2
* Driver for Epson's RTC module RX-8025 SA/NB
4
* Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
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* Copyright (C) 2005 by Digi International Inc.
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* Modified by fengjh at rising.com.cn
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* <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
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* Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
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* Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
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* Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/bcd.h>
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#include <linux/i2c.h>
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#include <linux/list.h>
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#include <linux/rtc.h>
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/* Register definitions */
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#define RX8025_REG_SEC 0x00
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#define RX8025_REG_MIN 0x01
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#define RX8025_REG_HOUR 0x02
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#define RX8025_REG_WDAY 0x03
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#define RX8025_REG_MDAY 0x04
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#define RX8025_REG_MONTH 0x05
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#define RX8025_REG_YEAR 0x06
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#define RX8025_REG_DIGOFF 0x07
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#define RX8025_REG_ALWMIN 0x08
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#define RX8025_REG_ALWHOUR 0x09
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#define RX8025_REG_ALWWDAY 0x0a
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#define RX8025_REG_ALDMIN 0x0b
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#define RX8025_REG_ALDHOUR 0x0c
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/* 0x0d is reserved */
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#define RX8025_REG_CTRL1 0x0e
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#define RX8025_REG_CTRL2 0x0f
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#define RX8025_BIT_CTRL1_CT (7 << 0)
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/* 1 Hz periodic level irq */
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#define RX8025_BIT_CTRL1_CT_1HZ 4
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#define RX8025_BIT_CTRL1_TEST (1 << 3)
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#define RX8025_BIT_CTRL1_1224 (1 << 5)
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#define RX8025_BIT_CTRL1_DALE (1 << 6)
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#define RX8025_BIT_CTRL1_WALE (1 << 7)
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#define RX8025_BIT_CTRL2_DAFG (1 << 0)
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#define RX8025_BIT_CTRL2_WAFG (1 << 1)
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#define RX8025_BIT_CTRL2_CTFG (1 << 2)
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#define RX8025_BIT_CTRL2_PON (1 << 4)
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#define RX8025_BIT_CTRL2_XST (1 << 5)
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#define RX8025_BIT_CTRL2_VDET (1 << 6)
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/* Clock precision adjustment */
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#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
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#define RX8025_ADJ_DATA_MAX 62
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#define RX8025_ADJ_DATA_MIN -62
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static const struct i2c_device_id rx8025_id[] = {
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MODULE_DEVICE_TABLE(i2c, rx8025_id);
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struct i2c_client *client;
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struct rtc_device *rtc;
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struct work_struct work;
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static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
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int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
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dev_err(&client->dev, "Unable to read register #%d\n", number);
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static int rx8025_read_regs(struct i2c_client *client,
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int number, u8 length, u8 *values)
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int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
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dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
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number, number + length - 1);
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return ret < 0 ? ret : -EIO;
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static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
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int ret = i2c_smbus_write_byte_data(client, number << 4, value);
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dev_err(&client->dev, "Unable to write register #%d\n",
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static int rx8025_write_regs(struct i2c_client *client,
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int number, u8 length, u8 *values)
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int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
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dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
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number, number + length - 1);
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static irqreturn_t rx8025_irq(int irq, void *dev_id)
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struct i2c_client *client = dev_id;
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struct rx8025_data *rx8025 = i2c_get_clientdata(client);
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disable_irq_nosync(irq);
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schedule_work(&rx8025->work);
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static void rx8025_work(struct work_struct *work)
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struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
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struct i2c_client *client = rx8025->client;
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struct mutex *lock = &rx8025->rtc->ops_lock;
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if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
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if (!(status & RX8025_BIT_CTRL2_XST))
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dev_warn(&client->dev, "Oscillation stop was detected,"
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"you may have to readjust the clock\n");
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if (status & RX8025_BIT_CTRL2_CTFG) {
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status &= ~RX8025_BIT_CTRL2_CTFG;
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rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
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if (status & RX8025_BIT_CTRL2_DAFG) {
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status &= RX8025_BIT_CTRL2_DAFG;
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if (rx8025_write_reg(client, RX8025_REG_CTRL1,
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rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
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rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
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/* acknowledge IRQ */
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rx8025_write_reg(client, RX8025_REG_CTRL2,
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status | RX8025_BIT_CTRL2_XST);
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if (!rx8025->exiting)
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enable_irq(client->irq);
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static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
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struct rx8025_data *rx8025 = dev_get_drvdata(dev);
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err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
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dev_dbg(dev, "%s: read 0x%02x 0x%02x "
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"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
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date[0], date[1], date[2], date[3], date[4],
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dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
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dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
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if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
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dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
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dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
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+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
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dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
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dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
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dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
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if (dt->tm_year < 70)
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dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
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dt->tm_sec, dt->tm_min, dt->tm_hour,
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dt->tm_mday, dt->tm_mon, dt->tm_year);
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return rtc_valid_tm(dt);
