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