irport.c

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/*********************************************************************
 * 
 * Filename:	  irport.c
 * Version:	  1.0
 * Description:   Half duplex serial port SIR driver for IrDA. 
 * Status:	  Experimental.
 * Author:	  Dag Brattli <[e-mail]>
 * Created at:	  Sun Aug  3 13:49:59 1997
 * Modified at:   Fri Jan 28 20:22:38 2000
 * Modified by:   Dag Brattli <[e-mail]>
 * Sources:	  serial.c by Linus Torvalds 
 * 
 *     Copyright (c) 1997, 1998, 1999-2000 Dag Brattli, All Rights Reserved.
 *     
 *     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., 59 Temple Place, Suite 330, Boston, 
 *     MA 02111-1307 USA
 *
 *     This driver is ment to be a small half duplex serial driver to be
 *     used for IR-chipsets that has a UART (16550) compatibility mode. 
 *     Eventually it will replace irtty, because of irtty has some 
 *     problems that is hard to get around when we don't have control
 *     over the serial driver. This driver may also be used by FIR 
 *     drivers to handle SIR mode for them.
 *
 ********************************************************************/

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/malloc.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/serial_reg.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/rtnetlink.h>

#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/io.h>

#include <net/irda/irda.h>
#include <net/irda/irmod.h>
#include <net/irda/wrapper.h>
#include <net/irda/irport.h>

#define IO_EXTENT 8

/* 
 * Currently you'll need to set these values using insmod like this:
 * insmod irport io=0x3e8 irq=11
 */
static unsigned int io[]  = { ~0, ~0, ~0, ~0 };
static unsigned int irq[] = { 0, 0, 0, 0 };

static unsigned int qos_mtt_bits = 0x03;

static struct irport_cb *dev_self[] = { NULL, NULL, NULL, NULL};
static char *driver_name = "irport";

static void irport_write_wakeup(struct irport_cb *self);
static int  irport_write(int iobase, int fifo_size, __u8 *buf, int len);
static void irport_receive(struct irport_cb *self);

static int  irport_net_init(struct net_device *dev);
static int  irport_net_ioctl(struct net_device *dev, struct ifreq *rq, 
			     int cmd);
static int  irport_is_receiving(struct irport_cb *self);
static int  irport_set_dtr_rts(struct net_device *dev, int dtr, int rts);
static int  irport_raw_write(struct net_device *dev, __u8 *buf, int len);
static struct net_device_stats *irport_net_get_stats(struct net_device *dev);
static int irport_change_speed_complete(struct irda_task *task);
static void irport_timeout(struct net_device *dev);

EXPORT_SYMBOL(irport_open);
EXPORT_SYMBOL(irport_close);
EXPORT_SYMBOL(irport_start);
EXPORT_SYMBOL(irport_stop);
EXPORT_SYMBOL(irport_interrupt);
EXPORT_SYMBOL(irport_hard_xmit);
EXPORT_SYMBOL(irport_timeout);
EXPORT_SYMBOL(irport_change_speed);
EXPORT_SYMBOL(irport_net_open);
EXPORT_SYMBOL(irport_net_close);

int __init irport_init(void)
{
 	int i;

 	for (i=0; (io[i] < 2000) && (i < 4); i++) {
 		int ioaddr = io[i];
 		if (check_region(ioaddr, IO_EXTENT))
 			continue;
 		if (irport_open(i, io[i], irq[i]) != NULL)
 			return 0;
 	}
	/* 
	 * Maybe something failed, but we can still be usable for FIR drivers 
	 */
 	return 0;
}

/*
 * Function irport_cleanup ()
 *
 *    Close all configured ports
 *
 */
#ifdef MODULE
static void irport_cleanup(void)
{
 	int i;

        IRDA_DEBUG( 4, __FUNCTION__ "()\n");

	for (i=0; i < 4; i++) {
 		if (dev_self[i])
 			irport_close(dev_self[i]);
 	}
}
#endif /* MODULE */

struct irport_cb *
irport_open(int i, unsigned int iobase, unsigned int irq)
{
	struct net_device *dev;
	struct irport_cb *self;
	int ret;
	int err;

