gpio.c

linux内核源码

	filp->private_data = (void *)priv;

	return 0;
}

static int
gpio_release(struct inode *inode, struct file *filp)
{
	struct gpio_private *p;
	struct gpio_private *todel;

	spin_lock(&gpio_lock);

        p = alarmlist;
        todel = (struct gpio_private *)filp->private_data;

	/* unlink from alarmlist and free the private structure */

	if (p == todel) {
		alarmlist = todel->next;
	} else {
		while (p->next != todel)
			p = p->next;
		p->next = todel->next;
	}

	kfree(todel);
	/* Check if there are still any alarms set */
	p = alarmlist;
	while (p) {
		if (p->highalarm | p->lowalarm) {
			gpio_some_alarms = 1;
			spin_unlock(&gpio_lock);
			return 0;
		}
		p = p->next;
	}
	gpio_some_alarms = 0;
	spin_unlock(&gpio_lock);
	return 0;
}

/* Main device API. ioctl's to read/set/clear bits, as well as to 
 * set alarms to wait for using a subsequent select().
 */

unsigned long inline setget_input(struct gpio_private *priv, unsigned long arg)
{
	/* Set direction 0=unchanged 1=input, 
	 * return mask with 1=input 
	 */
	unsigned long flags;
	if (USE_PORTS(priv)) {
		local_irq_save(flags);
		*priv->dir = *priv->dir_shadow &= 
		~((unsigned char)arg & priv->changeable_dir);
		local_irq_restore(flags);
		return ~(*priv->dir_shadow) & 0xFF; /* Only 8 bits */
	} else if (priv->minor == GPIO_MINOR_G) {
		/* We must fiddle with R_GEN_CONFIG to change dir */
		local_irq_save(flags);
		if (((arg & dir_g_in_bits) != arg) && 
		    (arg & changeable_dir_g)) {
			arg &= changeable_dir_g;
			/* Clear bits in genconfig to set to input */
			if (arg & (1<<0)) {
				genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g0dir);
				dir_g_in_bits |= (1<<0);
				dir_g_out_bits &= ~(1<<0);
			}
			if ((arg & 0x0000FF00) == 0x0000FF00) {
				genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g8_15dir);
				dir_g_in_bits |= 0x0000FF00;
				dir_g_out_bits &= ~0x0000FF00;
			}
			if ((arg & 0x00FF0000) == 0x00FF0000) {
				genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g16_23dir);
				dir_g_in_bits |= 0x00FF0000;
				dir_g_out_bits &= ~0x00FF0000;
			}
			if (arg & (1<<24)) {
				genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g24dir);
				dir_g_in_bits |= (1<<24);
				dir_g_out_bits &= ~(1<<24);
			}
			D(printk(KERN_INFO "gpio: SETINPUT on port G set "
				 "genconfig to 0x%08lX "
				 "in_bits: 0x%08lX "
				 "out_bits: 0x%08lX\n",
			         (unsigned long)genconfig_shadow,
			         dir_g_in_bits, dir_g_out_bits));
			*R_GEN_CONFIG = genconfig_shadow;
			/* Must be a >120 ns delay before writing this again */
				
		}
		local_irq_restore(flags);
		return dir_g_in_bits;
	}
	return 0;
} /* setget_input */

