pwmtachtool/src/pwmtach.c - openbmc/openbmc-tools - Gitiles


 /*
  * Simple interface library for fan control operations
  * This file provides interface functions to support pwmtachtool.
  * Copyright (C) <2019>  <American Megatrends International LLC>
  *
  */

 #include <stdio.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <errno.h>
 #include <string.h>
 #include "libpwmtach.h"
 #include "pwmtach_ioctl.h"
 #include "EINTR_wrappers.h"
 #include <stdlib.h>

 void select_sleep(time_t sec,suseconds_t usec)
 {
 	struct timeval tv;

 	tv.tv_sec = sec;
 	tv.tv_usec = usec;

 	while(sigwrap_select(0, NULL, NULL, NULL, &tv) < 0);
 }

 //support acessing driver using sysfs device file
 static char DevNodeFileName[50];
 #define HWMON_DIR "/sys/class/hwmon"

 //build the pwm and tach access device node file name, and mapping pwm/tach number starting from 1.
 #define BUILD_PWM_NODE_NAME(buffer,DEV_ID,PWM_NUM)	    snprintf(buffer, sizeof(buffer), "%s%d%s%d", HWMON_DIR "/hwmon",DEV_ID, "/pwm", PWM_NUM+1)
 #define BUILD_TACH_NODE_NAME(buffer,DEV_ID,TACH_NUM)	snprintf(buffer, sizeof(buffer), "%s%d%s%d%s", HWMON_DIR "/hwmon",DEV_ID, "/fan", TACH_NUM+1,"_input")
 #define BUILD_FAN_REG_NAME(buffer,DEV_ID,FAN_NUM)	snprintf(buffer, sizeof(buffer), "%s%d%s%d%s", HWMON_DIR "/hwmon",DEV_ID, "/of_node/fan@", FAN_NUM,"/reg")

 //predefine FAN RPM range, must defined at some where for configuration.
 #define RPM_MAX         38600
 #define RPM_MIN         7500
 #define COUNTERRES_DEF  100

 /* Check hwmon if exist or not */
 static int pwmtach_directory_check(void)
 {
 	int retval = 0;
 	struct stat sb;
 	if (!(stat("/sys/class/hwmon", &sb) == 0 && S_ISDIR(sb.st_mode)))
 	{
 		printf("\"/sys/class/hwmon\" not exist!\n");
 		retval = -1;
 	}
 	return retval;
 }
 //Notice: dutycycle_value is one byte (0-255)
 static int SET_PWM_DUTYCYCLE_VALUE ( pwmtach_ioctl_data  *ppwmtach_arg )
 {
 	int retval = 0;
 	unsigned char dutycycle_value;
 	int fd;
 	char duty_num[5];

 	retval = pwmtach_directory_check();
 	if(retval != 0)
 	{
 		return retval;
 	}

 	dutycycle_value = ppwmtach_arg->dutycycle;
 	BUILD_PWM_NODE_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->pwmnumber);
 	retval = access(DevNodeFileName,F_OK);
 	if(retval != 0)
 	{
 		return retval;
 	}

 	fd = sigwrap_open(DevNodeFileName, O_WRONLY);
 	if (fd < 0) {
 		return fd;
 	}

 	snprintf(duty_num,5, "%d", dutycycle_value);

 	if ( write(fd, duty_num, strlen (duty_num)) != (ssize_t )strlen(duty_num)){
 		printf("%s: Error write dutycycle value %d to pwm %d\n",__FUNCTION__,dutycycle_value,ppwmtach_arg->pwmnumber);
 		retval = -1;
 	}
 	(void)sigwrap_close(fd);

 	return retval;
 }

 //Notice: dutycycle_percentage value should be between 1 to 99.
 static int SET_PWM_DUTYCYCLE ( pwmtach_ioctl_data  *ppwmtach_arg)
 {
 	int retval = 0;
 	unsigned char dutycycle_value;

 	if(ppwmtach_arg->dutycycle > 100)
 	{
 		return -1;
 	}

 	dutycycle_value = (ppwmtach_arg->dutycycle*255)/100;
 	ppwmtach_arg->dutycycle = dutycycle_value;
 	retval = SET_PWM_DUTYCYCLE_VALUE(ppwmtach_arg);
 	return retval;
 }

 static int GET_PWM_DUTYCYCLE ( pwmtach_ioctl_data  *ppwmtach_arg )
 {
 	int retval = 0;
 	int fd;
 	char duty_num[5];

 	retval = pwmtach_directory_check();
 	if(retval != 0)
 	{//printf("%s,error 0\n",__FUNCTION__);
 		return retval;
 	}

