drivers/acorn/char/pcf8583.c

   1 /*
   2  *  linux/drivers/acorn/char/pcf8583.c
   3  *
   4  *  Copyright (C) 2000 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Driver for PCF8583 RTC & RAM chip
  11  */
  12 #include <linux/i2c.h>
  13 #include <linux/slab.h>
  14 #include <linux/string.h>
  15 #include <linux/mc146818rtc.h>
  16 #include <linux/init.h>
  17 #include <linux/errno.h>
  18 #include <linux/bcd.h>
  19
  20 #include "pcf8583.h"
  21
  22 static struct i2c_driver pcf8583_driver;
  23
  24 static unsigned short ignore[] = { I2C_CLIENT_END };
  25 static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END };
  26
  27 static struct i2c_client_address_data addr_data = {
  28         .normal_i2c             = normal_addr,
  29         .probe                  = ignore,
  30         .ignore                 = ignore,
  31         .force                  = ignore,
  32 };
  33
  34 #define DAT(x) ((unsigned int)(x->dev.driver_data))
  35
  36 static int
  37 pcf8583_attach(struct i2c_adapter *adap, int addr, int kind)
  38 {
  39         struct i2c_client *c;
  40         unsigned char buf[1], ad[1] = { 0 };
  41         struct i2c_msg msgs[2] = {
  42                 { addr, 0,        1, ad  },
  43                 { addr, I2C_M_RD, 1, buf }
  44         };
  45
  46         c = kmalloc(sizeof(*c), GFP_KERNEL);
  47         if (!c)
  48                 return -ENOMEM;
  49
  50         memset(c, 0, sizeof(*c));
  51         c->addr         = addr;
  52         c->adapter      = adap;
  53         c->driver       = &pcf8583_driver;
  54
  55         if (i2c_transfer(c->adapter, msgs, 2) == 2)
  56                 DAT(c) = buf[0];
  57
  58         return i2c_attach_client(c);
  59 }
  60
  61 static int
  62 pcf8583_probe(struct i2c_adapter *adap)
  63 {
  64         return i2c_probe(adap, &addr_data, pcf8583_attach);
  65 }
  66
  67 static int
  68 pcf8583_detach(struct i2c_client *client)
  69 {
  70         i2c_detach_client(client);
  71         kfree(client);
  72         return 0;
  73 }
  74
  75 static int
  76 pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
  77 {
  78         unsigned char buf[8], addr[1] = { 1 };
  79         struct i2c_msg msgs[2] = {
  80                 { client->addr, 0,        1, addr },
  81                 { client->addr, I2C_M_RD, 6, buf  }
  82         };
  83         int ret = -EIO;
  84
  85         memset(buf, 0, sizeof(buf));
  86
  87         ret = i2c_transfer(client->adapter, msgs, 2);
  88         if (ret == 2) {
  89                 dt->year_off = buf[4] >> 6;
  90                 dt->wday     = buf[5] >> 5;
  91
  92                 buf[4] &= 0x3f;
  93                 buf[5] &= 0x1f;
  94
  95                 dt->cs       = BCD_TO_BIN(buf[0]);
  96                 dt->secs     = BCD_TO_BIN(buf[1]);
  97                 dt->mins     = BCD_TO_BIN(buf[2]);
  98                 dt->hours    = BCD_TO_BIN(buf[3]);
  99                 dt->mday     = BCD_TO_BIN(buf[4]);
 100                 dt->mon      = BCD_TO_BIN(buf[5]);
 101
 102                 ret = 0;
 103         }
 104
 105         return ret;
 106 }
 107
 108 static int
 109 pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
 110 {
 111         unsigned char buf[8];
 112         int ret, len = 6;
 113
 114         buf[0] = 0;
 115         buf[1] = DAT(client) | 0x80;
 116         buf[2] = BIN_TO_BCD(dt->cs);
 117         buf[3] = BIN_TO_BCD(dt->secs);
 118         buf[4] = BIN_TO_BCD(dt->mins);
 119         buf[5] = BIN_TO_BCD(dt->hours);
 120
 121         if (datetoo) {
 122                 len = 8;
 123                 buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
 124                 buf[7] = BIN_TO_BCD(dt->mon)  | (dt->wday << 5);
 125         }
 126
 127         ret = i2c_master_send(client, (char *)buf, len);
 128         if (ret == len)
 129                 ret = 0;
 130
 131         buf[1] = DAT(client);
 132         i2c_master_send(client, (char *)buf, 2);
 133
 134         return ret;
 135 }
 136
 137 static int
 138 pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
 139 {
 140         *ctrl = DAT(client);
 141         return 0;
 142 }
 143
 144 static int
 145 pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
 146 {
 147         unsigned char buf[2];
 148
 149         buf[0] = 0;
 150         buf[1] = *ctrl;
 151         DAT(client) = *ctrl;
 152
 153         return i2c_master_send(client, (char *)buf, 2);
 154 }
 155
 156 static int
 157 pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
 158 {
 159         unsigned char addr[1];
 160         struct i2c_msg msgs[2] = {
 161                 { client->addr, 0,        1, addr },
 162                 { client->addr, I2C_M_RD, 0, mem->data }
 163         };
 164
 165         if (mem->loc < 8)
 166                 return -EINVAL;
 167
 168         addr[0] = mem->loc;
 169         msgs[1].len = mem->nr;
 170
 171         return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
 172 }
 173
 174 static int
 175 pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
 176 {
 177         unsigned char addr[1];
 178         struct i2c_msg msgs[2] = {
 179                 { client->addr, 0, 1, addr },
 180                 { client->addr, 0, 0, mem->data }
 181         };
 182
 183         if (mem->loc < 8)
 184                 return -EINVAL;
 185
 186         addr[0] = mem->loc;
 187         msgs[1].len = mem->nr;
 188
 189         return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
 190 }
 191
 192 static int
 193 pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
 194 {
 195         switch (cmd) {
 196         case RTC_GETDATETIME:
 197                 return pcf8583_get_datetime(client, arg);
 198
 199         case RTC_SETTIME:
 200                 return pcf8583_set_datetime(client, arg, 0);
 201
 202         case RTC_SETDATETIME:
 203                 return pcf8583_set_datetime(client, arg, 1);
 204
 205         case RTC_GETCTRL:
 206                 return pcf8583_get_ctrl(client, arg);
 207
 208         case RTC_SETCTRL:
 209                 return pcf8583_set_ctrl(client, arg);
 210
 211         case MEM_READ:
 212                 return pcf8583_read_mem(client, arg);
 213
 214         case MEM_WRITE:
 215                 return pcf8583_write_mem(client, arg);
 216
 217         default:
 218                 return -EINVAL;
 219         }
 220 }
 221
 222 static struct i2c_driver pcf8583_driver = {
 223         .name           = "PCF8583",
 224         .id             = I2C_DRIVERID_PCF8583,
 225         .flags          = I2C_DF_NOTIFY,
 226         .attach_adapter = pcf8583_probe,
 227         .detach_client  = pcf8583_detach,
 228         .command        = pcf8583_command
 229 };
 230
 231 static __init int pcf8583_init(void)
 232 {
 233         return i2c_add_driver(&pcf8583_driver);
 234 }
 235
 236 __initcall(pcf8583_init);