/*
* An I2C driver for Ricoh RS5C372 and RV5C38[67] RTCs
*
* Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
* Copyright (C) 2006 Tower Technologies
*
* 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.
*/
#include <linux/i2c.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#define DRV_VERSION "0.5"
/*
* Ricoh has a family of I2C based RTCs, which differ only slightly from
* each other. Differences center on pinout (e.g. how many interrupts,
* output clock, etc) and how the control registers are used. The '372
* is significant only because that's the one this driver first supported.
*/
#define RS5C372_REG_SECS 0
#define RS5C372_REG_MINS 1
#define RS5C372_REG_HOURS 2
#define RS5C372_REG_WDAY 3
#define RS5C372_REG_DAY 4
#define RS5C372_REG_MONTH 5
#define RS5C372_REG_YEAR 6
#define RS5C372_REG_TRIM 7
# define RS5C372_TRIM_XSL 0x80
# define RS5C372_TRIM_MASK 0x7F
#define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
#define RS5C_REG_ALARM_A_HOURS 9
#define RS5C_REG_ALARM_A_WDAY 10
#define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
#define RS5C_REG_ALARM_B_HOURS 12
#define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
#define RS5C_REG_CTRL1 14
# define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
# define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
# define RV5C387_CTRL1_24 (1 << 5)
# define RS5C372A_CTRL1_SL1 (1 << 5)
# define RS5C_CTRL1_CT_MASK (7 << 0)
# define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
# define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
#define RS5C_REG_CTRL2 15
# define RS5C372_CTRL2_24 (1 << 5)
# define RS5C_CTRL2_XSTP (1 << 4)
# define RS5C_CTRL2_CTFG (1 << 2)
# define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
# define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
/* to read (style 1) or write registers starting at R */
#define RS5C_ADDR(R) (((R) << 4) | 0)
enum rtc_type {
rtc_undef = 0,
rtc_rs5c372a,
rtc_rs5c372b,
rtc_rv5c386,
rtc_rv5c387a,
};
/* REVISIT: this assumes that:
* - we're in the 21st century, so it's safe to ignore the century
* bit for rv5c38[67] (REG_MONTH bit 7);
* - we should use ALARM_A not ALARM_B (may be wrong on some boards)
*/
struct rs5c372 {
struct i2c_client *client;
struct rtc_device *rtc;
enum rtc_type type;
unsigned time24:1;
unsigned has_irq:1;
char buf[17];
char *regs;
};
static int rs5c_get_regs(struct rs5c372 *rs5c)
{
struct i2c_client *client = rs5c->client;
struct i2c_msg msgs[] = {
{ client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
};
/* This implements the third reading method from the datasheet, using
* an internal address that's reset after each transaction (by STOP)
* to 0x0f ... so we read extra registers, and skip the first one.
*
* The first method doesn't work with the iop3xx adapter driver, on at
* least 80219 chips; this works around that bug.