 	BUILD_PWM_NODE_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->pwmnumber);
 	retval = access(DevNodeFileName,F_OK);
 	if(retval != 0)
 	{printf("%s,error 2,%s not exist\n",__FUNCTION__,DevNodeFileName);
 		return retval;
 	}
 	fd = sigwrap_open(DevNodeFileName, O_RDONLY);
 	if (fd < 0) {printf("%s,error 3\n",__FUNCTION__);
 		return fd;
 	}
 	read(fd, duty_num, 5);
 	ppwmtach_arg->dutycycle = atoi(duty_num);
 	printf("%s:dutycycle value %d to pwm %d\n",__FUNCTION__,ppwmtach_arg->dutycycle,ppwmtach_arg->pwmnumber);
 	(void)sigwrap_close(fd);

 	return retval;
 }
 int GET_TACH_SPEED (pwmtach_ioctl_data *ppwmtach_arg )
 {
 	int retval = 0;
 	int fd;
 	char data[6];

 	retval = pwmtach_directory_check();
 	if(retval != 0)
 	{printf("%s,error 0\n",__FUNCTION__);
 		return retval;
 	}
 	BUILD_TACH_NODE_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->tachnumber);
 	retval = access(DevNodeFileName,F_OK);
 	if(retval != 0)
 	{printf("%s,error 2,%s not exist\n",__FUNCTION__,DevNodeFileName);
 		return retval;
 	}

 	fd = sigwrap_open(DevNodeFileName, O_RDONLY);
 	if (fd < 0) {printf("%s,error 3\n",__FUNCTION__);
 		return fd;
 	}
 	memset(data, 0, 6);
 	read(fd, data, 6);
 	ppwmtach_arg->rpmvalue = atoi(data);
 	(void)sigwrap_close(fd);
 	printf("%s:rpm value %d\n",__FUNCTION__,ppwmtach_arg->rpmvalue);
 	return retval;
 }
 //mapping function of fan to tach
 //using direct mapping as default
 #define GET_TACH_NUMBER(FAN_NUMBER)     FAN_NUMBER
 //mapping fan number to pwm number
 //using information in fan@number reg item, to look up the pwm index
 static int GET_PWM_NUMBER(pwmtach_ioctl_data *ppwmtach_arg)
 {
 	int retval = 0;
 	int fd;
 	int reg_val = 0;

 	retval = pwmtach_directory_check();
 	if(retval != 0)
 	{printf("%s,error 0\n",__FUNCTION__);
 		return retval;
 	}
 	BUILD_FAN_REG_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->fannumber);
 	retval = access(DevNodeFileName,F_OK);
 	if(retval != 0)
 	{printf("%s,error 2,%s not exist\n",__FUNCTION__,DevNodeFileName);
 		return retval;
 	}

