123_driver; | |
66 | ||
67 | struct pcf2123_sysfs_reg { | |
f3d2570a | 68 | struct device_attribute attr; |
7f3923a1 CV |
69 | char name[2]; |
70 | }; | |
71 | ||
72 | struct 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 | */ | |
82 | static inline void pcf2123_delay_trec(void) | |
83 | { | |
84 | ndelay(30); | |
85 | } | |
86 | ||
87 | static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr, | |
88 | char *buffer) | |
89 | { | |
90 | struct spi_device *spi = to_spi_device(dev); | |
f3d2570a | 91 | struct pcf2123_sysfs_reg *r; |
7f3923a1 | 92 | u8 txbuf[1], rxbuf[1]; |
f3d2570a | 93 | unsigned long reg; |
7f3923a1 CV |
94 | int ret; |
95 | ||
f3d2570a CV |
96 | r = container_of(attr, struct pcf2123_sysfs_reg, attr); |
97 | ||
4c5591c1 JH |
98 | ret = kstrtoul(r->name, 16, ®); |
99 | if (ret) | |
100 | return ret; | |
f3d2570a CV |
101 | |
102 | txbuf[0] = PCF2123_READ | reg; | |
7f3923a1 CV |
103 | ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1); |
104 | if (ret < 0) | |
f3d2570a | 105 | return -EIO; |
7f3923a1 | 106 | pcf2123_delay_trec(); |
f3d2570a | 107 | return sprintf(buffer, "0x%x\n", rxbuf[0]); |
7f3923a1 CV |
108 | } |
109 | ||
110 | static 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); | |
f3d2570a | 113 | struct pcf2123_sysfs_reg *r; |
7f3923a1 | 114 | u8 txbuf[2]; |
f3d2570a CV |
115 | unsigned long reg; |
116 | unsigned long val; | |
117 | ||
7f3923a1 CV |
118 | int ret; |
119 | ||
f3d2570a CV |
120 | r = container_of(attr, struct pcf2123_sysfs_reg, attr); |
121 | ||
4c5591c1 JH |
122 | ret = kstrtoul(r->name, 16, ®); |
123 | if (ret) | |
124 | return ret; | |
125 | ||
126 | ret = kstrtoul(buffer, 10, &val); | |
127 | if (ret) | |
128 | return ret; | |
f3d2570a CV |
129 | |
130 | txbuf[0] = PCF2123_WRITE | reg; | |
131 | txbuf[1] = val; | |
7f3923a1 CV |
132 | ret = spi_write(spi, txbuf, sizeof(txbuf)); |
133 | if (ret < 0) | |
134 | return -EIO; | |
135 | pcf2123_delay_trec(); | |
136 | return count; | |
137 | } | |
138 | ||
139 | static 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 | ||
821f51c4 | 168 | return rtc_valid_tm(tm); |
7f3923a1 CV |
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 | ||
5a167f45 | 222 | static int pcf2123_probe(struct spi_device *spi) |
7f3923a1 CV |
223 | { |
224 | struct rtc_device *rtc; | |
225 | struct pcf2123_plat_data *pdata; | |
226 | u8 txbuf[2], rxbuf[2]; | |
227 | int ret, i; | |
228 | ||
dd48ccc4 JH |
229 | pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data), |
230 | GFP_KERNEL); | |
7f3923a1 CV |
231 | 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) | |
f3d2570a | 242 | goto kfree_exit; |
7f3923a1 CV |
243 | 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) | |
f3d2570a | 252 | goto kfree_exit; |
7f3923a1 CV |
253 | 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"); | |
35623715 | 269 | ret = -ENODEV; |
7f3923a1 CV |
270 | 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 */ | |
dd48ccc4 | 286 | rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name, |
7f3923a1 CV |
287 | &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++) { | |
5ed12f12 | 298 | sysfs_attr_init(&pdata->regs[i].attr.attr); |
7f3923a1 CV |
299 | 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); | |
f3d2570a | 308 | goto sysfs_exit; |
7f3923a1 CV |
309 | } |
310 | } | |
311 | ||
312 | return 0; | |
f3d2570a CV |
313 | |
314 | sysfs_exit: | |
315 | for (i--; i >= 0; i--) | |
316 | device_remove_file(&spi->dev, &pdata->regs[i].attr); | |
317 | ||
7f3923a1 | 318 | kfree_exit: |
7f3923a1 CV |
319 | spi->dev.platform_data = NULL; |
320 | return ret; | |
321 | } | |
322 | ||
5a167f45 | 323 | static int pcf2123_remove(struct spi_device *spi) |
7f3923a1 | 324 | { |
ffc75bb8 | 325 | struct pcf2123_plat_data *pdata = dev_get_platdata(&spi->dev); |
7f3923a1 CV |
326 | int i; |
327 | ||
328 | if (pdata) { | |
7f3923a1 CV |
329 | for (i = 0; i < 16; i++) |
330 | if (pdata->regs[i].name[0]) | |
331 | device_remove_file(&spi->dev, | |
332 | &pdata->regs[i].attr); | |
7f3923a1 CV |
333 | } |
334 | ||
335 | return 0; | |
336 | } | |
337 | ||
3fc70077 JC |
338 | #ifdef CONFIG_OF |
339 | static const struct of_device_id pcf2123_dt_ids[] = { | |
340 | { .compatible = "nxp,rtc-pcf2123", }, | |
341 | { /* sentinel */ } | |
342 | }; | |
343 | MODULE_DEVICE_TABLE(of, pcf2123_dt_ids); | |
344 | #endif | |
345 | ||
7f3923a1 CV |
346 | static struct spi_driver pcf2123_driver = { |
347 | .driver = { | |
348 | .name = "rtc-pcf2123", | |
3fc70077 | 349 | .of_match_table = of_match_ptr(pcf2123_dt_ids), |
7f3923a1 CV |
350 | }, |
351 | .probe = pcf2123_probe, | |
5a167f45 | 352 | .remove = pcf2123_remove, |
7f3923a1 CV |
353 | }; |
354 | ||
109e9418 | 355 | module_spi_driver(pcf2123_driver); |
7f3923a1 CV |
356 | |
357 | MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>"); | |
358 | MODULE_DESCRIPTION("NXP PCF2123 RTC driver"); | |
359 | MODULE_LICENSE("GPL"); | |
360 | MODULE_VERSION(DRV_VERSION); |