*/
if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
pr_debug("%s: can't read registers\n", rs5c->rtc->name);
return -EIO;
}
dev_dbg(&client->dev,
"%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
"%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
rs5c->regs[0], rs5c->regs[1], rs5c->regs[2], rs5c->regs[3],
rs5c->regs[4], rs5c->regs[5], rs5c->regs[6], rs5c->regs[7],
rs5c->regs[8], rs5c->regs[9], rs5c->regs[10], rs5c->regs[11],
rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
return 0;
}
static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
{
unsigned hour;
if (rs5c->time24)
return BCD2BIN(reg & 0x3f);
hour = BCD2BIN(reg & 0x1f);
if (hour == 12)
hour = 0;
if (reg & 0x20)
hour += 12;
return hour;
}
static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
{
if (rs5c->time24)
return BIN2BCD(hour);
if (hour > 12)
return 0x20 | BIN2BCD(hour - 12);
if (hour == 12)
return 0x20 | BIN2BCD(12);
if (hour == 0)
return BIN2BCD(12);
return BIN2BCD(hour);
}
static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct rs5c372 *rs5c = i2c_get_clientdata(client);
int status = rs5c_get_regs(rs5c);
if (status < 0)
return status;
tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
/* tm->tm_mon is zero-based */
tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
/* year is 1900 + tm->tm_year */
tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__FUNCTION__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* rtc might need initialization */
return rtc_valid_tm(tm);
}
static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct rs5c372 *rs5c = i2c_get_clientdata(client);
unsigned char buf[8];
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__FUNCTION__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
buf[0] = RS5C_ADDR(RS5C372_REG_SECS);
buf[1] = BIN2BCD(tm->tm_sec);
buf[2] = BIN2BCD(tm->tm_min);
buf[3] = rs5c_hr2reg(rs5c, tm->tm_hour);
buf[4] = BIN2BCD(tm->tm_wday);
buf[5] = BIN2BCD(tm->tm_mday);
buf[6] = BIN2BCD(tm->tm_mon + 1);
buf[7] = BIN2BCD(tm->tm_year - 100);
if ((i2c_master_send(client, buf, 8)) != 8) {
dev_err(&client->dev, "%s: write error\n", __FUNCTION__);
return -EIO;
}
return 0;
}
#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
#define NEED_TRIM
#endif
#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
#define NEED_TRIM
#endif
#ifdef NEED_TRIM
static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
{
struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
if (osc)
*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
if (trim) {
dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, tmp);
tmp &= RS5C372_TRIM_MASK;
if (tmp & 0x3e) {
int t = tmp & 0x3f;
if (tmp & 0x40)
t = (~t | (s8)0xc0) + 1;
else
t = t - 1;
tmp = t * 2;
} else
tmp = 0;
*trim = tmp;
}
return 0;
}
#endif
static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return rs5c372_get_datetime(to_i2c_client(dev), tm);
}
static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return rs5c372_set_datetime(to_i2c_client(dev), tm);
}
#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
static int
rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = to_i2c_client(dev);
struct rs5c372 *rs5c = i2c_get_clientdata(client);
unsigned char buf[2];
int status;
buf[1] = rs5c->regs[RS5C_REG_CTRL1];
switch (cmd) {
case RTC_UIE_OFF:
case RTC_UIE_ON:
/* some 327a modes use a different IRQ pin for 1Hz irqs */
if (rs5c->type == rtc_rs5c372a
&& (buf[1] & RS5C372A_CTRL1_SL1))
return -ENOIOCTLCMD;
case RTC_AIE_OFF:
case RTC_AIE_ON:
/* these irq management calls only make sense for chips
* which are wired up to an IRQ.
*/
if (!rs5c->has_irq)
return -ENOIOCTLCMD;
break;
default:
return -ENOIOCTLCMD;
}
status = rs5c_get_regs(rs5c);
if (status < 0)
return status;
buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
switch (cmd) {
case RTC_AIE_OFF: /* alarm off */
buf[1] &= ~RS5C_CTRL1_AALE;
break;
case RTC_AIE_ON: /* alarm on */
buf[1] |= RS5C_CTRL1_AALE;
break;
case RTC_UIE_OFF: /* update off */
buf[1] &= ~RS5C_CTRL1_CT_MASK;
break;
case RTC_UIE_ON: /* update on */
buf[1] &= ~RS5C_CTRL1_CT_MASK;
buf[1] |= RS5C_CTRL1_CT4;
break;
}
if ((i2c_master_send(client, buf, 2)) != 2) {
printk(KERN_WARNING "%s: can't update alarm\n",
rs5c->rtc->name);
status = -EIO;
} else
rs5c->regs[RS5C_REG_CTRL1] = buf[1];
return status;
}
#else
#define rs5c_rtc_ioctl NULL
#endif
/* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
* which only exposes a polled programming interface; and since
* these calls map directly to those EFI requests; we don't demand
* we have an IRQ for this chip when we go through this API.
*
* The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
* though, managed through RTC_AIE_{ON,OFF} requests.