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static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
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struct rx8025_data *rx8025 = dev_get_drvdata(dev);
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* BUG: The HW assumes every year that is a multiple of 4 to be a leap
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* year. Next time this is wrong is 2100, which will not be a leap
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* Here the read-only bits are written as "0". I'm not sure if that
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date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
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date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
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if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
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date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
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date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
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| bin2bcd((dt->tm_hour + 11) % 12 + 1);
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date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
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date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
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date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
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date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
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"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
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date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
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return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
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static int rx8025_init_client(struct i2c_client *client, int *need_reset)
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struct rx8025_data *rx8025 = i2c_get_clientdata(client);
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err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
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/* Keep test bit zero ! */
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rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
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if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
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dev_warn(&client->dev, "power-on reset was detected, "
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"you may have to readjust the clock\n");
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if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
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dev_warn(&client->dev, "a power voltage drop was detected, "
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"you may have to readjust the clock\n");
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if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
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dev_warn(&client->dev, "Oscillation stop was detected,"
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"you may have to readjust the clock\n");
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if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
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dev_warn(&client->dev, "Alarm was detected\n");
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if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
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if (*need_reset || need_clear) {
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ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
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RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
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RX8025_BIT_CTRL2_DAFG);
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ctrl2 |= RX8025_BIT_CTRL2_XST;
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err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
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static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
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struct rx8025_data *rx8025 = dev_get_drvdata(dev);
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struct i2c_client *client = rx8025->client;
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if (client->irq <= 0)
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err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
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err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
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dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
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__func__, ald[0], ald[1], ctrl2);
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/* Hardware alarms precision is 1 minute! */
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t->time.tm_min = bcd2bin(ald[0] & 0x7f);
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if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
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t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
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t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
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+ (ald[1] & 0x20 ? 12 : 0);
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t->time.tm_wday = -1;
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t->time.tm_mday = -1;
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t->time.tm_year = -1;
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dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
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t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
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t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
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t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
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t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
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static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
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struct i2c_client *client = to_i2c_client(dev);
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struct rx8025_data *rx8025 = dev_get_drvdata(dev);
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if (client->irq <= 0)
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/* Hardware alarm precision is 1 minute! */
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ald[0] = bin2bcd(t->time.tm_min);
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if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
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ald[1] = bin2bcd(t->time.tm_hour);
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ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
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| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
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dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
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if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
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rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
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err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
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err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
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rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
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err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
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static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
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struct rx8025_data *rx8025 = dev_get_drvdata(dev);
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ctrl1 = rx8025->ctrl1;
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ctrl1 |= RX8025_BIT_CTRL1_DALE;
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ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
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if (ctrl1 != rx8025->ctrl1) {
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rx8025->ctrl1 = ctrl1;
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err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
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static struct rtc_class_ops rx8025_rtc_ops = {
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.read_time = rx8025_get_time,
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.set_time = rx8025_set_time,
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.read_alarm = rx8025_read_alarm,
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.set_alarm = rx8025_set_alarm,
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.alarm_irq_enable = rx8025_alarm_irq_enable,
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* Clock precision adjustment support
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* According to the RX8025 SA/NB application manual the frequency and
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* temperature characteristics can be approximated using the following
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* df = a * (ut - t)**2
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* df: Frequency deviation in any temperature
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* a : Coefficient = (-35 +-5) * 10**-9
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* ut: Ultimate temperature in degree = +25 +-5 degree
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* t : Any temperature in degree
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* Note that the clock adjustment in ppb must be entered (which is
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* the negative value of the deviation).
