Commit 9c0c5705 authored by G. Liakhovetski's avatar G. Liakhovetski Committed by Linus Torvalds
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[PATCH] drivers/acorn/char/pcf8583.[hc] vs. RTC subsystem



A port of the driver for the pcf8583 i2c rtc controller to the generic RTC
framework by Alessandro Zummo.  Based on
drivers/acorn/char/{pcf8583.[hc],i2c.c}.  Hopefully, acorn can be converted
too to use this driver in the future.
Signed-off-by: default avatarG. Liakhovetski <gl@dsa-ac.de>
Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 655066c3
......@@ -132,6 +132,16 @@ config RTC_DRV_PCF8563
This driver can also be built as a module. If so, the module
will be called rtc-pcf8563.
config RTC_DRV_PCF8583
tristate "Philips PCF8583"
depends on RTC_CLASS && I2C
help
If you say yes here you get support for the
Philips PCF8583 RTC chip.
This driver can also be built as a module. If so, the module
will be called rtc-pcf8583.
config RTC_DRV_RS5C372
tristate "Ricoh RS5C372A/B"
depends on RTC_CLASS && I2C
......
......@@ -16,6 +16,7 @@ obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o
obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o
obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o
obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o
......
/*
* drivers/rtc/rtc-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
*
* Converted to the generic RTC susbsystem by G. Liakhovetski (2006)
*/
#include <linux/module.h>
#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>
struct rtc_mem {
unsigned int loc;
unsigned int nr;
unsigned char *data;
};
struct pcf8583 {
struct i2c_client client;
struct rtc_device *rtc;
unsigned char ctrl;
};
#define CTRL_STOP 0x80
#define CTRL_HOLD 0x40
#define CTRL_32KHZ 0x00
#define CTRL_MASK 0x08
#define CTRL_ALARMEN 0x04
#define CTRL_ALARM 0x02
#define CTRL_TIMER 0x01
static unsigned short normal_i2c[] = { I2C_CLIENT_END };
/* Module parameters */
I2C_CLIENT_INSMOD;
static struct i2c_driver pcf8583_driver;
#define get_ctrl(x) ((struct pcf8583 *)i2c_get_clientdata(x))->ctrl
#define set_ctrl(x, v) get_ctrl(x) = v
#define CMOS_YEAR (64 + 128)
#define CMOS_CHECKSUM (63)
static int pcf8583_get_datetime(struct i2c_client *client, struct rtc_time *dt)
{
unsigned char buf[8], addr[1] = { 1 };
struct i2c_msg msgs[2] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = addr,
}, {
.addr = client->addr,
.flags = I2C_M_RD,
.len = 6,
.buf = buf,
}
};
int ret;
memset(buf, 0, sizeof(buf));
ret = i2c_transfer(client->adapter, msgs, 2);
if (ret == 2) {
dt->tm_year = buf[4] >> 6;
dt->tm_wday = buf[5] >> 5;
buf[4] &= 0x3f;
buf[5] &= 0x1f;
dt->tm_sec = BCD_TO_BIN(buf[1]);
dt->tm_min = BCD_TO_BIN(buf[2]);
dt->tm_hour = BCD_TO_BIN(buf[3]);
dt->tm_mday = BCD_TO_BIN(buf[4]);
dt->tm_mon = BCD_TO_BIN(buf[5]);
}
return ret == 2 ? 0 : -EIO;
}
static int pcf8583_set_datetime(struct i2c_client *client, struct rtc_time *dt, int datetoo)
{
unsigned char buf[8];
int ret, len = 6;
buf[0] = 0;
buf[1] = get_ctrl(client) | 0x80;
buf[2] = 0;
buf[3] = BIN_TO_BCD(dt->tm_sec);
buf[4] = BIN_TO_BCD(dt->tm_min);
buf[5] = BIN_TO_BCD(dt->tm_hour);
if (datetoo) {
len = 8;
buf[6] = BIN_TO_BCD(dt->tm_mday) | (dt->tm_year << 6);
buf[7] = BIN_TO_BCD(dt->tm_mon) | (dt->tm_wday << 5);
}
ret = i2c_master_send(client, (char *)buf, len);
if (ret != len)
return -EIO;
buf[1] = get_ctrl(client);
ret = i2c_master_send(client, (char *)buf, 2);
return ret == 2 ? 0 : -EIO;
}
static int pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
{
*ctrl = get_ctrl(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;
set_ctrl(client, *ctrl);
return i2c_master_send(client, (char *)buf, 2);
}
static int pcf8583_read_mem(struct i2c_client *client, struct rtc_mem *mem)
{
unsigned char addr[1];
struct i2c_msg msgs[2] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = addr,
}, {
.addr = client->addr,
.flags = I2C_M_RD,
.len = mem->nr,
.buf = mem->data,
}
};
if (mem->loc < 8)
return -EINVAL;
addr[0] = mem->loc;
return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
}
static int pcf8583_write_mem(struct i2c_client *client, struct rtc_mem *mem)
{
unsigned char addr[1];
struct i2c_msg msgs[2] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = addr,
}, {
.addr = client->addr,
.flags = I2C_M_NOSTART,
.len = mem->nr,
.buf = mem->data,
}
};
if (mem->loc < 8)
return -EINVAL;
addr[0] = mem->loc;
return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
}
static int pcf8583_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char ctrl, year[2];
struct rtc_mem mem = { CMOS_YEAR, sizeof(year), year };
int real_year, year_offset, err;
/*
* Ensure that the RTC is running.