*/
static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
struct rs5c372 *rs5c = i2c_get_clientdata(client);
int status;
status = rs5c_get_regs(rs5c);
if (status < 0)
return status;
/* report alarm time */
t->time.tm_sec = 0;
t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
t->time.tm_mday = -1;
t->time.tm_mon = -1;
t->time.tm_year = -1;
t->time.tm_wday = -1;
t->time.tm_yday = -1;
t->time.tm_isdst = -1;
/* ... and status */
t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
return 0;
}
static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
struct rs5c372 *rs5c = i2c_get_clientdata(client);
int status;
unsigned char buf[4];
/* only handle up to 24 hours in the future, like RTC_ALM_SET */
if (t->time.tm_mday != -1
|| t->time.tm_mon != -1
|| t->time.tm_year != -1)
return -EINVAL;
/* REVISIT: round up tm_sec */
/* if needed, disable irq (clears pending status) */
status = rs5c_get_regs(rs5c);
if (status < 0)
return status;
if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
buf[1] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
if (i2c_master_send(client, buf, 2) != 2) {
pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
return -EIO;
}
rs5c->regs[RS5C_REG_CTRL1] = buf[1];
}
/* set alarm */
buf[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN);
buf[1] = BIN2BCD(t->time.tm_min);
buf[2] = rs5c_hr2reg(rs5c, t->time.tm_hour);
buf[3] = 0x7f; /* any/all days */
if ((i2c_master_send(client, buf, 4)) != 4) {
pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
return -EIO;
}
/* ... and maybe enable its irq */
if (t->enabled) {
buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
buf[1] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
if ((i2c_master_send(client, buf, 2)) != 2)
printk(KERN_WARNING "%s: can't enable alarm\n",
rs5c->rtc->name);
rs5c->regs[RS5C_REG_CTRL1] = buf[1];
}
return 0;
}
#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
{
int err, osc, trim;
err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
if (err == 0) {
seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
osc / 1000, osc % 1000);
seq_printf(seq, "trim\t\t: %d\n", trim);
}
return 0;
}
#else
#define rs5c372_rtc_proc NULL
#endif
static const struct rtc_class_ops rs5c372_rtc_ops = {
.proc = rs5c372_rtc_proc,
.ioctl = rs5c_rtc_ioctl,
.read_time = rs5c372_rtc_read_time,
.set_time = rs5c372_rtc_set_time,
.read_alarm = rs5c_read_alarm,
.set_alarm = rs5c_set_alarm,
};
#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
struct device_attribute *attr, char *buf)
{
int err, trim;
err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
if (err)
return err;
return sprintf(buf, "%d\n", trim);
}
static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
struct device_attribute *attr, char *buf)
{
int err, osc;
err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
if (err)
return err;
return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
}
static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
static int rs5c_sysfs_register(struct device *dev)
{
int err;
err = device_create_file(dev, &dev_attr_trim);
if (err)
return err;
err = device_create_file(dev, &dev_attr_osc);
if (err)
device_remove_file(dev, &dev_attr_trim);
return err;
}
static void rs5c_sysfs_unregister(struct device *dev)
{
device_remove_file(dev, &dev_attr_trim);
device_remove_file(dev, &dev_attr_osc);
}
#else
static int rs5c_sysfs_register(struct device *dev)
{
return 0;
}
static void rs5c_sysfs_unregister(struct device *dev)
{
/* nothing */
}
#endif /* SYSFS */
static struct i2c_driver rs5c372_driver;
static int rs5c372_probe(struct i2c_client *client)
{
int err = 0;
struct rs5c372 *rs5c372;
struct rtc_time tm;
dev_dbg(&client->dev, "%s\n", __FUNCTION__);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
err = -ENODEV;
goto exit;
}
if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
/* we read registers 0x0f then 0x00-0x0f; skip the first one */
rs5c372->regs=&rs5c372->buf[1];
rs5c372->client = client;
i2c_set_clientdata(client, rs5c372);
err = rs5c_get_regs(rs5c372);
if (err < 0)
goto exit_kfree;
if (strcmp(client->name, "rs5c372a") == 0)
rs5c372->type = rtc_rs5c372a;
else if (strcmp(client->name, "rs5c372b") == 0)
rs5c372->type = rtc_rs5c372b;
else if (strcmp(client->name, "rv5c386") == 0)
rs5c372->type = rtc_rv5c386;
else if (strcmp(client->name, "rv5c387a") == 0)
rs5c372->type = rtc_rv5c387a;
else {
rs5c372->type = rtc_rs5c372b;
dev_warn(&client->dev, "assuming rs5c372b\n");
}
/* clock may be set for am/pm or 24 hr time */
switch (rs5c372->type) {
case rtc_rs5c372a:
case rtc_rs5c372b:
/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
* so does periodic irq, except some 327a modes.
