Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 1 | /* |
| 2 | * An rtc/i2c driver for the Dallas DS1672 |
| 3 | * Copyright 2005 Alessandro Zummo |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/i2c.h> |
| 12 | #include <linux/rtc.h> |
| 13 | |
| 14 | #define DRV_VERSION "0.2" |
| 15 | |
| 16 | /* Addresses to scan: none. This chip cannot be detected. */ |
| 17 | static unsigned short normal_i2c[] = { I2C_CLIENT_END }; |
| 18 | |
| 19 | /* Insmod parameters */ |
| 20 | I2C_CLIENT_INSMOD; |
| 21 | |
| 22 | /* Registers */ |
| 23 | |
| 24 | #define DS1672_REG_CNT_BASE 0 |
| 25 | #define DS1672_REG_CONTROL 4 |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 26 | #define DS1672_REG_CONTROL_EOSC 0x80 |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 27 | #define DS1672_REG_TRICKLE 5 |
| 28 | |
| 29 | |
| 30 | /* Prototypes */ |
| 31 | static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind); |
| 32 | |
| 33 | /* |
| 34 | * In the routines that deal directly with the ds1672 hardware, we use |
| 35 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch |
| 36 | * Epoch is initialized as 2000. Time is set to UTC. |
| 37 | */ |
| 38 | static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) |
| 39 | { |
| 40 | unsigned long time; |
| 41 | unsigned char addr = DS1672_REG_CNT_BASE; |
| 42 | unsigned char buf[4]; |
| 43 | |
| 44 | struct i2c_msg msgs[] = { |
| 45 | { client->addr, 0, 1, &addr }, /* setup read ptr */ |
| 46 | { client->addr, I2C_M_RD, 4, buf }, /* read date */ |
| 47 | }; |
| 48 | |
| 49 | /* read date registers */ |
| 50 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { |
| 51 | dev_err(&client->dev, "%s: read error\n", __FUNCTION__); |
| 52 | return -EIO; |
| 53 | } |
| 54 | |
| 55 | dev_dbg(&client->dev, |
| 56 | "%s: raw read data - counters=%02x,%02x,%02x,%02x\n" |
| 57 | __FUNCTION__, |
| 58 | buf[0], buf[1], buf[2], buf[3]); |
| 59 | |
| 60 | time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; |
| 61 | |
| 62 | rtc_time_to_tm(time, tm); |
| 63 | |
| 64 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " |
| 65 | "mday=%d, mon=%d, year=%d, wday=%d\n", |
| 66 | __FUNCTION__, |
| 67 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
| 68 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) |
| 74 | { |
| 75 | int xfer; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 76 | unsigned char buf[6]; |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 77 | |
| 78 | buf[0] = DS1672_REG_CNT_BASE; |
| 79 | buf[1] = secs & 0x000000FF; |
| 80 | buf[2] = (secs & 0x0000FF00) >> 8; |
| 81 | buf[3] = (secs & 0x00FF0000) >> 16; |
| 82 | buf[4] = (secs & 0xFF000000) >> 24; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 83 | buf[5] = 0; /* set control reg to enable counting */ |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 84 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 85 | xfer = i2c_master_send(client, buf, 6); |
| 86 | if (xfer != 6) { |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 87 | dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer); |
| 88 | return -EIO; |
| 89 | } |
| 90 | |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm) |
| 95 | { |
| 96 | unsigned long secs; |
| 97 | |
| 98 | dev_dbg(&client->dev, |
| 99 | "%s: secs=%d, mins=%d, hours=%d, ", |
| 100 | "mday=%d, mon=%d, year=%d, wday=%d\n", |
| 101 | __FUNCTION__, |
| 102 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
| 103 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
| 104 | |
| 105 | rtc_tm_to_time(tm, &secs); |
| 106 | |
| 107 | return ds1672_set_mmss(client, secs); |
| 108 | } |
| 109 | |
| 110 | static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 111 | { |
| 112 | return ds1672_get_datetime(to_i2c_client(dev), tm); |
| 113 | } |
| 114 | |
| 115 | static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| 116 | { |
| 117 | return ds1672_set_datetime(to_i2c_client(dev), tm); |
| 118 | } |
| 119 | |
| 120 | static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) |
| 121 | { |
| 122 | return ds1672_set_mmss(to_i2c_client(dev), secs); |
| 123 | } |
| 124 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 125 | static int ds1672_get_control(struct i2c_client *client, u8 *status) |
| 126 | { |
| 127 | unsigned char addr = DS1672_REG_CONTROL; |
| 128 | |
| 129 | struct i2c_msg msgs[] = { |
| 130 | { client->addr, 0, 1, &addr }, /* setup read ptr */ |
| 131 | { client->addr, I2C_M_RD, 1, status }, /* read control */ |
| 132 | }; |
| 133 | |
| 134 | /* read control register */ |
| 135 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { |
| 136 | dev_err(&client->dev, "%s: read error\n", __FUNCTION__); |
| 137 | return -EIO; |
