590 lines
14 KiB
C
590 lines
14 KiB
C
/*
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* An i2c driver for the Xicor/Intersil X1205 RTC
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* Copyright 2004 Karen Spearel
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* Copyright 2005 Alessandro Zummo
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*
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* please send all reports to:
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* Karen Spearel <kas111 at gmail dot com>
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* Alessandro Zummo <a.zummo@towertech.it>
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*
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* based on a lot of other RTC drivers.
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*
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* Information and datasheet:
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* http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/i2c.h>
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#include <linux/bcd.h>
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#include <linux/rtc.h>
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#include <linux/delay.h>
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#define DRV_VERSION "1.0.8"
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/* offsets into CCR area */
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#define CCR_SEC 0
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#define CCR_MIN 1
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#define CCR_HOUR 2
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#define CCR_MDAY 3
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#define CCR_MONTH 4
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#define CCR_YEAR 5
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#define CCR_WDAY 6
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#define CCR_Y2K 7
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#define X1205_REG_SR 0x3F /* status register */
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#define X1205_REG_Y2K 0x37
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#define X1205_REG_DW 0x36
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#define X1205_REG_YR 0x35
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#define X1205_REG_MO 0x34
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#define X1205_REG_DT 0x33
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#define X1205_REG_HR 0x32
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#define X1205_REG_MN 0x31
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#define X1205_REG_SC 0x30
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#define X1205_REG_DTR 0x13
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#define X1205_REG_ATR 0x12
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#define X1205_REG_INT 0x11
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#define X1205_REG_0 0x10
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#define X1205_REG_Y2K1 0x0F
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#define X1205_REG_DWA1 0x0E
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#define X1205_REG_YRA1 0x0D
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#define X1205_REG_MOA1 0x0C
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#define X1205_REG_DTA1 0x0B
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#define X1205_REG_HRA1 0x0A
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#define X1205_REG_MNA1 0x09
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#define X1205_REG_SCA1 0x08
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#define X1205_REG_Y2K0 0x07
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#define X1205_REG_DWA0 0x06
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#define X1205_REG_YRA0 0x05
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#define X1205_REG_MOA0 0x04
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#define X1205_REG_DTA0 0x03
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#define X1205_REG_HRA0 0x02
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#define X1205_REG_MNA0 0x01
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#define X1205_REG_SCA0 0x00
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#define X1205_CCR_BASE 0x30 /* Base address of CCR */
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#define X1205_ALM0_BASE 0x00 /* Base address of ALARM0 */
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#define X1205_SR_RTCF 0x01 /* Clock failure */
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#define X1205_SR_WEL 0x02 /* Write Enable Latch */
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#define X1205_SR_RWEL 0x04 /* Register Write Enable */
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#define X1205_DTR_DTR0 0x01
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#define X1205_DTR_DTR1 0x02
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#define X1205_DTR_DTR2 0x04
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#define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */
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static struct i2c_driver x1205_driver;
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/*
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* In the routines that deal directly with the x1205 hardware, we use
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* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
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* Epoch is initialized as 2000. Time is set to UTC.
