原创 isl1208的linux驱动

 return 0;
}

static int isl1208_i2c_get_sr(void)
{
 u8 sr;
 i2c_read_reg(isl1208_i2c_client, ISL1208_REG_SR,&sr);
 return sr;
}

static int isl1208_i2c_get_atr(struct i2c_client *client)
{
 int atr ;
 u8 val;
 i2c_read_reg(client, ISL1208_REG_ATR, &val);
 atr = val;
 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 ;
 u8 val;
 i2c_read_reg(client, ISL1208_REG_DTR,&val);
 dtr = val;
 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 (isl1208_i2c_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 (&isl1208_i2c_client, ISL1208_REG_USR1, buf,
ISL1208_USR_SECTION_LEN);
}
/*
static int isl1208_rtc_proc(char *seq)
{

 int sr, dtr, atr, usr;

 sr = isl1208_i2c_get_sr();
 if (sr < 0) {
  dev_err(&isl1208_i2c_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 rtc_time *tm)
{
 int sr;
 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };

 sr = isl1208_i2c_get_sr();
 if (sr < 0) {
  dev_err(&isl1208_i2c_client->dev, "%s: reading SR failed\n", __func__);
  return -EIO;
 }
 sr = isl1208_i2c_read_regs(isl1208_i2c_client, 0, regs, ISL1208_RTC_SECTION_LEN);
 if (sr < 0) {
  dev_err(&isl1208_i2c_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 rtc_wkalrm *alarm)
{
 struct rtc_time *const tm = &alarm->time;
 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
 int sr;

 sr = isl1208_i2c_get_sr();
 if (sr < 0) {
  dev_err(&isl1208_i2c_client->dev, "%s: reading SR failed\n", __func__);
  return sr;
 }

 sr = isl1208_i2c_read_regs(isl1208_i2c_client, ISL1208_REG_SCA, regs,
      ISL1208_ALARM_SECTION_LEN);
 if (sr < 0) {
  dev_err(&isl1208_i2c_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 void  isl1208_rtc_read_time(struct rtc_time *tm)
{       
  isl1208_i2c_read_time(tm);
}

static int isl1208_i2c_set_time(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();

 /* set WRTC */
 sr = i2c_write_reg (isl1208_i2c_client, ISL1208_REG_SR,
           sr | ISL1208_REG_SR_WRTC);

 /* write RTC registers */
 sr = isl1208_i2c_set_regs(isl1208_i2c_client, 0, regs, ISL1208_RTC_SECTION_LEN);

 sr = isl1208_i2c_get_sr();
 /* clear WRTC again */
 sr = i2c_write_reg (isl1208_i2c_client, ISL1208_REG_SR,
           sr & ~ISL1208_REG_SR_WRTC);

 return 0;
}

static int isl1208_rtc_set_time( struct rtc_time *tm)
{
 return isl1208_i2c_set_time(tm);
}

static void isl1208_rtc_read_alarm( struct rtc_wkalrm *alarm)
{
  isl1208_i2c_read_alarm(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(&isl1208_i2c_client);
 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(&isl1208_i2c_client);
 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(&isl1208_i2c_client);
 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(&isl1208_i2c_client, 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;
 u8 sr;
    
 //struct rtc_time tm;
 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
  rc = -ENODEV;
  goto failout;
 }
 isl1208_i2c_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
 if (isl1208_i2c_client == NULL) {
  rc = -ENOMEM;
  goto failout;
 }
 isl1208_i2c_client->addr = addr;
 isl1208_i2c_client->adapter = adapter;
 isl1208_i2c_client->driver = &isl1208_driver;
 isl1208_i2c_client->flags = I2C_CLIENT_ALLOW_USE;
 strcpy(isl1208_i2c_client->name, DRV_NAME);
 
 
 if (kind < 0) {
  rc = isl1208_i2c_validate_client(isl1208_i2c_client);
  if (rc < 0)
   goto failout;
 }
 
 rc = i2c_attach_client(isl1208_i2c_client);
 if (rc < 0)
  goto failout;
 
 dev_info(&isl1208_i2c_client->dev,
   "chip found, driver version " DRV_VERSION "\n");
 
        sr="0";
        i2c_write_reg(isl1208_i2c_client,ISL1208_REG_SR,sr);
        
 rc = isl1208_i2c_get_sr();
 printk("isl1208 sr reg : %x\n", rc);
 if (rc < 0) {
  dev_err(&isl1208_i2c_client->dev, "reading status failed\n");
  goto failout_unregister;
 }

 if (rc & ISL1208_REG_SR_RTCF)
  dev_warn(&isl1208_i2c_client->dev, "rtc power failure detected, "
    "please set clock.\n");

 rc = device_create_file(&isl1208_i2c_client->dev, &dev_attr_atrim);
 if (rc < 0)
  goto failout_unregister;
 rc = device_create_file(&isl1208_i2c_client->dev, &dev_attr_dtrim);
 if (rc < 0)
  goto failout_atrim;
 rc = device_create_file(&isl1208_i2c_client->dev, &dev_attr_usr);
 if (rc < 0)
  goto failout_dtrim;
     register_rtc(&isl1208_rtc_ops);
           

 return 0;

 failout_dtrim:
  printk("failout_dtrim\n");
 device_remove_file(&isl1208_i2c_client->dev, &dev_attr_dtrim);
 failout_atrim:
  printk("failout_atrim\n");
 device_remove_file(&isl1208_i2c_client->dev, &dev_attr_atrim);
 failout_unregister:
  printk("failout_unregister\n");
 i2c_detach_client(isl1208_i2c_client);
 failout:

 kfree(isl1208_i2c_client);
 return rc;
}

static int i2c_read_reg(struct i2c_client *client, u8 reg, u8 * val)
{
        int err = 0;

        struct i2c_msg msg[1];
        unsigned char data[1];

        if (!client->adapter) {
                err = -ENODEV;
        } else {
                msg->addr = client->addr;
                msg->flags = 0;
                msg->len = 1;
                msg->buf = data;
                data[0] = reg;
                err = i2c_transfer(client->adapter, msg, 1);
                if (err >= 0) {
                        msg->flags = I2C_M_RD;
                        err = i2c_transfer(client->adapter, msg, 1);
                        if (err >= 0) {
                                *val = data[0];
                       }
                }
        }
        return err;
}

static int i2c_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
        int err = 0;

       struct i2c_msg msg[1];
       unsigned char data[2];

       if (!client->adapter) {
               err = -ENODEV;
       } else {
                msg->addr = client->addr;
                msg->flags = 0;
                msg->len = 2;
                msg->buf = data;
                data[0] = reg;
                data[1] = val;
                err = i2c_transfer(client->adapter, msg, 1);
         }
//         debug_print(KERN_INFO " i2c data write \n");

        return err;
}

static int
isl1208_attach_adapter (struct i2c_adapter *adapter)
{
 return isl1208_probe(adapter,ISL1208_I2C_ADDR>>1 ,-1);
}

static int
isl1208_detach_client(struct i2c_client *client)
{
 int rc;
        unregister_rtc(&isl1208_rtc_ops);
 if(!client->adapter){
  return -ENODEV;
 }else
 {
  rc = i2c_detach_client(client);
  client->adapter = NULL;
 }

 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);