unsigned long inline setget_output(struct gpio_private *priv, unsigned long arg)
{
	unsigned long flags;
	if (USE_PORTS(priv)) {
		local_irq_save(flags);
		*priv->dir = *priv->dir_shadow |= 
		  ((unsigned char)arg & priv->changeable_dir);
		local_irq_restore(flags);
		return *priv->dir_shadow;
	} else if (priv->minor == GPIO_MINOR_G) {
		/* We must fiddle with R_GEN_CONFIG to change dir */			
		local_irq_save(flags);
		if (((arg & dir_g_out_bits) != arg) &&
		    (arg & changeable_dir_g)) {
			/* Set bits in genconfig to set to output */
			if (arg & (1<<0)) {
				genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g0dir);
				dir_g_out_bits |= (1<<0);
				dir_g_in_bits &= ~(1<<0);
			}
			if ((arg & 0x0000FF00) == 0x0000FF00) {
				genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g8_15dir);
				dir_g_out_bits |= 0x0000FF00;
				dir_g_in_bits &= ~0x0000FF00;
			}
			if ((arg & 0x00FF0000) == 0x00FF0000) {
				genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g16_23dir);
				dir_g_out_bits |= 0x00FF0000;
				dir_g_in_bits &= ~0x00FF0000;
			}
			if (arg & (1<<24)) {
				genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g24dir);
				dir_g_out_bits |= (1<<24);
				dir_g_in_bits &= ~(1<<24);
			}
			D(printk(KERN_INFO "gpio: SETOUTPUT on port G set "
				 "genconfig to 0x%08lX "
				 "in_bits: 0x%08lX "
				 "out_bits: 0x%08lX\n",
			         (unsigned long)genconfig_shadow,
			         dir_g_in_bits, dir_g_out_bits));
			*R_GEN_CONFIG = genconfig_shadow;
			/* Must be a >120 ns delay before writing this again */
		}
		local_irq_restore(flags);
		return dir_g_out_bits & 0x7FFFFFFF;
	}
	return 0;
} /* setget_output */

static int
gpio_leds_ioctl(unsigned int cmd, unsigned long arg);

static int
gpio_ioctl(struct inode *inode, struct file *file,
	   unsigned int cmd, unsigned long arg)
{
	unsigned long flags;
	unsigned long val;
        int ret = 0;

	struct gpio_private *priv = (struct gpio_private *)file->private_data;
	if (_IOC_TYPE(cmd) != ETRAXGPIO_IOCTYPE) {
		return -EINVAL;
	}

	spin_lock(&gpio_lock);

