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linux/drivers/rtc/rtc-rs5c313.c
kogiidena 4ac24b3ba9 rtc-rs5c313.c: add error handling to avoid hardware hangup 
Add error processing.  Hanging up by an infinite loop is evaded.

Signed-off-by: kogiidena <kogiidena@eggplant.ddo.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:35 -07:00

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/*
* Ricoh RS5C313 RTC device/driver
* Copyright (C) 2007 Nobuhiro Iwamatsu
*
* 2005-09-19 modifed by kogiidena
*
* Based on the old drivers/char/rs5c313_rtc.c by:
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
*
* Based on code written by Paul Gortmaker.
* Copyright (C) 1996 Paul Gortmaker
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Based on other minimal char device drivers, like Alan's
* watchdog, Ted's random, etc. etc.
*
* 1.07 Paul Gortmaker.
* 1.08 Miquel van Smoorenburg: disallow certain things on the
* DEC Alpha as the CMOS clock is also used for other things.
* 1.09 Nikita Schmidt: epoch support and some Alpha cleanup.
* 1.09a Pete Zaitcev: Sun SPARC
* 1.09b Jeff Garzik: Modularize, init cleanup
* 1.09c Jeff Garzik: SMP cleanup
* 1.10 Paul Barton-Davis: add support for async I/O
* 1.10a Andrea Arcangeli: Alpha updates
* 1.10b Andrew Morton: SMP lock fix
* 1.10c Cesar Barros: SMP locking fixes and cleanup
* 1.10d Paul Gortmaker: delete paranoia check in rtc_exit
* 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness.
* 1.11 Takashi Iwai: Kernel access functions
* rtc_register/rtc_unregister/rtc_control
* 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
* 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
* CONFIG_HPET_EMULATE_RTC
* 1.13 Nobuhiro Iwamatsu: Updata driver.
*/
#include <linux/module.h>
#include <linux/err.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/bcd.h>
#include <linux/delay.h>
#include <asm/io.h>
#define DRV_NAME "rs5c313"
#define DRV_VERSION "1.13"
#ifdef CONFIG_SH_LANDISK
/*****************************************************/
/* LANDISK dependence part of RS5C313 */
/*****************************************************/
#define SCSMR1 0xFFE00000
#define SCSCR1 0xFFE00008
#define SCSMR1_CA 0x80
#define SCSCR1_CKE 0x03
#define SCSPTR1 0xFFE0001C
#define SCSPTR1_EIO 0x80
#define SCSPTR1_SPB1IO 0x08
#define SCSPTR1_SPB1DT 0x04
#define SCSPTR1_SPB0IO 0x02
#define SCSPTR1_SPB0DT 0x01
#define SDA_OEN SCSPTR1_SPB1IO
#define SDA SCSPTR1_SPB1DT
#define SCL_OEN SCSPTR1_SPB0IO
#define SCL SCSPTR1_SPB0DT
/* RICOH RS5C313 CE port */
#define RS5C313_CE 0xB0000003
/* RICOH RS5C313 CE port bit */
#define RS5C313_CE_RTCCE 0x02
/* SCSPTR1 data */
unsigned char scsptr1_data;
#define RS5C313_CEENABLE ctrl_outb(RS5C313_CE_RTCCE, RS5C313_CE);
#define RS5C313_CEDISABLE ctrl_outb(0x00, RS5C313_CE)
#define RS5C313_MISCOP ctrl_outb(0x02, 0xB0000008)
static void rs5c313_init_port(void)
{
/* Set SCK as I/O port and Initialize SCSPTR1 data & I/O port. */
ctrl_outb(ctrl_inb(SCSMR1) & ~SCSMR1_CA, SCSMR1);
ctrl_outb(ctrl_inb(SCSCR1) & ~SCSCR1_CKE, SCSCR1);
/* And Initialize SCL for RS5C313 clock */
scsptr1_data = ctrl_inb(SCSPTR1) | SCL; /* SCL:H */
ctrl_outb(scsptr1_data, SCSPTR1);
scsptr1_data = ctrl_inb(SCSPTR1) | SCL_OEN; /* SCL output enable */
ctrl_outb(scsptr1_data, SCSPTR1);
RS5C313_CEDISABLE; /* CE:L */
}
static void rs5c313_write_data(unsigned char data)
{
int i;
for (i = 0; i < 8; i++) {
/* SDA:Write Data */
scsptr1_data = (scsptr1_data & ~SDA) |
((((0x80 >> i) & data) >> (7 - i)) << 2);
ctrl_outb(scsptr1_data, SCSPTR1);
if (i == 0) {
