Re: FW: LED driver

[Hans Schillstrom <hans.schillstrom@pwav.com>]

[-- Attachment #1: Type: text/plain, Size: 1864 bytes --]

Hi,
I have made a driver for our mpc8270 board 
It is based upon Denx led_driver and made for 2.6 kernel
(See atached file)

To control the leds you have to perfom some ioctl's
first create your devices 
mknod led0 c 151 0 ...

Example howto use it:

void led_off( int file )
{
  if (ioctl(file,STATUSLED_SET,0) < 0)
    perror("led off: ");
}
void led_blink( int file )
{
  if (ioctl(file,STATUSLED_SET,1) < 0)
    perror("led blink: ");
}
void led_on( int file )
{
  if (ioctl(file,STATUSLED_SET,2) < 0)
    perror("led on: ");
}
void led_per( int file, int period )
{
  if (ioctl(file,STATUSLED_PERIOD,period) < 0)
    perror("led on: ");
}

...

int led0 = open("/dev/led0",O_RDWR)
...
  led_blink(led0);	/* turn on green LED */
..
/Hans


On Thu, 2005-03-17 at 06:15, srinivas.surabhi@wipro.com wrote:
> 
> -----Original Message-----
> From: Srinivas Surabhi (WT01 - TELECOM SOLUTIONS)
> Sent: Thursday, March 17, 2005 7:53 AM
> To: linuxppc-embedded@ozlabs.org
> Subject: LED driver
> 
> Hi,
> 
> I am working on the MPC8270 board having connected GPIO 3 lines
> connected to 3 LEDs. So can any one help me in finding out the best
> solution of controlling the LEDs from MVlinux (kernel and user space) or
> any pointers who has done it before.
> 
> Thanks & Rgds
> SS
> 
> 
> 
> 
> Confidentiality Notice
> 
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> 

[-- Attachment #2: rcb8270_led.c --]
[-- Type: text/x-c, Size: 17175 bytes --]


/******************************************************************************
 *
 * (C) Copyright 2004
 * LGP Allgon AB
 * Hans Schillstrom, hans.schillstrom@lgpallgon.com
 *
 * Based upon DENX status_led.c
 *
 * This Device driver handles LED blinks etc., Relay outputs and Alarm inputs
 *
 ******************************************************************************/

/*
 * Standard in kernel modules
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/version.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <asm/types.h>
#include <asm/uaccess.h>

#include <linux/interrupt.h>
#include <asm/immap_cpm2.h>
#include <asm/cpm2.h>
#include <asm/mpc8260.h>

#undef	DEBUG

#ifdef	DEBUG
# define debugk(fmt,args...)	printk(fmt ,##args)
#else
# define debugk(fmt,args...)
#endif

/*
 * Deal with CONFIG_MODVERSIONS
 */
#if CONFIG_MODVERSIONS==1
/* # define MODVERSIONS */
# include <linux/modversions.h>
#endif

/*
 * For character devices
 */
#include <linux/fs.h>		/* character device definitions	*/

/* ioctl's */
#define STATUSLED_GET		_IOR('L', 1, unsigned long)
#define STATUSLED_SET		_IOW('L', 2, unsigned long)
#define STATUSLED_PERIOD	_IOW('L', 3, unsigned long)
#define	STATUS_SWITCH_GET	_IOR('L', 4, unsigned long)
#define STATUS_RESET_GET	_IOR('L', 5, unsigned long)
#define STATUS_RESET_SET	_IOW('L', 6, unsigned long)

#define STATUS_LED_PAR		im_ioport.iop_pparc
#define STATUS_LED_DIR		im_ioport.iop_pdirc
#define STATUS_LED_DAT		im_ioport.iop_pdatc

#define	STATUS_LED_OFF		0
#define STATUS_LED_BLINKING	1
#define STATUS_LED_ON		2

#define STATUS_RELAY_BIT0	0x00000008	/* RELAY 1 bit 28 */
#define STATUS_RELAY_PERIOD0	(HZ)
#define STATUS_RELAY_STATE0	STATUS_LED_OFF

