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/bcd.h>
  18 #include <linux/i2c.h>
  19 #include <linux/slab.h>
  20 #include <linux/string.h>
  21 #include <linux/rtc.h>          /* get the user-level API */
  22 #include <linux/init.h>
  23
  24 #include "rtc8564.h"
  25
  26 #ifdef DEBUG
  27 # define _DBG(x, fmt, args...) do{ if (debug>=x) printk(KERN_DEBUG"%s: " fmt "\n", __FUNCTION__, ##args); } while(0);
  28 #else
  29 # define _DBG(x, fmt, args...) do { } while(0);
  30 #endif
  31
  32 #define _DBGRTCTM(x, rtctm) if (debug>=x) printk("%s: secs=%d, mins=%d, hours=%d, mday=%d, " \
  33                         "mon=%d, year=%d, wday=%d VL=%d\n", __FUNCTION__, \
  34                         (rtctm).secs, (rtctm).mins, (rtctm).hours, (rtctm).mday, \
  35                         (rtctm).mon, (rtctm).year, (rtctm).wday, (rtctm).vl);
  36
  37 struct rtc8564_data {
  38         struct i2c_client client;
  39         u16 ctrl;
  40 };
  41
  42 static inline u8 _rtc8564_ctrl1(struct i2c_client *client)
  43 {
  44         struct rtc8564_data *data = i2c_get_clientdata(client);
  45         return data->ctrl & 0xff;
  46 }
  47 static inline u8 _rtc8564_ctrl2(struct i2c_client *client)
  48 {
  49         struct rtc8564_data *data = i2c_get_clientdata(client);
  50         return (data->ctrl & 0xff00) >> 8;
  51 }
  52
  53 #define CTRL1(c) _rtc8564_ctrl1(c)
  54 #define CTRL2(c) _rtc8564_ctrl2(c)
  55
  56 static int debug;;
  57 module_param(debug, int, S_IRUGO | S_IWUSR);
  58
  59 static struct i2c_driver rtc8564_driver;
  60
  61 static unsigned short ignore[] = { I2C_CLIENT_END };
  62 static unsigned short normal_addr[] = { 0x51, I2C_CLIENT_END };
  63
  64 static struct i2c_client_address_data addr_data = {
  65         .normal_i2c             = normal_addr,
  66         .probe                  = ignore,
  67         .ignore                 = ignore,
  68 };
  69
  70 static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem);
  71 static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem);
  72
  73 static int rtc8564_read(struct i2c_client *client, unsigned char adr,
  74                         unsigned char *buf, unsigned char len)
  75 {
  76         int ret = -EIO;
  77         unsigned char addr[1] = { adr };
  78         struct i2c_msg msgs[2] = {
  79                 {client->addr, 0, 1, addr},
  80                 {client->addr, I2C_M_RD, len, buf}
  81         };
  82
  83         _DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, buf, len);
  84
  85         if (!buf) {
  86                 ret = -EINVAL;
  87                 goto done;
  88         }
  89
  90         ret = i2c_transfer(client->adapter, msgs, 2);
  91         if (ret == 2) {
  92                 ret = 0;
  93         }
  94
  95 done:
  96         return ret;
  97 }
  98
  99 static int rtc8564_write(struct i2c_client *client, unsigned char adr,
 100                          unsigned char *data, unsigned char len)
 101 {
 102         int ret = 0;
 103         unsigned char _data[16];
 104         struct i2c_msg wr;
 105         int i;
 106
 107         if (!data || len > 15) {
 108                 ret = -EINVAL;
 109                 goto done;
 110         }
 111
 112         _DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, data, len);
 113
 114         _data[0] = adr;
 115         for (i = 0; i < len; i++) {
 116                 _data[i + 1] = data[i];
 117                 _DBG(5, "data[%d] = 0x%02x (%d)", i, data[i], data[i]);
 118         }
 119
 120         wr.addr = client->addr;
 121         wr.flags = 0;
 122         wr.len = len + 1;
 123         wr.buf = _data;
 124
 125         ret = i2c_transfer(client->adapter, &wr, 1);
 126         if (ret == 1) {
 127                 ret = 0;
 128         }
 129
 130 done:
 131         return ret;
 132 }
 133
 134 static int rtc8564_attach(struct i2c_adapter *adap, int addr, int kind)