 	fd = sigwrap_open(DevNodeFileName, O_RDONLY);
 	if (fd < 0) {printf("%s,error 3\n",__FUNCTION__);
 		return fd;
 	}
 	read(fd, &reg_val, sizeof(int));
 	if(reg_val < 0)
 	{
 		retval = -1;
 	}else
 	{
 		retval = reg_val >> 24; //get the highest byte
 		printf("%s:fan %d, pwm %d, val 0x%X\n",__FUNCTION__,ppwmtach_arg->fannumber,retval,reg_val);
 		printf("%s\n",DevNodeFileName);
 	}
 	(void)sigwrap_close(fd);
 	// printf("%s:rpm value %d\n",__FUNCTION__,ppwmtach_arg->rpmvalue);
 	return retval;
 }
 static int pwmtach_action(  pwmtach_ioctl_data* argp, int command )
 {
 	int retval = 0;
 	// printf("%s, Command 0x%X:Dev:%d,Pwm:0x%X,Fan:0x%x,Tach:0x%X\n",__FUNCTION__,command,argp->dev_id,argp->pwmnumber,argp->fannumber,argp->tachnumber);
 	switch(command)
 	{
 		case SET_DUTY_CYCLE_BY_PWM_CHANNEL:
 			retval = SET_PWM_DUTYCYCLE(argp);
 			break;
 		case SET_DUTY_CYCLE_VALUE_BY_PWM_CHANNEL:
 		case SET_DUTY_CYCLE:
 			retval = SET_PWM_DUTYCYCLE_VALUE(argp);
 			break;
 		case GET_TACH_VALUE_BY_TACH_CHANNEL:
 			retval = GET_TACH_SPEED(argp);
 			break;
 		case GET_TACH_VALUE: //used to get fan speed
 			argp->tachnumber = GET_TACH_NUMBER(argp->fannumber);
 			retval = GET_TACH_SPEED(argp);
 			break;
 		case GET_DUTY_CYCLE:
 			retval = GET_PWM_DUTYCYCLE(argp);
 			break;
 		case GET_FAN_RPM_RANGE:
 			argp->max_rpm = RPM_MAX;
 			argp->min_rpm = RPM_MIN;
 			break;
 		case INIT_PWMTACH: //assume that init complete
 			argp->pwmnumber         = GET_PWM_NUMBER(argp);; //since we don't have the fan to pwm mapping, just using direct map for workarround.
 			argp->counterresvalue   = COUNTERRES_DEF; //since driver don't support COUNTERRES, just using default value for workarround.
 			retval = GET_PWM_DUTYCYCLE(argp);
 			break;
 		case END_OF_FUNC_TABLE:
 		default:
 			printf("%s, Command 0x%X not support!\n",__FUNCTION__,command);
 			retval = -1;
 	}
 	return( retval );
 }

 int get_tach_speed ( unsigned int dev_id, unsigned char tach_number, unsigned int *rpm_value )
 {
 	pwmtach_ioctl_data pwmtach_arg;
 	int retval = 0;

 	pwmtach_arg.dev_id = dev_id;
 	pwmtach_arg.tachnumber = tach_number;
 	retval = pwmtach_action( &pwmtach_arg, GET_TACH_VALUE_BY_TACH_CHANNEL);
 	if(retval != -1)
 		*rpm_value = pwmtach_arg.rpmvalue;
 	return retval;
 }

 //Notice: dutycycle_percentage value should be between 1 to 99.
 int set_pwm_dutycycle ( unsigned int dev_id, unsigned char pwm_number, unsigned char dutycycle_percentage )
 {
 	pwmtach_ioctl_data pwmtach_arg;
 	int retval = 0;

 	pwmtach_arg.dev_id = dev_id;
 	pwmtach_arg.pwmnumber = pwm_number;
 	pwmtach_arg.dutycycle= dutycycle_percentage;
 	retval = pwmtach_action( &pwmtach_arg, SET_DUTY_CYCLE_BY_PWM_CHANNEL);

 	return retval;
 }

 //Notice: dutycycle_value is one byte (0-255)
 int set_pwm_dutycycle_value ( unsigned int dev_id, unsigned char pwm_number, unsigned char dutycycle_value )
 {
 	pwmtach_ioctl_data pwmtach_arg;
 	int retval = 0;

 	pwmtach_arg.dev_id = dev_id;
 	pwmtach_arg.pwmnumber = pwm_number;
 	pwmtach_arg.dutycycle= dutycycle_value;
 	retval = pwmtach_action( &pwmtach_arg, SET_DUTY_CYCLE_VALUE_BY_PWM_CHANNEL);

 	return retval;
 }

 int get_pwm_dutycycle ( unsigned int dev_id, unsigned char pwm_number, unsigned char *dutycycle_percentage )
 {
 	pwmtach_ioctl_data pwmtach_arg;
 	int retval = 0;

 	pwmtach_arg.dev_id = dev_id;
 	pwmtach_arg.pwmnumber = pwm_number;
 	retval = pwmtach_action(&pwmtach_arg, GET_DUTY_CYCLE);
 	if(retval != -1)
 		*dutycycle_percentage = pwmtach_arg.dutycycle;
 	return retval;