	switch (_IOC_NR(cmd)) {
	case IO_READBITS: /* Use IO_READ_INBITS and IO_READ_OUTBITS instead */
		// read the port
		if (USE_PORTS(priv)) {
			ret =  *priv->port;
		} else if (priv->minor == GPIO_MINOR_G) {
			ret =  (*R_PORT_G_DATA) & 0x7FFFFFFF;
		}
		break;
	case IO_SETBITS:
		local_irq_save(flags);
		// set changeable bits with a 1 in arg
		if (USE_PORTS(priv)) {
			*priv->port = *priv->shadow |= 
			  ((unsigned char)arg & priv->changeable_bits);
		} else if (priv->minor == GPIO_MINOR_G) {
			*R_PORT_G_DATA = port_g_data_shadow |= (arg & dir_g_out_bits);
		}
		local_irq_restore(flags);
		break;
	case IO_CLRBITS:
		local_irq_save(flags);
		// clear changeable bits with a 1 in arg
		if (USE_PORTS(priv)) {
			*priv->port = *priv->shadow &= 
			 ~((unsigned char)arg & priv->changeable_bits);
		} else if (priv->minor == GPIO_MINOR_G) {
			*R_PORT_G_DATA = port_g_data_shadow &= ~((unsigned long)arg & dir_g_out_bits);
		}
		local_irq_restore(flags);
		break;
	case IO_HIGHALARM:
		// set alarm when bits with 1 in arg go high
		priv->highalarm |= arg;
		gpio_some_alarms = 1;
		break;
	case IO_LOWALARM:
		// set alarm when bits with 1 in arg go low
		priv->lowalarm |= arg;
		gpio_some_alarms = 1;
		break;
	case IO_CLRALARM:
		// clear alarm for bits with 1 in arg
		priv->highalarm &= ~arg;
		priv->lowalarm  &= ~arg;
		{
			/* Must update gpio_some_alarms */
			struct gpio_private *p = alarmlist;
			int some_alarms;
			some_alarms = 0;
			while (p) {
				if (p->highalarm | p->lowalarm) {
					some_alarms = 1;
					break;
				}
				p = p->next;
			}
			gpio_some_alarms = some_alarms;
		}
		break;
	case IO_READDIR: /* Use IO_SETGET_INPUT/OUTPUT instead! */
		/* Read direction 0=input 1=output */
		if (USE_PORTS(priv)) {
			ret = *priv->dir_shadow;
		} else if (priv->minor == GPIO_MINOR_G) {
			/* Note: Some bits are both in and out,
			 * Those that are dual is set here as well.
			 */
			ret = (dir_g_shadow | dir_g_out_bits) & 0x7FFFFFFF;
		}
		break;
	case IO_SETINPUT: /* Use IO_SETGET_INPUT instead! */
		/* Set direction 0=unchanged 1=input, 
		 * return mask with 1=input 
		 */
		ret = setget_input(priv, arg) & 0x7FFFFFFF;
		break;
	case IO_SETOUTPUT: /* Use IO_SETGET_OUTPUT instead! */
		/* Set direction 0=unchanged 1=output, 
		 * return mask with 1=output 
		 */
		ret =  setget_output(priv, arg) & 0x7FFFFFFF;
		break;
	case IO_SHUTDOWN:
		SOFT_SHUTDOWN();
		break;
	case IO_GET_PWR_BT:
#if defined (CONFIG_ETRAX_SOFT_SHUTDOWN)
		ret = (*R_PORT_G_DATA & ( 1 << CONFIG_ETRAX_POWERBUTTON_BIT));
#else
		ret = 0;
#endif
		break;
	case IO_CFG_WRITE_MODE:
		priv->clk_mask = arg & 0xFF;
		priv->data_mask = (arg >> 8) & 0xFF;
		priv->write_msb = (arg >> 16) & 0x01;
		/* Check if we're allowed to change the bits and
		 * the direction is correct
		 */
		if (!((priv->clk_mask & priv->changeable_bits) &&
		      (priv->data_mask & priv->changeable_bits) &&
		      (priv->clk_mask & *priv->dir_shadow) &&
		      (priv->data_mask & *priv->dir_shadow)))
		{
			priv->clk_mask = 0;
			priv->data_mask = 0;
			ret = -EPERM;
		}
		break;
	case IO_READ_INBITS: 
		/* *arg is result of reading the input pins */
		if (USE_PORTS(priv)) {
			val = *priv->port;
		} else if (priv->minor == GPIO_MINOR_G) {
			val = *R_PORT_G_DATA;
		}
		if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
			ret = -EFAULT;
		break;
	case IO_READ_OUTBITS:
		 /* *arg is result of reading the output shadow */
		if (USE_PORTS(priv)) {
			val = *priv->shadow;
		} else if (priv->minor == GPIO_MINOR_G) {
			val = port_g_data_shadow;
		}
		if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
			ret = -EFAULT;
		break;
	case IO_SETGET_INPUT: 
		/* bits set in *arg is set to input,
		 * *arg updated with current input pins.
		 */
		if (copy_from_user(&val, (unsigned long*)arg, sizeof(val)))
		{
			ret = -EFAULT;
			break;
		}
		val = setget_input(priv, val);
		if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
			ret = -EFAULT;
		break;
	case IO_SETGET_OUTPUT:
		/* bits set in *arg is set to output,
		 * *arg updated with current output pins.
		 */
		if (copy_from_user(&val, (unsigned long*)arg, sizeof(val)))
		{
			ret = -EFAULT;
			break;
		}
		val = setget_output(priv, val);
		if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
			ret = -EFAULT;
		break;
	default:
		if (priv->minor == GPIO_MINOR_LEDS)
			ret = gpio_leds_ioctl(cmd, arg);
		else
			ret = -EINVAL;
	} /* switch */

	spin_unlock(&gpio_lock);
	return ret;
}

static int
gpio_leds_ioctl(unsigned int cmd, unsigned long arg)
{
	unsigned char green;
	unsigned char red;

	switch (_IOC_NR(cmd)) {
	case IO_LEDACTIVE_SET:
		green = ((unsigned char) arg) & 1;
		red   = (((unsigned char) arg) >> 1) & 1;
		LED_ACTIVE_SET_G(green);
		LED_ACTIVE_SET_R(red);
		break;

	case IO_LED_SETBIT:
		LED_BIT_SET(arg);
		break;

	case IO_LED_CLRBIT:
		LED_BIT_CLR(arg);
		break;

	default:
		return -EINVAL;
	} /* switch */

	return 0;
}

const struct file_operations gpio_fops = {
	.owner       = THIS_MODULE,
	.poll        = gpio_poll,
	.ioctl       = gpio_ioctl,
	.write       = gpio_write,
	.open        = gpio_open,
	.release     = gpio_release,
};


void ioif_watcher(const unsigned int gpio_in_available,
		  const unsigned int gpio_out_available,
		  const unsigned char pa_available,
		  const unsigned char pb_available)
{
	unsigned long int flags;
	D(printk("gpio.c: ioif_watcher called\n"));
	D(printk("gpio.c: G in: 0x%08x G out: 0x%08x PA: 0x%02x PB: 0x%02x\n",
		 gpio_in_available, gpio_out_available, pa_available, pb_available));

	spin_lock_irqsave(&gpio_lock, flags);

	dir_g_in_bits = gpio_in_available;
	dir_g_out_bits = gpio_out_available;

