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linux-sg2042/drivers/rtc/rtc-rx8025.c

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/*
* Driver for Epson's RTC module RX-8025 SA/NB
*
* Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
*
* Copyright (C) 2005 by Digi International Inc.
* All rights reserved.
*
* Modified by fengjh at rising.com.cn
* <lm-sensors@lm-sensors.org>
* 2006.11
*
* Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
* Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
* Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
*
* 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/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtc.h>
/* Register definitions */
#define RX8025_REG_SEC 0x00
#define RX8025_REG_MIN 0x01
#define RX8025_REG_HOUR 0x02
#define RX8025_REG_WDAY 0x03
#define RX8025_REG_MDAY 0x04
#define RX8025_REG_MONTH 0x05
#define RX8025_REG_YEAR 0x06
#define RX8025_REG_DIGOFF 0x07
#define RX8025_REG_ALWMIN 0x08
#define RX8025_REG_ALWHOUR 0x09
#define RX8025_REG_ALWWDAY 0x0a
#define RX8025_REG_ALDMIN 0x0b
#define RX8025_REG_ALDHOUR 0x0c
/* 0x0d is reserved */
#define RX8025_REG_CTRL1 0x0e
#define RX8025_REG_CTRL2 0x0f
#define RX8025_BIT_CTRL1_CT (7 << 0)
/* 1 Hz periodic level irq */
#define RX8025_BIT_CTRL1_CT_1HZ 4
#define RX8025_BIT_CTRL1_TEST BIT(3)
#define RX8025_BIT_CTRL1_1224 BIT(5)
#define RX8025_BIT_CTRL1_DALE BIT(6)
#define RX8025_BIT_CTRL1_WALE BIT(7)
#define RX8025_BIT_CTRL2_DAFG BIT(0)
#define RX8025_BIT_CTRL2_WAFG BIT(1)
#define RX8025_BIT_CTRL2_CTFG BIT(2)
#define RX8025_BIT_CTRL2_PON BIT(4)
#define RX8025_BIT_CTRL2_XST BIT(5)
#define RX8025_BIT_CTRL2_VDET BIT(6)
/* Clock precision adjustment */
#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
#define RX8025_ADJ_DATA_MAX 62
#define RX8025_ADJ_DATA_MIN -62
static const struct i2c_device_id rx8025_id[] = {
{ "rx8025", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, rx8025_id);
struct rx8025_data {
struct i2c_client *client;
struct rtc_device *rtc;
u8 ctrl1;
};
static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
{
return i2c_smbus_read_byte_data(client, number << 4);
}
static int rx8025_read_regs(const struct i2c_client *client,
u8 number, u8 length, u8 *values)
{
int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
values);
if (ret != length)
return ret < 0 ? ret : -EIO;
return 0;
}
static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
u8 value)
{
return i2c_smbus_write_byte_data(client, number << 4, value);
}
static s32 rx8025_write_regs(const struct i2c_client *client,
u8 number, u8 length, const u8 *values)
{
return i2c_smbus_write_i2c_block_data(client, number << 4,
length, values);
}
static int rx8025_check_validity(struct device *dev)
{
struct rx8025_data *rx8025 = dev_get_drvdata(dev);
int ctrl2;
ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
if (ctrl2 < 0)
return ctrl2;
if (ctrl2 & RX8025_BIT_CTRL2_VDET)
dev_warn(dev, "power voltage drop detected\n");
if (ctrl2 & RX8025_BIT_CTRL2_PON) {
dev_warn(dev, "power-on reset detected, date is invalid\n");
return -EINVAL;
}
if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
dev_warn(dev, "crystal stopped, date is invalid\n");
return -EINVAL;
}
return 0;
}
static int rx8025_reset_validity(struct i2c_client *client)
{
int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
if (ctrl2 < 0)
return ctrl2;
ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
return rx8025_write_reg(client, RX8025_REG_CTRL2,
ctrl2 | RX8025_BIT_CTRL2_XST);
}
static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct rx8025_data *rx8025 = i2c_get_clientdata(client);
struct mutex *lock = &rx8025->rtc->ops_lock;
int status;
mutex_lock(lock);
