/*
   * abituguru.c Copyright (c) 2005-2006 Hans de Goede <hdegoede@redhat.com>
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  /*
   * This driver supports the sensor part of the first and second revision of
   * the custom Abit uGuru chip found on Abit uGuru motherboards. Note: because
   * of lack of specs the CPU/RAM voltage & frequency control is not supported!
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/module.h>
  #include <linux/sched.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/jiffies.h>
  #include <linux/mutex.h>
  #include <linux/err.h>
  #include <linux/delay.h>
  #include <linux/platform_device.h>
  #include <linux/hwmon.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/dmi.h>
  #include <linux/io.h>
  
  /* Banks */
  #define ABIT_UGURU_ALARM_BANK			0x20 /* 1x 3 bytes */
  #define ABIT_UGURU_SENSOR_BANK1			0x21 /* 16x volt and temp */
  #define ABIT_UGURU_FAN_PWM			0x24 /* 3x 5 bytes */
  #define ABIT_UGURU_SENSOR_BANK2			0x26 /* fans */
  /* max nr of sensors in bank1, a bank1 sensor can be in, temp or nc */
  #define ABIT_UGURU_MAX_BANK1_SENSORS		16
  /*
   * Warning if you increase one of the 2 MAX defines below to 10 or higher you
   * should adjust the belonging _NAMES_LENGTH macro for the 2 digit number!
   */
  /* max nr of sensors in bank2, currently mb's with max 6 fans are known */
  #define ABIT_UGURU_MAX_BANK2_SENSORS		6
  /* max nr of pwm outputs, currently mb's with max 5 pwm outputs are known */
  #define ABIT_UGURU_MAX_PWMS			5
  /* uGuru sensor bank 1 flags */			     /* Alarm if: */
  #define ABIT_UGURU_TEMP_HIGH_ALARM_ENABLE	0x01 /*  temp over warn */
  #define ABIT_UGURU_VOLT_HIGH_ALARM_ENABLE	0x02 /*  volt over max */
  #define ABIT_UGURU_VOLT_LOW_ALARM_ENABLE	0x04 /*  volt under min */
  #define ABIT_UGURU_TEMP_HIGH_ALARM_FLAG		0x10 /* temp is over warn */
  #define ABIT_UGURU_VOLT_HIGH_ALARM_FLAG		0x20 /* volt is over max */
  #define ABIT_UGURU_VOLT_LOW_ALARM_FLAG		0x40 /* volt is under min */
  /* uGuru sensor bank 2 flags */			     /* Alarm if: */
  #define ABIT_UGURU_FAN_LOW_ALARM_ENABLE		0x01 /*   fan under min */
  /* uGuru sensor bank common flags */
  #define ABIT_UGURU_BEEP_ENABLE			0x08 /* beep if alarm */
  #define ABIT_UGURU_SHUTDOWN_ENABLE		0x80 /* shutdown if alarm */
  /* uGuru fan PWM (speed control) flags */
  #define ABIT_UGURU_FAN_PWM_ENABLE		0x80 /* enable speed control */
  /* Values used for conversion */
  #define ABIT_UGURU_FAN_MAX			15300 /* RPM */
  /* Bank1 sensor types */
  #define ABIT_UGURU_IN_SENSOR			0
  #define ABIT_UGURU_TEMP_SENSOR			1
  #define ABIT_UGURU_NC				2
  /*
   * In many cases we need to wait for the uGuru to reach a certain status, most
   * of the time it will reach this status within 30 - 90 ISA reads, and thus we
   * can best busy wait. This define gives the total amount of reads to try.
   */
  #define ABIT_UGURU_WAIT_TIMEOUT			125
  /*
   * However sometimes older versions of the uGuru seem to be distracted and they
   * do not respond for a long time. To handle this we sleep before each of the
   * last ABIT_UGURU_WAIT_TIMEOUT_SLEEP tries.
   */
  #define ABIT_UGURU_WAIT_TIMEOUT_SLEEP		5
  /*
   * Normally all expected status in abituguru_ready, are reported after the
   * first read, but sometimes not and we need to poll.
   */
  #define ABIT_UGURU_READY_TIMEOUT		5
  /* Maximum 3 retries on timedout reads/writes, delay 200 ms before retrying */
  #define ABIT_UGURU_MAX_RETRIES			3
  #define ABIT_UGURU_RETRY_DELAY			(HZ/5)
  /* Maximum 2 timeouts in abituguru_update_device, iow 3 in a row is an error */
  #define ABIT_UGURU_MAX_TIMEOUTS			2
  /* utility macros */
  #define ABIT_UGURU_NAME				"abituguru"
  #define ABIT_UGURU_DEBUG(level, format, arg...)		\
  	do {						\
  		if (level <= verbose)			\
  			pr_debug(format , ## arg);	\
  	} while (0)
  
  /* Macros to help calculate the sysfs_names array length */
  /*
   * sum of strlen of: in??_input\0, in??_{min,max}\0, in??_{min,max}_alarm\0,
   * in??_{min,max}_alarm_enable\0, in??_beep\0, in??_shutdown\0
   */
  #define ABITUGURU_IN_NAMES_LENGTH	(11 + 2 * 9 + 2 * 15 + 2 * 22 + 10 + 14)
  /*
   * sum of strlen of: temp??_input\0, temp??_max\0, temp??_crit\0,
   * temp??_alarm\0, temp??_alarm_enable\0, temp??_beep\0, temp??_shutdown\0
   */
  #define ABITUGURU_TEMP_NAMES_LENGTH	(13 + 11 + 12 + 13 + 20 + 12 + 16)
  /*
   * sum of strlen of: fan?_input\0, fan?_min\0, fan?_alarm\0,
   * fan?_alarm_enable\0, fan?_beep\0, fan?_shutdown\0
   */
  #define ABITUGURU_FAN_NAMES_LENGTH	(11 + 9 + 11 + 18 + 10 + 14)
  /*
   * sum of strlen of: pwm?_enable\0, pwm?_auto_channels_temp\0,
   * pwm?_auto_point{1,2}_pwm\0, pwm?_auto_point{1,2}_temp\0
   */
  #define ABITUGURU_PWM_NAMES_LENGTH	(12 + 24 + 2 * 21 + 2 * 22)
  /* IN_NAMES_LENGTH > TEMP_NAMES_LENGTH so assume all bank1 sensors are in */
  #define ABITUGURU_SYSFS_NAMES_LENGTH	( \
  	ABIT_UGURU_MAX_BANK1_SENSORS * ABITUGURU_IN_NAMES_LENGTH + \
  	ABIT_UGURU_MAX_BANK2_SENSORS * ABITUGURU_FAN_NAMES_LENGTH + \
  	ABIT_UGURU_MAX_PWMS * ABITUGURU_PWM_NAMES_LENGTH)
  
  /*
   * All the macros below are named identical to the oguru and oguru2 programs
   * reverse engineered by Olle Sandberg, hence the names might not be 100%
   * logical. I could come up with better names, but I prefer keeping the names
   * identical so that this driver can be compared with his work more easily.
   */
  /* Two i/o-ports are used by uGuru */
  #define ABIT_UGURU_BASE				0x00E0
  /* Used to tell uGuru what to read and to read the actual data */
  #define ABIT_UGURU_CMD				0x00
  /* Mostly used to check if uGuru is busy */
  #define ABIT_UGURU_DATA				0x04
  #define ABIT_UGURU_REGION_LENGTH		5
  /* uGuru status' */
  #define ABIT_UGURU_STATUS_WRITE			0x00 /* Ready to be written */
  #define ABIT_UGURU_STATUS_READ			0x01 /* Ready to be read */
  #define ABIT_UGURU_STATUS_INPUT			0x08 /* More input */
  #define ABIT_UGURU_STATUS_READY			0x09 /* Ready to be written */
  
  /* Constants */
  /* in (Volt) sensors go up to 3494 mV, temp to 255000 millidegrees Celsius */
  static const int abituguru_bank1_max_value[2] = { 3494, 255000 };
  /*
   * Min / Max allowed values for sensor2 (fan) alarm threshold, these values
   * correspond to 300-3000 RPM
   */
  static const u8 abituguru_bank2_min_threshold = 5;
  static const u8 abituguru_bank2_max_threshold = 50;
  /*
   * Register 0 is a bitfield, 1 and 2 are pwm settings (255 = 100%), 3 and 4
   * are temperature trip points.
   */
  static const int abituguru_pwm_settings_multiplier[5] = { 0, 1, 1, 1000, 1000 };
  /*
   * Min / Max allowed values for pwm_settings. Note: pwm1 (CPU fan) is a
   * special case the minimum allowed pwm% setting for this is 30% (77) on
   * some MB's this special case is handled in the code!
   */
  static const u8 abituguru_pwm_min[5] = { 0, 170, 170, 25, 25 };
  static const u8 abituguru_pwm_max[5] = { 0, 255, 255, 75, 75 };
  
