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    Subject[RFC][PATCH 6/7] RTC subsystem, x1205 driver

    This patch is a port of the existing x1205
    driver under the new RTC subsystem.

    It is actually under test within the NSLU2
    project (http://www.nslu2-linux.org) and
    it is working quite well.

    It is the first driver under this new subsystem
    and should be used as a guide to port other
    drivers.

    Ideally, at some point in the future, all
    RTC drivers will reside under linux/rtc.

    Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
    --

    drivers/rtc/Kconfig | 10
    drivers/rtc/Makefile | 3
    drivers/rtc/rtc-x1205.c | 727 ++++++++++++++++++++++++++++++++++++++++++++++++
    3 files changed, 740 insertions(+)

    --- linux.orig/drivers/rtc/Kconfig 2005-12-26 19:33:32.000000000 +0100
    +++ linux/drivers/rtc/Kconfig 2005-12-26 19:35:01.000000000 +0100
    @@ -55,4 +55,14 @@
    comment "RTC drivers"
    depends on RTC_CLASS

    +config RTC_DRV_X1205
    + tristate "Xicor/Intersil X1205 RTC chip"
    + depends on RTC_CLASS && I2C
    + help
    + If you say yes here you get support for the
    + Xicor/Intersil X1205 RTC chip.
    +
    + This driver can also be built as a module. If so, the module
    + will be called rtc-x1205.
    +
    endmenu
    --- linux.orig/drivers/rtc/Makefile 2005-12-26 19:33:32.000000000 +0100
    +++ linux/drivers/rtc/Makefile 2005-12-26 19:35:01.000000000 +0100
    @@ -8,3 +8,6 @@
    obj-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
    obj-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o
    obj-$(CONFIG_RTC_INTF_DEV) += rtc-dev.o
    +
    +obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
    +
    --- /dev/null 1970-01-01 00:00:00.000000000 +0000
    +++ linux/drivers/rtc/rtc-x1205.c 2005-12-26 19:33:46.000000000 +0100
    @@ -0,0 +1,727 @@
    +/*
    + * An i2c driver for the Xicor/Intersil X1205 RTC
    + * Copyright 2004 Karen Spearel
    + * Copyright 2005 Alessandro Zummo
    + *
    + * please send all reports to:
    + * kas11 at tampabay dot rr dot com
    + * a dot zummo at towertech dot it
    + *
    + * based on a lot of other RTC drivers.
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License as published by
    + * the Free Software Foundation; either version 2 of the License, or
    + * (at your option) any later version.
    + */
    +
    +#include <linux/module.h>
    +#include <linux/init.h>
    +#include <linux/slab.h>
    +#include <linux/err.h>
    +#include <linux/i2c.h>
    +#include <linux/string.h>
    +#include <linux/bcd.h>
    +#include <linux/rtc.h>
    +#include <linux/delay.h>
    +
    +#define DRV_VERSION "1.0.5"
    +
    +/* Addresses to scan: none. This chip is located at
    + * 0x6f and uses a two bytes register addressing.
    + * Two bytes need to be written to read a single register,
    + * while most other chips just require one and take the second
    + * one as the data to be written. To prevent corrupting
    + * unknown chips, the user must explicitely set the probe parameter.
