diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-11-18 10:48:49 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-18 10:48:49 -0500 |
| commit | 73f56c0d35e6427081a4eabd620d8b8d8a35bd09 (patch) | |
| tree | 9fe1a2577baea03f3a6ec4a5e79f3ff26c4ee0ae /drivers/rtc/rtc-rx8581.c | |
| parent | 0af40a4b1050c050e62eb1dc30b82d5ab22bf221 (diff) | |
| parent | 8501c45cc32c311ae755a2d5ac8c4a5f04908d42 (diff) | |
Merge branch 'iommu-fixes-2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent
Diffstat (limited to 'drivers/rtc/rtc-rx8581.c')
| -rw-r--r-- | drivers/rtc/rtc-rx8581.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c new file mode 100644 index 000000000000..c9522f3bc21c --- /dev/null +++ b/drivers/rtc/rtc-rx8581.c | |||
| @@ -0,0 +1,281 @@ | |||
| 1 | /* | ||
| 2 | * An I2C driver for the Epson RX8581 RTC | ||
| 3 | * | ||
| 4 | * Author: Martyn Welch <martyn.welch@gefanuc.com> | ||
| 5 | * Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc. | ||
| 6 | * | ||
| 7 | * This program is free software; you can redistribute it and/or modify | ||
| 8 | * it under the terms of the GNU General Public License version 2 as | ||
| 9 | * published by the Free Software Foundation. | ||
| 10 | * | ||
| 11 | * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC) | ||
| 12 | * Copyright 2005-06 Tower Technologies | ||
| 13 | */ | ||
| 14 | |||
| 15 | #include <linux/module.h> | ||
| 16 | #include <linux/i2c.h> | ||
| 17 | #include <linux/bcd.h> | ||
| 18 | #include <linux/rtc.h> | ||
| 19 | #include <linux/log2.h> | ||
| 20 | |||
| 21 | #define DRV_VERSION "0.1" | ||
| 22 | |||
| 23 | #define RX8581_REG_SC 0x00 /* Second in BCD */ | ||
| 24 | #define RX8581_REG_MN 0x01 /* Minute in BCD */ | ||
| 25 | #define RX8581_REG_HR 0x02 /* Hour in BCD */ | ||
| 26 | #define RX8581_REG_DW 0x03 /* Day of Week */ | ||
| 27 | #define RX8581_REG_DM 0x04 /* Day of Month in BCD */ | ||
| 28 | #define RX8581_REG_MO 0x05 /* Month in BCD */ | ||
| 29 | #define RX8581_REG_YR 0x06 /* Year in BCD */ | ||
| 30 | #define RX8581_REG_RAM 0x07 /* RAM */ | ||
| 31 | #define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/ | ||
| 32 | #define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */ | ||
| 33 | #define RX8581_REG_ADM 0x0A | ||
| 34 | #define RX8581_REG_ADW 0x0A | ||
| 35 | #define RX8581_REG_TMR0 0x0B | ||
| 36 | #define RX8581_REG_TMR1 0x0C | ||
| 37 | #define RX8581_REG_EXT 0x0D /* Extension Register */ | ||
| 38 | #define RX8581_REG_FLAG 0x0E /* Flag Register */ | ||
| 39 | #define RX8581_REG_CTRL 0x0F /* Control Register */ | ||
| 40 | |||
| 41 | |||
| 42 | /* Flag Register bit definitions */ | ||
| 43 | #define RX8581_FLAG_UF 0x20 /* Update */ | ||
| 44 | #define RX8581_FLAG_TF 0x10 /* Timer */ | ||
| 45 | #define RX8581_FLAG_AF 0x08 /* Alarm */ | ||
| 46 | #define RX8581_FLAG_VLF 0x02 /* Voltage Low */ | ||
| 47 | |||
| 48 | /* Control Register bit definitions */ | ||
| 49 | #define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */ | ||
| 50 | #define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */ | ||
| 51 | #define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */ | ||
| 52 | #define RX8581_CTRL_STOP 0x02 /* STOP bit */ | ||
| 53 | #define RX8581_CTRL_RESET 0x01 /* RESET bit */ | ||
| 54 | |||
| 55 | static struct i2c_driver rx8581_driver; | ||
| 56 | |||
| 57 | /* | ||
| 58 | * In the routines that deal directly with the rx8581 hardware, we use | ||
| 59 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. | ||
| 60 | */ | ||
| 61 | static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm) | ||
| 62 | { | ||
| 63 | unsigned char date[7]; | ||
| 64 | int data, err; | ||
| 65 | |||
| 66 | /* First we ensure that the "update flag" is not set, we read the | ||
| 67 | * time and date then re-read the "update flag". If the update flag | ||
| 68 | * has been set, we know that the time has changed during the read so | ||