  
  /* Insmod parameters */
  static bool force;
  module_param(force, bool, 0);
  MODULE_PARM_DESC(force, "Set to one to force detection.");
  static int bank1_types[ABIT_UGURU_MAX_BANK1_SENSORS] = { -1, -1, -1, -1, -1,
  	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 };
  module_param_array(bank1_types, int, NULL, 0);
  MODULE_PARM_DESC(bank1_types, "Bank1 sensortype autodetection override:
  "
  	"   -1 autodetect
  "
  	"    0 volt sensor
  "
  	"    1 temp sensor
  "
  	"    2 not connected");
  static int fan_sensors;
  module_param(fan_sensors, int, 0);
  MODULE_PARM_DESC(fan_sensors, "Number of fan sensors on the uGuru "
  	"(0 = autodetect)");
  static int pwms;
  module_param(pwms, int, 0);
  MODULE_PARM_DESC(pwms, "Number of PWMs on the uGuru "
  	"(0 = autodetect)");
  
  /* Default verbose is 2, since this driver is still in the testing phase */
  static int verbose = 2;
  module_param(verbose, int, 0644);
  MODULE_PARM_DESC(verbose, "How verbose should the driver be? (0-3):
  "
  	"   0 normal output
  "
  	"   1 + verbose error reporting
  "
  	"   2 + sensors type probing info
  "
  	"   3 + retryable error reporting");
  
  
  /*
   * For the Abit uGuru, we need to keep some data in memory.
   * The structure is dynamically allocated, at the same time when a new
   * abituguru device is allocated.
   */
  struct abituguru_data {
  	struct device *hwmon_dev;	/* hwmon registered device */
  	struct mutex update_lock;	/* protect access to data and uGuru */
  	unsigned long last_updated;	/* In jiffies */
  	unsigned short addr;		/* uguru base address */
  	char uguru_ready;		/* is the uguru in ready state? */
  	unsigned char update_timeouts;	/*
  					 * number of update timeouts since last
  					 * successful update
  					 */
  
  	/*
  	 * The sysfs attr and their names are generated automatically, for bank1
  	 * we cannot use a predefined array because we don't know beforehand
  	 * of a sensor is a volt or a temp sensor, for bank2 and the pwms its
  	 * easier todo things the same way.  For in sensors we have 9 (temp 7)
  	 * sysfs entries per sensor, for bank2 and pwms 6.
  	 */
  	struct sensor_device_attribute_2 sysfs_attr[
  		ABIT_UGURU_MAX_BANK1_SENSORS * 9 +
  		ABIT_UGURU_MAX_BANK2_SENSORS * 6 + ABIT_UGURU_MAX_PWMS * 6];
  	/* Buffer to store the dynamically generated sysfs names */
  	char sysfs_names[ABITUGURU_SYSFS_NAMES_LENGTH];
  
  	/* Bank 1 data */
  	/* number of and addresses of [0] in, [1] temp sensors */
  	u8 bank1_sensors[2];
  	u8 bank1_address[2][ABIT_UGURU_MAX_BANK1_SENSORS];
  	u8 bank1_value[ABIT_UGURU_MAX_BANK1_SENSORS];
  	/*
  	 * This array holds 3 entries per sensor for the bank 1 sensor settings
  	 * (flags, min, max for voltage / flags, warn, shutdown for temp).
  	 */
  	u8 bank1_settings[ABIT_UGURU_MAX_BANK1_SENSORS][3];
  	/*
  	 * Maximum value for each sensor used for scaling in mV/millidegrees
  	 * Celsius.
  	 */
  	int bank1_max_value[ABIT_UGURU_MAX_BANK1_SENSORS];
  
  	/* Bank 2 data, ABIT_UGURU_MAX_BANK2_SENSORS entries for bank2 */
  	u8 bank2_sensors; /* actual number of bank2 sensors found */
  	u8 bank2_value[ABIT_UGURU_MAX_BANK2_SENSORS];
  	u8 bank2_settings[ABIT_UGURU_MAX_BANK2_SENSORS][2]; /* flags, min */
  
  	/* Alarms 2 bytes for bank1, 1 byte for bank2 */
  	u8 alarms[3];
  
  	/* Fan PWM (speed control) 5 bytes per PWM */
  	u8 pwms; /* actual number of pwms found */
  	u8 pwm_settings[ABIT_UGURU_MAX_PWMS][5];
  };
  
  static const char *never_happen = "This should never happen.";
  static const char *report_this =
  	"Please report this to the abituguru maintainer (see MAINTAINERS)";
  
  /* wait till the uguru is in the specified state */
  static int abituguru_wait(struct abituguru_data *data, u8 state)
  {
  	int timeout = ABIT_UGURU_WAIT_TIMEOUT;
  
  	while (inb_p(data->addr + ABIT_UGURU_DATA) != state) {
  		timeout--;
  		if (timeout == 0)
  			return -EBUSY;
  		/*
  		 * sleep a bit before our last few tries, see the comment on
  		 * this where ABIT_UGURU_WAIT_TIMEOUT_SLEEP is defined.
  		 */
  		if (timeout <= ABIT_UGURU_WAIT_TIMEOUT_SLEEP)
  			msleep(0);
  	}
  	return 0;
  }
  
  /* Put the uguru in ready for input state */
  static int abituguru_ready(struct abituguru_data *data)
  {
  	int timeout = ABIT_UGURU_READY_TIMEOUT;
  
  	if (data->uguru_ready)
  		return 0;
  
  	/* Reset? / Prepare for next read/write cycle */
  	outb(0x00, data->addr + ABIT_UGURU_DATA);
  
  	/* Wait till the uguru is ready */
  	if (abituguru_wait(data, ABIT_UGURU_STATUS_READY)) {
  		ABIT_UGURU_DEBUG(1,
  			"timeout exceeded waiting for ready state
  ");
  		return -EIO;
  	}
  
  	/* Cmd port MUST be read now and should contain 0xAC */
  	while (inb_p(data->addr + ABIT_UGURU_CMD) != 0xAC) {
  		timeout--;
  		if (timeout == 0) {
  			ABIT_UGURU_DEBUG(1,
  			   "CMD reg does not hold 0xAC after ready command
  ");
  			return -EIO;
  		}
  		msleep(0);
  	}
  
  	/*
  	 * After this the ABIT_UGURU_DATA port should contain
  	 * ABIT_UGURU_STATUS_INPUT
  	 */
  	timeout = ABIT_UGURU_READY_TIMEOUT;
  	while (inb_p(data->addr + ABIT_UGURU_DATA) != ABIT_UGURU_STATUS_INPUT) {
  		timeout--;
  		if (timeout == 0) {
  			ABIT_UGURU_DEBUG(1,
  				"state != more input after ready command
  ");
  			return -EIO;
  		}
  		msleep(0);
  	}
  
  	data->uguru_ready = 1;
  	return 0;
  }
  
  /*
   * Send the bank and then sensor address to the uGuru for the next read/write
   * cycle. This function gets called as the first part of a read/write by
   * abituguru_read and abituguru_write. This function should never be
   * called by any other function.
   */
  static int abituguru_send_address(struct abituguru_data *data,
  	u8 bank_addr, u8 sensor_addr, int retries)
  {
  	/*
  	 * assume the caller does error handling itself if it has not requested
  	 * any retries, and thus be quiet.
  	 */
  	int report_errors = retries;
  
  	for (;;) {
  		/*
  		 * Make sure the uguru is ready and then send the bank address,
  		 * after this the uguru is no longer "ready".
  		 */
  		if (abituguru_ready(data) != 0)
  			return -EIO;
  		outb(bank_addr, data->addr + ABIT_UGURU_DATA);
  		data->uguru_ready = 0;
  
