Subversion Repositories test_project

/*

 * Intersil ISL1208 rtc class driver

 *

 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>

 *

 *  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/i2c.h>

#include <linux/bcd.h>

#include <linux/rtc.h>

#define DRV_NAME "isl1208"

#define DRV_VERSION "0.2"

/* Register map */

/* rtc section */

#define ISL1208_REG_SC  0x00

#define ISL1208_REG_MN  0x01

#define ISL1208_REG_HR  0x02

#define ISL1208_REG_HR_MIL     (1<<7) /* 24h/12h mode */

#define ISL1208_REG_HR_PM      (1<<5) /* PM/AM bit in 12h mode */

#define ISL1208_REG_DT  0x03

#define ISL1208_REG_MO  0x04

#define ISL1208_REG_YR  0x05

#define ISL1208_REG_DW  0x06

#define ISL1208_RTC_SECTION_LEN 7

/* control/status section */

#define ISL1208_REG_SR  0x07

#define ISL1208_REG_SR_ARST    (1<<7) /* auto reset */

#define ISL1208_REG_SR_XTOSCB  (1<<6) /* crystal oscillator */

#define ISL1208_REG_SR_WRTC    (1<<4) /* write rtc */

#define ISL1208_REG_SR_ALM     (1<<2) /* alarm */

#define ISL1208_REG_SR_BAT     (1<<1) /* battery */

#define ISL1208_REG_SR_RTCF    (1<<0) /* rtc fail */

#define ISL1208_REG_INT 0x08

#define ISL1208_REG_09  0x09 /* reserved */

#define ISL1208_REG_ATR 0x0a

#define ISL1208_REG_DTR 0x0b

/* alarm section */

#define ISL1208_REG_SCA 0x0c

#define ISL1208_REG_MNA 0x0d

#define ISL1208_REG_HRA 0x0e

#define ISL1208_REG_DTA 0x0f

#define ISL1208_REG_MOA 0x10

#define ISL1208_REG_DWA 0x11

#define ISL1208_ALARM_SECTION_LEN 6

/* user section */

#define ISL1208_REG_USR1 0x12

#define ISL1208_REG_USR2 0x13

#define ISL1208_USR_SECTION_LEN 2

/* i2c configuration */

#define ISL1208_I2C_ADDR 0xde

static unsigned short normal_i2c[] = {

        ISL1208_I2C_ADDR>>1, I2C_CLIENT_END

};

I2C_CLIENT_INSMOD; /* defines addr_data */

static int isl1208_attach_adapter(struct i2c_adapter *adapter);

static int isl1208_detach_client(struct i2c_client *client);

static struct i2c_driver isl1208_driver = {

        .driver         = {

                .name   = DRV_NAME,

        },

        .id             = I2C_DRIVERID_ISL1208,

        .attach_adapter = &isl1208_attach_adapter,

        .detach_client  = &isl1208_detach_client,

};

/* block read */

static int

isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],

                       unsigned len)

{

        u8 reg_addr[1] = { reg };

        struct i2c_msg msgs[2] = {

                { client->addr, client->flags, sizeof(reg_addr), reg_addr },

                { client->addr, client->flags | I2C_M_RD, len, buf }

        };

        int ret;

        BUG_ON(len == 0);

        BUG_ON(reg > ISL1208_REG_USR2);

        BUG_ON(reg + len > ISL1208_REG_USR2 + 1);

        ret = i2c_transfer(client->adapter, msgs, 2);

        if (ret > 0)

                ret = 0;

        return ret;

}

/* block write */

static int

isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],

                       unsigned len)

{

        u8 i2c_buf[ISL1208_REG_USR2 + 2];

        struct i2c_msg msgs[1] = {

                { client->addr, client->flags, len + 1, i2c_buf }

        };

        int ret;

        BUG_ON(len == 0);

        BUG_ON(reg > ISL1208_REG_USR2);

        BUG_ON(reg + len > ISL1208_REG_USR2 + 1);

        i2c_buf[0] = reg;

        memcpy(&i2c_buf[1], &buf[0], len);

        ret = i2c_transfer(client->adapter, msgs, 1);

        if (ret > 0)

                ret = 0;

        return ret;