| 69 | * we repeat the whole process again. | ||
| 70 | */ | ||
| 71 | data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG); | ||
| 72 | if (data < 0) { | ||
| 73 | dev_err(&client->dev, "Unable to read device flags\n"); | ||
| 74 | return -EIO; | ||
| 75 | } | ||
| 76 | |||
| 77 | do { | ||
| 78 | /* If update flag set, clear it */ | ||
| 79 | if (data & RX8581_FLAG_UF) { | ||
| 80 | err = i2c_smbus_write_byte_data(client, | ||
| 81 | RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF)); | ||
| 82 | if (err != 0) { | ||
| 83 | dev_err(&client->dev, "Unable to write device " | ||
| 84 | "flags\n"); | ||
| 85 | return -EIO; | ||
| 86 | } | ||
| 87 | } | ||
| 88 | |||
| 89 | /* Now read time and date */ | ||
| 90 | err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC, | ||
| 91 | 7, date); | ||
| 92 | if (err < 0) { | ||
| 93 | dev_err(&client->dev, "Unable to read date\n"); | ||
| 94 | return -EIO; | ||
| 95 | } | ||
| 96 | |||
| 97 | /* Check flag register */ | ||
| 98 | data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG); | ||
| 99 | if (data < 0) { | ||
| 100 | dev_err(&client->dev, "Unable to read device flags\n"); | ||
| 101 | return -EIO; | ||
| 102 | } | ||
| 103 | } while (data & RX8581_FLAG_UF); | ||
| 104 | |||
| 105 | if (data & RX8581_FLAG_VLF) | ||
| 106 | dev_info(&client->dev, | ||
| 107 | "low voltage detected, date/time is not reliable.\n"); | ||
| 108 | |||
| 109 | dev_dbg(&client->dev, | ||
| 110 | "%s: raw data is sec=%02x, min=%02x, hr=%02x, " | ||
| 111 | "wday=%02x, mday=%02x, mon=%02x, year=%02x\n", | ||
| 112 | __func__, | ||
| 113 | date[0], date[1], date[2], date[3], date[4], date[5], date[6]); | ||
| 114 | |||
| 115 | tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F); | ||
| 116 | tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F); | ||
| 117 | tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */ | ||
| 118 | tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F); | ||
| 119 | tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F); | ||
| 120 | tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ | ||
| 121 | tm->tm_year = bcd2bin(date[RX8581_REG_YR]); | ||
| 122 | if (tm->tm_year < 70) | ||
| 123 | tm->tm_year += 100; /* assume we are in 1970...2069 */ | ||
| 124 | |||
| 125 | |||
| 126 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | ||
| 127 | "mday=%d, mon=%d, year=%d, wday=%d\n", | ||
| 128 | __func__, | ||
| 129 | tm->tm_sec, tm->tm_min, tm->tm_hour, | ||
| 130 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | ||
| 131 | |||
| 132 | err = rtc_valid_tm(tm); | ||
| 133 | if (err < 0) | ||
| 134 | dev_err(&client->dev, "retrieved date/time is not valid.\n"); | ||
| 135 | |||
| 136 | return err; | ||
| 137 | } | ||
| 138 | |||
| 139 | static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm) | ||
| 140 | { | ||
| 141 | int data, err; | ||
| 142 | unsigned char buf[7]; | ||
| 143 | |||
| 144 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | ||
| 145 | "mday=%d, mon=%d, year=%d, wday=%d\n", | ||
| 146 | __func__, | ||
| 147 | tm->tm_sec, tm->tm_min, tm->tm_hour, | ||
| 148 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | ||
| 149 | |||
| 150 | /* hours, minutes and seconds */ | ||
| 151 | buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec); | ||
| 152 | buf[RX8581_REG_MN] = bin2bcd(tm->tm_min); | ||
| 153 | buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour); | ||
| 154 | |||
| 155 | buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday); | ||
| 156 | |||
| 157 | /* month, 1 - 12 */ | ||
| 158 | buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1); | ||
| 159 | |||
| 160 | /* year and century */ | ||
| 161 | buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100); | ||
| 162 | buf[RX8581_REG_DW] = (0x1 << tm->tm_wday); | ||
| 163 | |||
| 164 | /* Stop the clock */ | ||
| 165 | data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL); | ||