 }

 int set_fan_speed ( unsigned int dev_id, unsigned char fan_number, unsigned int rpm_value )
 {
 	int retval = 0;
 	unsigned int retries = 20;
 	unsigned char firsttime = 1;
 	unsigned char duty_cycle_increasing = 0;
 	unsigned char reached90percent = 0;
 	unsigned char reached5percent = 0;
 	unsigned long desiredrpm = rpm_value;
 	pwmtach_ioctl_data          pwmtach_arg;
 	pwmtach_data_t* indata = (pwmtach_data_t*) &pwmtach_arg;

 	indata->dev_id = dev_id;
 	indata->fannumber = fan_number;
 	indata->rpmvalue = rpm_value;
 	indata->counterresvalue = 0;
 	indata->dutycycle = 0;
 	indata->prevdutycycle = 0;

 	retval = pwmtach_action( indata, GET_FAN_RPM_RANGE);
 	if ((rpm_value < indata->min_rpm) || (rpm_value > indata->max_rpm))
 	{
 		printf("Out of range Fan Speed value for fan.\n");
 		return -1;
 	}
 	retval = pwmtach_action ( indata, INIT_PWMTACH );

 	while (retries--)
 	{
 		/* Wait for 1 seconds */
 		select_sleep(0,1*1000*1000);
 		if ((retval = pwmtach_action( indata, GET_TACH_VALUE )) != 0)
 		{
 			indata->dutycycle = indata->prevdutycycle;
 			retval = pwmtach_action( indata, SET_DUTY_CYCLE);
 			return -1;
 		}
 		else
 		{
 			indata->prevdutycycle = indata->dutycycle;
 			if (indata->rpmvalue > (desiredrpm + 50))
 			{
 				if (indata->dutycycle <= ((indata->counterresvalue*10)/100))
 				{
 					if (reached5percent == 1)
 					{
 						printf("\nSpeed is set to minimum possible speed of %d RPM.\n",indata->rpmvalue);
 						break;
 					}
 					reached5percent = 1;
 				}
 				else
 				{
 					indata->dutycycle -= ((5 * indata->counterresvalue)/100);
 				}
 			}
 			else if (indata->rpmvalue < (desiredrpm - 50))
 			{
 				if (indata->dutycycle >= indata->counterresvalue)
 				{
 					if (reached90percent == 1)
 					{
 						printf("\nSpeed is set to maximum possible speed of %d RPM.\n",indata->rpmvalue);
 						break;
 					}
 					reached90percent = 1;
 				}
 				else
 				{
 					indata->dutycycle += ((5 * indata->counterresvalue)/100);
 				}
 			}
 			else
 			{
 				break;
 			}

 			retval = pwmtach_action (indata, SET_DUTY_CYCLE);
 			printf("After update: dutycycle=%d, rpmvalue=%d\n", indata->dutycycle, indata->rpmvalue);

 			if(indata->prevdutycycle < indata->dutycycle)
 			{       /* Duty Cycle increasing */
 				if ((firsttime == 0) && (duty_cycle_increasing == 0))
 				{
 					indata->dutycycle = indata->prevdutycycle;
 					retval = pwmtach_action( indata, SET_DUTY_CYCLE);
 					printf("\n");
 					return 0;
 				}
 				duty_cycle_increasing = 1;
 			}
 			else
 			{       /* Duty Cycle decreasing */
 				if ((firsttime == 0) && (duty_cycle_increasing == 1))
 				{
 					indata->dutycycle = indata->prevdutycycle;
 					retval = pwmtach_action( indata, SET_DUTY_CYCLE);
 					printf("\n");
 					return 0;
 				}
 				duty_cycle_increasing = 0;
 			}
 			if (firsttime == 1)
 				firsttime = 0;
 		}
 		printf("retry %d : dt=%d, ps=%d, cr=%d\n", retries, indata->dutycycle, indata->prescalervalue, indata->counterresvalue);
 	}
 	return 0;