 135 {
 136         int ret;
 137         struct i2c_client *new_client;
 138         struct rtc8564_data *d;
 139         unsigned char data[10];
 140         unsigned char ad[1] = { 0 };
 141         struct i2c_msg ctrl_wr[1] = {
 142                 {addr, 0, 2, data}
 143         };
 144         struct i2c_msg ctrl_rd[2] = {
 145                 {addr, 0, 1, ad},
 146                 {addr, I2C_M_RD, 2, data}
 147         };
 148
 149         d = kzalloc(sizeof(struct rtc8564_data), GFP_KERNEL);
 150         if (!d) {
 151                 ret = -ENOMEM;
 152                 goto done;
 153         }
 154         new_client = &d->client;
 155
 156         strlcpy(new_client->name, "RTC8564", I2C_NAME_SIZE);
 157         i2c_set_clientdata(new_client, d);
 158         new_client->addr = addr;
 159         new_client->adapter = adap;
 160         new_client->driver = &rtc8564_driver;
 161
 162         _DBG(1, "client=%p", new_client);
 163
 164         /* init ctrl1 reg */
 165         data[0] = 0;
 166         data[1] = 0;
 167         ret = i2c_transfer(new_client->adapter, ctrl_wr, 1);
 168         if (ret != 1) {
 169                 printk(KERN_INFO "rtc8564: cant init ctrl1\n");
 170                 ret = -ENODEV;
 171                 goto done;
 172         }
 173
 174         /* read back ctrl1 and ctrl2 */
 175         ret = i2c_transfer(new_client->adapter, ctrl_rd, 2);
 176         if (ret != 2) {
 177                 printk(KERN_INFO "rtc8564: cant read ctrl\n");
 178                 ret = -ENODEV;
 179                 goto done;
 180         }
 181
 182         d->ctrl = data[0] | (data[1] << 8);
 183
 184         _DBG(1, "RTC8564_REG_CTRL1=%02x, RTC8564_REG_CTRL2=%02x",
 185              data[0], data[1]);
 186
 187         ret = i2c_attach_client(new_client);
 188 done:
 189         if (ret) {
 190                 kfree(d);
 191         }
 192         return ret;
 193 }
 194
 195 static int rtc8564_probe(struct i2c_adapter *adap)
 196 {
 197         return i2c_probe(adap, &addr_data, rtc8564_attach);
 198 }
 199
 200 static int rtc8564_detach(struct i2c_client *client)
 201 {
 202         i2c_detach_client(client);
 203         kfree(i2c_get_clientdata(client));
 204         return 0;
 205 }
 206
 207 static int rtc8564_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
 208 {
 209         int ret = -EIO;
 210         unsigned char buf[15];
 211
 212         _DBG(1, "client=%p, dt=%p", client, dt);
 213
 214         if (!dt)
 215                 return -EINVAL;
 216
 217         memset(buf, 0, sizeof(buf));
 218
 219         ret = rtc8564_read(client, 0, buf, 15);
 220         if (ret)
 221                 return ret;
 222
 223         /* century stored in minute alarm reg */
 224         dt->year = BCD2BIN(buf[RTC8564_REG_YEAR]);
 225         dt->year += 100 * BCD2BIN(buf[RTC8564_REG_AL_MIN] & 0x3f);
 226         dt->mday = BCD2BIN(buf[RTC8564_REG_DAY] & 0x3f);
 227         dt->wday = BCD2BIN(buf[RTC8564_REG_WDAY] & 7);
 228         dt->mon = BCD2BIN(buf[RTC8564_REG_MON_CENT] & 0x1f);
 229
 230         dt->secs = BCD2BIN(buf[RTC8564_REG_SEC] & 0x7f);
 231         dt->vl = (buf[RTC8564_REG_SEC] & 0x80) == 0x80;
 232         dt->mins = BCD2BIN(buf[RTC8564_REG_MIN] & 0x7f);
 233         dt->hours = BCD2BIN(buf[RTC8564_REG_HR] & 0x3f);
 234
 235         _DBGRTCTM(2, *dt);
 236
 237         return 0;
 238 }
 239
 240 static int
 241 rtc8564_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
 242 {
 243         int ret, len = 5;
 244         unsigned char buf[15];
 245
 246         _DBG(1, "client=%p, dt=%p", client, dt);
 247
 248         if (!dt)
 249                 return -EINVAL;
 250
 251         _DBGRTCTM(2, *dt);
 252
 253         buf[RTC8564_REG_CTRL1] = CTRL1(client) | RTC8564_CTRL1_STOP;
 254         buf[RTC8564_REG_CTRL2] = CTRL2(client);
 255         buf[RTC8564_REG_SEC] = BIN2BCD(dt->secs);