	IRDA_DEBUG(0, __FUNCTION__ "()\n");

	/*
	 *  Allocate new instance of the driver
	 */
	self = kmalloc(sizeof(struct irport_cb), GFP_KERNEL);
	if (!self) {
		ERROR(__FUNCTION__ "(), can't allocate memory for "
		      "control block!\n");
		return NULL;
	}
	memset(self, 0, sizeof(struct irport_cb));
	spin_lock_init(&self->lock);

	/* Need to store self somewhere */
	dev_self[i] = self;
	self->priv = self;
	self->index = i;

	/* Initialize IO */
	self->io.sir_base  = iobase;
        self->io.sir_ext   = IO_EXTENT;
        self->io.irq       = irq;
        self->io.fifo_size = 16;

	/* Lock the port that we need */
	ret = check_region(self->io.sir_base, self->io.sir_ext);
	if (ret < 0) { 
		IRDA_DEBUG(0, __FUNCTION__ "(), can't get iobase of 0x%03x\n",
			   self->io.sir_base);
		return NULL;
	}
	request_region(self->io.sir_base, self->io.sir_ext, driver_name);

	/* Initialize QoS for this device */
	irda_init_max_qos_capabilies(&self->qos);
	
	self->qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|
		IR_115200;

	self->qos.min_turn_time.bits = qos_mtt_bits;
	irda_qos_bits_to_value(&self->qos);
	
	self->flags = IFF_SIR|IFF_PIO;

	/* Specify how much memory we want */
	self->rx_buff.truesize = 4000; 
	self->tx_buff.truesize = 4000;
	
	/* Allocate memory if needed */
	if (self->rx_buff.truesize > 0) {
		self->rx_buff.head = (__u8 *) kmalloc(self->rx_buff.truesize,
						      GFP_KERNEL);
		if (self->rx_buff.head == NULL)
			return NULL;
		memset(self->rx_buff.head, 0, self->rx_buff.truesize);
	}
	if (self->tx_buff.truesize > 0) {
		self->tx_buff.head = (__u8 *) kmalloc(self->tx_buff.truesize, 
						      GFP_KERNEL);
		if (self->tx_buff.head == NULL) {
			kfree(self->rx_buff.head);
			return NULL;
		}
		memset(self->tx_buff.head, 0, self->tx_buff.truesize);
	}	
	self->rx_buff.in_frame = FALSE;
	self->rx_buff.state = OUTSIDE_FRAME;
	self->tx_buff.data = self->tx_buff.head;
	self->rx_buff.data = self->rx_buff.head;
	self->mode = IRDA_IRLAP;

	if (!(dev = dev_alloc("irda%d", &err))) {
		ERROR(__FUNCTION__ "(), dev_alloc() failed!\n");
		return NULL;
	}
	self->netdev = dev;

	/* May be overridden by piggyback drivers */
 	dev->priv = (void *) self;
	self->interrupt    = irport_interrupt;
	self->change_speed = irport_change_speed;

	/* Override the network functions we need to use */
	dev->init            = irport_net_init;
	dev->hard_start_xmit = irport_hard_xmit;
	dev->tx_timeout	     = irport_timeout;
	dev->watchdog_timeo  = HZ;  /* Allow time enough for speed change */
	dev->open            = irport_net_open;
	dev->stop            = irport_net_close;
	dev->get_stats	     = irport_net_get_stats;
	dev->do_ioctl        = irport_net_ioctl;

	/* Make ifconfig display some details */
	dev->base_addr = iobase;
	dev->irq = irq;

	rtnl_lock();
	err = register_netdevice(dev);
	rtnl_unlock();
	if (err) {
		ERROR(__FUNCTION__ "(), register_netdev() failed!\n");
		return NULL;
	}
	MESSAGE("IrDA: Registered device %s\n", dev->name);

	return self;
}

int irport_close(struct irport_cb *self)
{
	ASSERT(self != NULL, return -1;);

