drivers/i2c/chips/rtc8564.c

   1 /*
   2  *  linux/drivers/i2c/chips/rtc8564.c
   3  *
   4  *  Copyright (C) 2002-2004 Stefan Eletzhofer
   5  *
   6  *      based on linux/drivers/acron/char/pcf8583.c
   7  *  Copyright (C) 2000 Russell King
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * Driver for system3's EPSON RTC 8564 chip
  14  */
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/i2c.h>
  18 #include <linux/slab.h>
  19 #include <linux/string.h>
  20 #include <linux/rtc.h>          /* get the user-level API */
  21 #include <linux/init.h>
  22
  23 #include "rtc8564.h"
  24
  25 #ifdef DEBUG
  26 # define _DBG(x, fmt, args...) do{ if (debug>=x) printk(KERN_DEBUG"%s: " fmt "\n", __FUNCTION__, ##args); } while(0);
  27 #else
  28 # define _DBG(x, fmt, args...) do { } while(0);
  29 #endif
  30
  31 #define _DBGRTCTM(x, rtctm) if (debug>=x) printk("%s: secs=%d, mins=%d, hours=%d, mday=%d, " \
  32                         "mon=%d, year=%d, wday=%d VL=%d\n", __FUNCTION__, \
  33                         (rtctm).secs, (rtctm).mins, (rtctm).hours, (rtctm).mday, \
  34                         (rtctm).mon, (rtctm).year, (rtctm).wday, (rtctm).vl);
  35
  36 struct rtc8564_data {
  37         struct i2c_client client;
  38         u16 ctrl;
  39 };
  40
  41 static inline u8 _rtc8564_ctrl1(struct i2c_client *client)
  42 {
  43         struct rtc8564_data *data = i2c_get_clientdata(client);
  44         return data->ctrl & 0xff;
  45 }
  46 static inline u8 _rtc8564_ctrl2(struct i2c_client *client)
  47 {
  48         struct rtc8564_data *data = i2c_get_clientdata(client);
  49         return (data->ctrl & 0xff00) >> 8;
  50 }
  51
  52 #define CTRL1(c) _rtc8564_ctrl1(c)
  53 #define CTRL2(c) _rtc8564_ctrl2(c)
  54
  55 #define BCD_TO_BIN(val) (((val)&15) + ((val)>>4)*10)
  56 #define BIN_TO_BCD(val) ((((val)/10)<<4) + (val)%10)
  57
  58 static int debug;;
  59 module_param(debug, int, S_IRUGO | S_IWUSR);
  60
  61 static struct i2c_driver rtc8564_driver;
  62
  63 static unsigned short ignore[] = { I2C_CLIENT_END };
  64 static unsigned short normal_addr[] = { 0x51, I2C_CLIENT_END };
  65
  66 static struct i2c_client_address_data addr_data = {
  67         .normal_i2c             = normal_addr,
  68         .probe                  = ignore,
  69         .ignore                 = ignore,
  70 };
  71
  72 static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem);
  73 static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem);
  74
  75 static int rtc8564_read(struct i2c_client *client, unsigned char adr,
  76                         unsigned char *buf, unsigned char len)
  77 {
  78         int ret = -EIO;
  79         unsigned char addr[1] = { adr };
  80         struct i2c_msg msgs[2] = {
  81                 {client->addr, 0, 1, addr},
  82                 {client->addr, I2C_M_RD, len, buf}
  83         };
  84
  85         _DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, buf, len);
  86
  87         if (!buf) {
  88                 ret = -EINVAL;
  89                 goto done;
  90         }
  91
  92         ret = i2c_transfer(client->adapter, msgs, 2);
  93         if (ret == 2) {
  94                 ret = 0;
  95         }
  96
  97 done:
  98         return ret;
  99 }
 100
 101 static int rtc8564_write(struct i2c_client *client, unsigned char adr,
 102                          unsigned char *data, unsigned char len)
 103 {
 104         int ret = 0;
 105         unsigned char _data[16];
 106         struct i2c_msg wr;
 107         int i;
 108
 109         if (!data || len > 15) {
 110                 ret = -EINVAL;
 111                 goto done;
 112         }
 113
 114         _DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, data, len);
 115
 116         _data[0] = adr;
 117         for (i = 0; i < len; i++) {
 118                 _data[i + 1] = data[i];
 119                 _DBG(5, "data[%d] = 0x%02x (%d)", i, data[i], data[i]);
 120         }
 121
 122         wr.addr = client->addr;
 123         wr.flags = 0;
 124         wr.len = len + 1;
 125         wr.buf = _data;
 126
 127         ret = i2c_transfer(client->adapter, &wr, 1);
