/*
* An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
*
* Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
* Copyright (C) 2006 Tower Technologies
* Copyright (C) 2008 Paul Mundt
*
* 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>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/of_device.h>
/*
* 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 R2025_CTRL2_XST (1 << 5)
# define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2025S/D */
# 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_r2025sd,
rtc_r2221tl,
rtc_rs5c372a,
rtc_rs5c372b,
rtc_rv5c386,
rtc_rv5c387a,
};
static const struct i2c_device_id rs5c372_id[] = {
{ "r2025sd", rtc_r2025sd },
{ "r2221tl", rtc_r2221tl },
{ "rs5c372a", rtc_rs5c372a },
{ "rs5c372b", rtc_rs5c372b },
{ "rv5c386", rtc_rv5c386 },
{ "rv5c387a", rtc_rv5c387a },
{ }
};
MODULE_DEVICE_TABLE(i2c, rs5c372_id);
static const struct of_device_id rs5c372_of_match[] = {
{
.compatible = "ricoh,r2025sd",
.data = (void *)rtc_r2025sd
},
{
.compatible = "ricoh,r2221tl",
.data = (void *)rtc_r2221tl
},
{
.compatible = "ricoh,rs5c372a",
.data = (void *)rtc_rs5c372a
},
{
.compatible = "ricoh,rs5c372b",
.data = (void *)rtc_rs5c372b
},
{
.compatible = "ricoh,rv5c386",
.data = (void *)rtc_rv5c386
},
{
.compatible = "ricoh,rv5c387a",
.data = (void *)rtc_rv5c387a
},
{ }
};
MODULE_DEVICE_TABLE(of, rs5c372_of_match);
/* 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;
unsigned smbus:1;
char buf[17];
char *regs;
};
static int rs5c_get_regs(struct rs5c372 *rs5c)
{
struct i2c_client *client = rs5c->client;
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = sizeof(rs5c->buf),
.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.
*
* The third method on the other hand doesn't work for the SMBus-only
* configurations, so we use the the first method there, stripping off
* the extra register in the process.
*/
if (rs5c->smbus) {
int addr = RS5C_ADDR(RS5C372_REG_SECS);
int size = sizeof(rs5c->buf) - 1;
if (i2c_smbus_read_i2c_block_data(client, addr, size,
rs5c->buf + 1) != size) {
dev_warn(&client->dev, "can't read registers\n");
return -EIO;
}
} else {
if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
dev_warn(&client->dev, "can't read registers\n");
return -EIO;
}
}
dev_dbg(&client->dev,
"%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
rs5c->regs + 0, rs5c->regs[3],
rs5c->regs + 4, rs5c->regs[7],
rs5c->regs + 8, rs5c->regs + 11,
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_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
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",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
return 0;
}
static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
struct rs5c372 *rs5c = i2c_get_clientdata(client);
unsigned char buf[7];
int addr;
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
addr = RS5C_ADDR(RS5C372_REG_SECS);
buf[0] = bin2bcd(tm->tm_sec);
buf[1] = bin2bcd(tm->tm_min);
buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
buf[3] = bin2bcd(tm->tm_wday);
buf[4] = bin2bcd(tm->tm_mday);
buf[5] = bin2bcd(tm->tm_mon + 1);
buf[6] = bin2bcd(tm->tm_year - 100);
if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
dev_err(&client->dev, "%s: write error\n", __func__);
return -EIO;
}
return 0;
}
#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
#define NEED_TRIM
#endif
#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
#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", __func__, 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 rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct i2c_client *client = to_i2c_client(dev);
struct rs5c372 *rs5c = i2c_get_clientdata(client);
unsigned char buf;
int status, addr;
buf = rs5c->regs[RS5C_REG_CTRL1];
if (!rs5c->has_irq)
return -EINVAL;
status = rs5c_get_regs(rs5c);
if (status < 0)
return status;
addr = RS5C_ADDR(RS5C_REG_CTRL1);
if (enabled)
buf |= RS5C_CTRL1_AALE;
else
buf &= ~RS5C_CTRL1_AALE;
if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
dev_warn(dev, "can't update alarm\n");
status = -EIO;
} else
rs5c->regs[RS5C_REG_CTRL1] = buf;
return status;
}
/* 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]);
/* ... 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, addr, i;
unsigned char buf[3];
/* 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) {
addr = RS5C_ADDR(RS5C_REG_CTRL1);
buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
dev_dbg(dev, "can't disable alarm\n");