*/
if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
rs5c372->time24 = 1;
break;
case rtc_rv5c386:
case rtc_rv5c387a:
if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
rs5c372->time24 = 1;
/* alarm uses ALARM_W; and nINTRB for alarm and periodic
* irq, on both 386 and 387
*/
break;
default:
dev_err(&client->dev, "unknown RTC type\n");
goto exit_kfree;
}
/* if the oscillator lost power and no other software (like
* the bootloader) set it up, do it here.
*/
if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP) {
unsigned char buf[3];
rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
buf[1] = rs5c372->regs[RS5C_REG_CTRL1];
buf[2] = rs5c372->regs[RS5C_REG_CTRL2];
/* use 24hr mode */
switch (rs5c372->type) {
case rtc_rs5c372a:
case rtc_rs5c372b:
buf[2] |= RS5C372_CTRL2_24;
rs5c372->time24 = 1;
break;
case rtc_rv5c386:
case rtc_rv5c387a:
buf[1] |= RV5C387_CTRL1_24;
rs5c372->time24 = 1;
break;
default:
/* impossible */
break;
}
if ((i2c_master_send(client, buf, 3)) != 3) {
dev_err(&client->dev, "setup error\n");
goto exit_kfree;
}
rs5c372->regs[RS5C_REG_CTRL1] = buf[1];
rs5c372->regs[RS5C_REG_CTRL2] = buf[2];
}
if (rs5c372_get_datetime(client, &tm) < 0)
dev_warn(&client->dev, "clock needs to be set\n");
dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
({ char *s; switch (rs5c372->type) {
case rtc_rs5c372a: s = "rs5c372a"; break;
case rtc_rs5c372b: s = "rs5c372b"; break;
case rtc_rv5c386: s = "rv5c386"; break;
case rtc_rv5c387a: s = "rv5c387a"; break;
default: s = "chip"; break;
}; s;}),
rs5c372->time24 ? "24hr" : "am/pm"
);
/* REVISIT use client->irq to register alarm irq ... */
rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
&client->dev, &rs5c372_rtc_ops, THIS_MODULE);
if (IS_ERR(rs5c372->rtc)) {
err = PTR_ERR(rs5c372->rtc);
goto exit_kfree;
}
err = rs5c_sysfs_register(&client->dev);
if (err)
goto exit_devreg;
return 0;
exit_devreg:
rtc_device_unregister(rs5c372->rtc);
exit_kfree:
kfree(rs5c372);
exit:
return err;
}
static int rs5c372_remove(struct i2c_client *client)
{
struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
rtc_device_unregister(rs5c372->rtc);
rs5c_sysfs_unregister(&client->dev);
kfree(rs5c372);
return 0;
}
static struct i2c_driver rs5c372_driver = {
.driver = {
.name = "rtc-rs5c372",
},
.probe = rs5c372_probe,
.remove = rs5c372_remove,
};
static __init int rs5c372_init(void)
{
return i2c_add_driver(&rs5c372_driver);
}
static __exit void rs5c372_exit(void)
{
i2c_del_driver(&rs5c372_driver);
}
module_init(rs5c372_init);
module_exit(rs5c372_exit);
MODULE_AUTHOR(
"Pavel Mironchik <pmironchik@optifacio.net>, "
"Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