 128         if (ret == 1) {
 129                 ret = 0;
 130         }
 131
 132 done:
 133         return ret;
 134 }
 135
 136 static int rtc8564_attach(struct i2c_adapter *adap, int addr, int kind)
 137 {
 138         int ret;
 139         struct i2c_client *new_client;
 140         struct rtc8564_data *d;
 141         unsigned char data[10];
 142         unsigned char ad[1] = { 0 };
 143         struct i2c_msg ctrl_wr[1] = {
 144                 {addr, 0, 2, data}
 145         };
 146         struct i2c_msg ctrl_rd[2] = {
 147                 {addr, 0, 1, ad},
 148                 {addr, I2C_M_RD, 2, data}
 149         };
 150
 151         d = kmalloc(sizeof(struct rtc8564_data), GFP_KERNEL);
 152         if (!d) {
 153                 ret = -ENOMEM;
 154                 goto done;
 155         }
 156         memset(d, 0, sizeof(struct rtc8564_data));
 157         new_client = &d->client;
 158
 159         strlcpy(new_client->name, "RTC8564", I2C_NAME_SIZE);
 160         i2c_set_clientdata(new_client, d);
 161         new_client->flags = I2C_CLIENT_ALLOW_USE | I2C_DF_NOTIFY;
 162         new_client->addr = addr;
 163         new_client->adapter = adap;
 164         new_client->driver = &rtc8564_driver;
 165
 166         _DBG(1, "client=%p", new_client);
 167
 168         /* init ctrl1 reg */
 169         data[0] = 0;
 170         data[1] = 0;
 171         ret = i2c_transfer(new_client->adapter, ctrl_wr, 1);
 172         if (ret != 1) {
 173                 printk(KERN_INFO "rtc8564: cant init ctrl1\n");
 174                 ret = -ENODEV;
 175                 goto done;
 176         }
 177
 178         /* read back ctrl1 and ctrl2 */
 179         ret = i2c_transfer(new_client->adapter, ctrl_rd, 2);
 180         if (ret != 2) {
 181                 printk(KERN_INFO "rtc8564: cant read ctrl\n");
 182                 ret = -ENODEV;
 183                 goto done;
 184         }
 185
 186         d->ctrl = data[0] | (data[1] << 8);
 187
 188         _DBG(1, "RTC8564_REG_CTRL1=%02x, RTC8564_REG_CTRL2=%02x",
 189              data[0], data[1]);
 190
 191         ret = i2c_attach_client(new_client);
 192 done:
 193         if (ret) {
 194                 kfree(d);
 195         }
 196         return ret;
 197 }
 198
 199 static int rtc8564_probe(struct i2c_adapter *adap)
 200 {
 201         return i2c_probe(adap, &addr_data, rtc8564_attach);
 202 }
 203
 204 static int rtc8564_detach(struct i2c_client *client)
 205 {
 206         i2c_detach_client(client);
 207         kfree(i2c_get_clientdata(client));
 208         return 0;
 209 }
 210
 211 static int rtc8564_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
 212 {
 213         int ret = -EIO;
 214         unsigned char buf[15];
 215
 216         _DBG(1, "client=%p, dt=%p", client, dt);
 217
 218         if (!dt)
 219                 return -EINVAL;
 220
 221         memset(buf, 0, sizeof(buf));
 222
 223         ret = rtc8564_read(client, 0, buf, 15);
 224         if (ret)
 225                 return ret;
 226
 227         /* century stored in minute alarm reg */
 228         dt->year = BCD_TO_BIN(buf[RTC8564_REG_YEAR]);
 229         dt->year += 100 * BCD_TO_BIN(buf[RTC8564_REG_AL_MIN] & 0x3f);
 230         dt->mday = BCD_TO_BIN(buf[RTC8564_REG_DAY] & 0x3f);
 231         dt->wday = BCD_TO_BIN(buf[RTC8564_REG_WDAY] & 7);
 232         dt->mon = BCD_TO_BIN(buf[RTC8564_REG_MON_CENT] & 0x1f);
 233
 234         dt->secs = BCD_TO_BIN(buf[RTC8564_REG_SEC] & 0x7f);
 235         dt->vl = (buf[RTC8564_REG_SEC] & 0x80) == 0x80;
 236         dt->mins = BCD_TO_BIN(buf[RTC8564_REG_MIN] & 0x7f);
 237         dt->hours = BCD_TO_BIN(buf[RTC8564_REG_HR] & 0x3f);
 238
 239         _DBGRTCTM(2, *dt);
 240
 241         return 0;
 242 }
 243
 244 static int
 245 rtc8564_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
 246 {
 247         int ret, len = 5;
 248         unsigned char buf[15];
 249
 250         _DBG(1, "client=%p, dt=%p", client, dt);
 251
 252         if (!dt)
 253                 return -EINVAL;
 254
 255         _DBGRTCTM(2, *dt);
 256
 257         buf[RTC8564_REG_CTRL1] = CTRL1(client) | RTC8564_CTRL1_STOP;