    + */
    +
    +static unsigned short normal_i2c[] = { I2C_CLIENT_END };
    +
    +/* Insmod parameters */
    +I2C_CLIENT_INSMOD;
    +I2C_CLIENT_MODULE_PARM(hctosys,
    + "Set the system time from the hardware clock upon initialization");
    +
    +/* offsets into CCR area */
    +
    +#define CCR_SEC 0
    +#define CCR_MIN 1
    +#define CCR_HOUR 2
    +#define CCR_MDAY 3
    +#define CCR_MONTH 4
    +#define CCR_YEAR 5
    +#define CCR_WDAY 6
    +#define CCR_Y2K 7
    +
    +#define X1205_REG_SR 0x3F /* status register */
    +#define X1205_REG_Y2K 0x37
    +#define X1205_REG_DW 0x36
    +#define X1205_REG_YR 0x35
    +#define X1205_REG_MO 0x34
    +#define X1205_REG_DT 0x33
    +#define X1205_REG_HR 0x32
    +#define X1205_REG_MN 0x31
    +#define X1205_REG_SC 0x30
    +#define X1205_REG_DTR 0x13
    +#define X1205_REG_ATR 0x12
    +#define X1205_REG_INT 0x11
    +#define X1205_REG_0 0x10
    +#define X1205_REG_Y2K1 0x0F
    +#define X1205_REG_DWA1 0x0E
    +#define X1205_REG_YRA1 0x0D
    +#define X1205_REG_MOA1 0x0C
    +#define X1205_REG_DTA1 0x0B
    +#define X1205_REG_HRA1 0x0A
    +#define X1205_REG_MNA1 0x09
    +#define X1205_REG_SCA1 0x08
    +#define X1205_REG_Y2K0 0x07
    +#define X1205_REG_DWA0 0x06
    +#define X1205_REG_YRA0 0x05
    +#define X1205_REG_MOA0 0x04
    +#define X1205_REG_DTA0 0x03
    +#define X1205_REG_HRA0 0x02
    +#define X1205_REG_MNA0 0x01
    +#define X1205_REG_SCA0 0x00
    +
    +#define X1205_CCR_BASE 0x30 /* Base address of CCR */
    +#define X1205_ALM0_BASE 0x00 /* Base address of ALARM0 */
    +
    +#define X1205_SR_RTCF 0x01 /* Clock failure */
    +#define X1205_SR_WEL 0x02 /* Write Enable Latch */
    +#define X1205_SR_RWEL 0x04 /* Register Write Enable */
    +
    +#define X1205_DTR_DTR0 0x01
    +#define X1205_DTR_DTR1 0x02
    +#define X1205_DTR_DTR2 0x04
    +
    +#define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */
    +
    +/* Prototypes */
    +static int x1205_attach(struct i2c_adapter *adapter);
    +static int x1205_detach(struct i2c_client *client);
    +static int x1205_probe(struct i2c_adapter *adapter, int address, int kind);
    +
    +static struct i2c_driver x1205_driver = {
    + .owner = THIS_MODULE,
    + .name = "x1205",
    + .flags = I2C_DF_NOTIFY,
    + .attach_adapter = &x1205_attach,
    + .detach_client = &x1205_detach,
    +};
    +
    +/*
    + * In the routines that deal directly with the x1205 hardware, we use
    + * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
    + * Epoch is initialized as 2000. Time is set to UTC.
    + */
    +static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
    + unsigned char reg_base)
    +{
    + unsigned char dt_addr[2] = { 0, reg_base };
    +
    + unsigned char buf[8];
    +
    + struct i2c_msg msgs[] = {
    + { client->addr, 0, 2, dt_addr }, /* setup read ptr */
    + { client->addr, I2C_M_RD, 8, buf }, /* read date */
    + };
    +
    + /* read date registers */
    + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
    + dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
    + return -EIO;
    + }
    +
    + dev_dbg(&client->dev,
    + "%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
    + "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
    + __FUNCTION__,
    + buf[0], buf[1], buf[2], buf[3],
    + buf[4], buf[5], buf[6], buf[7]);
    +
    + tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
    + tm->tm_min = BCD2BIN(buf[CCR_MIN]);
    + tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
    + tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
    + tm->tm_mon = BCD2BIN(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
    + tm->tm_year = BCD2BIN(buf[CCR_YEAR])
    + + (BCD2BIN(buf[CCR_Y2K]) * 100) - 1900;
    + tm->tm_wday = buf[CCR_WDAY];
    +
    + 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);
    +
    + return 0;
    +}
    +
    +static int x1205_get_status(struct i2c_client *client, unsigned char *sr)
    +{
    + static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
    +
    + struct i2c_msg msgs[] = {
    + { client->addr, 0, 2, sr_addr }, /* setup read ptr */
    + { client->addr, I2C_M_RD, 1, sr }, /* read status */
    + };
    +
    + /* read status register */
    + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
    + dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