 }

 int get_fan_speed ( unsigned int dev_id, unsigned char fan_number, unsigned int *rpm_value )
 {
 	pwmtach_ioctl_data pwmtach_arg;
 	int retval = 0;

 	pwmtach_arg.dev_id = dev_id;
 	pwmtach_arg.fannumber = fan_number;
 	retval = pwmtach_action( &pwmtach_arg, GET_TACH_VALUE );
 	if(retval != -1)
 		*rpm_value = pwmtach_arg.rpmvalue;
 	return retval;
 }

	/*
	* Simple interface library for fan control operations
	* This file provides interface functions to support pwmtachtool.
	* Copyright (C) <2019> <American Megatrends International LLC>
	*
	*/

	#include <stdio.h>
	#include <unistd.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <sys/ioctl.h>
	#include <errno.h>
	#include <string.h>
	#include "libpwmtach.h"
	#include "pwmtach_ioctl.h"
	#include "EINTR_wrappers.h"
	#include <stdlib.h>

	void select_sleep(time_t sec,suseconds_t usec)
	{
	struct timeval tv;

	tv.tv_sec = sec;
	tv.tv_usec = usec;

	while(sigwrap_select(0, NULL, NULL, NULL, &tv) < 0);
	}

	//support acessing driver using sysfs device file
	static char DevNodeFileName[50];
	#define HWMON_DIR "/sys/class/hwmon"

	//build the pwm and tach access device node file name, and mapping pwm/tach number starting from 1.
	#define BUILD_PWM_NODE_NAME(buffer,DEV_ID,PWM_NUM) snprintf(buffer, sizeof(buffer), "%s%d%s%d", HWMON_DIR "/hwmon",DEV_ID, "/pwm", PWM_NUM+1)
	#define BUILD_TACH_NODE_NAME(buffer,DEV_ID,TACH_NUM) snprintf(buffer, sizeof(buffer), "%s%d%s%d%s", HWMON_DIR "/hwmon",DEV_ID, "/fan", TACH_NUM+1,"_input")
	#define BUILD_FAN_REG_NAME(buffer,DEV_ID,FAN_NUM) snprintf(buffer, sizeof(buffer), "%s%d%s%d%s", HWMON_DIR "/hwmon",DEV_ID, "/of_node/fan@", FAN_NUM,"/reg")

	//predefine FAN RPM range, must defined at some where for configuration.
	#define RPM_MAX 38600
	#define RPM_MIN 7500
	#define COUNTERRES_DEF 100

	/* Check hwmon if exist or not */
	static int pwmtach_directory_check(void)
	{
	int retval = 0;
	struct stat sb;
	if (!(stat("/sys/class/hwmon", &sb) == 0 && S_ISDIR(sb.st_mode)))
	{
	printf("\"/sys/class/hwmon\" not exist!\n");
	retval = -1;
	}
	return retval;
	}
	//Notice: dutycycle_value is one byte (0-255)
	static int SET_PWM_DUTYCYCLE_VALUE ( pwmtach_ioctl_data *ppwmtach_arg )
	{
	int retval = 0;
	unsigned char dutycycle_value;
	int fd;
	char duty_num[5];

	retval = pwmtach_directory_check();
	if(retval != 0)
	{
	return retval;
	}

	dutycycle_value = ppwmtach_arg->dutycycle;
	BUILD_PWM_NODE_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->pwmnumber);
	retval = access(DevNodeFileName,F_OK);
	if(retval != 0)
	{
	return retval;
	}

	fd = sigwrap_open(DevNodeFileName, O_WRONLY);
	if (fd < 0) {
	return fd;
	}

	snprintf(duty_num,5, "%d", dutycycle_value);

	if ( write(fd, duty_num, strlen (duty_num)) != (ssize_t )strlen(duty_num)){
	printf("%s: Error write dutycycle value %d to pwm %d\n",__FUNCTION__,dutycycle_value,ppwmtach_arg->pwmnumber);
	retval = -1;
	}
	(void)sigwrap_close(fd);

	return retval;
	}

	//Notice: dutycycle_percentage value should be between 1 to 99.
	static int SET_PWM_DUTYCYCLE ( pwmtach_ioctl_data *ppwmtach_arg)
	{
	int retval = 0;
	unsigned char dutycycle_value;

	if(ppwmtach_arg->dutycycle > 100)
	{
	return -1;
	}

	dutycycle_value = (ppwmtach_arg->dutycycle*255)/100;
	ppwmtach_arg->dutycycle = dutycycle_value;
	retval = SET_PWM_DUTYCYCLE_VALUE(ppwmtach_arg);
	return retval;
	}

	static int GET_PWM_DUTYCYCLE ( pwmtach_ioctl_data *ppwmtach_arg )
	{
	int retval = 0;
	int fd;
	char duty_num[5];

	retval = pwmtach_directory_check();
	if(retval != 0)
	{//printf("%s,error 0\n",__FUNCTION__);
	return retval;
	}

