2005-04-17 00:20:36 +02:00
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/*
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* linux/drivers/i2c/chips/ds1337.c
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*
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* Copyright (C) 2005 James Chapman <jchapman@katalix.com>
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*
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2005-04-08 15:00:21 +02:00
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* based on linux/drivers/acorn/char/pcf8583.c
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2005-04-17 00:20:36 +02:00
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* Copyright (C) 2000 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Driver for Dallas Semiconductor DS1337 real time clock chip
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/i2c-sensor.h>
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#include <linux/string.h>
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#include <linux/rtc.h> /* get the user-level API */
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#include <linux/bcd.h>
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#include <linux/list.h>
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/* Device registers */
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#define DS1337_REG_HOUR 2
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#define DS1337_REG_DAY 3
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#define DS1337_REG_DATE 4
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#define DS1337_REG_MONTH 5
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#define DS1337_REG_CONTROL 14
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#define DS1337_REG_STATUS 15
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/* FIXME - how do we export these interface constants? */
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#define DS1337_GET_DATE 0
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#define DS1337_SET_DATE 1
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/*
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* Functions declaration
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*/
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static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END };
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static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
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SENSORS_INSMOD_1(ds1337);
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static int ds1337_attach_adapter(struct i2c_adapter *adapter);
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static int ds1337_detect(struct i2c_adapter *adapter, int address, int kind);
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static void ds1337_init_client(struct i2c_client *client);
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static int ds1337_detach_client(struct i2c_client *client);
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static int ds1337_command(struct i2c_client *client, unsigned int cmd,
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void *arg);
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/*
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* Driver data (common to all clients)
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*/
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static struct i2c_driver ds1337_driver = {
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.owner = THIS_MODULE,
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.name = "ds1337",
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.flags = I2C_DF_NOTIFY,
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.attach_adapter = ds1337_attach_adapter,
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.detach_client = ds1337_detach_client,
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.command = ds1337_command,
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};
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/*
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* Client data (each client gets its own)
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*/
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struct ds1337_data {
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struct i2c_client client;
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struct list_head list;
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int id;
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};
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/*
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* Internal variables
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*/
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static int ds1337_id;
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static LIST_HEAD(ds1337_clients);
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static inline int ds1337_read(struct i2c_client *client, u8 reg, u8 *value)
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{
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s32 tmp = i2c_smbus_read_byte_data(client, reg);
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if (tmp < 0)
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return -EIO;
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*value = tmp;
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return 0;
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}
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/*
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* Chip access functions
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*/
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static int ds1337_get_datetime(struct i2c_client *client, struct rtc_time *dt)
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{
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struct ds1337_data *data = i2c_get_clientdata(client);
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int result;
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u8 buf[7];
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u8 val;
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struct i2c_msg msg[2];
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u8 offs = 0;
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if (!dt) {
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dev_dbg(&client->adapter->dev, "%s: EINVAL: dt=NULL\n",
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__FUNCTION__);
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return -EINVAL;
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}
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msg[0].addr = client->addr;
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msg[0].flags = 0;
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msg[0].len = 1;
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msg[0].buf = &offs;
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msg[1].addr = client->addr;
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msg[1].flags = I2C_M_RD;
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msg[1].len = sizeof(buf);
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msg[1].buf = &buf[0];
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2005-04-08 15:00:21 +02:00
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result = i2c_transfer(client->adapter, msg, 2);
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2005-04-17 00:20:36 +02:00
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dev_dbg(&client->adapter->dev,
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"%s: [%d] %02x %02x %02x %02x %02x %02x %02x\n",
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__FUNCTION__, result, buf[0], buf[1], buf[2], buf[3],
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buf[4], buf[5], buf[6]);
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if (result >= 0) {
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dt->tm_sec = BCD_TO_BIN(buf[0]);
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dt->tm_min = BCD_TO_BIN(buf[1]);
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val = buf[2] & 0x3f;
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dt->tm_hour = BCD_TO_BIN(val);
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dt->tm_wday = BCD_TO_BIN(buf[3]) - 1;
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dt->tm_mday = BCD_TO_BIN(buf[4]);
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val = buf[5] & 0x7f;
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dt->tm_mon = BCD_TO_BIN(val);
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dt->tm_year = 1900 + BCD_TO_BIN(buf[6]);
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if (buf[5] & 0x80)