| 166 | if (data < 0) { | ||
| 167 | dev_err(&client->dev, "Unable to read control register\n"); | ||
| 168 | return -EIO; | ||
| 169 | } | ||
| 170 | |||
| 171 | err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG, | ||
| 172 | (data | RX8581_CTRL_STOP)); | ||
| 173 | if (err < 0) { | ||
| 174 | dev_err(&client->dev, "Unable to write control register\n"); | ||
| 175 | return -EIO; | ||
| 176 | } | ||
| 177 | |||
| 178 | /* write register's data */ | ||
| 179 | err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf); | ||
| 180 | if (err < 0) { | ||
| 181 | dev_err(&client->dev, "Unable to write to date registers\n"); | ||
| 182 | return -EIO; | ||
| 183 | } | ||
| 184 | |||
| 185 | /* Restart the clock */ | ||
| 186 | data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL); | ||
| 187 | if (data < 0) { | ||
| 188 | dev_err(&client->dev, "Unable to read control register\n"); | ||
| 189 | return -EIO; | ||
| 190 | } | ||
| 191 | |||
| 192 | err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG, | ||
| 193 | (data | ~(RX8581_CTRL_STOP))); | ||
| 194 | if (err != 0) { | ||
| 195 | dev_err(&client->dev, "Unable to write control register\n"); | ||
| 196 | return -EIO; | ||
| 197 | } | ||
| 198 | |||
| 199 | return 0; | ||
| 200 | } | ||
| 201 | |||
| 202 | static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm) | ||
| 203 | { | ||
| 204 | return rx8581_get_datetime(to_i2c_client(dev), tm); | ||
| 205 | } | ||
| 206 | |||
| 207 | static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm) | ||
| 208 | { | ||
| 209 | return rx8581_set_datetime(to_i2c_client(dev), tm); | ||
| 210 | } | ||
| 211 | |||
| 212 | static const struct rtc_class_ops rx8581_rtc_ops = { | ||
| 213 | .read_time = rx8581_rtc_read_time, | ||
| 214 | .set_time = rx8581_rtc_set_time, | ||
| 215 | }; | ||
| 216 | |||
| 217 | static int __devinit rx8581_probe(struct i2c_client *client, | ||
| 218 | const struct i2c_device_id *id) | ||
| 219 | { | ||
| 220 | struct rtc_device *rtc; | ||
| 221 | |||
| 222 | dev_dbg(&client->dev, "%s\n", __func__); | ||
| 223 | |||
| 224 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | ||
| 225 | return -ENODEV; | ||
| 226 | |||
| 227 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | ||
| 228 | |||
| 229 | rtc = rtc_device_register(rx8581_driver.driver.name, | ||
| 230 | &client->dev, &rx8581_rtc_ops, THIS_MODULE); | ||
| 231 | |||
| 232 | if (IS_ERR(rtc)) | ||
| 233 | return PTR_ERR(rtc); | ||
| 234 | |||
| 235 | i2c_set_clientdata(client, rtc); | ||
| 236 | |||
| 237 | return 0; | ||
| 238 | } | ||
| 239 | |||
| 240 | static int __devexit rx8581_remove(struct i2c_client *client) | ||
| 241 | { | ||
| 242 | struct rtc_device *rtc = i2c_get_clientdata(client); | ||
| 243 | |||
| 244 | rtc_device_unregister(rtc); | ||
| 245 | |||
| 246 | return 0; | ||
| 247 | } | ||
| 248 | |||
| 249 | static const struct i2c_device_id rx8581_id[] = { | ||
| 250 | { "rx8581", 0 }, | ||
| 251 | { } | ||
| 252 | }; | ||
| 253 | MODULE_DEVICE_TABLE(i2c, rx8581_id); | ||
| 254 | |||
| 255 | static struct i2c_driver rx8581_driver = { | ||
| 256 | .driver = { | ||
| 257 | .name = "rtc-rx8581", | ||
| 258 | .owner = THIS_MODULE, | ||
| 259 | }, | ||
| 260 | .probe = rx8581_probe, | ||
| 261 | .remove = __devexit_p(rx8581_remove), | ||
| 262 | .id_table = rx8581_id, | ||
| 263 | }; | ||
| 264 | |||
| 265 | static int __init rx8581_init(void) | ||
| 266 | { | ||
| 267 | return i2c_add_driver(&rx8581_driver); | ||
| 268 | } | ||
| 269 | |||
| 270 | static void __exit rx8581_exit(void) | ||
| 271 | { | ||
| 272 | i2c_del_driver(&rx8581_driver); | ||
| 273 | } | ||
| 274 | |||
| 275 | MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com>"); | ||
| 276 | MODULE_DESCRIPTION("Epson RX-8581 RTC driver"); | ||
| 277 | MODULE_LICENSE("GPL"); | ||
| 278 | MODULE_VERSION(DRV_VERSION); | ||
| 279 | |||
| 280 | module_init(rx8581_init); | ||
| 281 | module_exit(rx8581_exit); | ||