| 138 | } |
| 139 | |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | /* following are the sysfs callback functions */ |
| 144 | static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf) |
| 145 | { |
| 146 | struct i2c_client *client = to_i2c_client(dev); |
| 147 | char *state = "enabled"; |
| 148 | u8 control; |
| 149 | int err; |
| 150 | |
| 151 | err = ds1672_get_control(client, &control); |
| 152 | if (err) |
| 153 | return err; |
| 154 | |
| 155 | if (control & DS1672_REG_CONTROL_EOSC) |
| 156 | state = "disabled"; |
| 157 | |
| 158 | return sprintf(buf, "%s\n", state); |
| 159 | } |
| 160 | |
| 161 | static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); |
| 162 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 163 | static struct rtc_class_ops ds1672_rtc_ops = { |
| 164 | .read_time = ds1672_rtc_read_time, |
| 165 | .set_time = ds1672_rtc_set_time, |
| 166 | .set_mmss = ds1672_rtc_set_mmss, |
| 167 | }; |
| 168 | |
| 169 | static int ds1672_attach(struct i2c_adapter *adapter) |
| 170 | { |
| 171 | dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); |
| 172 | return i2c_probe(adapter, &addr_data, ds1672_probe); |
| 173 | } |
| 174 | |
| 175 | static int ds1672_detach(struct i2c_client *client) |
| 176 | { |
| 177 | int err; |
| 178 | struct rtc_device *rtc = i2c_get_clientdata(client); |
| 179 | |
| 180 | dev_dbg(&client->dev, "%s\n", __FUNCTION__); |
| 181 | |
| 182 | if (rtc) |
| 183 | rtc_device_unregister(rtc); |
| 184 | |
| 185 | if ((err = i2c_detach_client(client))) |
| 186 | return err; |
| 187 | |
| 188 | kfree(client); |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | static struct i2c_driver ds1672_driver = { |
| 194 | .driver = { |
| 195 | .name = "ds1672", |
| 196 | }, |
| 197 | .id = I2C_DRIVERID_DS1672, |
| 198 | .attach_adapter = &ds1672_attach, |
| 199 | .detach_client = &ds1672_detach, |
| 200 | }; |
| 201 | |
| 202 | static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind) |
| 203 | { |
| 204 | int err = 0; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 205 | u8 control; |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 206 | struct i2c_client *client; |
| 207 | struct rtc_device *rtc; |
| 208 | |
| 209 | dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); |
| 210 | |
| 211 | if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { |
| 212 | err = -ENODEV; |
| 213 | goto exit; |
| 214 | } |
| 215 | |
| 216 | if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { |
| 217 | err = -ENOMEM; |
| 218 | goto exit; |
| 219 | } |
| 220 | |
| 221 | /* I2C client */ |
| 222 | client->addr = address; |
| 223 | client->driver = &ds1672_driver; |
| 224 | client->adapter = adapter; |
| 225 | |
| 226 | strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE); |
| 227 | |
| 228 | /* Inform the i2c layer */ |
| 229 | if ((err = i2c_attach_client(client))) |
| 230 | goto exit_kfree; |
| 231 | |
| 232 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); |
| 233 | |
| 234 | rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev, |
| 235 | &ds1672_rtc_ops, THIS_MODULE); |
| 236 | |
| 237 | if (IS_ERR(rtc)) { |
| 238 | err = PTR_ERR(rtc); |
| 239 | dev_err(&client->dev, |
| 240 | "unable to register the class device\n"); |
| 241 | goto exit_detach; |
| 242 | } |
| 243 | |
| 244 | i2c_set_clientdata(client, rtc); |
| 245 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame^] | 246 | /* read control register */ |
| 247 | err = ds1672_get_control(client, &control); |
| 248 | if (err) { |
| 249 | dev_err(&client->dev, "%s: read error\n", __FUNCTION__); |
| 250 | goto exit_detach; |
| 251 | } |
| 252 | |
| 253 | if (control & DS1672_REG_CONTROL_EOSC) |
| 254 | dev_warn(&client->dev, "Oscillator not enabled. " |
| 255 | "Set time to enable.\n"); |
| 256 | |
| 257 | /* Register sysfs hooks */ |
| 258 | device_create_file(&client->dev, &dev_attr_control); |
| 259 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 260 | return 0; |
| 261 | |
| 262 | exit_detach: |
| 263 | i2c_detach_client(client); |
| 264 | |
| 265 | exit_kfree: |
| 266 | kfree(client); |
| 267 | |
| 268 | exit: |
| 269 | return err; |
| 270 | } |
| 271 | |
| 272 | static int __init ds1672_init(void) |
| 273 | { |
| 274 | return i2c_add_driver(&ds1672_driver); |
| 275 | } |
| 276 | |
| 277 | static void __exit ds1672_exit(void) |
| 278 | { |
| 279 | i2c_del_driver(&ds1672_driver); |
| 280 | } |
| 281 | |
| 282 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
| 283 | MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); |
| 284 | MODULE_LICENSE("GPL"); |
| 285 | MODULE_VERSION(DRV_VERSION); |
| 286 | |
| 287 | module_init(ds1672_init); |
| 288 | module_exit(ds1672_exit); |