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         .normal_i2c_range       = ignore,
  30         .probe                  = ignore,
  31         .probe_range            = ignore,
  32         .ignore                 = ignore,
  33         .ignore_range           = ignore,
  34         .force                  = ignore,
  35 };
  36
  37 #define DAT(x) ((unsigned int)(x->dev.driver_data))
  38
  39 static int
  40 pcf8583_attach(struct i2c_adapter *adap, int addr, int kind)
  41 {
  42         struct i2c_client *c;
  43         unsigned char buf[1], ad[1] = { 0 };
  44         struct i2c_msg msgs[2] = {
  45                 { addr, 0,        1, ad  },
  46                 { addr, I2C_M_RD, 1, buf }
  47         };
  48
  49         c = kmalloc(sizeof(*c), GFP_KERNEL);
  50         if (!c)
  51                 return -ENOMEM;
  52
  53         memset(c, 0, sizeof(*c));
  54         c->addr         = addr;
  55         c->adapter      = adap;
  56         c->driver       = &pcf8583_driver;
  57
  58         if (i2c_transfer(c->adapter, msgs, 2) == 2)
  59                 DAT(c) = buf[0];
  60
  61         return i2c_attach_client(c);
  62 }
  63
  64 static int
  65 pcf8583_probe(struct i2c_adapter *adap)
  66 {
  67         return i2c_probe(adap, &addr_data, pcf8583_attach);
  68 }
  69
  70 static int
  71 pcf8583_detach(struct i2c_client *client)
  72 {
  73         i2c_detach_client(client);
  74         kfree(client);
  75         return 0;
  76 }
  77
  78 static int
  79 pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
  80 {
  81         unsigned char buf[8], addr[1] = { 1 };
  82         struct i2c_msg msgs[2] = {
  83                 { client->addr, 0,        1, addr },
  84                 { client->addr, I2C_M_RD, 6, buf  }
  85         };
  86         int ret = -EIO;
  87
  88         memset(buf, 0, sizeof(buf));
  89
  90         ret = i2c_transfer(client->adapter, msgs, 2);
  91         if (ret == 2) {
  92                 dt->year_off = buf[4] >> 6;
  93                 dt->wday     = buf[5] >> 5;
  94
  95                 buf[4] &= 0x3f;
  96                 buf[5] &= 0x1f;
  97
  98                 dt->cs       = BCD_TO_BIN(buf[0]);
  99                 dt->secs     = BCD_TO_BIN(buf[1]);
 100                 dt->mins     = BCD_TO_BIN(buf[2]);
 101                 dt->hours    = BCD_TO_BIN(buf[3]);
 102                 dt->mday     = BCD_TO_BIN(buf[4]);
 103                 dt->mon      = BCD_TO_BIN(buf[5]);
 104
 105                 ret = 0;
 106         }
 107
 108         return ret;
 109 }
 110
 111 static int
 112 pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
 113 {
 114         unsigned char buf[8];
 115         int ret, len = 6;
 116
 117         buf[0] = 0;
 118         buf[1] = DAT(client) | 0x80;
 119         buf[2] = BIN_TO_BCD(dt->cs);
 120         buf[3] = BIN_TO_BCD(dt->secs);
 121         buf[4] = BIN_TO_BCD(dt->mins);
 122         buf[5] = BIN_TO_BCD(dt->hours);
 123
 124         if (datetoo) {
 125                 len = 8;
 126                 buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
 127                 buf[7] = BIN_TO_BCD(dt->mon)  | (dt->wday << 5);
 128         }
 129
 130         ret = i2c_master_send(client, (char *)buf, len);
 131         if (ret == len)
 132                 ret = 0;
 133
 134         buf[1] = DAT(client);
 135         i2c_master_send(client, (char *)buf, 2);
 136
 137         return ret;
 138 }
 139
 140 static int
 141 pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
 142 {
 143         *ctrl = DAT(client);
 144         return 0;
 145 }
 146
 147 static int
 148 pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
 149 {
 150         unsigned char buf[2];
 151
 152         buf[0] = 0;
 153         buf[1] = *ctrl;
 154         DAT(client) = *ctrl;
 155
 156         return i2c_master_send(client, (char *)buf, 2);
 157 }
 158
 159 static int
 160 pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
 161 {
 162         unsigned char addr[1];
 163         struct i2c_msg msgs[2] = {
 164                 { client->addr, 0,        1, addr },
 165                 { client->addr, I2C_M_RD, 0, mem->data }
 166         };
 167
 168         if (mem->loc < 8)
 169                 return -EINVAL;
 170
 171         addr[0] = mem->loc;
 172         msgs[1].len = mem->nr;
 173
 174         return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
 175 }
 176
 177 static int
 178 pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
 179 {
 180         unsigned char addr[1];
 181         struct i2c_msg msgs[2] = {
 182                 { client->addr, 0, 1, addr },
 183                 { client->addr, 0, 0, mem->data }
 184         };
 185
 186         if (mem->loc < 8)
 187                 return -EINVAL;
 188
 189         addr[0] = mem->loc;
 190         msgs[1].len = mem->nr;
 191
 192         return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
 193 }
 194
 195 static int
 196 pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
 197 {
 198         switch (cmd) {
 199         case RTC_GETDATETIME:
 200                 return pcf8583_get_datetime(client, arg);
 201
 202         case RTC_SETTIME:
 203                 return pcf8583_set_datetime(client, arg, 0);
 204
 205         case RTC_SETDATETIME:
 206                 return pcf8583_set_datetime(client, arg, 1);
 207
 208         case RTC_GETCTRL:
 209                 return pcf8583_get_ctrl(client, arg);
 210
 211         case RTC_SETCTRL:
 212                 return pcf8583_set_ctrl(client, arg);
 213
 214         case MEM_READ:
 215                 return pcf8583_read_mem(client, arg);
 216
 217         case MEM_WRITE:
 218                 return pcf8583_write_mem(client, arg);
 219
 220         default:
 221                 return -EINVAL;
 222         }
 223 }
 224
 225 static struct i2c_driver pcf8583_driver = {
 226         .name           = "PCF8583",
 227         .id             = I2C_DRIVERID_PCF8583,
 228         .flags          = I2C_DF_NOTIFY,
 229         .attach_adapter = pcf8583_probe,
 230         .detach_client  = pcf8583_detach,
 231         .command        = pcf8583_command
 232 };
 233
 234 static __init int pcf8583_init(void)
 235 {
 236         return i2c_add_driver(&pcf8583_driver);
 237 }
 238
 239 __initcall(pcf8583_init);