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/*
* 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 =
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