scsptr1_data |= SDA_OEN; /* SDA:output enable */
ctrl_outb(scsptr1_data, SCSPTR1);
}
ndelay(700);
scsptr1_data &= ~SCL; /* SCL:L */
ctrl_outb(scsptr1_data, SCSPTR1);
ndelay(700);
scsptr1_data |= SCL; /* SCL:H */
ctrl_outb(scsptr1_data, SCSPTR1);
}
scsptr1_data &= ~SDA_OEN; /* SDA:output disable */
ctrl_outb(scsptr1_data, SCSPTR1);
}
static unsigned char rs5c313_read_data(void)
{
int i;
unsigned char data = 0;
for (i = 0; i < 8; i++) {
ndelay(700);
/* SDA:Read Data */
data |= ((ctrl_inb(SCSPTR1) & SDA) >> 2) << (7 - i);
scsptr1_data &= ~SCL; /* SCL:L */
ctrl_outb(scsptr1_data, SCSPTR1);
ndelay(700);
scsptr1_data |= SCL; /* SCL:H */
ctrl_outb(scsptr1_data, SCSPTR1);
}
return data & 0x0F;
}
#endif /* CONFIG_SH_LANDISK */
/*****************************************************/
/* machine independence part of RS5C313 */
/*****************************************************/
/* RICOH RS5C313 address */
#define RS5C313_ADDR_SEC 0x00
#define RS5C313_ADDR_SEC10 0x01
#define RS5C313_ADDR_MIN 0x02
#define RS5C313_ADDR_MIN10 0x03
#define RS5C313_ADDR_HOUR 0x04
#define RS5C313_ADDR_HOUR10 0x05
#define RS5C313_ADDR_WEEK 0x06
#define RS5C313_ADDR_INTINTVREG 0x07
#define RS5C313_ADDR_DAY 0x08
#define RS5C313_ADDR_DAY10 0x09
#define RS5C313_ADDR_MON 0x0A
#define RS5C313_ADDR_MON10 0x0B
#define RS5C313_ADDR_YEAR 0x0C
#define RS5C313_ADDR_YEAR10 0x0D
#define RS5C313_ADDR_CNTREG 0x0E
#define RS5C313_ADDR_TESTREG 0x0F
/* RICOH RS5C313 control register */
#define RS5C313_CNTREG_ADJ_BSY 0x01
#define RS5C313_CNTREG_WTEN_XSTP 0x02
#define RS5C313_CNTREG_12_24 0x04
#define RS5C313_CNTREG_CTFG 0x08
/* RICOH RS5C313 test register */
#define RS5C313_TESTREG_TEST 0x01
/* RICOH RS5C313 control bit */
#define RS5C313_CNTBIT_READ 0x40
#define RS5C313_CNTBIT_AD 0x20
#define RS5C313_CNTBIT_DT 0x10
static unsigned char rs5c313_read_reg(unsigned char addr)
{
rs5c313_write_data(addr | RS5C313_CNTBIT_READ | RS5C313_CNTBIT_AD);
return rs5c313_read_data();
}
static void rs5c313_write_reg(unsigned char addr, unsigned char data)
{
data &= 0x0f;
rs5c313_write_data(addr | RS5C313_CNTBIT_AD);
rs5c313_write_data(data | RS5C313_CNTBIT_DT);
return;
}
static inline unsigned char rs5c313_read_cntreg(void)
{
return rs5c313_read_reg(RS5C313_ADDR_CNTREG);
}
static inline void rs5c313_write_cntreg(unsigned char data)
{
rs5c313_write_reg(RS5C313_ADDR_CNTREG, data);
}
static inline void rs5c313_write_intintvreg(unsigned char data)
{
rs5c313_write_reg(RS5C313_ADDR_INTINTVREG, data);
}
static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
int data;
int cnt;
cnt = 0;
while (1) {
RS5C313_CEENABLE; /* CE:H */
/* Initialize control reg. 24 hour */
rs5c313_write_cntreg(0x04);
if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
break;
RS5C313_CEDISABLE;
ndelay(700); /* CE:L */
if (cnt++ > 100) {
dev_err(dev, "%s: timeout error\n", __FUNCTION__);
return -EIO;
}
}
data = rs5c313_read_reg(RS5C313_ADDR_SEC);
data |= (rs5c313_read_reg(RS5C313_ADDR_SEC10) << 4);
tm->tm_sec = BCD2BIN(data);
data = rs5c313_read_reg(RS5C313_ADDR_MIN);
data |= (rs5c313_read_reg(RS5C313_ADDR_MIN10) << 4);
tm->tm_min = BCD2BIN(data);
data = rs5c313_read_reg(RS5C313_ADDR_HOUR);
data |= (rs5c313_read_reg(RS5C313_ADDR_HOUR10) << 4);
tm->tm_hour = BCD2BIN(data);
data = rs5c313_read_reg(RS5C313_ADDR_DAY);
data |= (rs5c313_read_reg(RS5C313_ADDR_DAY10) << 4);
tm->tm_mday = BCD2BIN(data);
data = rs5c313_read_reg(RS5C313_ADDR_MON);
data |= (rs5c313_read_reg(RS5C313_ADDR_MON10) << 4);
tm->tm_mon = BCD2BIN(data) - 1;
data = rs5c313_read_reg(RS5C313_ADDR_YEAR);