	BUILD_PWM_NODE_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->pwmnumber);
	retval = access(DevNodeFileName,F_OK);
	if(retval != 0)
	{printf("%s,error 2,%s not exist\n",__FUNCTION__,DevNodeFileName);
	return retval;
	}
	fd = sigwrap_open(DevNodeFileName, O_RDONLY);
	if (fd < 0) {printf("%s,error 3\n",__FUNCTION__);
	return fd;
	}
	read(fd, duty_num, 5);
	ppwmtach_arg->dutycycle = atoi(duty_num);
	printf("%s:dutycycle value %d to pwm %d\n",__FUNCTION__,ppwmtach_arg->dutycycle,ppwmtach_arg->pwmnumber);
	(void)sigwrap_close(fd);

	return retval;
	}
	int GET_TACH_SPEED (pwmtach_ioctl_data *ppwmtach_arg )
	{
	int retval = 0;
	int fd;
	char data[6];

	retval = pwmtach_directory_check();
	if(retval != 0)
	{printf("%s,error 0\n",__FUNCTION__);
	return retval;
	}
	BUILD_TACH_NODE_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->tachnumber);
	retval = access(DevNodeFileName,F_OK);
	if(retval != 0)
	{printf("%s,error 2,%s not exist\n",__FUNCTION__,DevNodeFileName);
	return retval;
	}

	fd = sigwrap_open(DevNodeFileName, O_RDONLY);
	if (fd < 0) {printf("%s,error 3\n",__FUNCTION__);
	return fd;
	}
	memset(data, 0, 6);
	read(fd, data, 6);
	ppwmtach_arg->rpmvalue = atoi(data);
	(void)sigwrap_close(fd);
	printf("%s:rpm value %d\n",__FUNCTION__,ppwmtach_arg->rpmvalue);
	return retval;
	}
	//mapping function of fan to tach
	//using direct mapping as default
	#define GET_TACH_NUMBER(FAN_NUMBER) FAN_NUMBER
	//mapping fan number to pwm number
	//using information in fan@number reg item, to look up the pwm index
	static int GET_PWM_NUMBER(pwmtach_ioctl_data *ppwmtach_arg)
	{
	int retval = 0;
	int fd;
	int reg_val = 0;

	retval = pwmtach_directory_check();
	if(retval != 0)
	{printf("%s,error 0\n",__FUNCTION__);
	return retval;
	}
	BUILD_FAN_REG_NAME(DevNodeFileName,ppwmtach_arg->dev_id,ppwmtach_arg->fannumber);
	retval = access(DevNodeFileName,F_OK);
	if(retval != 0)
	{printf("%s,error 2,%s not exist\n",__FUNCTION__,DevNodeFileName);
	return retval;
	}