	/* Initialise the dir_g_shadow etc. depending on genconfig */
	/* 0=input 1=output */
	if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g0dir, out)) 
		dir_g_shadow |= (1 << 0);
	if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g8_15dir, out))
		dir_g_shadow |= 0x0000FF00;
	if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g16_23dir, out))
		dir_g_shadow |= 0x00FF0000;
	if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g24dir, out))
		dir_g_shadow |= (1 << 24);

	changeable_dir_g = changeable_dir_g_mask;
	changeable_dir_g &= dir_g_out_bits;
	changeable_dir_g &= dir_g_in_bits;
	/* Correct the bits that can change direction */ 
	dir_g_out_bits &= ~changeable_dir_g;
	dir_g_out_bits |= dir_g_shadow;
	dir_g_in_bits &= ~changeable_dir_g;
	dir_g_in_bits |= (~dir_g_shadow & changeable_dir_g);

	spin_unlock_irqrestore(&gpio_lock, flags);

	printk(KERN_INFO "GPIO port G: in_bits: 0x%08lX out_bits: 0x%08lX val: %08lX\n",
	       dir_g_in_bits, dir_g_out_bits, (unsigned long)*R_PORT_G_DATA);
	printk(KERN_INFO "GPIO port G: dir: %08lX changeable: %08lX\n",
	       dir_g_shadow, changeable_dir_g);
}

/* main driver initialization routine, called from mem.c */

static __init int
gpio_init(void)
{
	int res;
#if defined (CONFIG_ETRAX_CSP0_LEDS)
	int i;
#endif
        printk("gpio init\n");

	/* do the formalities */

	res = register_chrdev(GPIO_MAJOR, gpio_name, &gpio_fops);
	if (res < 0) {
		printk(KERN_ERR "gpio: couldn't get a major number.\n");
		return res;
	}

	/* Clear all leds */
#if defined (CONFIG_ETRAX_CSP0_LEDS) ||  defined (CONFIG_ETRAX_PA_LEDS) || defined (CONFIG_ETRAX_PB_LEDS)
	LED_NETWORK_SET(0);
	LED_ACTIVE_SET(0);
	LED_DISK_READ(0);
	LED_DISK_WRITE(0);

#if defined (CONFIG_ETRAX_CSP0_LEDS)
	for (i = 0; i < 32; i++) {
		LED_BIT_SET(i);
	}
#endif

#endif
	/* The I/O interface allocation watcher will be called when
	 * registering it. */
	if (cris_io_interface_register_watcher(ioif_watcher)){
		printk(KERN_WARNING "gpio_init: Failed to install IO if allocator watcher\n");
	}

	printk(KERN_INFO "ETRAX 100LX GPIO driver v2.5, (c) 2001, 2002, 2003, 2004 Axis Communications AB\n");
	/* We call etrax_gpio_wake_up_check() from timer interrupt and
	 * from cpu_idle() in kernel/process.c
	 * The check in cpu_idle() reduces latency from ~15 ms to ~6 ms
	 * in some tests.
	 */  
	if (request_irq(TIMER0_IRQ_NBR, gpio_poll_timer_interrupt,
			IRQF_SHARED | IRQF_DISABLED,"gpio poll", NULL)) {
		printk(KERN_CRIT "err: timer0 irq for gpio\n");
	}
	if (request_irq(PA_IRQ_NBR, gpio_pa_interrupt,
			IRQF_SHARED | IRQF_DISABLED,"gpio PA", NULL)) {
		printk(KERN_CRIT "err: PA irq for gpio\n");
	}
	

	return res;
}

/* this makes sure that gpio_init is called during kernel boot */

module_init(gpio_init);