status = rx8025_read_reg(client, RX8025_REG_CTRL2);
if (status < 0)
goto out;
if (!(status & RX8025_BIT_CTRL2_XST))
dev_warn(&client->dev, "Oscillation stop was detected,"
"you may have to readjust the clock\n");
if (status & RX8025_BIT_CTRL2_CTFG) {
/* periodic */
status &= ~RX8025_BIT_CTRL2_CTFG;
rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
}
if (status & RX8025_BIT_CTRL2_DAFG) {
/* alarm */
status &= RX8025_BIT_CTRL2_DAFG;
if (rx8025_write_reg(client, RX8025_REG_CTRL1,
rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
goto out;
rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
}
out:
mutex_unlock(lock);
return IRQ_HANDLED;
}
static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
{
struct rx8025_data *rx8025 = dev_get_drvdata(dev);
u8 date[7];
int err;
err = rx8025_check_validity(dev);
if (err)
return err;
err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
if (err)
return err;
dev_dbg(dev, "%s: read 0x%02x 0x%02x "
"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
date[0], date[1], date[2], date[3], date[4],
date[5], date[6]);
dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
else
dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
dt->tm_sec, dt->tm_min, dt->tm_hour,
dt->tm_mday, dt->tm_mon, dt->tm_year);
return rtc_valid_tm(dt);
}
static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
{
struct rx8025_data *rx8025 = dev_get_drvdata(dev);
u8 date[7];
int ret;
if ((dt->tm_year < 100) || (dt->tm_year > 199))
return -EINVAL;
/*
* Here the read-only bits are written as "0". I'm not sure if that
* is sound.
*/
date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
else
date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
| bin2bcd((dt->tm_hour + 11) % 12 + 1);
date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
dev_dbg(dev,
"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
__func__,
date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
if (ret < 0)
return ret;
return rx8025_reset_validity(rx8025->client);
}
static int rx8025_init_client(struct i2c_client *client)
{
struct rx8025_data *rx8025 = i2c_get_clientdata(client);
u8 ctrl[2], ctrl2;
int need_clear = 0;
int err;
err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
if (err)
goto out;
/* Keep test bit zero ! */
rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
dev_warn(&client->dev, "Alarm was detected\n");
need_clear = 1;
}
if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
need_clear = 1;
if (need_clear) {
ctrl2 = ctrl[1];
ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
RX8025_BIT_CTRL2_DAFG);
err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
}
out:
return err;
}
/* Alarm support */
static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct rx8025_data *rx8025 = dev_get_drvdata(dev);
struct i2c_client *client = rx8025->client;
u8 ald[2];
int ctrl2, err;
if (client->irq <= 0)
return -EINVAL;
err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
if (err)
return err;
ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
if (ctrl2 < 0)
return ctrl2;
dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
__func__, ald[0], ald[1], ctrl2);
/* Hardware alarms precision is 1 minute! */
t->time.tm_sec = 0;
t->time.tm_min = bcd2bin(ald[0] & 0x7f);
if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
else
t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
+ (ald[1] & 0x20 ? 12 : 0);
dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
__func__,
t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
return err;
}
static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
struct rx8025_data *rx8025 = dev_get_drvdata(dev);
u8 ald[2];
int err;
if (client->irq <= 0)
return -EINVAL;
/*
* Hardware alarm precision is 1 minute!