	/* We are not using any dongle anymore! */
	if (self->dongle)
		irda_device_dongle_cleanup(self->dongle);
	self->dongle = NULL;
	
	/* Remove netdevice */
	if (self->netdev) {
		rtnl_lock();
		unregister_netdevice(self->netdev);
		rtnl_unlock();
	}

	/* Release the IO-port that this driver is using */
	IRDA_DEBUG(0 , __FUNCTION__ "(), Releasing Region %03x\n", 
		   self->io.sir_base);
	release_region(self->io.sir_base, self->io.sir_ext);

	if (self->tx_buff.head)
		kfree(self->tx_buff.head);
	
	if (self->rx_buff.head)
		kfree(self->rx_buff.head);
	
	/* Remove ourselves */
	dev_self[self->index] = NULL;
	kfree(self);
	
	return 0;
}

void irport_start(struct irport_cb *self)
{
	unsigned long flags;
	int iobase;

	iobase = self->io.sir_base;

	spin_lock_irqsave(&self->lock, flags);

	irport_stop(self);

	/* Initialize UART */
	outb(UART_LCR_WLEN8, iobase+UART_LCR);  /* Reset DLAB */
	outb((UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2), iobase+UART_MCR);
	
	/* Turn on interrups */
	outb(UART_IER_RLSI | UART_IER_RDI |UART_IER_THRI, iobase+UART_IER);

	spin_unlock_irqrestore(&self->lock, flags);
}

void irport_stop(struct irport_cb *self)
{
	unsigned long flags;
	int iobase;

	iobase = self->io.sir_base;

	spin_lock_irqsave(&self->lock, flags);

	/* Reset UART */
	outb(0, iobase+UART_MCR);
	
	/* Turn off interrupts */
	outb(0, iobase+UART_IER);

	spin_unlock_irqrestore(&self->lock, flags);
}

/*
 * Function irport_probe (void)
 *
 *    Start IO port 
 *
 */
int irport_probe(int iobase)
{
	IRDA_DEBUG(4, __FUNCTION__ "(), iobase=%#x\n", iobase);

	return 0;
}

/*
 * Function irport_change_speed (self, speed)
 *
 *    Set speed of IrDA port to specified baudrate
 *
 */
void irport_change_speed(void *priv, __u32 speed)
{
	struct irport_cb *self = (struct irport_cb *) priv;
	unsigned long flags;
	int iobase; 
	int fcr;    /* FIFO control reg */
	int lcr;    /* Line control reg */
	int divisor;

	IRDA_DEBUG(2, __FUNCTION__ "(), Setting speed to: %d\n", speed);

	ASSERT(self != NULL, return;);

	iobase = self->io.sir_base;
	
	/* Update accounting for new speed */
	self->io.speed = speed;

	spin_lock_irqsave(&self->lock, flags);

	/* Turn off interrupts */
	outb(0, iobase+UART_IER); 

	divisor = SPEED_MAX/speed;
	
	fcr = UART_FCR_ENABLE_FIFO;

	/* 
	 * Use trigger level 1 to avoid 3 ms. timeout delay at 9600 bps, and
	 * almost 1,7 ms at 19200 bps. At speeds above that we can just forget
	 * about this timeout since it will always be fast enough. 
	 */
	if (self->io.speed < 38400)
		fcr |= UART_FCR_TRIGGER_1;
	else 
		fcr |= UART_FCR_TRIGGER_14;
        
	/* IrDA ports use 8N1 */
	lcr = UART_LCR_WLEN8;
	
	outb(UART_LCR_DLAB | lcr, iobase+UART_LCR); /* Set DLAB */
	outb(divisor & 0xff,      iobase+UART_DLL); /* Set speed */
	outb(divisor >> 8,	  iobase+UART_DLM);
	outb(lcr,		  iobase+UART_LCR); /* Set 8N1	*/
	outb(fcr,		  iobase+UART_FCR); /* Enable FIFO's */