}

/* simple check to see wether we have a isl1208 */

static int isl1208_i2c_validate_client(struct i2c_client *client)

{

        u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };

        u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {

                0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8

        };

        int i;

        int ret;

        ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);

        if (ret < 0)

                return ret;

        for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {

                if (regs[i] & zero_mask[i]) /* check if bits are cleared */

                        return -ENODEV;

        }

        return 0;

}

static int isl1208_i2c_get_sr(struct i2c_client *client)

{

        return i2c_smbus_read_byte_data(client, ISL1208_REG_SR) == -1 ? -EIO:0;

}

static int isl1208_i2c_get_atr(struct i2c_client *client)

{

        int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);

        if (atr < 0)

                return -EIO;

        /* The 6bit value in the ATR register controls the load

         * capacitance C_load * in steps of 0.25pF

         *

         * bit (1<<5) of the ATR register is inverted

         *

         * C_load(ATR=0x20) =  4.50pF

         * C_load(ATR=0x00) = 12.50pF

         * C_load(ATR=0x1f) = 20.25pF

         *

         */

        atr &= 0x3f; /* mask out lsb */

        atr ^= 1<<5; /* invert 6th bit */

        atr += 2*9; /* add offset of 4.5pF; unit[atr] = 0.25pF */

        return atr;

}

static int isl1208_i2c_get_dtr(struct i2c_client *client)

{

        int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);

        if (dtr < 0)

                return -EIO;

        /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */

        dtr = ((dtr & 0x3) * 20) * (dtr & (1<<2) ? -1 : 1);

        return dtr;

}

static int isl1208_i2c_get_usr(struct i2c_client *client)

{

        u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };

        int ret;

        ret = isl1208_i2c_read_regs (client, ISL1208_REG_USR1, buf,

                                   ISL1208_USR_SECTION_LEN);

        if (ret < 0)

                return ret;

        return (buf[1] << 8) | buf[0];

}

static int isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)

{

        u8 buf[ISL1208_USR_SECTION_LEN];

        buf[0] = usr & 0xff;

        buf[1] = (usr >> 8) & 0xff;

        return isl1208_i2c_set_regs (client, ISL1208_REG_USR1, buf,

                                     ISL1208_USR_SECTION_LEN);

}

static int isl1208_rtc_proc(struct device *dev, struct seq_file *seq)

{

        struct i2c_client *const client = to_i2c_client(dev);

        int sr, dtr, atr, usr;

        sr = isl1208_i2c_get_sr(client);

        if (sr < 0) {

                dev_err(&client->dev, "%s: reading SR failed\n", __func__);

                return sr;

        }

        seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",

                   (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",

                   (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",

                   (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",

                   (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",

                   (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",

                   (sr & ISL1208_REG_SR_ARST) ? " ARST" : "",

                   sr);

        seq_printf(seq, "batt_status\t: %s\n",

                   (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");

        dtr = isl1208_i2c_get_dtr(client);

        if (dtr >= 0 -1)

                seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);

        atr = isl1208_i2c_get_atr(client);

        if (atr >= 0)

                seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",

                           atr>>2, (atr&0x3)*25);

        usr = isl1208_i2c_get_usr(client);

        if (usr >= 0)

                seq_printf(seq, "user_data\t: 0x%.4x\n", usr);

        return 0;

}

static int isl1208_i2c_read_time(struct i2c_client *client,

                                 struct rtc_time *tm)

{

        int sr;

        u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };

        sr = isl1208_i2c_get_sr(client);

        if (sr < 0) {

                dev_err(&client->dev, "%s: reading SR failed\n", __func__);

                return -EIO;

        }

        sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);

        if (sr < 0) {

                dev_err(&client->dev, "%s: reading RTC section failed\n",

                        __func__);

                return sr;

        }

        tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]);

        tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]);

        { /* HR field has a more complex interpretation */

                const u8 _hr = regs[ISL1208_REG_HR];

                if (_hr & ISL1208_REG_HR_MIL) /* 24h format */

                        tm->tm_hour = BCD2BIN(_hr & 0x3f);

                else { // 12h format

                        tm->tm_hour = BCD2BIN(_hr & 0x1f);