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dt->tm_year += 100;
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dev_dbg(&client->adapter->dev, "%s: secs=%d, mins=%d, "
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"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
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__FUNCTION__, dt->tm_sec, dt->tm_min,
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dt->tm_hour, dt->tm_mday,
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dt->tm_mon, dt->tm_year, dt->tm_wday);
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} else {
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dev_err(&client->adapter->dev, "ds1337[%d]: error reading "
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"data! %d\n", data->id, result);
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result = -EIO;
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}
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return result;
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}
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static int ds1337_set_datetime(struct i2c_client *client, struct rtc_time *dt)
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{
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struct ds1337_data *data = i2c_get_clientdata(client);
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int result;
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u8 buf[8];
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u8 val;
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struct i2c_msg msg[1];
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if (!dt) {
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dev_dbg(&client->adapter->dev, "%s: EINVAL: dt=NULL\n",
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__FUNCTION__);
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return -EINVAL;
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}
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dev_dbg(&client->adapter->dev, "%s: secs=%d, mins=%d, hours=%d, "
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"mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__,
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dt->tm_sec, dt->tm_min, dt->tm_hour,
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dt->tm_mday, dt->tm_mon, dt->tm_year, dt->tm_wday);
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buf[0] = 0; /* reg offset */
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buf[1] = BIN_TO_BCD(dt->tm_sec);
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buf[2] = BIN_TO_BCD(dt->tm_min);
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buf[3] = BIN_TO_BCD(dt->tm_hour) | (1 << 6);
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buf[4] = BIN_TO_BCD(dt->tm_wday) + 1;
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buf[5] = BIN_TO_BCD(dt->tm_mday);
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buf[6] = BIN_TO_BCD(dt->tm_mon);
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if (dt->tm_year >= 2000) {
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val = dt->tm_year - 2000;
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buf[6] |= (1 << 7);
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} else {
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val = dt->tm_year - 1900;
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}
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buf[7] = BIN_TO_BCD(val);
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msg[0].addr = client->addr;
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msg[0].flags = 0;
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msg[0].len = sizeof(buf);
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msg[0].buf = &buf[0];
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2005-04-08 15:00:21 +02:00
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result = i2c_transfer(client->adapter, msg, 1);
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2005-04-17 00:20:36 +02:00
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if (result < 0) {
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dev_err(&client->adapter->dev, "ds1337[%d]: error "
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"writing data! %d\n", data->id, result);
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result = -EIO;
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} else {
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result = 0;
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}
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return result;
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}
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static int ds1337_command(struct i2c_client *client, unsigned int cmd,
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void *arg)
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{
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dev_dbg(&client->adapter->dev, "%s: cmd=%d\n", __FUNCTION__, cmd);
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switch (cmd) {
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case DS1337_GET_DATE:
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return ds1337_get_datetime(client, arg);
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case DS1337_SET_DATE:
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return ds1337_set_datetime(client, arg);
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default:
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return -EINVAL;
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}
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}
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/*
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* Public API for access to specific device. Useful for low-level
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* RTC access from kernel code.
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*/
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int ds1337_do_command(int id, int cmd, void *arg)
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{
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struct list_head *walk;
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struct list_head *tmp;
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struct ds1337_data *data;
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list_for_each_safe(walk, tmp, &ds1337_clients) {
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data = list_entry(walk, struct ds1337_data, list);
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if (data->id == id)
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return ds1337_command(&data->client, cmd, arg);
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}
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return -ENODEV;
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}
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static int ds1337_attach_adapter(struct i2c_adapter *adapter)
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{
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return i2c_detect(adapter, &addr_data, ds1337_detect);
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}
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/*
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* The following function does more than just detection. If detection
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* succeeds, it also registers the new chip.
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*/
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static int ds1337_detect(struct i2c_adapter *adapter, int address, int kind)
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{
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struct i2c_client *new_client;
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struct ds1337_data *data;
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int err = 0;
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const char *name = "";
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_I2C))
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goto exit;
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if (!(data = kmalloc(sizeof(struct ds1337_data), GFP_KERNEL))) {
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err = -ENOMEM;
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goto exit;
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}
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memset(data, 0, sizeof(struct ds1337_data));
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INIT_LIST_HEAD(&data->list);
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/* The common I2C client data is placed right before the
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* DS1337-specific data.