* round up to nearest minute
*/
if (t->time.tm_sec) {
time64_t alarm_time = rtc_tm_to_time64(&t->time);
alarm_time += 60 - t->time.tm_sec;
rtc_time64_to_tm(alarm_time, &t->time);
}
ald[0] = bin2bcd(t->time.tm_min);
if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
ald[1] = bin2bcd(t->time.tm_hour);
else
ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
rx8025->ctrl1);
if (err)
return err;
}
err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
if (err)
return err;
if (t->enabled) {
rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
rx8025->ctrl1);
if (err)
return err;
}
return 0;
}
static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct rx8025_data *rx8025 = dev_get_drvdata(dev);
u8 ctrl1;
int err;
ctrl1 = rx8025->ctrl1;
if (enabled)
ctrl1 |= RX8025_BIT_CTRL1_DALE;
else
ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
if (ctrl1 != rx8025->ctrl1) {
rx8025->ctrl1 = ctrl1;
err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
rx8025->ctrl1);
if (err)
return err;
}
return 0;
}
static const struct rtc_class_ops rx8025_rtc_ops = {
.read_time = rx8025_get_time,
.set_time = rx8025_set_time,
.read_alarm = rx8025_read_alarm,
.set_alarm = rx8025_set_alarm,
.alarm_irq_enable = rx8025_alarm_irq_enable,
};
/*
* Clock precision adjustment support
*
* According to the RX8025 SA/NB application manual the frequency and
* temperature characteristics can be approximated using the following
* equation:
*
* df = a * (ut - t)**2
*
* df: Frequency deviation in any temperature
* a : Coefficient = (-35 +-5) * 10**-9
* ut: Ultimate temperature in degree = +25 +-5 degree
* t : Any temperature in degree
*
* Note that the clock adjustment in ppb must be entered (which is
* the negative value of the deviation).
*/
static int rx8025_get_clock_adjust(struct device *dev, int *adj)
{
struct i2c_client *client = to_i2c_client(dev);
int digoff;
digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
if (digoff < 0)
return digoff;
*adj = digoff >= 64 ? digoff - 128 : digoff;
if (*adj > 0)
(*adj)--;
*adj *= -RX8025_ADJ_RESOLUTION;
return 0;
}
static int rx8025_set_clock_adjust(struct device *dev, int adj)
{
struct i2c_client *client = to_i2c_client(dev);
u8 digoff;
int err;
adj /= -RX8025_ADJ_RESOLUTION;
if (adj > RX8025_ADJ_DATA_MAX)
adj = RX8025_ADJ_DATA_MAX;
else if (adj < RX8025_ADJ_DATA_MIN)
adj = RX8025_ADJ_DATA_MIN;
else if (adj > 0)
adj++;
else if (adj < 0)
adj += 128;
digoff = adj;
err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
if (err)
return err;
dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
return 0;
}
static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int err, adj;
err = rx8025_get_clock_adjust(dev, &adj);
if (err)
return err;
return sprintf(buf, "%d\n", adj);
}
static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int adj, err;
if (sscanf(buf, "%i", &adj) != 1)
return -EINVAL;
err = rx8025_set_clock_adjust(dev, adj);
return err ? err : count;
}
static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
rx8025_sysfs_show_clock_adjust,
rx8025_sysfs_store_clock_adjust);
static int rx8025_sysfs_register(struct device *dev)
{
return device_create_file(dev, &dev_attr_clock_adjust_ppb);
}
static void rx8025_sysfs_unregister(struct device *dev)
{
device_remove_file(dev, &dev_attr_clock_adjust_ppb);
}
static int rx8025_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
struct rx8025_data *rx8025;
int err = 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK)) {
dev_err(&adapter->dev,
"doesn't support required functionality\n");
return -EIO;
}
rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
if (!rx8025)
return -ENOMEM;
rx8025->client = client;
i2c_set_clientdata(client, rx8025);
err = rx8025_init_client(client);
if (err)
return err;
rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
&rx8025_rtc_ops, THIS_MODULE);
if (IS_ERR(rx8025->rtc)) {
dev_err(&client->dev, "unable to register the class device\n");
return PTR_ERR(rx8025->rtc);
}
if (client->irq > 0) {
dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
rx8025_handle_irq,
IRQF_ONESHOT,
"rx8025", client);
if (err) {
dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
client->irq = 0;
}
}
rx8025->rtc->max_user_freq = 1;
/* the rx8025 alarm only supports a minute accuracy */
rx8025->rtc->uie_unsupported = 1;
err = rx8025_sysfs_register(&client->dev);
return err;
}
static int rx8025_remove(struct i2c_client *client)
{
rx8025_sysfs_unregister(&client->dev);
return 0;
}
static struct i2c_driver rx8025_driver = {
.driver = {
.name = "rtc-rx8025",
},
.probe = rx8025_probe,
.remove = rx8025_remove,
.id_table = rx8025_id,
};
module_i2c_driver(rx8025_driver);
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
MODULE_LICENSE("GPL");
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