    + return -EIO;
    + }
    +
    + return 0;
    +}
    +
    +static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
    + int datetoo, u8 reg_base)
    +{
    + int i, xfer;
    + unsigned char buf[8];
    +
    + static const unsigned char wel[3] = { 0, X1205_REG_SR,
    + X1205_SR_WEL };
    +
    + static const unsigned char rwel[3] = { 0, X1205_REG_SR,
    + X1205_SR_WEL | X1205_SR_RWEL };
    +
    + static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
    +
    + dev_dbg(&client->dev,
    + "%s: secs=%d, mins=%d, hours=%d\n",
    + __FUNCTION__,
    + tm->tm_sec, tm->tm_min, tm->tm_hour);
    +
    + buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
    + buf[CCR_MIN] = BIN2BCD(tm->tm_min);
    +
    + /* set hour and 24hr bit */
    + buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;
    +
    + /* should we also set the date? */
    + if (datetoo) {
    + dev_dbg(&client->dev,
    + "%s: mday=%d, mon=%d, year=%d, wday=%d\n",
    + __FUNCTION__,
    + tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
    +
    + buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
    +
    + /* month, 1 - 12 */
    + buf[CCR_MONTH] = BIN2BCD(tm->tm_mon + 1);
    +
    + /* year, since the rtc epoch*/
    + buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
    + buf[CCR_WDAY] = tm->tm_wday & 0x07;
    + buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
    + }
    +
    + /* this sequence is required to unlock the chip */
    + xfer = i2c_master_send(client, wel, 3);
    + if (xfer != 3) {
    + dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer);
    + return -EIO;
    + }
    +
    + xfer = i2c_master_send(client, rwel, 3);
    + if (xfer != 3) {
    + dev_err(&client->dev, "%s: rwel - %d\n", __FUNCTION__, xfer);
    + return -EIO;
    + }
    +
    + /* write register's data */
    + for (i = 0; i < (datetoo ? 8 : 3); i++) {
    + unsigned char rdata[3] = { 0, reg_base + i, buf[i] };
    +
    + xfer = i2c_master_send(client, rdata, 3);
    + if (xfer != 3) {
    + dev_err(&client->dev,
    + "%s: xfer=%d addr=%02x, data=%02x\n",
    + __FUNCTION__,
    + xfer, rdata[1], rdata[2]);
    + return -EIO;
    + }
    + };
    +
    + /* disable further writes */
    + xfer = i2c_master_send(client, diswe, 3);
    + if (xfer != 3) {
    + dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer);
    + return -EIO;
    + }
    +
    + return 0;
    +}
    +
    +static int x1205_fix_osc(struct i2c_client *client)
    +{
    + int err;
    + struct rtc_time tm;
    +
    + tm.tm_hour = 0;
    + tm.tm_min = 0;
    + tm.tm_sec = 0;
    +
    + if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0)
    + dev_err(&client->dev,
    + "unable to restart the clock\n");
    +
    + return err;
    +}
    +
    +static int x1205_get_dtrim(struct i2c_client *client, int *trim)
    +{
    + unsigned char dtr;
    + static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
    +
    + struct i2c_msg msgs[] = {
    + { client->addr, 0, 2, dtr_addr }, /* setup read ptr */
    + { client->addr, I2C_M_RD, 1, &dtr }, /* read dtr */
    + };
    +
    + /* read dtr register */
    + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
    + dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
    + return -EIO;
    + }
    +
    + dev_dbg(&client->dev, "%s: raw dtr=%x\n", __FUNCTION__, dtr);
    +
    + *trim = 0;
    +
    + if (dtr & X1205_DTR_DTR0)
    + *trim += 20;
    +
    + if (dtr & X1205_DTR_DTR1)
    + *trim += 10;
    +
    + if (dtr & X1205_DTR_DTR2)
    + *trim = -*trim;
    +
    + return 0;
    +}
    +
    +static int x1205_get_atrim(struct i2c_client *client, int *trim)
    +{
    + s8 atr;
    + static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
    +
    + struct i2c_msg msgs[] = {
    + { client->addr, 0, 2, atr_addr }, /* setup read ptr */
    + { client->addr, I2C_M_RD, 1, &atr }, /* read atr */
    + };
    +
    + /* read atr register */
    + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
    + dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
    + return -EIO;
    + }
    +
    + dev_dbg(&client->dev, "%s: raw atr=%x\n", __FUNCTION__, atr);
    +
    + /* atr is a two's complement value on 6 bits,
    + * perform sign extension. The formula is
    + * Catr = (atr * 0.25pF) + 11.00pF.
