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/*
* linux/drivers/acorn/char/pcf8583.c
*
* Copyright (C) 2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Driver for PCF8583 RTC & RAM chip
*/
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/mc146818rtc.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/bcd.h>
#include "pcf8583.h"
static struct i2c_driver pcf8583_driver;
static unsigned short ignore[] = { I2C_CLIENT_END };
static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END };
static struct i2c_client_address_data addr_data = {
.normal_i2c = normal_addr,
.probe = ignore,
.ignore = ignore,
.force = ignore,
};
#define DAT(x) ((unsigned int)(x->dev.driver_data))
static int
pcf8583_attach(struct i2c_adapter *adap, int addr, int kind)
{
struct i2c_client *c;
unsigned char buf[1], ad[1] = { 0 };
struct i2c_msg msgs[2] = {
{ addr, 0, 1, ad },
{ addr, I2C_M_RD, 1, buf }
};
c = kmalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return -ENOMEM;
memset(c, 0, sizeof(*c));
c->addr = addr;
c->adapter = adap;
c->driver = &pcf8583_driver;
if (i2c_transfer(c->adapter, msgs, 2) == 2)
DAT(c) = buf[0];
return i2c_attach_client(c);
}
static int
pcf8583_probe(struct i2c_adapter *adap)
{
return i2c_probe(adap, &addr_data, pcf8583_attach);
}
static int
pcf8583_detach(struct i2c_client *client)
{
i2c_detach_client(client);
kfree(client);
return 0;
}
static int
pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
{
unsigned char buf[8], addr[1] = { 1 };
struct i2c_msg msgs[2] = {
{ client->addr, 0, 1, addr },
{ client->addr, I2C_M_RD, 6, buf }
};
int ret = -EIO;
memset(buf, 0, sizeof(buf));
ret = i2c_transfer(client->adapter, msgs, 2);
if (ret == 2) {
dt->year_off = buf[4] >> 6;
dt->wday = buf[5] >> 5;
buf[4] &= 0x3f;
buf[5] &= 0x1f;
dt->cs = BCD_TO_BIN(buf[0]);
dt->secs = BCD_TO_BIN(buf[1]);
dt->mins = BCD_TO_BIN(buf[2]);
dt->hours = BCD_TO_BIN(buf[3]);
dt->mday = BCD_TO_BIN(buf[4]);
dt->mon = BCD_TO_BIN(buf[5]);
ret = 0;
}
return ret;
}
static int
pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
{
unsigned char buf[8];
int ret, len = 6;
buf[0] = 0;
buf[1] = DAT(client) | 0x80;
buf[2] = BIN_TO_BCD(dt->cs);
buf[3] = BIN_TO_BCD(dt->secs);
buf[4] = BIN_TO_BCD(dt->mins);
buf[5] = BIN_TO_BCD(dt->hours);
if (datetoo) {
len = 8;
buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
buf[7] = BIN_TO_BCD(dt->mon) | (dt->wday << 5);
}
ret = i2c_master_send(client, (char *)buf, len);
if (ret == len)
ret = 0;
buf[1] = DAT(client);
i2c_master_send(client, (char *)buf, 2);
return ret;
}
static int
pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
{
*ctrl = DAT(client);
return 0;
}
static int
pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
{
unsigned char buf[2];
buf[0] = 0;
buf[1] = *ctrl;
DAT(client) = *ctrl;
return i2c_master_send(client, (char *)buf, 2);
}
static int
pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
{
unsigned char addr[1];
struct i2c_msg msgs[2] = {
{ client->addr, 0, 1, addr },
{ client->addr, I2C_M_RD, 0, mem->data }
};
if (mem->loc < 8)
return -EINVAL;
addr[0] = mem->loc;
msgs[1].len = mem->nr;
return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
}
static int
pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
{
unsigned char addr[1];
struct i2c_msg msgs[2] = {
{ client->addr, 0, 1, addr },
{ client->addr, 0, 0, mem->data }
};
if (mem->loc < 8)
return -EINVAL;
addr[0] = mem->loc;
msgs[1].len = mem->nr;
return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
}
static int
pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
{
switch (cmd) {
case RTC_GETDATETIME:
return pcf8583_get_datetime(client, arg);
case RTC_SETTIME:
return pcf8583_set_datetime(client, arg, 0);
case RTC_SETDATETIME:
return pcf8583_set_datetime(client, arg, 1);
case RTC_GETCTRL:
return pcf8583_get_ctrl(client, arg);
case RTC_SETCTRL:
return pcf8583_set_ctrl(client, arg);
case MEM_READ:
return pcf8583_read_mem(client, arg);
case MEM_WRITE:
return pcf8583_write_mem(client, arg);
default:
return -EINVAL;
}
}
static struct i2c_driver pcf8583_driver = {
.name = "PCF8583",
.id = I2C_DRIVERID_PCF8583,
.flags = I2C_DF_NOTIFY,
.attach_adapter = pcf8583_probe,
.detach_client = pcf8583_detach,
.command = pcf8583_command
};
static __init int pcf8583_init(void)
{
return i2c_add_driver(&pcf8583_driver);
}
__initcall(pcf8583_init);
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