  		/*
  		 * Wait till the uguru is ABIT_UGURU_STATUS_INPUT state again
  		 * and send the sensor addr
  		 */
  		if (abituguru_wait(data, ABIT_UGURU_STATUS_INPUT)) {
  			if (retries) {
  				ABIT_UGURU_DEBUG(3, "timeout exceeded "
  					"waiting for more input state, %d "
  					"tries remaining
  ", retries);
  				set_current_state(TASK_UNINTERRUPTIBLE);
  				schedule_timeout(ABIT_UGURU_RETRY_DELAY);
  				retries--;
  				continue;
  			}
  			if (report_errors)
  				ABIT_UGURU_DEBUG(1, "timeout exceeded "
  					"waiting for more input state "
  					"(bank: %d)
  ", (int)bank_addr);
  			return -EBUSY;
  		}
  		outb(sensor_addr, data->addr + ABIT_UGURU_CMD);
  		return 0;
  	}
  }
  
  /*
   * Read count bytes from sensor sensor_addr in bank bank_addr and store the
   * result in buf, retry the send address part of the read retries times.
   */
  static int abituguru_read(struct abituguru_data *data,
  	u8 bank_addr, u8 sensor_addr, u8 *buf, int count, int retries)
  {
  	int i;
  
  	/* Send the address */
  	i = abituguru_send_address(data, bank_addr, sensor_addr, retries);
  	if (i)
  		return i;
  
  	/* And read the data */
  	for (i = 0; i < count; i++) {
  		if (abituguru_wait(data, ABIT_UGURU_STATUS_READ)) {
  			ABIT_UGURU_DEBUG(retries ? 1 : 3,
  				"timeout exceeded waiting for "
  				"read state (bank: %d, sensor: %d)
  ",
  				(int)bank_addr, (int)sensor_addr);
  			break;
  		}
  		buf[i] = inb(data->addr + ABIT_UGURU_CMD);
  	}
  
  	/* Last put the chip back in ready state */
  	abituguru_ready(data);
  
  	return i;
  }
  
  /*
   * Write count bytes from buf to sensor sensor_addr in bank bank_addr, the send
   * address part of the write is always retried ABIT_UGURU_MAX_RETRIES times.
   */
  static int abituguru_write(struct abituguru_data *data,
  	u8 bank_addr, u8 sensor_addr, u8 *buf, int count)
  {
  	/*
  	 * We use the ready timeout as we have to wait for 0xAC just like the
  	 * ready function
  	 */
  	int i, timeout = ABIT_UGURU_READY_TIMEOUT;
  
  	/* Send the address */
  	i = abituguru_send_address(data, bank_addr, sensor_addr,
  		ABIT_UGURU_MAX_RETRIES);
  	if (i)
  		return i;
  
  	/* And write the data */
  	for (i = 0; i < count; i++) {
  		if (abituguru_wait(data, ABIT_UGURU_STATUS_WRITE)) {
  			ABIT_UGURU_DEBUG(1, "timeout exceeded waiting for "
  				"write state (bank: %d, sensor: %d)
  ",
  				(int)bank_addr, (int)sensor_addr);
  			break;
  		}
  		outb(buf[i], data->addr + ABIT_UGURU_CMD);
  	}
  
  	/*
  	 * Now we need to wait till the chip is ready to be read again,
  	 * so that we can read 0xAC as confirmation that our write has
  	 * succeeded.
  	 */
  	if (abituguru_wait(data, ABIT_UGURU_STATUS_READ)) {
  		ABIT_UGURU_DEBUG(1, "timeout exceeded waiting for read state "
  			"after write (bank: %d, sensor: %d)
  ", (int)bank_addr,
  			(int)sensor_addr);
  		return -EIO;
  	}
  
  	/* Cmd port MUST be read now and should contain 0xAC */
  	while (inb_p(data->addr + ABIT_UGURU_CMD) != 0xAC) {
  		timeout--;
  		if (timeout == 0) {
  			ABIT_UGURU_DEBUG(1, "CMD reg does not hold 0xAC after "
  				"write (bank: %d, sensor: %d)
  ",
  				(int)bank_addr, (int)sensor_addr);
  			return -EIO;
  		}
  		msleep(0);
  	}
  
  	/* Last put the chip back in ready state */
  	abituguru_ready(data);
  
  	return i;
  }
  
  /*
   * Detect sensor type. Temp and Volt sensors are enabled with
   * different masks and will ignore enable masks not meant for them.
   * This enables us to test what kind of sensor we're dealing with.
   * By setting the alarm thresholds so that we will always get an
   * alarm for sensor type X and then enabling the sensor as sensor type
   * X, if we then get an alarm it is a sensor of type X.
   */
  static int
  abituguru_detect_bank1_sensor_type(struct abituguru_data *data,
  				   u8 sensor_addr)
  {
  	u8 val, test_flag, buf[3];
  	int i, ret = -ENODEV; /* error is the most common used retval :| */
  
  	/* If overriden by the user return the user selected type */
  	if (bank1_types[sensor_addr] >= ABIT_UGURU_IN_SENSOR &&
  			bank1_types[sensor_addr] <= ABIT_UGURU_NC) {
  		ABIT_UGURU_DEBUG(2, "assuming sensor type %d for bank1 sensor "
  			"%d because of \"bank1_types\" module param
  ",
  			bank1_types[sensor_addr], (int)sensor_addr);
  		return bank1_types[sensor_addr];
  	}
  
  	/* First read the sensor and the current settings */
  	if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK1, sensor_addr, &val,
  			1, ABIT_UGURU_MAX_RETRIES) != 1)
  		return -ENODEV;
  
  	/* Test val is sane / usable for sensor type detection. */
  	if ((val < 10u) || (val > 250u)) {
  		pr_warn("bank1-sensor: %d reading (%d) too close to limits, "
  			"unable to determine sensor type, skipping sensor
  ",
  			(int)sensor_addr, (int)val);
  		/*
  		 * assume no sensor is there for sensors for which we can't
  		 * determine the sensor type because their reading is too close
  		 * to their limits, this usually means no sensor is there.
  		 */
  		return ABIT_UGURU_NC;
  	}
  
  	ABIT_UGURU_DEBUG(2, "testing bank1 sensor %d
  ", (int)sensor_addr);
  	/*
  	 * Volt sensor test, enable volt low alarm, set min value ridiculously
  	 * high, or vica versa if the reading is very high. If its a volt
  	 * sensor this should always give us an alarm.
  	 */
  	if (val <= 240u) {
  		buf[0] = ABIT_UGURU_VOLT_LOW_ALARM_ENABLE;
  		buf[1] = 245;
  		buf[2] = 250;
  		test_flag = ABIT_UGURU_VOLT_LOW_ALARM_FLAG;
  	} else {
  		buf[0] = ABIT_UGURU_VOLT_HIGH_ALARM_ENABLE;
  		buf[1] = 5;
  		buf[2] = 10;
  		test_flag = ABIT_UGURU_VOLT_HIGH_ALARM_FLAG;
  	}
  
  	if (abituguru_write(data, ABIT_UGURU_SENSOR_BANK1 + 2, sensor_addr,
  			buf, 3) != 3)
  		goto abituguru_detect_bank1_sensor_type_exit;
  	/*
  	 * Now we need 20 ms to give the uguru time to read the sensors
  	 * and raise a voltage alarm
  	 */
  	set_current_state(TASK_UNINTERRUPTIBLE);
  	schedule_timeout(HZ/50);
  	/* Check for alarm and check the alarm is a volt low alarm. */
  	if (abituguru_read(data, ABIT_UGURU_ALARM_BANK, 0, buf, 3,
  			ABIT_UGURU_MAX_RETRIES) != 3)
  		goto abituguru_detect_bank1_sensor_type_exit;
  	if (buf[sensor_addr/8] & (0x01 << (sensor_addr % 8))) {
  		if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK1 + 1,
  				sensor_addr, buf, 3,
  				ABIT_UGURU_MAX_RETRIES) != 3)
  			goto abituguru_detect_bank1_sensor_type_exit;
  		if (buf[0] & test_flag) {
  			ABIT_UGURU_DEBUG(2, "  found volt sensor
  ");
  			ret = ABIT_UGURU_IN_SENSOR;
  			goto abituguru_detect_bank1_sensor_type_exit;
  		} else
  			ABIT_UGURU_DEBUG(2, "  alarm raised during volt "
  				"sensor test, but volt range flag not set
  ");
  	} else
  		ABIT_UGURU_DEBUG(2, "  alarm not raised during volt sensor "
  			"test
  ");
  