    + */
    + if (atr & 0x20)
    + atr |= 0xC0;
    +
    + dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __FUNCTION__, atr, atr);
    +
    + *trim = (atr * 250) + 11000;
    +
    + dev_dbg(&client->dev, "%s: real=%d\n", __FUNCTION__, *trim);
    +
    + return 0;
    +}
    +
    +static int x1205_hctosys(struct i2c_client *client)
    +{
    + int err;
    +
    + struct rtc_time tm;
    + struct timespec tv;
    + unsigned char sr;
    +
    + if ((err = x1205_get_status(client, &sr)) < 0)
    + return err;
    +
    + /* Don't set if we had a power failure */
    + if (sr & X1205_SR_RTCF)
    + return -EINVAL;
    +
    + if ((err = x1205_get_datetime(client, &tm, X1205_CCR_BASE)) < 0)
    + return err;
    +
    + /* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
    + * whether it stores the most close value or the value with partial
    + * seconds truncated. However, it is important that we use it to store
    + * the truncated value. This is because otherwise it is necessary,
    + * in an rtc sync function, to read both xtime.tv_sec and
    + * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read
    + * of >32bits is not possible. So storing the most close value would
    + * slow down the sync API. So here we have the truncated value and
    + * the best guess is to add 0.5s.
    + */
    +
    + tv.tv_nsec = NSEC_PER_SEC >> 1;
    +
    + rtc_tm_to_time(&tm, &tv.tv_sec);
    +
    + do_settimeofday(&tv);
    +
    + dev_info(&client->dev,
    + "setting the system clock to %d-%d-%d %d:%d:%d\n",
    + tm.tm_year + 1900, tm.tm_mon + 1,
    + tm.tm_mday, tm.tm_hour, tm.tm_min,
    + tm.tm_sec);
    +
    + return 0;
    +}
    +
    +struct x1205_limit
    +{
    + unsigned char reg;
    + unsigned char mask;
    + unsigned char min;
    + unsigned char max;
    +};
    +
    +static int x1205_validate_client(struct i2c_client *client)
    +{
    + int i, xfer;
    +
    + /* Probe array. We will read the register at the specified
    + * address and check if the given bits are zero.
    + */
    + static const unsigned char probe_zero_pattern[] = {
    + /* register, mask */
    + X1205_REG_SR, 0x18,
    + X1205_REG_DTR, 0xF8,
    + X1205_REG_ATR, 0xC0,
    + X1205_REG_INT, 0x18,
    + X1205_REG_0, 0xFF,
    + };
    +
    + static const struct x1205_limit probe_limits_pattern[] = {
    + /* register, mask, min, max */
    + { X1205_REG_Y2K, 0xFF, 19, 20 },
    + { X1205_REG_DW, 0xFF, 0, 6 },
    + { X1205_REG_YR, 0xFF, 0, 99 },
    + { X1205_REG_MO, 0xFF, 0, 12 },
    + { X1205_REG_DT, 0xFF, 0, 31 },
    + { X1205_REG_HR, 0x7F, 0, 23 },
    + { X1205_REG_MN, 0xFF, 0, 59 },
    + { X1205_REG_SC, 0xFF, 0, 59 },
    + { X1205_REG_Y2K1, 0xFF, 19, 20 },
    + { X1205_REG_Y2K0, 0xFF, 19, 20 },
    + };
    +
    + /* check that registers have bits a 0 where expected */
    + for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
    + unsigned char buf;
    +
    + unsigned char addr[2] = { 0, probe_zero_pattern[i] };
    +