                        if (_hr & ISL1208_REG_HR_PM) /* PM flag set */

                                tm->tm_hour += 12;

                }

        }

        tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]);

        tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */

        tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100;

        tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]);

        return 0;

}

static int isl1208_i2c_read_alarm(struct i2c_client *client,

                                  struct rtc_wkalrm *alarm)

{

        struct rtc_time *const tm = &alarm->time;

        u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };

        int sr;

        sr = isl1208_i2c_get_sr(client);

        if (sr < 0) {

                dev_err(&client->dev, "%s: reading SR failed\n", __func__);

                return sr;

        }

        sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,

                                  ISL1208_ALARM_SECTION_LEN);

        if (sr < 0) {

                dev_err(&client->dev, "%s: reading alarm section failed\n",

                        __func__);

                return sr;

        }

        /* MSB of each alarm register is an enable bit */

        tm->tm_sec  = BCD2BIN(regs[ISL1208_REG_SCA-ISL1208_REG_SCA] & 0x7f);

        tm->tm_min  = BCD2BIN(regs[ISL1208_REG_MNA-ISL1208_REG_SCA] & 0x7f);

        tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA-ISL1208_REG_SCA] & 0x3f);

        tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA-ISL1208_REG_SCA] & 0x3f);

        tm->tm_mon  = BCD2BIN(regs[ISL1208_REG_MOA-ISL1208_REG_SCA] & 0x1f)-1;

        tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA-ISL1208_REG_SCA] & 0x03);

        return 0;

}

static int isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

        return isl1208_i2c_read_time(to_i2c_client(dev), tm);

}

static int isl1208_i2c_set_time(struct i2c_client *client,

                                struct rtc_time const *tm)

{

        int sr;

        u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };

        regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec);

        regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min);

        regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL;

        regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday);

        regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1);

        regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100);

        regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7);

        sr = isl1208_i2c_get_sr(client);

        if (sr < 0) {

                dev_err(&client->dev, "%s: reading SR failed\n", __func__);

                return sr;

        }

        /* set WRTC */

        sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR,

                                       sr | ISL1208_REG_SR_WRTC);

        if (sr < 0) {

                dev_err(&client->dev, "%s: writing SR failed\n", __func__);

                return sr;

        }

        /* write RTC registers */

        sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);

        if (sr < 0) {

                dev_err(&client->dev, "%s: writing RTC section failed\n",

                        __func__);

                return sr;

        }

        /* clear WRTC again */

        sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR,

                                       sr & ~ISL1208_REG_SR_WRTC);

        if (sr < 0) {

                dev_err(&client->dev, "%s: writing SR failed\n", __func__);

                return sr;

        }

        return 0;

}

static int isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

        return isl1208_i2c_set_time(to_i2c_client(dev), tm);

}

static int isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)

{

        return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);

}

static const struct rtc_class_ops isl1208_rtc_ops = {

        .proc           = isl1208_rtc_proc,

        .read_time      = isl1208_rtc_read_time,

        .set_time       = isl1208_rtc_set_time,

        .read_alarm     = isl1208_rtc_read_alarm,

        //.set_alarm    = isl1208_rtc_set_alarm,

};

/* sysfs interface */

static ssize_t isl1208_sysfs_show_atrim(struct device *dev,

                                        struct device_attribute *attr,

                                        char *buf)

{

        int atr;

        atr = isl1208_i2c_get_atr(to_i2c_client(dev));

        if (atr < 0)

                return atr;

        return sprintf(buf, "%d.%.2d pF\n", atr>>2, (atr&0x3)*25);

}

static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);

static ssize_t isl1208_sysfs_show_dtrim(struct device *dev,

                                        struct device_attribute *attr,

                                        char *buf)

{

        int dtr;

        dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));

        if (dtr < 0)

                return dtr;

        return sprintf(buf, "%d ppm\n", dtr);

