Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 42 | #include <linux/slab.h> |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 43 | #include <linux/rtc.h> |
| 44 | #include <linux/spi/spi.h> |
Paul Gortmaker | 2113852 | 2011-05-27 09:57:25 -0400 | [diff] [blame] | 45 | #include <linux/module.h> |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 46 | |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 47 | #define DRV_VERSION "0.6" |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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 { |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 66 | struct device_attribute attr; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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); |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 89 | struct pcf2123_sysfs_reg *r; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 90 | u8 txbuf[1], rxbuf[1]; |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 91 | unsigned long reg; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 92 | int ret; |
| 93 | |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 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; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 100 | ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1); |
| 101 | if (ret < 0) |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 102 | return -EIO; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 103 | pcf2123_delay_trec(); |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 104 | return sprintf(buffer, "0x%x\n", rxbuf[0]); |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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); |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 110 | struct pcf2123_sysfs_reg *r; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 111 | u8 txbuf[2]; |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 112 | unsigned long reg; |
| 113 | unsigned long val; |
| 114 | |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 115 | int ret; |
| 116 | |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 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; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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) |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 240 | goto kfree_exit; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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) |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 250 | goto kfree_exit; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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); |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 304 | goto sysfs_exit; |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 305 | } |
| 306 | } |
| 307 | |
| 308 | return 0; |
Chris Verges | f3d2570a | 2009-09-22 16:46:22 -0700 | [diff] [blame] | 309 | |
| 310 | sysfs_exit: |
| 311 | for (i--; i >= 0; i--) |
| 312 | device_remove_file(&spi->dev, &pdata->regs[i].attr); |
| 313 | |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 314 | kfree_exit: |
| 315 | kfree(pdata); |
| 316 | spi->dev.platform_data = NULL; |
| 317 | return ret; |
| 318 | } |
| 319 | |
Uwe Kleine-König | b51e829 | 2010-03-05 13:44:21 -0800 | [diff] [blame] | 320 | static int __devexit pcf2123_remove(struct spi_device *spi) |
Chris Verges | 7f3923a | 2009-09-22 16:46:20 -0700 | [diff] [blame] | 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", |
| 343 | .bus = &spi_bus_type, |
| 344 | .owner = THIS_MODULE, |
| 345 | }, |
| 346 | .probe = pcf2123_probe, |
| 347 | .remove = __devexit_p(pcf2123_remove), |
| 348 | }; |
| 349 | |
| 350 | static int __init pcf2123_init(void) |
| 351 | { |
| 352 | return spi_register_driver(&pcf2123_driver); |
| 353 | } |
| 354 | |
| 355 | static void __exit pcf2123_exit(void) |
| 356 | { |
| 357 | spi_unregister_driver(&pcf2123_driver); |
| 358 | } |
| 359 | |
| 360 | MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>"); |
| 361 | MODULE_DESCRIPTION("NXP PCF2123 RTC driver"); |
| 362 | MODULE_LICENSE("GPL"); |
| 363 | MODULE_VERSION(DRV_VERSION); |
| 364 | |
| 365 | module_init(pcf2123_init); |
| 366 | module_exit(pcf2123_exit); |