	fd = sigwrap_open(DevNodeFileName, O_RDONLY);
	if (fd < 0) {printf("%s,error 3\n",__FUNCTION__);
	return fd;
	}
	read(fd, &reg_val, sizeof(int));
	if(reg_val < 0)
	{
	retval = -1;
	}else
	{
	retval = reg_val >> 24; //get the highest byte
	printf("%s:fan %d, pwm %d, val 0x%X\n",__FUNCTION__,ppwmtach_arg->fannumber,retval,reg_val);
	printf("%s\n",DevNodeFileName);
	}
	(void)sigwrap_close(fd);
	// printf("%s:rpm value %d\n",__FUNCTION__,ppwmtach_arg->rpmvalue);
	return retval;
	}
	static int pwmtach_action( pwmtach_ioctl_data* argp, int command )
	{
	int retval = 0;
	// printf("%s, Command 0x%X:Dev:%d,Pwm:0x%X,Fan:0x%x,Tach:0x%X\n",__FUNCTION__,command,argp->dev_id,argp->pwmnumber,argp->fannumber,argp->tachnumber);
	switch(command)
	{
	case SET_DUTY_CYCLE_BY_PWM_CHANNEL:
	retval = SET_PWM_DUTYCYCLE(argp);
	break;
	case SET_DUTY_CYCLE_VALUE_BY_PWM_CHANNEL:
	case SET_DUTY_CYCLE:
	retval = SET_PWM_DUTYCYCLE_VALUE(argp);
	break;
	case GET_TACH_VALUE_BY_TACH_CHANNEL:
	retval = GET_TACH_SPEED(argp);
	break;
	case GET_TACH_VALUE: //used to get fan speed
	argp->tachnumber = GET_TACH_NUMBER(argp->fannumber);
	retval = GET_TACH_SPEED(argp);
	break;
	case GET_DUTY_CYCLE:
	retval = GET_PWM_DUTYCYCLE(argp);
	break;
	case GET_FAN_RPM_RANGE:
	argp->max_rpm = RPM_MAX;
	argp->min_rpm = RPM_MIN;
	break;
	case INIT_PWMTACH: //assume that init complete
	argp->pwmnumber = GET_PWM_NUMBER(argp);; //since we don't have the fan to pwm mapping, just using direct map for workarround.
	argp->counterresvalue = COUNTERRES_DEF; //since driver don't support COUNTERRES, just using default value for workarround.
	retval = GET_PWM_DUTYCYCLE(argp);
	break;
	case END_OF_FUNC_TABLE:
	default:
	printf("%s, Command 0x%X not support!\n",__FUNCTION__,command);
	retval = -1;
	}
	return( retval );
	}

	int get_tach_speed ( unsigned int dev_id, unsigned char tach_number, unsigned int *rpm_value )
	{
	pwmtach_ioctl_data pwmtach_arg;
	int retval = 0;

	pwmtach_arg.dev_id = dev_id;
	pwmtach_arg.tachnumber = tach_number;
	retval = pwmtach_action( &pwmtach_arg, GET_TACH_VALUE_BY_TACH_CHANNEL);
	if(retval != -1)
	*rpm_value = pwmtach_arg.rpmvalue;
	return retval;
	}

	//Notice: dutycycle_percentage value should be between 1 to 99.
	int set_pwm_dutycycle ( unsigned int dev_id, unsigned char pwm_number, unsigned char dutycycle_percentage )
	{
	pwmtach_ioctl_data pwmtach_arg;
	int retval = 0;

	pwmtach_arg.dev_id = dev_id;
	pwmtach_arg.pwmnumber = pwm_number;
	pwmtach_arg.dutycycle= dutycycle_percentage;
	retval = pwmtach_action( &pwmtach_arg, SET_DUTY_CYCLE_BY_PWM_CHANNEL);

	return retval;
	}

	//Notice: dutycycle_value is one byte (0-255)
	int set_pwm_dutycycle_value ( unsigned int dev_id, unsigned char pwm_number, unsigned char dutycycle_value )
	{
	pwmtach_ioctl_data pwmtach_arg;
	int retval = 0;

	pwmtach_arg.dev_id = dev_id;
	pwmtach_arg.pwmnumber = pwm_number;
	pwmtach_arg.dutycycle= dutycycle_value;
	retval = pwmtach_action( &pwmtach_arg, SET_DUTY_CYCLE_VALUE_BY_PWM_CHANNEL);

	return retval;
	}

	int get_pwm_dutycycle ( unsigned int dev_id, unsigned char pwm_number, unsigned char *dutycycle_percentage )
	{
	pwmtach_ioctl_data pwmtach_arg;
	int retval = 0;

	pwmtach_arg.dev_id = dev_id;
	pwmtach_arg.pwmnumber = pwm_number;
	retval = pwmtach_action(&pwmtach_arg, GET_DUTY_CYCLE);
	if(retval != -1)
	*dutycycle_percentage = pwmtach_arg.dutycycle;
	return retval;