data |= (rs5c313_read_reg(RS5C313_ADDR_YEAR10) << 4);
tm->tm_year = BCD2BIN(data);
if (tm->tm_year < 70)
tm->tm_year += 100;
data = rs5c313_read_reg(RS5C313_ADDR_WEEK);
tm->tm_wday = BCD2BIN(data);
RS5C313_CEDISABLE;
ndelay(700); /* CE:L */
return 0;
}
static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
int data;
int cnt;
cnt = 0;
/* busy check. */
while (1) {
RS5C313_CEENABLE; /* CE:H */
/* Initiatlize control reg. 24 hour */
rs5c313_write_cntreg(0x04);
if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
break;
RS5C313_MISCOP;
RS5C313_CEDISABLE;
ndelay(700); /* CE:L */
if (cnt++ > 100) {
dev_err(dev, "%s: timeout error\n", __FUNCTION__);
return -EIO;
}
}
data = BIN2BCD(tm->tm_sec);
rs5c313_write_reg(RS5C313_ADDR_SEC, data);
rs5c313_write_reg(RS5C313_ADDR_SEC10, (data >> 4));
data = BIN2BCD(tm->tm_min);
rs5c313_write_reg(RS5C313_ADDR_MIN, data );
rs5c313_write_reg(RS5C313_ADDR_MIN10, (data >> 4));
data = BIN2BCD(tm->tm_hour);
rs5c313_write_reg(RS5C313_ADDR_HOUR, data);
rs5c313_write_reg(RS5C313_ADDR_HOUR10, (data >> 4));
data = BIN2BCD(tm->tm_mday);
rs5c313_write_reg(RS5C313_ADDR_DAY, data);
rs5c313_write_reg(RS5C313_ADDR_DAY10, (data>> 4));
data = BIN2BCD(tm->tm_mon + 1);
rs5c313_write_reg(RS5C313_ADDR_MON, data);
rs5c313_write_reg(RS5C313_ADDR_MON10, (data >> 4));
data = BIN2BCD(tm->tm_year % 100);
rs5c313_write_reg(RS5C313_ADDR_YEAR, data);
rs5c313_write_reg(RS5C313_ADDR_YEAR10, (data >> 4));
data = BIN2BCD(tm->tm_wday);
rs5c313_write_reg(RS5C313_ADDR_WEEK, data);
RS5C313_CEDISABLE; /* CE:H */
ndelay(700);
return 0;
}
static void rs5c313_check_xstp_bit(void)
{
struct rtc_time tm;
int cnt;
RS5C313_CEENABLE; /* CE:H */
if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
/* INT interval reg. OFF */
rs5c313_write_intintvreg(0x00);
/* Initialize control reg. 24 hour & adjust */
rs5c313_write_cntreg(0x07);
/* busy check. */
for (cnt = 0; cnt < 100; cnt++) {
if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
break;
RS5C313_MISCOP;
}
memset(&tm, 0, sizeof(struct rtc_time));
tm.tm_mday = 1;
tm.tm_mon = 1 - 1;
tm.tm_year = 2000 - 1900;
rs5c313_rtc_set_time(NULL, &tm);
printk(KERN_ERR "RICHO RS5C313: invalid value, resetting to "
"1 Jan 2000\n");
}
RS5C313_CEDISABLE;
ndelay(700); /* CE:L */
}
static const struct rtc_class_ops rs5c313_rtc_ops = {
.read_time = rs5c313_rtc_read_time,
.set_time = rs5c313_rtc_set_time,
};
static int rs5c313_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc = rtc_device_register("rs5c313", &pdev->dev,
&rs5c313_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
platform_set_drvdata(pdev, rtc);
return 0;
}
static int __devexit rs5c313_rtc_remove(struct platform_device *pdev)
{
struct rtc_device *rtc = platform_get_drvdata( pdev );
rtc_device_unregister(rtc);
return 0;
}
static struct platform_driver rs5c313_rtc_platform_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.probe = rs5c313_rtc_probe,
.remove = __devexit_p( rs5c313_rtc_remove ),
};
static int __init rs5c313_rtc_init(void)
{
int err;
err = platform_driver_register(&rs5c313_rtc_platform_driver);
if (err)
return err;
rs5c313_init_port();
rs5c313_check_xstp_bit();
return 0;
}
static void __exit rs5c313_rtc_exit(void)
{
platform_driver_unregister( &rs5c313_rtc_platform_driver );
}
module_init(rs5c313_rtc_init);
module_exit(rs5c313_rtc_exit);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("kogiidena , Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
MODULE_DESCRIPTION("Ricoh RS5C313 RTC device driver");
MODULE_LICENSE("GPL");
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