  	/*
  	 * Temp sensor test, enable sensor as a temp sensor, set beep value
  	 * ridiculously low (but not too low, otherwise uguru ignores it).
  	 * If its a temp sensor this should always give us an alarm.
  	 */
  	buf[0] = ABIT_UGURU_TEMP_HIGH_ALARM_ENABLE;
  	buf[1] = 5;
  	buf[2] = 10;
  	if (abituguru_write(data, ABIT_UGURU_SENSOR_BANK1 + 2, sensor_addr,
  			buf, 3) != 3)
  		goto abituguru_detect_bank1_sensor_type_exit;
  	/*
  	 * Now we need 50 ms to give the uguru time to read the sensors
  	 * and raise a temp alarm
  	 */
  	set_current_state(TASK_UNINTERRUPTIBLE);
  	schedule_timeout(HZ/20);
  	/* Check for alarm and check the alarm is a temp high alarm. */
  	if (abituguru_read(data, ABIT_UGURU_ALARM_BANK, 0, buf, 3,
  			ABIT_UGURU_MAX_RETRIES) != 3)
  		goto abituguru_detect_bank1_sensor_type_exit;
  	if (buf[sensor_addr/8] & (0x01 << (sensor_addr % 8))) {
  		if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK1 + 1,
  				sensor_addr, buf, 3,
  				ABIT_UGURU_MAX_RETRIES) != 3)
  			goto abituguru_detect_bank1_sensor_type_exit;
  		if (buf[0] & ABIT_UGURU_TEMP_HIGH_ALARM_FLAG) {
  			ABIT_UGURU_DEBUG(2, "  found temp sensor
  ");
  			ret = ABIT_UGURU_TEMP_SENSOR;
  			goto abituguru_detect_bank1_sensor_type_exit;
  		} else
  			ABIT_UGURU_DEBUG(2, "  alarm raised during temp "
  				"sensor test, but temp high flag not set
  ");
  	} else
  		ABIT_UGURU_DEBUG(2, "  alarm not raised during temp sensor "
  			"test
  ");
  
  	ret = ABIT_UGURU_NC;
  abituguru_detect_bank1_sensor_type_exit:
  	/*
  	 * Restore original settings, failing here is really BAD, it has been
  	 * reported that some BIOS-es hang when entering the uGuru menu with
  	 * invalid settings present in the uGuru, so we try this 3 times.
  	 */
  	for (i = 0; i < 3; i++)
  		if (abituguru_write(data, ABIT_UGURU_SENSOR_BANK1 + 2,
  				sensor_addr, data->bank1_settings[sensor_addr],
  				3) == 3)
  			break;
  	if (i == 3) {
  		pr_err("Fatal error could not restore original settings. %s %s
  ",
  		       never_happen, report_this);
  		return -ENODEV;
  	}
  	return ret;
  }
  
  /*
   * These functions try to find out how many sensors there are in bank2 and how
   * many pwms there are. The purpose of this is to make sure that we don't give
   * the user the possibility to change settings for non-existent sensors / pwm.
   * The uGuru will happily read / write whatever memory happens to be after the
   * memory storing the PWM settings when reading/writing to a PWM which is not
   * there. Notice even if we detect a PWM which doesn't exist we normally won't
   * write to it, unless the user tries to change the settings.
   *
   * Although the uGuru allows reading (settings) from non existing bank2
   * sensors, my version of the uGuru does seem to stop writing to them, the
   * write function above aborts in this case with:
   * "CMD reg does not hold 0xAC after write"
   *
   * Notice these 2 tests are non destructive iow read-only tests, otherwise
   * they would defeat their purpose. Although for the bank2_sensors detection a
   * read/write test would be feasible because of the reaction above, I've
   * however opted to stay on the safe side.
   */
  static void
  abituguru_detect_no_bank2_sensors(struct abituguru_data *data)
  {
  	int i;
  
  	if (fan_sensors > 0 && fan_sensors <= ABIT_UGURU_MAX_BANK2_SENSORS) {
  		data->bank2_sensors = fan_sensors;
  		ABIT_UGURU_DEBUG(2, "assuming %d fan sensors because of "
  			"\"fan_sensors\" module param
  ",
  			(int)data->bank2_sensors);
  		return;
  	}
  
  	ABIT_UGURU_DEBUG(2, "detecting number of fan sensors
  ");
  	for (i = 0; i < ABIT_UGURU_MAX_BANK2_SENSORS; i++) {
  		/*
  		 * 0x89 are the known used bits:
  		 * -0x80 enable shutdown
  		 * -0x08 enable beep
  		 * -0x01 enable alarm
  		 * All other bits should be 0, but on some motherboards
  		 * 0x40 (bit 6) is also high for some of the fans??
  		 */
  		if (data->bank2_settings[i][0] & ~0xC9) {
  			ABIT_UGURU_DEBUG(2, "  bank2 sensor %d does not seem "
  				"to be a fan sensor: settings[0] = %02X
  ",
  				i, (unsigned int)data->bank2_settings[i][0]);
  			break;
  		}
  
  		/* check if the threshold is within the allowed range */
  		if (data->bank2_settings[i][1] <
  				abituguru_bank2_min_threshold) {
  			ABIT_UGURU_DEBUG(2, "  bank2 sensor %d does not seem "
  				"to be a fan sensor: the threshold (%d) is "
  				"below the minimum (%d)
  ", i,
  				(int)data->bank2_settings[i][1],
  				(int)abituguru_bank2_min_threshold);
  			break;
  		}
  		if (data->bank2_settings[i][1] >
  				abituguru_bank2_max_threshold) {
  			ABIT_UGURU_DEBUG(2, "  bank2 sensor %d does not seem "
  				"to be a fan sensor: the threshold (%d) is "
  				"above the maximum (%d)
  ", i,
  				(int)data->bank2_settings[i][1],
  				(int)abituguru_bank2_max_threshold);
  			break;
  		}
  	}
  
  	data->bank2_sensors = i;
  	ABIT_UGURU_DEBUG(2, " found: %d fan sensors
  ",
  		(int)data->bank2_sensors);
  }
  
  static void
  abituguru_detect_no_pwms(struct abituguru_data *data)
  {
  	int i, j;
  
  	if (pwms > 0 && pwms <= ABIT_UGURU_MAX_PWMS) {
  		data->pwms = pwms;
  		ABIT_UGURU_DEBUG(2, "assuming %d PWM outputs because of "
  			"\"pwms\" module param
  ", (int)data->pwms);
  		return;
  	}
  
  	ABIT_UGURU_DEBUG(2, "detecting number of PWM outputs
  ");
  	for (i = 0; i < ABIT_UGURU_MAX_PWMS; i++) {
  		/*
  		 * 0x80 is the enable bit and the low
  		 * nibble is which temp sensor to use,
  		 * the other bits should be 0
  		 */
  		if (data->pwm_settings[i][0] & ~0x8F) {
  			ABIT_UGURU_DEBUG(2, "  pwm channel %d does not seem "
  				"to be a pwm channel: settings[0] = %02X
  ",
  				i, (unsigned int)data->pwm_settings[i][0]);
  			break;
  		}
  
  		/*
  		 * the low nibble must correspond to one of the temp sensors
  		 * we've found
  		 */
  		for (j = 0; j < data->bank1_sensors[ABIT_UGURU_TEMP_SENSOR];
  				j++) {
  			if (data->bank1_address[ABIT_UGURU_TEMP_SENSOR][j] ==
  					(data->pwm_settings[i][0] & 0x0F))
  				break;
  		}
  		if (j == data->bank1_sensors[ABIT_UGURU_TEMP_SENSOR]) {
  			ABIT_UGURU_DEBUG(2, "  pwm channel %d does not seem "
  				"to be a pwm channel: %d is not a valid temp "
  				"sensor address
  ", i,
  				data->pwm_settings[i][0] & 0x0F);
  			break;
  		}
  
  		/* check if all other settings are within the allowed range */
  		for (j = 1; j < 5; j++) {
  			u8 min;
  			/* special case pwm1 min pwm% */
  			if ((i == 0) && ((j == 1) || (j == 2)))
  				min = 77;
  			else
  				min = abituguru_pwm_min[j];
  			if (data->pwm_settings[i][j] < min) {
  				ABIT_UGURU_DEBUG(2, "  pwm channel %d does "
  					"not seem to be a pwm channel: "
  					"setting %d (%d) is below the minimum "
  					"value (%d)
  ", i, j,
  					(int)data->pwm_settings[i][j],
  					(int)min);
  				goto abituguru_detect_no_pwms_exit;
  			}
  			if (data->pwm_settings[i][j] > abituguru_pwm_max[j]) {
  				ABIT_UGURU_DEBUG(2, "  pwm channel %d does "
  					"not seem to be a pwm channel: "
  					"setting %d (%d) is above the maximum "
  					"value (%d)
  ", i, j,
  					(int)data->pwm_settings[i][j],
  					(int)abituguru_pwm_max[j]);
  				goto abituguru_detect_no_pwms_exit;
  			}
  		}
  