#define STATUS_RELAY_BIT1	0x10000040	/* RELAY 2 bit 25 */
#define STATUS_RELAY_PERIOD1	(HZ)
#define STATUS_RELAY_STATE1	STATUS_LED_OFF

#define STATUS_LED_BIT		0x20000000	/* LED 0 is on PC.2	OPERATE_LED */
#define STATUS_LED_PERIOD	(HZ)
#define STATUS_LED_STATE	STATUS_LED_BLINKING

#define STATUS_LED_BIT1	0x10000000	        /* LED 1 is on PC.3	ALARM_LED   */
#define STATUS_LED_PERIOD1	(HZ)
#define STATUS_LED_STATE1	STATUS_LED_ON

#define STATUS_LED_BIT2	0x08000000	        /* LED 2 is on PC.4	BOOT_LED    */
#define STATUS_LED_PERIOD2	(HZ)
#define STATUS_LED_STATE2	STATUS_LED_OFF

#define STATUS_LED_ACTIVE	0		/* LED on for bit == 1	*/
#define STATUS_LED_BOOT	2		/* LED 0 used for boot status */

#define PCMCIA_LED		0
#define STATUS_LED		1
#define FRONT_LED		2


#define	LED_MAJOR	151	/* Reserverd for "Front panel LEDs" */

#define DRIVER_VERSION	"$Revision: 1.0 $"

static void statusled_blink (unsigned long minor);

/*
 * Device Declarations
 * PB25 & PB28
 */
typedef struct {
  uint	iop_pdirx;
  uint	iop_pparx;
  uint	iop_psorx;
  uint	iop_podrx;
  uint	iop_pdatx;
  char	res1[12];
} iop ;

typedef struct {
	unsigned long		mask;
	int			state;
	int			period;
	int			flags;
        int                     pol;      // Polarity
        iop                     *iptr;
	struct timer_list	timer;
} led_dev_t;

#define	SL_FLAG_OPEN	1

led_dev_t led_dev[] = {
    {	STATUS_LED_BIT,
	STATUS_LED_STATE,
	STATUS_LED_PERIOD,
	0,
        STATUS_LED_ACTIVE,
        (iop*)&((cpm2_map_t *)IMAP_ADDR)->STATUS_LED_DIR,
	{ function: statusled_blink, data: 0UL /* minor 0 */ },
    },
#if defined(STATUS_LED_BIT1)
    {	STATUS_LED_BIT1,
	STATUS_LED_STATE1,
	STATUS_LED_PERIOD1,
	0,
        STATUS_LED_ACTIVE,
        (iop*)&((cpm2_map_t *)IMAP_ADDR)->im_ioport.iop_pdirc,
	{ function: statusled_blink, data: 1UL /* minor 1 */ },
    },
#endif	/* STATUS_LED_BIT1 */
#if defined(STATUS_LED_BIT2)
    {	STATUS_LED_BIT2,
	STATUS_LED_STATE2,
	STATUS_LED_PERIOD2,
	0,
        STATUS_LED_ACTIVE,
        (iop*)&((cpm2_map_t *)IMAP_ADDR)->im_ioport.iop_pdirc,
	{ function: statusled_blink, data: 2UL /* minor 2 */ },
    },
#endif	/* STATUS_RELAY_0 */
    {	STATUS_RELAY_BIT0,
        STATUS_RELAY_STATE0,
        STATUS_RELAY_PERIOD0,
        0,
        1,
        (iop*)&((cpm2_map_t *)IMAP_ADDR)->im_ioport.iop_pdirb,
        { function: statusled_blink, data: 2UL /* minor 2 */ },
    },
    {	STATUS_RELAY_BIT1,
        STATUS_RELAY_STATE1,
        STATUS_RELAY_PERIOD1,
        0,
        1,
        (iop*)&((cpm2_map_t *)IMAP_ADDR)->im_ioport.iop_pdirb,
        { function: statusled_blink, data: 2UL /* minor 2 */ },
    },
};

