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
  18 #include "pcf8583.h"
  19
  20 static struct i2c_driver pcf8583_driver;
  21
  22 static unsigned short ignore[] = { I2C_CLIENT_END };
  23 static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END };
  24
  25 static struct i2c_client_address_data addr_data = {
  26         normal_i2c:             normal_addr,
  27         normal_i2c_range:       ignore,
  28         probe:                  ignore,
  29         probe_range:            ignore,
  30         ignore:                 ignore,
  31         ignore_range:           ignore,
  32         force:                  ignore,
  33 };
  34
  35 #define DAT(x) ((unsigned int)(x->data))
  36
  37 static int
  38 pcf8583_attach(struct i2c_adapter *adap, int addr, unsigned short flags,
  39                int kind)
  40 {
  41         struct i2c_client *c;
  42         unsigned char buf[1], ad[1] = { 0 };
  43         struct i2c_msg msgs[2] = {
  44                 { addr, 0,        1, ad  },
  45                 { addr, I2C_M_RD, 1, buf }
  46         };
  47
  48         c = kmalloc(sizeof(*c), GFP_KERNEL);
  49         if (!c)
  50                 return -ENOMEM;
  51
  52         strcpy(c->name, "PCF8583");
  53         c->id           = pcf8583_driver.id;
  54         c->flags        = 0;
  55         c->addr         = addr;
  56         c->adapter      = adap;
  57         c->driver       = &pcf8583_driver;
  58         c->data         = NULL;
  59
  60         if (i2c_transfer(c->adapter, msgs, 2) == 2)
  61                 DAT(c) = buf[0];
  62
  63         return i2c_attach_client(c);
  64 }
  65
  66 static int
  67 pcf8583_probe(struct i2c_adapter *adap)
  68 {
  69         return i2c_probe(adap, &addr_data, pcf8583_attach);
  70 }
  71
  72 static int
  73 pcf8583_detach(struct i2c_client *client)
  74 {
  75         i2c_detach_client(client);
  76         kfree(client);
  77         return 0;
  78 }
  79
  80 static int
  81 pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
  82 {
  83         unsigned char buf[8], addr[1] = { 1 };
  84         struct i2c_msg msgs[2] = {
  85                 { client->addr, 0,        1, addr },
  86                 { client->addr, I2C_M_RD, 6, buf  }
  87         };
  88         int ret = -EIO;
  89
  90         memset(buf, 0, sizeof(buf));
  91
  92         ret = i2c_transfer(client->adapter, msgs, 2);
  93         if (ret == 2) {
  94                 dt->year_off = buf[4] >> 6;
  95                 dt->wday     = buf[5] >> 5;
  96
  97                 buf[4] &= 0x3f;
  98                 buf[5] &= 0x1f;
  99
 100                 dt->cs       = BCD_TO_BIN(buf[0]);
 101                 dt->secs     = BCD_TO_BIN(buf[1]);
 102                 dt->mins     = BCD_TO_BIN(buf[2]);
 103                 dt->hours    = BCD_TO_BIN(buf[3]);
 104                 dt->mday     = BCD_TO_BIN(buf[4]);
 105                 dt->mon      = BCD_TO_BIN(buf[5]);
 106
 107                 ret = 0;
 108         }
 109
 110         return ret;
 111 }
 112
 113 static int
 114 pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
 115 {
 116         unsigned char buf[8];
 117         int ret, len = 6;
 118
 119         buf[0] = 0;
 120         buf[1] = DAT(client) | 0x80;
 121         buf[2] = BIN_TO_BCD(dt->cs);
 122         buf[3] = BIN_TO_BCD(dt->secs);
 123         buf[4] = BIN_TO_BCD(dt->mins);
 124         buf[5] = BIN_TO_BCD(dt->hours);
 125
 126         if (datetoo) {
 127                 len = 8;
 128                 buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
 129                 buf[7] = BIN_TO_BCD(dt->mon)  | (dt->wday << 5);
 130         }
 131
 132         ret = i2c_master_send(client, (char *)buf, len);
 133         if (ret == len)
 134                 ret = 0;
 135
 136         buf[1] = DAT(client);
 137         i2c_master_send(client, (char *)buf, 2);
 138
 139         return ret;
 140 }
 141
 142 static int
 143 pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
 144 {
 145         *ctrl = DAT(client);
 146         return 0;
 147 }
 148
 149 static int
 150 pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
 151 {
 152         unsigned char buf[2];
 153
 154         buf[0] = 0;
 155         buf[1] = *ctrl;
 156         DAT(client) = *ctrl;
 157
 158         return i2c_master_send(client, (char *)buf, 2);
 159 }
 160
 161 static int
 162 pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
 163 {
 164         unsigned char addr[1];
 165         struct i2c_msg msgs[2] = {
 166                 { client->addr, 0,        1, addr },
 167                 { client->addr, I2C_M_RD, 0, mem->data }
 168         };
 169
 170         if (mem->loc < 8)
 171                 return -EINVAL;
 172
 173         addr[0] = mem->loc;
 174         msgs[1].len = mem->nr;
 175
 176         return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
 177 }
 178
 179 static int
 180 pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
 181 {
 182         unsigned char addr[1];
 183         struct i2c_msg msgs[2] = {
 184                 { client->addr, 0, 1, addr },
 185                 { client->addr, 0, 0, mem->data }
 186         };
 187
 188         if (mem->loc < 8)
 189                 return -EINVAL;
 190
 191         addr[0] = mem->loc;
 192         msgs[1].len = mem->nr;
 193
 194         return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
 195 }
 196
 197 static int
 198 pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
 199 {
 200         switch (cmd) {
 201         case RTC_GETDATETIME:
 202                 return pcf8583_get_datetime(client, arg);
 203
 204         case RTC_SETTIME:
 205                 return pcf8583_set_datetime(client, arg, 0);
 206
 207         case RTC_SETDATETIME:
 208                 return pcf8583_set_datetime(client, arg, 1);
 209
 210         case RTC_GETCTRL:
 211                 return pcf8583_get_ctrl(client, arg);
 212
 213         case RTC_SETCTRL:
 214                 return pcf8583_set_ctrl(client, arg);
 215
 216         case MEM_READ:
 217                 return pcf8583_read_mem(client, arg);
 218
 219         case MEM_WRITE:
 220                 return pcf8583_write_mem(client, arg);
 221
 222         default:
 223                 return -EINVAL;
 224         }
 225 }
 226
 227 static struct i2c_driver pcf8583_driver = {
 228         name:           "PCF8583",
 229         id:             I2C_DRIVERID_PCF8583,
 230         flags:          I2C_DF_NOTIFY,
 231         attach_adapter: pcf8583_probe,
 232         detach_client:  pcf8583_detach,
 233         command:        pcf8583_command
 234 };
 235
 236 static __init int pcf8583_init(void)
 237 {
 238         return i2c_add_driver(&pcf8583_driver);
 239 }
 240
 241 __initcall(pcf8583_init);