 256         buf[RTC8564_REG_MIN] = BIN2BCD(dt->mins);
 257         buf[RTC8564_REG_HR] = BIN2BCD(dt->hours);
 258
 259         if (datetoo) {
 260                 len += 5;
 261                 buf[RTC8564_REG_DAY] = BIN2BCD(dt->mday);
 262                 buf[RTC8564_REG_WDAY] = BIN2BCD(dt->wday);
 263                 buf[RTC8564_REG_MON_CENT] = BIN2BCD(dt->mon) & 0x1f;
 264                 /* century stored in minute alarm reg */
 265                 buf[RTC8564_REG_YEAR] = BIN2BCD(dt->year % 100);
 266                 buf[RTC8564_REG_AL_MIN] = BIN2BCD(dt->year / 100);
 267         }
 268
 269         ret = rtc8564_write(client, 0, buf, len);
 270         if (ret) {
 271                 _DBG(1, "error writing data! %d", ret);
 272         }
 273
 274         buf[RTC8564_REG_CTRL1] = CTRL1(client);
 275         ret = rtc8564_write(client, 0, buf, 1);
 276         if (ret) {
 277                 _DBG(1, "error writing data! %d", ret);
 278         }
 279
 280         return ret;
 281 }
 282
 283 static int rtc8564_get_ctrl(struct i2c_client *client, unsigned int *ctrl)
 284 {
 285         struct rtc8564_data *data = i2c_get_clientdata(client);
 286
 287         if (!ctrl)
 288                 return -1;
 289
 290         *ctrl = data->ctrl;
 291         return 0;
 292 }
 293
 294 static int rtc8564_set_ctrl(struct i2c_client *client, unsigned int *ctrl)
 295 {
 296         struct rtc8564_data *data = i2c_get_clientdata(client);
 297         unsigned char buf[2];
 298
 299         if (!ctrl)
 300                 return -1;
 301
 302         buf[0] = *ctrl & 0xff;
 303         buf[1] = (*ctrl & 0xff00) >> 8;
 304         data->ctrl = *ctrl;
 305
 306         return rtc8564_write(client, 0, buf, 2);
 307 }
 308
 309 static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem)
 310 {
 311
 312         if (!mem)
 313                 return -EINVAL;
 314
 315         return rtc8564_read(client, mem->loc, mem->data, mem->nr);
 316 }
 317
 318 static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem)
 319 {
 320
 321         if (!mem)
 322                 return -EINVAL;
 323
 324         return rtc8564_write(client, mem->loc, mem->data, mem->nr);
 325 }
 326
 327 static int
 328 rtc8564_command(struct i2c_client *client, unsigned int cmd, void *arg)
 329 {
 330
 331         _DBG(1, "cmd=%d", cmd);
 332
 333         switch (cmd) {
 334         case RTC_GETDATETIME:
 335                 return rtc8564_get_datetime(client, arg);
 336
 337         case RTC_SETTIME:
 338                 return rtc8564_set_datetime(client, arg, 0);
 339
 340         case RTC_SETDATETIME:
 341                 return rtc8564_set_datetime(client, arg, 1);
 342
 343         case RTC_GETCTRL:
 344                 return rtc8564_get_ctrl(client, arg);
 345
 346         case RTC_SETCTRL:
 347                 return rtc8564_set_ctrl(client, arg);
 348
 349         case MEM_READ:
 350                 return rtc8564_read_mem(client, arg);
 351
 352         case MEM_WRITE:
 353                 return rtc8564_write_mem(client, arg);
 354
 355         default:
 356                 return -EINVAL;
 357         }
 358 }
 359
 360 static struct i2c_driver rtc8564_driver = {
 361         .owner          = THIS_MODULE,
 362         .name           = "RTC8564",
 363         .id             = I2C_DRIVERID_RTC8564,
 364         .attach_adapter = rtc8564_probe,
 365         .detach_client  = rtc8564_detach,
 366         .command        = rtc8564_command
 367 };
 368
 369 static __init int rtc8564_init(void)
 370 {
 371         return i2c_add_driver(&rtc8564_driver);
 372 }
 373
 374 static __exit void rtc8564_exit(void)
 375 {
 376         i2c_del_driver(&rtc8564_driver);
 377 }
 378
 379 MODULE_AUTHOR("Stefan Eletzhofer <Stefan.Eletzhofer@eletztrick.de>");
 380 MODULE_DESCRIPTION("EPSON RTC8564 Driver");
 381 MODULE_LICENSE("GPL");
 382
 383 module_init(rtc8564_init);
 384 module_exit(rtc8564_exit);