#define	MAX_LED_DEV	(sizeof(led_dev)/sizeof(led_dev_t))

/*
 * On the IVM* we handle 2 additional devices with this driver:
 * MAX_LED_DEV+0 => "Interlock Switch" and "Device Reset Monitor":
 *			Both are input pins, which are polled periodically,
 *			and the user can wait with select() for a status change.
 * MAX_LED_DEV+1 => "Device Reset Enable", an output device we can set or reset.
 */
#if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
# define MAX_IO_DEV	2
static int io_dev_flags[MAX_IO_DEV] = { 0, };	/* additional I/O devices */
#else
# define MAX_IO_DEV	0
#endif	/* CONFIG_IVMS8, CONFIG_IVML24 */

static volatile cpm2_map_t *limmr = 0;
/*
 * The name for our device, as it will appear in /proc/devices
 */
#define DEVICE_NAME "status_led"

/*
 * Prototypes
 */
static int statusled_init (void) __init;
static int statusled_open(struct inode *, struct file *);
static int statusled_release(struct inode *, struct file *);
# if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
static ssize_t statusled_read(struct file *, char *, size_t, loff_t *);
static unsigned int statusled_poll (struct file *, poll_table *);
# endif	/* CONFIG_IVMS8, CONFIG_IVML24 */
int init_module(void);
void cleanup_module(void);

static ssize_t statusled_ioctl(struct inode *, struct file *,
			    unsigned int, unsigned long);

static struct file_operations statusled_fops = {
	owner:		THIS_MODULE,
	open:		statusled_open,
	release:	statusled_release,
	ioctl: 		statusled_ioctl,
# if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
	read:		statusled_read,
	poll:		statusled_poll,
# endif	/* CONFIG_IVMS8, CONFIG_IVML24 */
};

static int Major;

/*
 * Initialize the driver - Register the character device
 */
static int __init statusled_init (void)
{
	int i;

	if (!limmr) {		/* init CPM ptr */
        limmr = (volatile cpm2_map_t *)IMAP_ADDR;
	}

	/*
	 * Register the character device
	 */
	if ((i = register_chrdev(LED_MAJOR, DEVICE_NAME, &statusled_fops)) < 0) {
		limmr = NULL;
		printk("Unable to get major %d for status LED driver: rc=%d\n",
			LED_MAJOR, i);
		return (i);
	}

	Major = LED_MAJOR;

	printk (KERN_INFO
		"Status LED driver " DRIVER_VERSION " initialized\n");

	for (i=0; i<MAX_LED_DEV; ++i) {
		led_dev[i].iptr->iop_pparx &= ~(led_dev[i].mask);
#ifdef STATUS_LED_ODR
		led_dev[i].iptr->iop_podrx &= ~(led_dev[i].mask);
#endif
		if (led_dev[i].state == STATUS_LED_ON) {
                    if( led_dev[i].pol == 0 )	/* start with LED on */
			led_dev[i].iptr->iop_pdatx &= ~(led_dev[i].mask);
                    else
			led_dev[i].iptr->iop_pdatx |=   led_dev[i].mask ;
		} else {
                    if( led_dev[i].pol == 0 )	/* start with LED off */
			led_dev[i].iptr->iop_pdatx |=   led_dev[i].mask ;
		    else
			led_dev[i].iptr->iop_pdatx &= ~(led_dev[i].mask);
		}
		led_dev[i].iptr->iop_pdirx |= led_dev[i].mask;

		statusled_blink(i);
	}

#if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
	/*
	 * We use the same function (originally for the ILOCK device only)
	 * to poll both the ILOCK and RESET_MON ports
	 */
	io_timer.function = status_io_poll;
	io_timer.data     = STATUS_ILOCK_PERIOD;