	}

	int set_fan_speed ( unsigned int dev_id, unsigned char fan_number, unsigned int rpm_value )
	{
	int retval = 0;
	unsigned int retries = 20;
	unsigned char firsttime = 1;
	unsigned char duty_cycle_increasing = 0;
	unsigned char reached90percent = 0;
	unsigned char reached5percent = 0;
	unsigned long desiredrpm = rpm_value;
	pwmtach_ioctl_data pwmtach_arg;
	pwmtach_data_t* indata = (pwmtach_data_t*) &pwmtach_arg;

	indata->dev_id = dev_id;
	indata->fannumber = fan_number;
	indata->rpmvalue = rpm_value;
	indata->counterresvalue = 0;
	indata->dutycycle = 0;
	indata->prevdutycycle = 0;

	retval = pwmtach_action( indata, GET_FAN_RPM_RANGE);
	if ((rpm_value < indata->min_rpm) \|\| (rpm_value > indata->max_rpm))
	{
	printf("Out of range Fan Speed value for fan.\n");
	return -1;
	}
	retval = pwmtach_action ( indata, INIT_PWMTACH );

	while (retries--)
	{
	/* Wait for 1 seconds */
	select_sleep(0,110001000);
	if ((retval = pwmtach_action( indata, GET_TACH_VALUE )) != 0)
	{
	indata->dutycycle = indata->prevdutycycle;
	retval = pwmtach_action( indata, SET_DUTY_CYCLE);
	return -1;
	}
	else
	{
	indata->prevdutycycle = indata->dutycycle;
	if (indata->rpmvalue > (desiredrpm + 50))
	{
	if (indata->dutycycle <= ((indata->counterresvalue*10)/100))
	{
	if (reached5percent == 1)
	{
	printf("\nSpeed is set to minimum possible speed of %d RPM.\n",indata->rpmvalue);
	break;
	}
	reached5percent = 1;
	}
	else
	{
	indata->dutycycle -= ((5 * indata->counterresvalue)/100);
	}
	}
	else if (indata->rpmvalue < (desiredrpm - 50))
	{
	if (indata->dutycycle >= indata->counterresvalue)
	{
	if (reached90percent == 1)
	{
	printf("\nSpeed is set to maximum possible speed of %d RPM.\n",indata->rpmvalue);
	break;
	}
	reached90percent = 1;
	}
	else
	{
	indata->dutycycle += ((5 * indata->counterresvalue)/100);
	}
	}
	else
	{
	break;
	}

	retval = pwmtach_action (indata, SET_DUTY_CYCLE);
	printf("After update: dutycycle=%d, rpmvalue=%d\n", indata->dutycycle, indata->rpmvalue);

	if(indata->prevdutycycle < indata->dutycycle)
	{ /* Duty Cycle increasing */
	if ((firsttime == 0) && (duty_cycle_increasing == 0))
	{
	indata->dutycycle = indata->prevdutycycle;
	retval = pwmtach_action( indata, SET_DUTY_CYCLE);
	printf("\n");
	return 0;
	}
	duty_cycle_increasing = 1;
	}
	else
	{ /* Duty Cycle decreasing */
	if ((firsttime == 0) && (duty_cycle_increasing == 1))
	{
	indata->dutycycle = indata->prevdutycycle;
	retval = pwmtach_action( indata, SET_DUTY_CYCLE);
	printf("\n");
	return 0;
	}
	duty_cycle_increasing = 0;
	}
	if (firsttime == 1)
	firsttime = 0;
	}
	printf("retry %d : dt=%d, ps=%d, cr=%d\n", retries, indata->dutycycle, indata->prescalervalue, indata->counterresvalue);
	}
	return 0;

	}

	int get_fan_speed ( unsigned int dev_id, unsigned char fan_number, unsigned int *rpm_value )
	{
	pwmtach_ioctl_data pwmtach_arg;
	int retval = 0;

	pwmtach_arg.dev_id = dev_id;
	pwmtach_arg.fannumber = fan_number;
	retval = pwmtach_action( &pwmtach_arg, GET_TACH_VALUE );
	if(retval != -1)
	*rpm_value = pwmtach_arg.rpmvalue;
	return retval;
	}