    + struct i2c_msg msgs[2] = {
    + { client->addr, 0, 2, addr },
    + { client->addr, I2C_M_RD, 1, &buf },
    + };
    +
    + xfer = i2c_transfer(client->adapter, msgs, 2);
    + if (xfer != 2) {
    + dev_err(&client->adapter->dev,
    + "%s: could not read register %x\n",
    + __FUNCTION__, addr[1]);
    +
    + return -EIO;
    + }
    +
    + if ((buf & probe_zero_pattern[i+1]) != 0) {
    + dev_err(&client->adapter->dev,
    + "%s: register=%02x, zero pattern=%d, value=%x\n",
    + __FUNCTION__, addr[1], i, buf);
    +
    + return -ENODEV;
    + }
    + }
    +
    + /* check limits (only registers with bcd values) */
    + for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
    + unsigned char reg, value;
    +
    + unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
    +
    + struct i2c_msg msgs[2] = {
    + { client->addr, 0, 2, addr },
    + { client->addr, I2C_M_RD, 1, &reg },
    + };
    +
    + xfer = i2c_transfer(client->adapter, msgs, 2);
    +
    + if (xfer != 2) {
    + dev_err(&client->adapter->dev,
    + "%s: could not read register %x\n",
    + __FUNCTION__, addr[1]);
    +
    + return -EIO;
    + }
    +
    + value = BCD2BIN(reg & probe_limits_pattern[i].mask);
    +
    + if (value > probe_limits_pattern[i].max ||
    + value < probe_limits_pattern[i].min) {
    + dev_dbg(&client->adapter->dev,
    + "%s: register=%x, lim pattern=%d, value=%d\n",
    + __FUNCTION__, addr[1], i, value);
    +
    + return -ENODEV;
    + }
    + }
    +
    + return 0;
    +}
    +
    +static int x1205_rtc_read_alarm(struct device *dev,
    + struct rtc_wkalrm *alrm)
    +{
    + return x1205_get_datetime(to_i2c_client(dev),
    + &alrm->time, X1205_ALM0_BASE);
    +}
    +
    +static int x1205_rtc_set_alarm(struct device *dev,
    + struct rtc_wkalrm *alrm)
    +{
    + return x1205_set_datetime(to_i2c_client(dev),
    + &alrm->time, 1, X1205_ALM0_BASE);
    +}
    +
    +static int x1205_rtc_read_time(struct device *dev,
    + struct rtc_time *tm)
    +{
    + return x1205_get_datetime(to_i2c_client(dev),
    + tm, X1205_CCR_BASE);
    +}
    +
    +static int x1205_rtc_set_time(struct device *dev,
    + struct rtc_time *tm)
    +{
    + if ((rtc_valid_tm(tm)) < 0)
    + return -EINVAL;
    +
    + return x1205_set_datetime(to_i2c_client(dev),
    + tm, 1, X1205_CCR_BASE);
    +}
    +
    +static int x1205_rtc_set_mmss(struct device *dev, unsigned long secs)
    +{
    + int err;
    +
    + struct rtc_time new_tm, old_tm;
    +
    + if ((err = x1205_rtc_read_time(dev, &old_tm) == 0))
    + return err;
    +
    + /* FIXME xtime.tv_nsec = old_tm.tm_sec * 10000000; */
    + new_tm.tm_sec = secs % 60;
    + secs /= 60;
    + new_tm.tm_min = secs % 60;
    + secs /= 60;
    + new_tm.tm_hour = secs % 24;
    +
    + /*
    + * avoid writing when we're going to change the day
    + * of the month. We will retry in the next minute.
    + * This basically means that if the RTC must not drift
    + * by more than 1 minute in 11 minutes.