	last_io_state = (char)status_io_test();
	changed_io_state = 0;

	init_timer(&io_timer);
	io_timer.expires = jiffies + io_timer.data;
	add_timer(&io_timer);
#endif	/* CONFIG_IVMS8, CONFIG_IVML24 */

	return (0);
}

/*
 * called whenever a process attempts to open the device
 */
static int statusled_open (struct inode *inode, struct file *file)
{
	int minor  = MINOR(inode->i_rdev);

	debugk ("statusled_open(%p,%p): minor %d\n", inode, file, minor);

	/*
	 * Allow for MAX_LED_DEV status LEDs
	 * On IVMS8 and IVML24: allow for additional I/O devices
	 */
	if (minor >= MAX_LED_DEV + MAX_IO_DEV)
		return (-ENXIO);

	if (!limmr)
		return (-ENODEV);

	/*
	 * exclusive open only
	 */
	if (minor < MAX_LED_DEV) {
		if (led_dev[minor].flags & SL_FLAG_OPEN)
			return -EBUSY;
		led_dev[minor].flags |= SL_FLAG_OPEN;
	}

	/*
	 * Make sure that the module isn't removed while
	 * the file is open by incrementing the usage count
	 */

	debugk ("LED_OPEN: minor %d  dir=0x%x  par=0x%x  dat=0x%x\n",
		minor,
		limmr->STATUS_LED_DIR, limmr->STATUS_LED_PAR, limmr->STATUS_LED_DAT);

	return 0;
}


/*
 * Called when a process closes the device.
 * Doesn't have a return value in version 2.0.x because it can't fail,
 * but in version 2.2.x it is allowed to fail
 */
static int statusled_release (struct inode *inode, struct file *file)
{
	int minor  = MINOR(inode->i_rdev);

	debugk ("statusled_release(%p,%p)\n", inode, file);

	if (!limmr)
		return (-ENODEV);

	/* We're now ready for our next caller */
	if (minor < MAX_LED_DEV) {
		led_dev[minor].flags &= ~SL_FLAG_OPEN;
	}

	debugk ("LED_CLOSE: dir=0x%x par=0x%x dat=0x%x\n",
		limmr->STATUS_LED_DIR, limmr->STATUS_LED_PAR, limmr->STATUS_LED_DAT);

	return 0;
}

#if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
/*
 * read entry point:
 * Only supported for interlock switch (return ENXIO for LED devices).
 * For the ilock switch, block until the next status change happens;
 * then return exactly one byte containing the current state
 * (0x00 switch open, 0x01 switch closed).
 */
static ssize_t statusled_read (struct file *file,
			       char *buf, size_t count, loff_t *ppos)
{
	DECLARE_WAITQUEUE(wait, current);
	int minor = MINOR(file->f_dentry->d_inode->i_rdev);
	int rc = 0;
	char c;

	if (minor != MAX_LED_DEV)
		return (-ENXIO);

	add_wait_queue(&statusled_wait, &wait);

	current->state = TASK_INTERRUPTIBLE;

	for (;;) {
		if (changed_io_state)
			break;

		if (file->f_flags & O_NONBLOCK) {
			rc = -EAGAIN;
			goto OUT;
		}

		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			goto OUT;
		}

		schedule ();
	}

	spin_lock (&statusled_lock);
	c = (char)status_io_test ();
	changed_io_state = 0;
	spin_unlock (&statusled_lock);

	/* Copy out */
	if ((rc = verify_area(VERIFY_WRITE, buf, 1)) != 0) {
		goto OUT;
	}

        rc = 1; copy_to_user((void *)buf, (void*)(&c), rc);