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*/
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static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
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unsigned char reg_base)
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{
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unsigned char dt_addr[2] = { 0, reg_base };
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unsigned char buf[8];
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struct i2c_msg msgs[] = {
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{ client->addr, 0, 2, dt_addr }, /* setup read ptr */
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{ client->addr, I2C_M_RD, 8, buf }, /* read date */
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};
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/* read date registers */
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if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
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dev_err(&client->dev, "%s: read error\n", __func__);
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return -EIO;
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}
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dev_dbg(&client->dev,
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"%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
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"mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
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__func__,
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buf[0], buf[1], buf[2], buf[3],
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buf[4], buf[5], buf[6], buf[7]);
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tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
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tm->tm_min = BCD2BIN(buf[CCR_MIN]);
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tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
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tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
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tm->tm_mon = BCD2BIN(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
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tm->tm_year = BCD2BIN(buf[CCR_YEAR])
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+ (BCD2BIN(buf[CCR_Y2K]) * 100) - 1900;
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tm->tm_wday = buf[CCR_WDAY];
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dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
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"mday=%d, mon=%d, year=%d, wday=%d\n",
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__func__,
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tm->tm_sec, tm->tm_min, tm->tm_hour,
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tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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return 0;
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}
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static int x1205_get_status(struct i2c_client *client, unsigned char *sr)
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{
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static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
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struct i2c_msg msgs[] = {
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{ client->addr, 0, 2, sr_addr }, /* setup read ptr */
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{ client->addr, I2C_M_RD, 1, sr }, /* read status */
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};
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/* read status register */
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if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
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dev_err(&client->dev, "%s: read error\n", __func__);
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return -EIO;
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}
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return 0;
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}
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static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
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int datetoo, u8 reg_base)
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{
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int i, xfer;
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unsigned char buf[8];
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static const unsigned char wel[3] = { 0, X1205_REG_SR,
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X1205_SR_WEL };
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static const unsigned char rwel[3] = { 0, X1205_REG_SR,
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X1205_SR_WEL | X1205_SR_RWEL };
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static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
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dev_dbg(&client->dev,
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"%s: secs=%d, mins=%d, hours=%d\n",
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__func__,
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tm->tm_sec, tm->tm_min, tm->tm_hour);
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buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
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buf[CCR_MIN] = BIN2BCD(tm->tm_min);
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/* set hour and 24hr bit */
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buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;
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/* should we also set the date? */
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if (datetoo) {
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dev_dbg(&client->dev,
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"%s: mday=%d, mon=%d, year=%d, wday=%d\n",
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__func__,
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tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
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/* month, 1 - 12 */
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buf[CCR_MONTH] = BIN2BCD(tm->tm_mon + 1);
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/* year, since the rtc epoch*/
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buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
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buf[CCR_WDAY] = tm->tm_wday & 0x07;
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buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
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}
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/* this sequence is required to unlock the chip */
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if ((xfer = i2c_master_send(client, wel, 3)) != 3) {
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dev_err(&client->dev, "%s: wel - %d\n", __func__, xfer);
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return -EIO;
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}
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if ((xfer = i2c_master_send(client, rwel, 3)) != 3) {
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dev_err(&client->dev, "%s: rwel - %d\n", __func__, xfer);
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return -EIO;
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}
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/* write register's data */
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for (i = 0; i < (datetoo ? 8 : 3); i++) {
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unsigned char rdata[3] = { 0, reg_base + i, buf[i] };
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xfer = i2c_master_send(client, rdata, 3);
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if (xfer != 3) {
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dev_err(&client->dev,
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"%s: xfer=%d addr=%02x, data=%02x\n",
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__func__,
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xfer, rdata[1], rdata[2]);
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return -EIO;
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}
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};
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/* disable further writes */
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if ((xfer = i2c_master_send(client, diswe, 3)) != 3) {
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dev_err(&client->dev, "%s: diswe - %d\n", __func__, xfer);
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return -EIO;
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}
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return 0;
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}
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static int x1205_fix_osc(struct i2c_client *client)
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{
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int err;
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struct rtc_time tm;
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tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
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if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0)
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dev_err(&client->dev,
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"unable to restart the oscillator\n");
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return err;
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}
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static int x1205_get_dtrim(struct i2c_client *client, int *trim)
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{
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unsigned char dtr;
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static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
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struct i2c_msg msgs[] = {
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{ client->addr, 0, 2, dtr_addr }, /* setup read ptr */
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{ client->addr, I2C_M_RD, 1, &dtr }, /* read dtr */
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};
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/* read dtr register */
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if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
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dev_err(&client->dev, "%s: read error\n", __func__);
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return -EIO;
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}
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dev_dbg(&client->dev, "%s: raw dtr=%x\n", __func__, dtr);
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*trim = 0;
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if (dtr & X1205_DTR_DTR0)
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*trim += 20;
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if (dtr & X1205_DTR_DTR1)
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*trim += 10;
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if (dtr & X1205_DTR_DTR2)
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*trim = -*trim;
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return 0;
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}
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static int x1205_get_atrim(struct i2c_client *client, int *trim)
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{
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s8 atr;
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static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
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struct i2c_msg msgs[] = {
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{ client->addr, 0, 2, atr_addr }, /* setup read ptr */
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{ client->addr, I2C_M_RD, 1, &atr }, /* read atr */
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};
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/* read atr register */
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if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
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dev_err(&client->dev, "%s: read error\n", __func__);
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return -EIO;
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}
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dev_dbg(&client->dev, "%s: raw atr=%x\n", __func__, atr);
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/* atr is a two's complement value on 6 bits,
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* perform sign extension. The formula is
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* Catr = (atr * 0.25pF) + 11.00pF.