}

static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);

static ssize_t isl1208_sysfs_show_usr(struct device *dev,

                                       struct device_attribute *attr,

                                       char *buf)

{

        int usr;

        usr = isl1208_i2c_get_usr(to_i2c_client(dev));

        if (usr < 0)

                return usr;

        return sprintf(buf, "0x%.4x\n", usr);

}

static ssize_t isl1208_sysfs_store_usr(struct device *dev,

                                       struct device_attribute *attr,

                                       const char *buf, size_t count)

{

        int usr = -1;

        if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {

                if (sscanf(buf, "%x", &usr) != 1)

                        return -EINVAL;

        } else {

                if (sscanf(buf, "%d", &usr) != 1)

                        return -EINVAL;

        }

        if (usr < 0 || usr > 0xffff)

                return -EINVAL;

        return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;

}

static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,

                   isl1208_sysfs_store_usr);

static int

isl1208_probe(struct i2c_adapter *adapter, int addr, int kind)

{

        int rc = 0;

        struct i2c_client *new_client = NULL;

        struct rtc_device *rtc = NULL;

        if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {

                rc = -ENODEV;

                goto failout;

        }

        new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);

        if (new_client == NULL) {

                rc = -ENOMEM;

                goto failout;

        }

        new_client->addr = addr;

        new_client->adapter = adapter;

        new_client->driver = &isl1208_driver;

        new_client->flags = 0;

        strcpy(new_client->name, DRV_NAME);

        if (kind < 0) {

                rc = isl1208_i2c_validate_client(new_client);

                if (rc < 0)

                        goto failout;

        }

        rc = i2c_attach_client(new_client);

        if (rc < 0)

                goto failout;

        dev_info(&new_client->dev,

                 "chip found, driver version " DRV_VERSION "\n");

        rtc = rtc_device_register(isl1208_driver.driver.name,

                                  &new_client->dev,

                                  &isl1208_rtc_ops, THIS_MODULE);

        if (IS_ERR(rtc)) {

                rc = PTR_ERR(rtc);

                goto failout_detach;

        }

        i2c_set_clientdata(new_client, rtc);

        rc = isl1208_i2c_get_sr(new_client);

        if (rc < 0) {

                dev_err(&new_client->dev, "reading status failed\n");

                goto failout_unregister;

        }

        if (rc & ISL1208_REG_SR_RTCF)

                dev_warn(&new_client->dev, "rtc power failure detected, "

                         "please set clock.\n");

        rc = device_create_file(&new_client->dev, &dev_attr_atrim);

        if (rc < 0)

                goto failout_unregister;

        rc = device_create_file(&new_client->dev, &dev_attr_dtrim);

        if (rc < 0)

                goto failout_atrim;

        rc = device_create_file(&new_client->dev, &dev_attr_usr);

        if (rc < 0)

                goto failout_dtrim;

        return 0;

 failout_dtrim:

        device_remove_file(&new_client->dev, &dev_attr_dtrim);

 failout_atrim:

        device_remove_file(&new_client->dev, &dev_attr_atrim);

 failout_unregister:

        rtc_device_unregister(rtc);

 failout_detach:

        i2c_detach_client(new_client);

 failout:

        kfree(new_client);

        return rc;

}

static int

isl1208_attach_adapter (struct i2c_adapter *adapter)

{

        return i2c_probe(adapter, &addr_data, isl1208_probe);

}

static int

isl1208_detach_client(struct i2c_client *client)

{

        int rc;

        struct rtc_device *const rtc = i2c_get_clientdata(client);

        if (rtc)

                rtc_device_unregister(rtc); /* do we need to kfree? */

        rc = i2c_detach_client(client);

        if (rc)

                return rc;

        kfree(client);

        return 0;

}

/* module management */

static int __init isl1208_init(void)

{

        return i2c_add_driver(&isl1208_driver);

}

static void __exit isl1208_exit(void)

{

        i2c_del_driver(&isl1208_driver);

}

MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");

MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");

MODULE_LICENSE("GPL");

MODULE_VERSION(DRV_VERSION);

module_init(isl1208_init);

module_exit(isl1208_exit);