OUT:
        current->state = TASK_RUNNING;
        remove_wait_queue(&statusled_wait, &wait);

	return (rc);
}

static unsigned int statusled_poll (struct file *file, poll_table *wait)
{
	poll_wait(file, &statusled_wait, wait);

	if (changed_io_state)
		return POLLIN | POLLRDNORM;

	return 0;
}

#endif	/* CONFIG_IVMS8, CONFIG_IVML24 */

/*
 * ioctl entry point:
 */

static ssize_t statusled_ioctl (
	struct inode *inode,
	struct file *file,
	unsigned int cmd,
	unsigned long arg)
{
	int minor  = MINOR(inode->i_rdev);
	int n;

	if (!limmr)
		return (-ENODEV);

	debugk ("IOCTL: minor=%d, cmd=%s, arg=%ld\n",
		minor,
		(cmd == STATUSLED_GET   ) ? "STATUSLED_GET"    :
		(cmd == STATUSLED_SET   ) ? "STATUSLED_SET"    :
		(cmd == STATUSLED_PERIOD) ? "STATUSLED_PERIOD" :
		"<unknown>",
		arg);

	if (minor < MAX_LED_DEV) {
		switch (cmd) {
		case STATUSLED_GET:
			switch (led_dev[minor].state) {
			case STATUS_LED_OFF:	n =  0;
						break;
			case STATUS_LED_ON:	n = -1;
						break;
			default:		n = led_dev[minor].period;
						break;
			}
			return (copy_to_user((int *)arg, &n, sizeof (int)));
		case STATUSLED_SET:
			switch (arg) {
			case STATUS_LED_OFF:
				debugk ("IOCTL: was %d, set %ld=OFF\n",
					led_dev[minor].state, arg);
				if (led_dev[minor].state == STATUS_LED_BLINKING)
					del_timer(&led_dev[minor].timer);
				led_dev[minor].state = arg;
                                if( led_dev[minor].pol == 0 )
				  led_dev[minor].iptr->iop_pdatx |=   led_dev[minor].mask ;
                                else
				  led_dev[minor].iptr->iop_pdatx &= ~(led_dev[minor].mask);

				return (0);
			case STATUS_LED_ON:
				debugk ("IOCTL: was %d, set %ld=ON\n",
					led_dev[minor].state, arg);
				if (led_dev[minor].state == STATUS_LED_BLINKING)
					del_timer(&led_dev[minor].timer);
				led_dev[minor].state = arg;
                                if( led_dev[minor].pol == 0 )
				  led_dev[minor].iptr->iop_pdatx &= ~(led_dev[minor].mask);
                                else
				  led_dev[minor].iptr->iop_pdatx |=   led_dev[minor].mask ;

				return (0);
			case STATUS_LED_BLINKING:
				debugk ("IOCTL: was %d, set %ld=BLINKING\n",
					led_dev[minor].state, arg);
				if (led_dev[minor].state == STATUS_LED_BLINKING)
					return (0);
				led_dev[minor].state = arg; /* must come first! */
				/* start blinking */
				statusled_blink (minor);
				return (0);
			}
			return (-EINVAL);
		case STATUSLED_PERIOD:
			led_dev[minor].period = arg;
			debugk ("IOCTL: set PERIOD=%d\n", arg);
			return (0);
		}
	}
#if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
	else {
		int m = minor - MAX_LED_DEV;

		switch (m) {
		case 0:		/* Interlock switch and device reset monitor */
		    if (cmd == STATUS_SWITCH_GET) {
			n = status_io_test ();
			return (copy_to_user((int *)arg, &n, sizeof (int)));
		    }
		    break;
		case 1:		/* Device reset enable output */
		    if (cmd == STATUS_RESET_GET) {
			if (limmr->im_ioport.iop_pcdat & STATUS_RESET_ENA) {
				n = 1;
			} else {
				n = 0;
			}
			return (copy_to_user((int *)arg, &n, sizeof (int)));
		    }
		    if (cmd == STATUS_RESET_SET) {
			if (arg == 0) {
				limmr->im_ioport.iop_pcdat &= ~STATUS_RESET_ENA;
			} else {
				limmr->im_ioport.iop_pcdat |=  STATUS_RESET_ENA;
			}
			return (0);
		    }
		    break;
		default:
		    break;
		}
	}
#endif
	return (-EINVAL);
}