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*/
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if (atr & 0x20)
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atr |= 0xC0;
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dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __func__, atr, atr);
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*trim = (atr * 250) + 11000;
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dev_dbg(&client->dev, "%s: real=%d\n", __func__, *trim);
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return 0;
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}
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struct x1205_limit
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{
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unsigned char reg, mask, min, max;
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};
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static int x1205_validate_client(struct i2c_client *client)
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{
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int i, xfer;
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/* Probe array. We will read the register at the specified
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* address and check if the given bits are zero.
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*/
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static const unsigned char probe_zero_pattern[] = {
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/* register, mask */
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X1205_REG_SR, 0x18,
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X1205_REG_DTR, 0xF8,
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X1205_REG_ATR, 0xC0,
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X1205_REG_INT, 0x18,
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X1205_REG_0, 0xFF,
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};
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static const struct x1205_limit probe_limits_pattern[] = {
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/* register, mask, min, max */
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{ X1205_REG_Y2K, 0xFF, 19, 20 },
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{ X1205_REG_DW, 0xFF, 0, 6 },
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{ X1205_REG_YR, 0xFF, 0, 99 },
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{ X1205_REG_MO, 0xFF, 0, 12 },
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{ X1205_REG_DT, 0xFF, 0, 31 },
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{ X1205_REG_HR, 0x7F, 0, 23 },
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{ X1205_REG_MN, 0xFF, 0, 59 },
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{ X1205_REG_SC, 0xFF, 0, 59 },
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{ X1205_REG_Y2K1, 0xFF, 19, 20 },
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{ X1205_REG_Y2K0, 0xFF, 19, 20 },
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};
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/* check that registers have bits a 0 where expected */
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for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
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unsigned char buf;
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unsigned char addr[2] = { 0, probe_zero_pattern[i] };
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struct i2c_msg msgs[2] = {
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{ client->addr, 0, 2, addr },
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{ client->addr, I2C_M_RD, 1, &buf },
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};
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if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
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dev_err(&client->dev,
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"%s: could not read register %x\n",
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__func__, probe_zero_pattern[i]);
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return -EIO;
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}
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if ((buf & probe_zero_pattern[i+1]) != 0) {
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dev_err(&client->dev,
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"%s: register=%02x, zero pattern=%d, value=%x\n",
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__func__, probe_zero_pattern[i], i, buf);
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return -ENODEV;
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}
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}
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/* check limits (only registers with bcd values) */
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for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
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unsigned char reg, value;
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unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
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struct i2c_msg msgs[2] = {
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{ client->addr, 0, 2, addr },
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{ client->addr, I2C_M_RD, 1, ® },
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};
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if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
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dev_err(&client->dev,
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"%s: could not read register %x\n",
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__func__, probe_limits_pattern[i].reg);
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return -EIO;
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}
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value = BCD2BIN(reg & probe_limits_pattern[i].mask);
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if (value > probe_limits_pattern[i].max ||
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value < probe_limits_pattern[i].min) {
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dev_dbg(&client->dev,
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"%s: register=%x, lim pattern=%d, value=%d\n",
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__func__, probe_limits_pattern[i].reg,
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i, value);
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return -ENODEV;
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}