return -EIO;
}
rs5c->regs[RS5C_REG_CTRL1] = buf[0];
}
/* set alarm */
buf[0] = bin2bcd(t->time.tm_min);
buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
buf[2] = 0x7f; /* any/all days */
for (i = 0; i < sizeof(buf); i++) {
addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
dev_dbg(dev, "can't set alarm time\n");
return -EIO;
}
}
/* ... and maybe enable its irq */
if (t->enabled) {
addr = RS5C_ADDR(RS5C_REG_CTRL1);
buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
dev_warn(dev, "can't enable alarm\n");
rs5c->regs[RS5C_REG_CTRL1] = buf[0];
}
return 0;
}
#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
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,
.read_time = rs5c372_rtc_read_time,
.set_time = rs5c372_rtc_set_time,
.read_alarm = rs5c_read_alarm,
.set_alarm = rs5c_set_alarm,
.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
};
#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
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 rs5c_oscillator_setup(struct rs5c372 *rs5c372)
{
unsigned char buf[2];
int addr, i, ret = 0;
if (rs5c372->type == rtc_r2025sd) {
if (rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST)
return ret;
rs5c372->regs[RS5C_REG_CTRL2] |= R2025_CTRL2_XST;
} else {
if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
return ret;
rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
}
addr = RS5C_ADDR(RS5C_REG_CTRL1);
buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
/* use 24hr mode */
switch (rs5c372->type) {
case rtc_rs5c372a:
case rtc_rs5c372b:
buf[1] |= RS5C372_CTRL2_24;
rs5c372->time24 = 1;
break;
case rtc_r2025sd:
case rtc_r2221tl:
case rtc_rv5c386:
case rtc_rv5c387a:
buf[0] |= RV5C387_CTRL1_24;
rs5c372->time24 = 1;
break;
default:
/* impossible */
break;
}
for (i = 0; i < sizeof(buf); i++) {
addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
if (unlikely(ret < 0))
return ret;
}
rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
return 0;
}
static int rs5c372_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err = 0;
int smbus_mode = 0;
struct rs5c372 *rs5c372;
dev_dbg(&client->dev, "%s\n", __func__);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
/*
* If we don't have any master mode adapter, try breaking
* it down in to the barest of capabilities.
*/
if (i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK))
smbus_mode = 1;
else {
/* Still no good, give up */
err = -ENODEV;
goto exit;
}
}
rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
GFP_KERNEL);
if (!rs5c372) {
err = -ENOMEM;
goto exit;
}
rs5c372->client = client;
i2c_set_clientdata(client, rs5c372);
if (client->dev.of_node)
rs5c372->type = (enum rtc_type)
of_device_get_match_data(&client->dev);
else
rs5c372->type = id->driver_data;
/* we read registers 0x0f then 0x00-0x0f; skip the first one */
rs5c372->regs = &rs5c372->buf[1];
rs5c372->smbus = smbus_mode;
err = rs5c_get_regs(rs5c372);
if (err < 0)
goto exit;
/* 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_r2025sd:
case rtc_r2221tl:
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;
}
/* if the oscillator lost power and no other software (like
* the bootloader) set it up, do it here.
*
* The R2025S/D does this a little differently than the other
* parts, so we special case that..
*/
err = rs5c_oscillator_setup(rs5c372);
if (unlikely(err < 0)) {
dev_err(&client->dev, "setup error\n");
goto exit;
}
dev_info(&client->dev, "%s found, %s\n",
({ char *s; switch (rs5c372->type) {
case rtc_r2025sd: s = "r2025sd"; break;
case rtc_r2221tl: s = "r2221tl"; break;
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 = devm_rtc_device_register(&client->dev,
rs5c372_driver.driver.name,
&rs5c372_rtc_ops, THIS_MODULE);
if (IS_ERR(rs5c372->rtc)) {
err = PTR_ERR(rs5c372->rtc);
goto exit;
}
err = rs5c_sysfs_register(&client->dev);
if (err)
goto exit;
return 0;
exit:
return err;
}
static int rs5c372_remove(struct i2c_client *client)
{
rs5c_sysfs_unregister(&client->dev);
return 0;
}
static struct i2c_driver rs5c372_driver = {
.driver = {
.name = "rtc-rs5c372",
.of_match_table = of_match_ptr(rs5c372_of_match),
},
.probe = rs5c372_probe,
.remove = rs5c372_remove,
.id_table = rs5c372_id,
};
module_i2c_driver(rs5c372_driver);
MODULE_AUTHOR(
"Pavel Mironchik <pmironchik@optifacio.net>, "
"Alessandro Zummo <a.zummo@towertech.it>, "
"Paul Mundt <lethal@linux-sh.org>");
MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
MODULE_LICENSE("GPL");