#if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
/*
 * Test status of interlock switch
 */
static int  status_io_test (void)
{
	int n = 0;

#if defined(CONFIG_IVMS8)
	spin_lock (&statusled_lock);
	if ((limmr->im_siu_conf.sc_sipend & STATUS_ILOCK_SWITCH) != 0)
		n |= STATUS_ILOCK_BIT;
	limmr->im_siu_conf.sc_sipend = STATUS_ILOCK_SWITCH;
	spin_unlock (&statusled_lock);
#elif defined(CONFIG_IVML24)
	if ((limmr->im_cpm.cp_pbdat & STATUS_ILOCK_SWITCH) != 0)
		n |= STATUS_ILOCK_BIT;
#endif
	if ((limmr->im_ioport.iop_pcdat & STATUS_RESET_MON) != 0)
		n |= STATUS_RESET_MON_BIT;
	return (n);
}

static void status_io_poll (unsigned long period)
{
	char c;

	spin_lock (&statusled_lock);
	c = (char)status_io_test ();
	if (c != last_io_state) {
		last_io_state = c;
		changed_io_state = 1;
	}
	spin_unlock (&statusled_lock);

	if (changed_io_state)
		wake_up_interruptible(&statusled_wait);

	init_timer(&io_timer);
	io_timer.expires = jiffies + io_timer.data;
	add_timer(&io_timer);
}
#endif	/* CONFIG_IVMS8, CONFIG_IVML24 */


/*
 * Timer controlled blink entry point.
 *
 * We delete the timer when the status is changed to non-blinking
 * or when the module is unloaded.
 */
static void statusled_blink (unsigned long minor)
{
	unsigned long flags;

	if (!limmr)
		return;

        if (led_dev[minor].state != STATUS_LED_BLINKING) {
		/* don't change any more */
		return;
	}

	limmr->STATUS_LED_DAT ^= led_dev[minor].mask;

	save_flags(flags);
	cli();

	init_timer(&led_dev[minor].timer);
	led_dev[minor].timer.expires = jiffies + led_dev[minor].period;
	add_timer(&led_dev[minor].timer);

	restore_flags(flags);
}


/******************************
 **** Module Declarations *****
 **************************** */

module_init (statusled_init);

#ifdef MODULE
/*
 * Cleanup - unregister the driver
 */
void statusled_cleanup (void)
{
	int minor, ret;

	/*
	 * Cleanup timer
	 */
	for (minor=0; minor<MAX_LED_DEV; ++minor) {
		if (led_dev[minor].state == STATUS_LED_BLINKING)
			del_timer(&led_dev[minor].timer);
                if( led_dev[minor].pol == 0 )
  		  led_dev[minor].iptr->iop_pdatx |=   led_dev[minor].mask ;
                else
		  led_dev[minor].iptr->iop_pdatx &= ~(led_dev[minor].mask);

		led_dev[minor].state = STATUS_LED_OFF;
	}
#if defined(CONFIG_IVMS8) || defined(CONFIG_IVML24)
	del_timer(&io_timer);
#endif	/* CONFIG_IVMS8, CONFIG_IVML24 */

	/*
	 * Unregister the device
	 */
	ret = unregister_chrdev (Major, DEVICE_NAME);

	/*
	 * If there's an error, report it
	 */
	if (ret < 0) {
		printk ("unregister_chrdev: error %d\n", ret);
	}
}

module_exit (statusled_cleanup);

MODULE_DESCRIPTION("RCB8270 led & relay driver");
MODULE_AUTHOR("Hans Schillstrom LPG Allgon AB <hans.schillstrom@pwav.com>");
MODULE_LICENSE("GPL");

#endif	/* MODULE */