  		/* check that min temp < max temp and min pwm < max pwm */
  		if (data->pwm_settings[i][1] >= data->pwm_settings[i][2]) {
  			ABIT_UGURU_DEBUG(2, "  pwm channel %d does not seem "
  				"to be a pwm channel: min pwm (%d) >= "
  				"max pwm (%d)
  ", i,
  				(int)data->pwm_settings[i][1],
  				(int)data->pwm_settings[i][2]);
  			break;
  		}
  		if (data->pwm_settings[i][3] >= data->pwm_settings[i][4]) {
  			ABIT_UGURU_DEBUG(2, "  pwm channel %d does not seem "
  				"to be a pwm channel: min temp (%d) >= "
  				"max temp (%d)
  ", i,
  				(int)data->pwm_settings[i][3],
  				(int)data->pwm_settings[i][4]);
  			break;
  		}
  	}
  
  abituguru_detect_no_pwms_exit:
  	data->pwms = i;
  	ABIT_UGURU_DEBUG(2, " found: %d PWM outputs
  ", (int)data->pwms);
  }
  
  /*
   * Following are the sysfs callback functions. These functions expect:
   * sensor_device_attribute_2->index:   sensor address/offset in the bank
   * sensor_device_attribute_2->nr:      register offset, bitmask or NA.
   */
  static struct abituguru_data *abituguru_update_device(struct device *dev);
  
  static ssize_t show_bank1_value(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = abituguru_update_device(dev);
  	if (!data)
  		return -EIO;
  	return sprintf(buf, "%d
  ", (data->bank1_value[attr->index] *
  		data->bank1_max_value[attr->index] + 128) / 255);
  }
  
  static ssize_t show_bank1_setting(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	return sprintf(buf, "%d
  ",
  		(data->bank1_settings[attr->index][attr->nr] *
  		data->bank1_max_value[attr->index] + 128) / 255);
  }
  
  static ssize_t show_bank2_value(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = abituguru_update_device(dev);
  	if (!data)
  		return -EIO;
  	return sprintf(buf, "%d
  ", (data->bank2_value[attr->index] *
  		ABIT_UGURU_FAN_MAX + 128) / 255);
  }
  
  static ssize_t show_bank2_setting(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	return sprintf(buf, "%d
  ",
  		(data->bank2_settings[attr->index][attr->nr] *
  		ABIT_UGURU_FAN_MAX + 128) / 255);
  }
  
  static ssize_t store_bank1_setting(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	unsigned long val;
  	ssize_t ret;
  
  	ret = kstrtoul(buf, 10, &val);
  	if (ret)
  		return ret;
  
  	ret = count;
  	val = (val * 255 + data->bank1_max_value[attr->index] / 2) /
  		data->bank1_max_value[attr->index];
  	if (val > 255)
  		return -EINVAL;
  
  	mutex_lock(&data->update_lock);
  	if (data->bank1_settings[attr->index][attr->nr] != val) {
  		u8 orig_val = data->bank1_settings[attr->index][attr->nr];
  		data->bank1_settings[attr->index][attr->nr] = val;
  		if (abituguru_write(data, ABIT_UGURU_SENSOR_BANK1 + 2,
  				attr->index, data->bank1_settings[attr->index],
  				3) <= attr->nr) {
  			data->bank1_settings[attr->index][attr->nr] = orig_val;
  			ret = -EIO;
  		}
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  static ssize_t store_bank2_setting(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	unsigned long val;
  	ssize_t ret;
  
  	ret = kstrtoul(buf, 10, &val);
  	if (ret)
  		return ret;
  
  	ret = count;
  	val = (val * 255 + ABIT_UGURU_FAN_MAX / 2) / ABIT_UGURU_FAN_MAX;
  
  	/* this check can be done before taking the lock */
  	if (val < abituguru_bank2_min_threshold ||
  			val > abituguru_bank2_max_threshold)
  		return -EINVAL;
  
  	mutex_lock(&data->update_lock);
  	if (data->bank2_settings[attr->index][attr->nr] != val) {
  		u8 orig_val = data->bank2_settings[attr->index][attr->nr];
  		data->bank2_settings[attr->index][attr->nr] = val;
  		if (abituguru_write(data, ABIT_UGURU_SENSOR_BANK2 + 2,
  				attr->index, data->bank2_settings[attr->index],
  				2) <= attr->nr) {
  			data->bank2_settings[attr->index][attr->nr] = orig_val;
  			ret = -EIO;
  		}
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  static ssize_t show_bank1_alarm(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = abituguru_update_device(dev);
  	if (!data)
  		return -EIO;
  	/*
  	 * See if the alarm bit for this sensor is set, and if the
  	 * alarm matches the type of alarm we're looking for (for volt
  	 * it can be either low or high). The type is stored in a few
  	 * readonly bits in the settings part of the relevant sensor.
  	 * The bitmask of the type is passed to us in attr->nr.
  	 */
  	if ((data->alarms[attr->index / 8] & (0x01 << (attr->index % 8))) &&
  			(data->bank1_settings[attr->index][0] & attr->nr))
  		return sprintf(buf, "1
  ");
  	else
  		return sprintf(buf, "0
  ");
  }
  
  static ssize_t show_bank2_alarm(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = abituguru_update_device(dev);
  	if (!data)
  		return -EIO;
  	if (data->alarms[2] & (0x01 << attr->index))
  		return sprintf(buf, "1
  ");
  	else
  		return sprintf(buf, "0
  ");
  }
  
  static ssize_t show_bank1_mask(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	if (data->bank1_settings[attr->index][0] & attr->nr)
  		return sprintf(buf, "1
  ");
  	else
  		return sprintf(buf, "0
  ");
  }
  
  static ssize_t show_bank2_mask(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	if (data->bank2_settings[attr->index][0] & attr->nr)
  		return sprintf(buf, "1
  ");
  	else
  		return sprintf(buf, "0
  ");
  }
  
  static ssize_t store_bank1_mask(struct device *dev,
  	struct device_attribute *devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	ssize_t ret;
  	u8 orig_val;
  	unsigned long mask;
  
  	ret = kstrtoul(buf, 10, &mask);
  	if (ret)
  		return ret;
  
  	ret = count;
  	mutex_lock(&data->update_lock);
  	orig_val = data->bank1_settings[attr->index][0];
  
  	if (mask)
  		data->bank1_settings[attr->index][0] |= attr->nr;
  	else
  		data->bank1_settings[attr->index][0] &= ~attr->nr;
  
  	if ((data->bank1_settings[attr->index][0] != orig_val) &&
  			(abituguru_write(data,
  			ABIT_UGURU_SENSOR_BANK1 + 2, attr->index,
  			data->bank1_settings[attr->index], 3) < 1)) {
  		data->bank1_settings[attr->index][0] = orig_val;
  		ret = -EIO;
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  static ssize_t store_bank2_mask(struct device *dev,
  	struct device_attribute *devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	ssize_t ret;
  	u8 orig_val;
  	unsigned long mask;
  
  	ret = kstrtoul(buf, 10, &mask);
  	if (ret)
  		return ret;
  
  	ret = count;
  	mutex_lock(&data->update_lock);
  	orig_val = data->bank2_settings[attr->index][0];
  
  	if (mask)
  		data->bank2_settings[attr->index][0] |= attr->nr;
  	else
  		data->bank2_settings[attr->index][0] &= ~attr->nr;
  
  	if ((data->bank2_settings[attr->index][0] != orig_val) &&
  			(abituguru_write(data,
  			ABIT_UGURU_SENSOR_BANK2 + 2, attr->index,
  			data->bank2_settings[attr->index], 2) < 1)) {
  		data->bank2_settings[attr->index][0] = orig_val;
  		ret = -EIO;
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  /* Fan PWM (speed control) */
  static ssize_t show_pwm_setting(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	return sprintf(buf, "%d
  ", data->pwm_settings[attr->index][attr->nr] *
  		abituguru_pwm_settings_multiplier[attr->nr]);
  }
  
  static ssize_t store_pwm_setting(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	u8 min;
  	unsigned long val;
  	ssize_t ret;
  
  	ret = kstrtoul(buf, 10, &val);
  	if (ret)
  		return ret;
  
  	ret = count;
  	val = (val + abituguru_pwm_settings_multiplier[attr->nr] / 2) /
  				abituguru_pwm_settings_multiplier[attr->nr];
  