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*/
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new_client = &data->client;
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i2c_set_clientdata(new_client, data);
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new_client->addr = address;
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new_client->adapter = adapter;
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new_client->driver = &ds1337_driver;
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new_client->flags = 0;
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/*
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* Now we do the remaining detection. A negative kind means that
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* the driver was loaded with no force parameter (default), so we
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* must both detect and identify the chip. A zero kind means that
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* the driver was loaded with the force parameter, the detection
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* step shall be skipped. A positive kind means that the driver
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* was loaded with the force parameter and a given kind of chip is
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* requested, so both the detection and the identification steps
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* are skipped.
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*
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* For detection, we read registers that are most likely to cause
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* detection failure, i.e. those that have more bits with fixed
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* or reserved values.
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*/
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/* Default to an DS1337 if forced */
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if (kind == 0)
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kind = ds1337;
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if (kind < 0) { /* detection and identification */
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u8 data;
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/* Check that status register bits 6-2 are zero */
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if ((ds1337_read(new_client, DS1337_REG_STATUS, &data) < 0) ||
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(data & 0x7c))
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goto exit_free;
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/* Check for a valid day register value */
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if ((ds1337_read(new_client, DS1337_REG_DAY, &data) < 0) ||
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(data == 0) || (data & 0xf8))
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goto exit_free;
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/* Check for a valid date register value */
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if ((ds1337_read(new_client, DS1337_REG_DATE, &data) < 0) ||
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(data == 0) || (data & 0xc0) || ((data & 0x0f) > 9) ||
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(data >= 0x32))
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goto exit_free;
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/* Check for a valid month register value */
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if ((ds1337_read(new_client, DS1337_REG_MONTH, &data) < 0) ||
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(data == 0) || (data & 0x60) || ((data & 0x0f) > 9) ||
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((data >= 0x13) && (data <= 0x19)))
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goto exit_free;
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/* Check that control register bits 6-5 are zero */
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if ((ds1337_read(new_client, DS1337_REG_CONTROL, &data) < 0) ||
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(data & 0x60))
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goto exit_free;
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kind = ds1337;
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}
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if (kind == ds1337)
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name = "ds1337";
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/* We can fill in the remaining client fields */
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strlcpy(new_client->name, name, I2C_NAME_SIZE);
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/* Tell the I2C layer a new client has arrived */
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if ((err = i2c_attach_client(new_client)))
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goto exit_free;
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/* Initialize the DS1337 chip */
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ds1337_init_client(new_client);
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/* Add client to local list */
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data->id = ds1337_id++;
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list_add(&data->list, &ds1337_clients);
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return 0;
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exit_free:
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kfree(data);
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exit:
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return err;
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}
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static void ds1337_init_client(struct i2c_client *client)
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{
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s32 val;
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/* Ensure that device is set in 24-hour mode */
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val = i2c_smbus_read_byte_data(client, DS1337_REG_HOUR);
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if ((val >= 0) && (val & (1 << 6)) == 0)
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|
|
i2c_smbus_write_byte_data(client, DS1337_REG_HOUR,
|
|
|
|
val | (1 << 6));
|
|
|
|
}
|
|
|
|
|
|
|
|
static int ds1337_detach_client(struct i2c_client *client)
|
|
|
|
{
|
|
|
|
int err;
|
|
|
|
struct ds1337_data *data = i2c_get_clientdata(client);
|
|
|
|
|
|
|
|
if ((err = i2c_detach_client(client))) {
|
|
|
|
dev_err(&client->dev, "Client deregistration failed, "
|
|
|
|
"client not detached.\n");
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
list_del(&data->list);
|
|
|
|
kfree(data);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int __init ds1337_init(void)
|
|
|
|
{
|
|
|
|
return i2c_add_driver(&ds1337_driver);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit ds1337_exit(void)
|
|
|
|
{
|
|
|
|
i2c_del_driver(&ds1337_driver);
|
|
|
|
}
|
|
|
|
|
|
|
|
MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
|
|
|
|
MODULE_DESCRIPTION("DS1337 RTC driver");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
|
|
|
|
module_init(ds1337_init);
|
|
|
|
module_exit(ds1337_exit);
|