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}
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return 0;
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}
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static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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return x1205_get_datetime(to_i2c_client(dev),
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&alrm->time, X1205_ALM0_BASE);
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}
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static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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return x1205_set_datetime(to_i2c_client(dev),
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&alrm->time, 1, X1205_ALM0_BASE);
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}
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static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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return x1205_get_datetime(to_i2c_client(dev),
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tm, X1205_CCR_BASE);
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}
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static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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return x1205_set_datetime(to_i2c_client(dev),
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tm, 1, X1205_CCR_BASE);
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}
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static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
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{
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int err, dtrim, atrim;
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if ((err = x1205_get_dtrim(to_i2c_client(dev), &dtrim)) == 0)
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seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
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if ((err = x1205_get_atrim(to_i2c_client(dev), &atrim)) == 0)
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seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
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atrim / 1000, atrim % 1000);
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return 0;
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}
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static const struct rtc_class_ops x1205_rtc_ops = {
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.proc = x1205_rtc_proc,
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.read_time = x1205_rtc_read_time,
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.set_time = x1205_rtc_set_time,
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.read_alarm = x1205_rtc_read_alarm,
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.set_alarm = x1205_rtc_set_alarm,
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};
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static ssize_t x1205_sysfs_show_atrim(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int err, atrim;
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err = x1205_get_atrim(to_i2c_client(dev), &atrim);
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if (err)
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return err;
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return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
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}
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static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
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static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int err, dtrim;
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err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
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if (err)
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|
return err;
|
|
|
|
return sprintf(buf, "%d ppm\n", dtrim);
|
|
}
|
|
static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
|
|
|
|
static int x1205_sysfs_register(struct device *dev)
|
|
{
|
|
int err;
|
|
|
|
err = device_create_file(dev, &dev_attr_atrim);
|
|
if (err)
|
|
return err;
|
|
|
|
err = device_create_file(dev, &dev_attr_dtrim);
|
|
if (err)
|
|
device_remove_file(dev, &dev_attr_atrim);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void x1205_sysfs_unregister(struct device *dev)
|
|
{
|
|
device_remove_file(dev, &dev_attr_atrim);
|
|
device_remove_file(dev, &dev_attr_dtrim);
|
|
}
|
|
|
|
|
|
static int x1205_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
int err = 0;
|
|
unsigned char sr;
|
|
struct rtc_device *rtc;
|
|
|
|
dev_dbg(&client->dev, "%s\n", __func__);
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
if (x1205_validate_client(client) < 0)
|
|
return -ENODEV;
|
|
|
|
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
|
|
|
|
rtc = rtc_device_register(x1205_driver.driver.name, &client->dev,
|
|
&x1205_rtc_ops, THIS_MODULE);
|
|
|
|
if (IS_ERR(rtc))
|
|
return PTR_ERR(rtc);
|
|
|
|
i2c_set_clientdata(client, rtc);
|
|
|
|
/* Check for power failures and eventualy enable the osc */
|
|
if ((err = x1205_get_status(client, &sr)) == 0) {
|
|
if (sr & X1205_SR_RTCF) {
|
|
dev_err(&client->dev,
|
|
"power failure detected, "
|
|
"please set the clock\n");
|
|
udelay(50);
|
|
x1205_fix_osc(client);
|
|
}
|
|
}
|
|
else
|
|
dev_err(&client->dev, "couldn't read status\n");
|
|
|
|
err = x1205_sysfs_register(&client->dev);
|
|
if (err)
|
|
goto exit_devreg;
|
|
|
|
return 0;
|
|
|
|
exit_devreg:
|
|
rtc_device_unregister(rtc);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int x1205_remove(struct i2c_client *client)
|
|
{
|
|
struct rtc_device *rtc = i2c_get_clientdata(client);
|
|
|
|
rtc_device_unregister(rtc);
|
|
x1205_sysfs_unregister(&client->dev);
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_device_id x1205_id[] = {
|
|
{ "x1205", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, x1205_id);
|
|
|
|
static struct i2c_driver x1205_driver = {
|
|
.driver = {
|
|
.name = "rtc-x1205",
|
|
},
|
|
.probe = x1205_probe,
|
|
.remove = x1205_remove,
|
|
.id_table = x1205_id,
|
|
};
|
|
|
|
static int __init x1205_init(void)
|
|
{
|
|
return i2c_add_driver(&x1205_driver);
|
|
}
|
|
|
|
static void __exit x1205_exit(void)
|
|
{
|
|
i2c_del_driver(&x1205_driver);
|
|
}
|
|
|
|
MODULE_AUTHOR(
|
|
"Karen Spearel <kas111 at gmail dot com>, "
|
|
"Alessandro Zummo <a.zummo@towertech.it>");
|
|
MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(DRV_VERSION);
|
|
|
|
module_init(x1205_init);
|
|
module_exit(x1205_exit);
|