  	/* special case pwm1 min pwm% */
  	if ((attr->index == 0) && ((attr->nr == 1) || (attr->nr == 2)))
  		min = 77;
  	else
  		min = abituguru_pwm_min[attr->nr];
  
  	/* this check can be done before taking the lock */
  	if (val < min || val > abituguru_pwm_max[attr->nr])
  		return -EINVAL;
  
  	mutex_lock(&data->update_lock);
  	/* this check needs to be done after taking the lock */
  	if ((attr->nr & 1) &&
  			(val >= data->pwm_settings[attr->index][attr->nr + 1]))
  		ret = -EINVAL;
  	else if (!(attr->nr & 1) &&
  			(val <= data->pwm_settings[attr->index][attr->nr - 1]))
  		ret = -EINVAL;
  	else if (data->pwm_settings[attr->index][attr->nr] != val) {
  		u8 orig_val = data->pwm_settings[attr->index][attr->nr];
  		data->pwm_settings[attr->index][attr->nr] = val;
  		if (abituguru_write(data, ABIT_UGURU_FAN_PWM + 1,
  				attr->index, data->pwm_settings[attr->index],
  				5) <= attr->nr) {
  			data->pwm_settings[attr->index][attr->nr] =
  				orig_val;
  			ret = -EIO;
  		}
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  static ssize_t show_pwm_sensor(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	int i;
  	/*
  	 * We need to walk to the temp sensor addresses to find what
  	 * the userspace id of the configured temp sensor is.
  	 */
  	for (i = 0; i < data->bank1_sensors[ABIT_UGURU_TEMP_SENSOR]; i++)
  		if (data->bank1_address[ABIT_UGURU_TEMP_SENSOR][i] ==
  				(data->pwm_settings[attr->index][0] & 0x0F))
  			return sprintf(buf, "%d
  ", i+1);
  
  	return -ENXIO;
  }
  
  static ssize_t store_pwm_sensor(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	ssize_t ret;
  	unsigned long val;
  	u8 orig_val;
  	u8 address;
  
  	ret = kstrtoul(buf, 10, &val);
  	if (ret)
  		return ret;
  
  	if (val == 0 || val > data->bank1_sensors[ABIT_UGURU_TEMP_SENSOR])
  		return -EINVAL;
  
  	val -= 1;
  	ret = count;
  	mutex_lock(&data->update_lock);
  	orig_val = data->pwm_settings[attr->index][0];
  	address = data->bank1_address[ABIT_UGURU_TEMP_SENSOR][val];
  	data->pwm_settings[attr->index][0] &= 0xF0;
  	data->pwm_settings[attr->index][0] |= address;
  	if (data->pwm_settings[attr->index][0] != orig_val) {
  		if (abituguru_write(data, ABIT_UGURU_FAN_PWM + 1, attr->index,
  				    data->pwm_settings[attr->index], 5) < 1) {
  			data->pwm_settings[attr->index][0] = orig_val;
  			ret = -EIO;
  		}
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  static ssize_t show_pwm_enable(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	int res = 0;
  	if (data->pwm_settings[attr->index][0] & ABIT_UGURU_FAN_PWM_ENABLE)
  		res = 2;
  	return sprintf(buf, "%d
  ", res);
  }
  
  static ssize_t store_pwm_enable(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	u8 orig_val;
  	ssize_t ret;
  	unsigned long user_val;
  
  	ret = kstrtoul(buf, 10, &user_val);
  	if (ret)
  		return ret;
  
  	ret = count;
  	mutex_lock(&data->update_lock);
  	orig_val = data->pwm_settings[attr->index][0];
  	switch (user_val) {
  	case 0:
  		data->pwm_settings[attr->index][0] &=
  			~ABIT_UGURU_FAN_PWM_ENABLE;
  		break;
  	case 2:
  		data->pwm_settings[attr->index][0] |= ABIT_UGURU_FAN_PWM_ENABLE;
  		break;
  	default:
  		ret = -EINVAL;
  	}
  	if ((data->pwm_settings[attr->index][0] != orig_val) &&
  			(abituguru_write(data, ABIT_UGURU_FAN_PWM + 1,
  			attr->index, data->pwm_settings[attr->index],
  			5) < 1)) {
  		data->pwm_settings[attr->index][0] = orig_val;
  		ret = -EIO;
  	}
  	mutex_unlock(&data->update_lock);
  	return ret;
  }
  
  static ssize_t show_name(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	return sprintf(buf, "%s
  ", ABIT_UGURU_NAME);
  }
  
  /* Sysfs attr templates, the real entries are generated automatically. */
  static const
  struct sensor_device_attribute_2 abituguru_sysfs_bank1_templ[2][9] = {
  	{
  	SENSOR_ATTR_2(in%d_input, 0444, show_bank1_value, NULL, 0, 0),
  	SENSOR_ATTR_2(in%d_min, 0644, show_bank1_setting,
  		store_bank1_setting, 1, 0),
  	SENSOR_ATTR_2(in%d_min_alarm, 0444, show_bank1_alarm, NULL,
  		ABIT_UGURU_VOLT_LOW_ALARM_FLAG, 0),
  	SENSOR_ATTR_2(in%d_max, 0644, show_bank1_setting,
  		store_bank1_setting, 2, 0),
  	SENSOR_ATTR_2(in%d_max_alarm, 0444, show_bank1_alarm, NULL,
  		ABIT_UGURU_VOLT_HIGH_ALARM_FLAG, 0),
  	SENSOR_ATTR_2(in%d_beep, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_BEEP_ENABLE, 0),
  	SENSOR_ATTR_2(in%d_shutdown, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_SHUTDOWN_ENABLE, 0),
  	SENSOR_ATTR_2(in%d_min_alarm_enable, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_VOLT_LOW_ALARM_ENABLE, 0),
  	SENSOR_ATTR_2(in%d_max_alarm_enable, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_VOLT_HIGH_ALARM_ENABLE, 0),
  	}, {
  	SENSOR_ATTR_2(temp%d_input, 0444, show_bank1_value, NULL, 0, 0),
  	SENSOR_ATTR_2(temp%d_alarm, 0444, show_bank1_alarm, NULL,
  		ABIT_UGURU_TEMP_HIGH_ALARM_FLAG, 0),
  	SENSOR_ATTR_2(temp%d_max, 0644, show_bank1_setting,
  		store_bank1_setting, 1, 0),
  	SENSOR_ATTR_2(temp%d_crit, 0644, show_bank1_setting,
  		store_bank1_setting, 2, 0),
  	SENSOR_ATTR_2(temp%d_beep, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_BEEP_ENABLE, 0),
  	SENSOR_ATTR_2(temp%d_shutdown, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_SHUTDOWN_ENABLE, 0),
  	SENSOR_ATTR_2(temp%d_alarm_enable, 0644, show_bank1_mask,
  		store_bank1_mask, ABIT_UGURU_TEMP_HIGH_ALARM_ENABLE, 0),
  	}
  };
  
  static const struct sensor_device_attribute_2 abituguru_sysfs_fan_templ[6] = {
  	SENSOR_ATTR_2(fan%d_input, 0444, show_bank2_value, NULL, 0, 0),
  	SENSOR_ATTR_2(fan%d_alarm, 0444, show_bank2_alarm, NULL, 0, 0),
  	SENSOR_ATTR_2(fan%d_min, 0644, show_bank2_setting,
  		store_bank2_setting, 1, 0),
  	SENSOR_ATTR_2(fan%d_beep, 0644, show_bank2_mask,
  		store_bank2_mask, ABIT_UGURU_BEEP_ENABLE, 0),
  	SENSOR_ATTR_2(fan%d_shutdown, 0644, show_bank2_mask,
  		store_bank2_mask, ABIT_UGURU_SHUTDOWN_ENABLE, 0),
  	SENSOR_ATTR_2(fan%d_alarm_enable, 0644, show_bank2_mask,
  		store_bank2_mask, ABIT_UGURU_FAN_LOW_ALARM_ENABLE, 0),
  };
  