    + */
    + if ((old_tm.tm_hour == 23 && old_tm.tm_min == 59) ||
    + (new_tm.tm_hour == 23 && new_tm.tm_min == 59))
    + return 1;
    +
    + return x1205_rtc_set_time(dev, &new_tm);
    +}
    +
    +static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
    +{
    + int err, dtrim, atrim;
    +
    + seq_printf(seq, "24hr\t\t: yes\n");
    +
    + err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
    + if (err == 0)
    + seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
    +
    + err = x1205_get_atrim(to_i2c_client(dev), &atrim);
    + if (err == 0)
    + seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
    + atrim / 1000, atrim % 1000);
    + return 0;
    +}
    +
    +static struct rtc_class_ops x1205_rtc_ops = {
    + .owner = THIS_MODULE,
    + .proc = x1205_rtc_proc,
    + .read_time = x1205_rtc_read_time,
    + .set_time = x1205_rtc_set_time,
    + .read_alarm = x1205_rtc_read_alarm,
    + .set_alarm = x1205_rtc_set_alarm,
    + .set_mmss = x1205_rtc_set_mmss,
    +};
    +
    +static ssize_t x1205_sysfs_show_atrim(struct device *dev,
    + struct device_attribute *attr, char *buf)
    +{
    + int atrim;
    +
    + if (x1205_get_atrim(to_i2c_client(dev), &atrim) == 0) {
    + return sprintf(buf, "%d.%02d pF\n",
    + atrim / 1000, atrim % 1000); }
    + return 0;
    +}
    +static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
    +
    +static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
    + struct device_attribute *attr, char *buf)
    +{
    + int dtrim;
    +
    + if (x1205_get_dtrim(to_i2c_client(dev), &dtrim) == 0) {
    + return sprintf(buf, "%d ppm\n", dtrim);
    + }
    + return 0;
    +}
    +static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
    +
    +
    +static int x1205_attach(struct i2c_adapter *adapter)
    +{
    + dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
    +
    + return i2c_probe(adapter, &addr_data, x1205_probe);
    +}
    +
    +static int x1205_probe(struct i2c_adapter *adapter, int address, int kind)
    +{
    + int err = 0;
    + unsigned char sr;
    + struct i2c_client *client;
    + struct rtc_device *rtc_dev;
    +
    + dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
    +
    + if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
    + err = -ENODEV;
    + goto exit;
    + }
    +
    + if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
    + err = -ENOMEM;
    + goto exit;
    + }
    +
    + /* I2C client */
    + client->addr = address;
    + client->driver = &x1205_driver;
    + client->adapter = adapter;
    +
    + strlcpy(client->name, "x1205", I2C_NAME_SIZE);
    +
    + /* Verify the chip is really an X1205 */
    + if (kind < 0) {
    + if (x1205_validate_client(client) < 0) {
    + err = -ENODEV;
    + goto exit_kfree;
    + }
    + }
    +
    + /* Inform the i2c layer */
    + if ((err = i2c_attach_client(client)))
    + goto exit_kfree;
    +
    + dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
    +
    + rtc_dev = rtc_device_register(&client->dev, &x1205_rtc_ops);
    + if (IS_ERR(rtc_dev)) {
    + err = PTR_ERR(rtc_dev);
    + dev_err(&client->dev,
    + "unable to register the class device\n");
    + goto exit_detach;
    + }
    +
    + i2c_set_clientdata(client, rtc_dev);
    +
    + /* 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");
    +
    + /* If requested, set the system time */
    + if (hctosys) {
    + if ((err = x1205_hctosys(client)) < 0)
    + dev_err(&client->dev,
    + "unable to set the system clock\n");
    + }
    +
    + device_create_file(&client->dev, &dev_attr_atrim);
    + device_create_file(&client->dev, &dev_attr_dtrim);
    +
    + return 0;
    +
    +exit_detach:
    + i2c_detach_client(client);
    +
    +exit_kfree:
    + kfree(client);
    +
    +exit:
    + return err;
    +}
    +
    +static int x1205_detach(struct i2c_client *client)
    +{
    + int err;
    + struct rtc_device *rtc_dev = i2c_get_clientdata(client);
    +
    + dev_dbg(&client->dev, "%s\n", __FUNCTION__);
    +
    + if (rtc_dev)
    + rtc_device_unregister(rtc_dev);
    +
    + if ((err = i2c_detach_client(client)))
    + return err;
    +
    + kfree(client);
    +
    + return 0;
    +}
    +
    +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 <kas11@tampabay.rr.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);
    -
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      Last update: 2005-12-26 20:24    [W:0.060 / U:389.968 seconds]
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