 258         buf[RTC8564_REG_CTRL2] = CTRL2(client);
 259         buf[RTC8564_REG_SEC] = BIN_TO_BCD(dt->secs);
 260         buf[RTC8564_REG_MIN] = BIN_TO_BCD(dt->mins);
 261         buf[RTC8564_REG_HR] = BIN_TO_BCD(dt->hours);
 262
 263         if (datetoo) {
 264                 len += 5;
 265                 buf[RTC8564_REG_DAY] = BIN_TO_BCD(dt->mday);
 266                 buf[RTC8564_REG_WDAY] = BIN_TO_BCD(dt->wday);
 267                 buf[RTC8564_REG_MON_CENT] = BIN_TO_BCD(dt->mon) & 0x1f;
 268                 /* century stored in minute alarm reg */
 269                 buf[RTC8564_REG_YEAR] = BIN_TO_BCD(dt->year % 100);
 270                 buf[RTC8564_REG_AL_MIN] = BIN_TO_BCD(dt->year / 100);
 271         }
 272
 273         ret = rtc8564_write(client, 0, buf, len);
 274         if (ret) {
 275                 _DBG(1, "error writing data! %d", ret);
 276         }
 277
 278         buf[RTC8564_REG_CTRL1] = CTRL1(client);
 279         ret = rtc8564_write(client, 0, buf, 1);
 280         if (ret) {
 281                 _DBG(1, "error writing data! %d", ret);
 282         }
 283
 284         return ret;
 285 }
 286
 287 static int rtc8564_get_ctrl(struct i2c_client *client, unsigned int *ctrl)
 288 {
 289         struct rtc8564_data *data = i2c_get_clientdata(client);
 290
 291         if (!ctrl)
 292                 return -1;
 293
 294         *ctrl = data->ctrl;
 295         return 0;
 296 }
 297
 298 static int rtc8564_set_ctrl(struct i2c_client *client, unsigned int *ctrl)
 299 {
 300         struct rtc8564_data *data = i2c_get_clientdata(client);
 301         unsigned char buf[2];
 302
 303         if (!ctrl)
 304                 return -1;
 305
 306         buf[0] = *ctrl & 0xff;
 307         buf[1] = (*ctrl & 0xff00) >> 8;
 308         data->ctrl = *ctrl;
 309
 310         return rtc8564_write(client, 0, buf, 2);
 311 }
 312
 313 static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem)
 314 {
 315
 316         if (!mem)
 317                 return -EINVAL;
 318
 319         return rtc8564_read(client, mem->loc, mem->data, mem->nr);
 320 }
 321
 322 static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem)
 323 {
 324
 325         if (!mem)
 326                 return -EINVAL;
 327
 328         return rtc8564_write(client, mem->loc, mem->data, mem->nr);
 329 }
 330
 331 static int
 332 rtc8564_command(struct i2c_client *client, unsigned int cmd, void *arg)
 333 {
 334
 335         _DBG(1, "cmd=%d", cmd);
 336
 337         switch (cmd) {
 338         case RTC_GETDATETIME:
 339                 return rtc8564_get_datetime(client, arg);
 340
 341         case RTC_SETTIME:
 342                 return rtc8564_set_datetime(client, arg, 0);
 343
 344         case RTC_SETDATETIME:
 345                 return rtc8564_set_datetime(client, arg, 1);
 346
 347         case RTC_GETCTRL:
 348                 return rtc8564_get_ctrl(client, arg);
 349
 350         case RTC_SETCTRL:
 351                 return rtc8564_set_ctrl(client, arg);
 352
 353         case MEM_READ:
 354                 return rtc8564_read_mem(client, arg);
 355
 356         case MEM_WRITE:
 357                 return rtc8564_write_mem(client, arg);
 358
 359         default:
 360                 return -EINVAL;
 361         }
 362 }
 363
 364 static struct i2c_driver rtc8564_driver = {
 365         .owner          = THIS_MODULE,
 366         .name           = "RTC8564",
 367         .id             = I2C_DRIVERID_RTC8564,
 368         .flags          = I2C_DF_NOTIFY,
 369         .attach_adapter = rtc8564_probe,
 370         .detach_client  = rtc8564_detach,
 371         .command        = rtc8564_command
 372 };
 373
 374 static __init int rtc8564_init(void)
 375 {
 376         return i2c_add_driver(&rtc8564_driver);
 377 }
 378
 379 static __exit void rtc8564_exit(void)
 380 {
 381         i2c_del_driver(&rtc8564_driver);
 382 }
 383
 384 MODULE_AUTHOR("Stefan Eletzhofer <Stefan.Eletzhofer@eletztrick.de>");
 385 MODULE_DESCRIPTION("EPSON RTC8564 Driver");
 386 MODULE_LICENSE("GPL");
 387
 388 module_init(rtc8564_init);
 389 module_exit(rtc8564_exit);