  static const struct sensor_device_attribute_2 abituguru_sysfs_pwm_templ[6] = {
  	SENSOR_ATTR_2(pwm%d_enable, 0644, show_pwm_enable,
  		store_pwm_enable, 0, 0),
  	SENSOR_ATTR_2(pwm%d_auto_channels_temp, 0644, show_pwm_sensor,
  		store_pwm_sensor, 0, 0),
  	SENSOR_ATTR_2(pwm%d_auto_point1_pwm, 0644, show_pwm_setting,
  		store_pwm_setting, 1, 0),
  	SENSOR_ATTR_2(pwm%d_auto_point2_pwm, 0644, show_pwm_setting,
  		store_pwm_setting, 2, 0),
  	SENSOR_ATTR_2(pwm%d_auto_point1_temp, 0644, show_pwm_setting,
  		store_pwm_setting, 3, 0),
  	SENSOR_ATTR_2(pwm%d_auto_point2_temp, 0644, show_pwm_setting,
  		store_pwm_setting, 4, 0),
  };
  
  static struct sensor_device_attribute_2 abituguru_sysfs_attr[] = {
  	SENSOR_ATTR_2(name, 0444, show_name, NULL, 0, 0),
  };
  
  static int abituguru_probe(struct platform_device *pdev)
  {
  	struct abituguru_data *data;
  	int i, j, used, sysfs_names_free, sysfs_attr_i, res = -ENODEV;
  	char *sysfs_filename;
  
  	/*
  	 * El weirdo probe order, to keep the sysfs order identical to the
  	 * BIOS and window-appliction listing order.
  	 */
  	const u8 probe_order[ABIT_UGURU_MAX_BANK1_SENSORS] = {
  		0x00, 0x01, 0x03, 0x04, 0x0A, 0x08, 0x0E, 0x02,
  		0x09, 0x06, 0x05, 0x0B, 0x0F, 0x0D, 0x07, 0x0C };
  
  	data = devm_kzalloc(&pdev->dev, sizeof(struct abituguru_data),
  			    GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	data->addr = platform_get_resource(pdev, IORESOURCE_IO, 0)->start;
  	mutex_init(&data->update_lock);
  	platform_set_drvdata(pdev, data);
  
  	/* See if the uGuru is ready */
  	if (inb_p(data->addr + ABIT_UGURU_DATA) == ABIT_UGURU_STATUS_INPUT)
  		data->uguru_ready = 1;
  
  	/*
  	 * Completely read the uGuru this has 2 purposes:
  	 * - testread / see if one really is there.
  	 * - make an in memory copy of all the uguru settings for future use.
  	 */
  	if (abituguru_read(data, ABIT_UGURU_ALARM_BANK, 0,
  			data->alarms, 3, ABIT_UGURU_MAX_RETRIES) != 3)
  		goto abituguru_probe_error;
  
  	for (i = 0; i < ABIT_UGURU_MAX_BANK1_SENSORS; i++) {
  		if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK1, i,
  				&data->bank1_value[i], 1,
  				ABIT_UGURU_MAX_RETRIES) != 1)
  			goto abituguru_probe_error;
  		if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK1+1, i,
  				data->bank1_settings[i], 3,
  				ABIT_UGURU_MAX_RETRIES) != 3)
  			goto abituguru_probe_error;
  	}
  	/*
  	 * Note: We don't know how many bank2 sensors / pwms there really are,
  	 * but in order to "detect" this we need to read the maximum amount
  	 * anyways. If we read sensors/pwms not there we'll just read crap
  	 * this can't hurt. We need the detection because we don't want
  	 * unwanted writes, which will hurt!
  	 */
  	for (i = 0; i < ABIT_UGURU_MAX_BANK2_SENSORS; i++) {
  		if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK2, i,
  				&data->bank2_value[i], 1,
  				ABIT_UGURU_MAX_RETRIES) != 1)
  			goto abituguru_probe_error;
  		if (abituguru_read(data, ABIT_UGURU_SENSOR_BANK2+1, i,
  				data->bank2_settings[i], 2,
  				ABIT_UGURU_MAX_RETRIES) != 2)
  			goto abituguru_probe_error;
  	}
  	for (i = 0; i < ABIT_UGURU_MAX_PWMS; i++) {
  		if (abituguru_read(data, ABIT_UGURU_FAN_PWM, i,
  				data->pwm_settings[i], 5,
  				ABIT_UGURU_MAX_RETRIES) != 5)
  			goto abituguru_probe_error;
  	}
  	data->last_updated = jiffies;
  
  	/* Detect sensor types and fill the sysfs attr for bank1 */
  	sysfs_attr_i = 0;
  	sysfs_filename = data->sysfs_names;
  	sysfs_names_free = ABITUGURU_SYSFS_NAMES_LENGTH;
  	for (i = 0; i < ABIT_UGURU_MAX_BANK1_SENSORS; i++) {
  		res = abituguru_detect_bank1_sensor_type(data, probe_order[i]);
  		if (res < 0)
  			goto abituguru_probe_error;
  		if (res == ABIT_UGURU_NC)
  			continue;
  
  		/* res 1 (temp) sensors have 7 sysfs entries, 0 (in) 9 */
  		for (j = 0; j < (res ? 7 : 9); j++) {
  			used = snprintf(sysfs_filename, sysfs_names_free,
  				abituguru_sysfs_bank1_templ[res][j].dev_attr.
  				attr.name, data->bank1_sensors[res] + res)
  				+ 1;
  			data->sysfs_attr[sysfs_attr_i] =
  				abituguru_sysfs_bank1_templ[res][j];
  			data->sysfs_attr[sysfs_attr_i].dev_attr.attr.name =
  				sysfs_filename;
  			data->sysfs_attr[sysfs_attr_i].index = probe_order[i];
  			sysfs_filename += used;
  			sysfs_names_free -= used;
  			sysfs_attr_i++;
  		}
  		data->bank1_max_value[probe_order[i]] =
  			abituguru_bank1_max_value[res];
  		data->bank1_address[res][data->bank1_sensors[res]] =
  			probe_order[i];
  		data->bank1_sensors[res]++;
  	}
  	/* Detect number of sensors and fill the sysfs attr for bank2 (fans) */
  	abituguru_detect_no_bank2_sensors(data);
  	for (i = 0; i < data->bank2_sensors; i++) {
  		for (j = 0; j < ARRAY_SIZE(abituguru_sysfs_fan_templ); j++) {
  			used = snprintf(sysfs_filename, sysfs_names_free,
  				abituguru_sysfs_fan_templ[j].dev_attr.attr.name,
  				i + 1) + 1;
  			data->sysfs_attr[sysfs_attr_i] =
  				abituguru_sysfs_fan_templ[j];
  			data->sysfs_attr[sysfs_attr_i].dev_attr.attr.name =
  				sysfs_filename;
  			data->sysfs_attr[sysfs_attr_i].index = i;
  			sysfs_filename += used;
  			sysfs_names_free -= used;
  			sysfs_attr_i++;
  		}
  	}
  	/* Detect number of sensors and fill the sysfs attr for pwms */
  	abituguru_detect_no_pwms(data);
  	for (i = 0; i < data->pwms; i++) {
  		for (j = 0; j < ARRAY_SIZE(abituguru_sysfs_pwm_templ); j++) {
  			used = snprintf(sysfs_filename, sysfs_names_free,
  				abituguru_sysfs_pwm_templ[j].dev_attr.attr.name,
  				i + 1) + 1;
  			data->sysfs_attr[sysfs_attr_i] =
  				abituguru_sysfs_pwm_templ[j];
  			data->sysfs_attr[sysfs_attr_i].dev_attr.attr.name =
  				sysfs_filename;
  			data->sysfs_attr[sysfs_attr_i].index = i;
  			sysfs_filename += used;
  			sysfs_names_free -= used;
  			sysfs_attr_i++;
  		}
  	}
  	/* Fail safe check, this should never happen! */
  	if (sysfs_names_free < 0) {
  		pr_err("Fatal error ran out of space for sysfs attr names. %s %s",
  		       never_happen, report_this);
  		res = -ENAMETOOLONG;
  		goto abituguru_probe_error;
  	}
  	pr_info("found Abit uGuru
  ");
  