*/
pcf8583_get_ctrl(client, &ctrl);
if (ctrl & (CTRL_STOP | CTRL_HOLD)) {
unsigned char new_ctrl = ctrl & ~(CTRL_STOP | CTRL_HOLD);
printk(KERN_WARNING "RTC: resetting control %02x -> %02x\n",
ctrl, new_ctrl);
if ((err = pcf8583_set_ctrl(client, &new_ctrl)) < 0)
return err;
}
if (pcf8583_get_datetime(client, tm) ||
pcf8583_read_mem(client, &mem))
return -EIO;
real_year = year[0];
/*
* The RTC year holds the LSB two bits of the current
* year, which should reflect the LSB two bits of the
* CMOS copy of the year. Any difference indicates
* that we have to correct the CMOS version.
*/
year_offset = tm->tm_year - (real_year & 3);
if (year_offset < 0)
/*
* RTC year wrapped. Adjust it appropriately.
*/
year_offset += 4;
tm->tm_year = real_year + year_offset + year[1] * 100;
return 0;
}
static int pcf8583_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char year[2], chk;
struct rtc_mem cmos_year = { CMOS_YEAR, sizeof(year), year };
struct rtc_mem cmos_check = { CMOS_CHECKSUM, 1, &chk };
int ret;
/*
* The RTC's own 2-bit year must reflect the least
* significant two bits of the CMOS year.
*/
ret = pcf8583_set_datetime(client, tm, 1);
if (ret)
return ret;
ret = pcf8583_read_mem(client, &cmos_check);
if (ret)
return ret;
ret = pcf8583_read_mem(client, &cmos_year);
if (ret)
return ret;
chk -= year[1] + year[0];
year[1] = tm->tm_year / 100;
year[0] = tm->tm_year % 100;
chk += year[1] + year[0];
ret = pcf8583_write_mem(client, &cmos_year);
if (ret)
return ret;
ret = pcf8583_write_mem(client, &cmos_check);
return ret;
}
static struct rtc_class_ops pcf8583_rtc_ops = {
.read_time = pcf8583_rtc_read_time,
.set_time = pcf8583_rtc_set_time,
};
static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind);
static int pcf8583_attach(struct i2c_adapter *adap)
{
return i2c_probe(adap, &addr_data, pcf8583_probe);
}
static int pcf8583_detach(struct i2c_client *client)
{
int err;
struct pcf8583 *pcf = i2c_get_clientdata(client);
struct rtc_device *rtc = pcf->rtc;
if (rtc)
rtc_device_unregister(rtc);
if ((err = i2c_detach_client(client)))
return err;
kfree(pcf);
return 0;
}
static struct i2c_driver pcf8583_driver = {
.driver = {
.name = "pcf8583",
},
.id = I2C_DRIVERID_PCF8583,
.attach_adapter = pcf8583_attach,
.detach_client = pcf8583_detach,
};
static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind)
{
struct pcf8583 *pcf;
struct i2c_client *client;
struct rtc_device *rtc;
unsigned char buf[1], ad[1] = { 0 };
int err;
struct i2c_msg msgs[2] = {
{
.addr = addr,
.flags = 0,
.len = 1,
.buf = ad,
}, {
.addr = addr,
.flags = I2C_M_RD,
.len = 1,
.buf = buf,
}
};
pcf = kzalloc(sizeof(*pcf), GFP_KERNEL);
if (!pcf)
return -ENOMEM;
client = &pcf->client;
client->addr = addr;
client->adapter = adap;
client->driver = &pcf8583_driver;
strlcpy(client->name, pcf8583_driver.driver.name, I2C_NAME_SIZE);
if (i2c_transfer(client->adapter, msgs, 2) != 2) {
err = -EIO;
goto exit_kfree;
}
err = i2c_attach_client(client);
if (err)
goto exit_kfree;
rtc = rtc_device_register(pcf8583_driver.driver.name, &client->dev,
&pcf8583_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
err = PTR_ERR(rtc);
goto exit_detach;
}
pcf->rtc = rtc;
i2c_set_clientdata(client, pcf);
set_ctrl(client, buf[0]);
return 0;
exit_detach:
i2c_detach_client(client);
exit_kfree:
kfree(pcf);
return err;
}
static __init int pcf8583_init(void)
{
return i2c_add_driver(&pcf8583_driver);
}
static __exit void pcf8583_exit(void)
{
i2c_del_driver(&pcf8583_driver);
}
module_init(pcf8583_init);
module_exit(pcf8583_exit);
MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("PCF8583 I2C RTC driver");
MODULE_LICENSE("GPL");
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