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static int rx8025_get_clock_adjust(struct device *dev, int *adj)
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struct i2c_client *client = to_i2c_client(dev);
458
err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
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*adj = digoff >= 64 ? digoff - 128 : digoff;
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*adj *= -RX8025_ADJ_RESOLUTION;
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static int rx8025_set_clock_adjust(struct device *dev, int adj)
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struct i2c_client *client = to_i2c_client(dev);
476
adj /= -RX8025_ADJ_RESOLUTION;
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if (adj > RX8025_ADJ_DATA_MAX)
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adj = RX8025_ADJ_DATA_MAX;
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else if (adj < RX8025_ADJ_DATA_MIN)
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adj = RX8025_ADJ_DATA_MIN;
487
err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
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dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
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static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
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struct device_attribute *attr,
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err = rx8025_get_clock_adjust(dev, &adj);
506
return sprintf(buf, "%d\n", adj);
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static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
510
struct device_attribute *attr,
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const char *buf, size_t count)
515
if (sscanf(buf, "%i", &adj) != 1)
518
err = rx8025_set_clock_adjust(dev, adj);
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return err ? err : count;
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static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
524
rx8025_sysfs_show_clock_adjust,
525
rx8025_sysfs_store_clock_adjust);
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static int rx8025_sysfs_register(struct device *dev)
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return device_create_file(dev, &dev_attr_clock_adjust_ppb);
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static void rx8025_sysfs_unregister(struct device *dev)
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device_remove_file(dev, &dev_attr_clock_adjust_ppb);
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static int __devinit rx8025_probe(struct i2c_client *client,
538
const struct i2c_device_id *id)
540
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
541
struct rx8025_data *rx8025;
542
int err, need_reset = 0;
544
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
545
| I2C_FUNC_SMBUS_I2C_BLOCK)) {
546
dev_err(&adapter->dev,
547
"doesn't support required functionality\n");
552
rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL);
554
dev_err(&adapter->dev, "failed to alloc memory\n");
559
rx8025->client = client;
560
i2c_set_clientdata(client, rx8025);
561
INIT_WORK(&rx8025->work, rx8025_work);
563
err = rx8025_init_client(client, &need_reset);
569
dev_info(&client->dev,
570
"bad conditions detected, resetting date\n");
571
rtc_time_to_tm(0, &tm); /* 1970/1/1 */
572
rx8025_set_time(&client->dev, &tm);
575
rx8025->rtc = rtc_device_register(client->name, &client->dev,
576
&rx8025_rtc_ops, THIS_MODULE);
577
if (IS_ERR(rx8025->rtc)) {
578
err = PTR_ERR(rx8025->rtc);
579
dev_err(&client->dev, "unable to register the class device\n");
583
if (client->irq > 0) {
584
dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
585
err = request_irq(client->irq, rx8025_irq,
586
0, "rx8025", client);
588
dev_err(&client->dev, "unable to request IRQ\n");
593
rx8025->rtc->irq_freq = 1;
594
rx8025->rtc->max_user_freq = 1;
596
err = rx8025_sysfs_register(&client->dev);
604
free_irq(client->irq, client);
607
rtc_device_unregister(rx8025->rtc);
613
dev_err(&adapter->dev, "probing for rx8025 failed\n");
617
static int __devexit rx8025_remove(struct i2c_client *client)
619
struct rx8025_data *rx8025 = i2c_get_clientdata(client);
620
struct mutex *lock = &rx8025->rtc->ops_lock;
622
if (client->irq > 0) {
627
free_irq(client->irq, client);
628
cancel_work_sync(&rx8025->work);
631
rx8025_sysfs_unregister(&client->dev);
632
rtc_device_unregister(rx8025->rtc);
637
static struct i2c_driver rx8025_driver = {
639
.name = "rtc-rx8025",
640
.owner = THIS_MODULE,
642
.probe = rx8025_probe,
643
.remove = __devexit_p(rx8025_remove),
644
.id_table = rx8025_id,
647
static int __init rx8025_init(void)
649
return i2c_add_driver(&rx8025_driver);
652
static void __exit rx8025_exit(void)
654
i2c_del_driver(&rx8025_driver);
657
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
658
MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
659
MODULE_LICENSE("GPL");
661
module_init(rx8025_init);
662
module_exit(rx8025_exit);