  	/* Register sysfs hooks */
  	for (i = 0; i < sysfs_attr_i; i++) {
  		res = device_create_file(&pdev->dev,
  					 &data->sysfs_attr[i].dev_attr);
  		if (res)
  			goto abituguru_probe_error;
  	}
  	for (i = 0; i < ARRAY_SIZE(abituguru_sysfs_attr); i++) {
  		res = device_create_file(&pdev->dev,
  					 &abituguru_sysfs_attr[i].dev_attr);
  		if (res)
  			goto abituguru_probe_error;
  	}
  
  	data->hwmon_dev = hwmon_device_register(&pdev->dev);
  	if (!IS_ERR(data->hwmon_dev))
  		return 0; /* success */
  
  	res = PTR_ERR(data->hwmon_dev);
  abituguru_probe_error:
  	for (i = 0; data->sysfs_attr[i].dev_attr.attr.name; i++)
  		device_remove_file(&pdev->dev, &data->sysfs_attr[i].dev_attr);
  	for (i = 0; i < ARRAY_SIZE(abituguru_sysfs_attr); i++)
  		device_remove_file(&pdev->dev,
  			&abituguru_sysfs_attr[i].dev_attr);
  	return res;
  }
  
  static int abituguru_remove(struct platform_device *pdev)
  {
  	int i;
  	struct abituguru_data *data = platform_get_drvdata(pdev);
  
  	hwmon_device_unregister(data->hwmon_dev);
  	for (i = 0; data->sysfs_attr[i].dev_attr.attr.name; i++)
  		device_remove_file(&pdev->dev, &data->sysfs_attr[i].dev_attr);
  	for (i = 0; i < ARRAY_SIZE(abituguru_sysfs_attr); i++)
  		device_remove_file(&pdev->dev,
  			&abituguru_sysfs_attr[i].dev_attr);
  
  	return 0;
  }
  
  static struct abituguru_data *abituguru_update_device(struct device *dev)
  {
  	int i, err;
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	/* fake a complete successful read if no update necessary. */
  	char success = 1;
  
  	mutex_lock(&data->update_lock);
  	if (time_after(jiffies, data->last_updated + HZ)) {
  		success = 0;
  		err = abituguru_read(data, ABIT_UGURU_ALARM_BANK, 0,
  				     data->alarms, 3, 0);
  		if (err != 3)
  			goto LEAVE_UPDATE;
  		for (i = 0; i < ABIT_UGURU_MAX_BANK1_SENSORS; i++) {
  			err = abituguru_read(data, ABIT_UGURU_SENSOR_BANK1,
  					     i, &data->bank1_value[i], 1, 0);
  			if (err != 1)
  				goto LEAVE_UPDATE;
  			err = abituguru_read(data, ABIT_UGURU_SENSOR_BANK1 + 1,
  					     i, data->bank1_settings[i], 3, 0);
  			if (err != 3)
  				goto LEAVE_UPDATE;
  		}
  		for (i = 0; i < data->bank2_sensors; i++) {
  			err = abituguru_read(data, ABIT_UGURU_SENSOR_BANK2, i,
  					     &data->bank2_value[i], 1, 0);
  			if (err != 1)
  				goto LEAVE_UPDATE;
  		}
  		/* success! */
  		success = 1;
  		data->update_timeouts = 0;
  LEAVE_UPDATE:
  		/* handle timeout condition */
  		if (!success && (err == -EBUSY || err >= 0)) {
  			/* No overflow please */
  			if (data->update_timeouts < 255u)
  				data->update_timeouts++;
  			if (data->update_timeouts <= ABIT_UGURU_MAX_TIMEOUTS) {
  				ABIT_UGURU_DEBUG(3, "timeout exceeded, will "
  					"try again next update
  ");
  				/* Just a timeout, fake a successful read */
  				success = 1;
  			} else
  				ABIT_UGURU_DEBUG(1, "timeout exceeded %d "
  					"times waiting for more input state
  ",
  					(int)data->update_timeouts);
  		}
  		/* On success set last_updated */
  		if (success)
  			data->last_updated = jiffies;
  	}
  	mutex_unlock(&data->update_lock);
  
  	if (success)
  		return data;
  	else
  		return NULL;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int abituguru_suspend(struct device *dev)
  {
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	/*
  	 * make sure all communications with the uguru are done and no new
  	 * ones are started
  	 */
  	mutex_lock(&data->update_lock);
  	return 0;
  }
  
  static int abituguru_resume(struct device *dev)
  {
  	struct abituguru_data *data = dev_get_drvdata(dev);
  	/* See if the uGuru is still ready */
  	if (inb_p(data->addr + ABIT_UGURU_DATA) != ABIT_UGURU_STATUS_INPUT)
  		data->uguru_ready = 0;
  	mutex_unlock(&data->update_lock);
  	return 0;
  }
  
  static SIMPLE_DEV_PM_OPS(abituguru_pm, abituguru_suspend, abituguru_resume);
  #define ABIT_UGURU_PM	(&abituguru_pm)
  #else
  #define ABIT_UGURU_PM	NULL
  #endif /* CONFIG_PM */
  
  static struct platform_driver abituguru_driver = {
  	.driver = {
  		.owner	= THIS_MODULE,
  		.name	= ABIT_UGURU_NAME,
  		.pm	= ABIT_UGURU_PM,
  	},
  	.probe		= abituguru_probe,
  	.remove		= abituguru_remove,
  };
  
  static int __init abituguru_detect(void)
  {
  	/*
  	 * See if there is an uguru there. After a reboot uGuru will hold 0x00
  	 * at DATA and 0xAC, when this driver has already been loaded once
  	 * DATA will hold 0x08. For most uGuru's CMD will hold 0xAC in either
  	 * scenario but some will hold 0x00.
  	 * Some uGuru's initially hold 0x09 at DATA and will only hold 0x08
  	 * after reading CMD first, so CMD must be read first!
  	 */
  	u8 cmd_val = inb_p(ABIT_UGURU_BASE + ABIT_UGURU_CMD);
  	u8 data_val = inb_p(ABIT_UGURU_BASE + ABIT_UGURU_DATA);
  	if (((data_val == 0x00) || (data_val == 0x08)) &&
  	    ((cmd_val == 0x00) || (cmd_val == 0xAC)))
  		return ABIT_UGURU_BASE;
  
  	ABIT_UGURU_DEBUG(2, "no Abit uGuru found, data = 0x%02X, cmd = "
  		"0x%02X
  ", (unsigned int)data_val, (unsigned int)cmd_val);
  
  	if (force) {
  		pr_info("Assuming Abit uGuru is present because of \"force\" parameter
  ");
  		return ABIT_UGURU_BASE;
  	}
  
  	/* No uGuru found */
  	return -ENODEV;
  }
  
  static struct platform_device *abituguru_pdev;
  
  static int __init abituguru_init(void)
  {
  	int address, err;
  	struct resource res = { .flags = IORESOURCE_IO };
  	const char *board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
  
  	/* safety check, refuse to load on non Abit motherboards */
  	if (!force && (!board_vendor ||
  			strcmp(board_vendor, "http://www.abit.com.tw/")))
  		return -ENODEV;
  
  	address = abituguru_detect();
  	if (address < 0)
  		return address;
  
  	err = platform_driver_register(&abituguru_driver);
  	if (err)
  		goto exit;
  
  	abituguru_pdev = platform_device_alloc(ABIT_UGURU_NAME, address);
  	if (!abituguru_pdev) {
  		pr_err("Device allocation failed
  ");
  		err = -ENOMEM;
  		goto exit_driver_unregister;
  	}
  
  	res.start = address;
  	res.end = address + ABIT_UGURU_REGION_LENGTH - 1;
  	res.name = ABIT_UGURU_NAME;
  
  	err = platform_device_add_resources(abituguru_pdev, &res, 1);
  	if (err) {
  		pr_err("Device resource addition failed (%d)
  ", err);
  		goto exit_device_put;
  	}
  
  	err = platform_device_add(abituguru_pdev);
  	if (err) {
  		pr_err("Device addition failed (%d)
  ", err);
  		goto exit_device_put;
  	}
  
  	return 0;
  
  exit_device_put:
  	platform_device_put(abituguru_pdev);
  exit_driver_unregister:
  	platform_driver_unregister(&abituguru_driver);
  exit:
  	return err;
  }
  
  static void __exit abituguru_exit(void)
  {
  	platform_device_unregister(abituguru_pdev);
  	platform_driver_unregister(&abituguru_driver);
  }
  
  MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
  MODULE_DESCRIPTION("Abit uGuru Sensor device");
  MODULE_LICENSE("GPL");
  
  module_init(abituguru_init);
  module_exit(abituguru_exit);