	/* Turn on interrups */
	outb(/*UART_IER_RLSI|*/UART_IER_RDI/*|UART_IER_THRI*/, iobase+UART_IER);

	spin_unlock_irqrestore(&self->lock, flags);
}

/*
 * Function __irport_change_speed (instance, state, param)
 *
 *    State machine for changing speed of the device. We do it this way since
 *    we cannot use schedule_timeout() when we are in interrupt context
 */
int __irport_change_speed(struct irda_task *task)
{
	struct irport_cb *self;
	__u32 speed = (__u32) task->param;
	int ret = 0;

	IRDA_DEBUG(2, __FUNCTION__ "(), <%ld>\n", jiffies); 

	self = (struct irport_cb *) task->instance;

	ASSERT(self != NULL, return -1;);

	switch (task->state) {
	case IRDA_TASK_INIT:
	case IRDA_TASK_WAIT:
		/* Are we ready to change speed yet? */
		if (self->tx_buff.len > 0) {
			task->state = IRDA_TASK_WAIT;

			/* Try again later */
			ret = MSECS_TO_JIFFIES(20);
			break;
		}

		if (self->dongle)
			irda_task_next_state(task, IRDA_TASK_CHILD_INIT);
		else
			irda_task_next_state(task, IRDA_TASK_CHILD_DONE);
		break;
	case IRDA_TASK_CHILD_INIT:
		/* Go to default speed */
		self->change_speed(self->priv, 9600);

		/* Change speed of dongle */
		if (irda_task_execute(self->dongle,
				      self->dongle->issue->change_speed, 
				      NULL, task, (void *) speed))
		{
			/* Dongle need more time to change its speed */
			irda_task_next_state(task, IRDA_TASK_CHILD_WAIT);

			/* Give dongle 1 sec to finish */
			ret = MSECS_TO_JIFFIES(1000);
		} else
			/* Child finished immediately */
			irda_task_next_state(task, IRDA_TASK_CHILD_DONE);
		break;
	case IRDA_TASK_CHILD_WAIT:
		WARNING(__FUNCTION__ 
			"(), changing speed of dongle timed out!\n");
		ret = -1;		
		break;
	case IRDA_TASK_CHILD_DONE:
		/* Finally we are ready to change the speed */
		self->change_speed(self->priv, speed);
		
		irda_task_next_state(task, IRDA_TASK_DONE);
		break;
	default:
		ERROR(__FUNCTION__ "(), unknown state %d\n", task->state);
		irda_task_next_state(task, IRDA_TASK_DONE);
		ret = -1;
		break;
	}	
	return ret;
}

/*
 * Function irport_write_wakeup (tty)
 *
 *    Called by the driver when there's room for more data.  If we have
 *    more packets to send, we send them here.
 *
 */
static void irport_write_wakeup(struct irport_cb *self)
{
	int actual = 0;
	int iobase;
	int fcr;

	ASSERT(self != NULL, return;);

	IRDA_DEBUG(4, __FUNCTION__ "()\n");

	iobase = self->io.sir_base;

	/* Finished with frame?  */
	if (self->tx_buff.len > 0)  {
		/* Write data left in transmit buffer */
		actual = irport_write(iobase, self->io.fifo_size, 
				      self->tx_buff.data, self->tx_buff.len);
		self->tx_buff.data += actual;
		self->tx_buff.len  -= actual;
	} else {
		/* 
		 *  Now serial buffer is almost free & we can start 
		 *  transmission of another packet. But first we must check
		 *  if we need to change the speed of the hardware
		 */
		if (self->new_speed) {
			IRDA_DEBUG(5, __FUNCTION__ "(), Changing speed!\n");
			irda_task_execute(self, __irport_change_speed, 
					  irport_change_speed_complete, 
					  NULL, (void *) self->new_speed);
			self->new_speed = 0;
		} else {
			/* Tell network layer that we want more frames */
			netif_wake_queue(self->netdev);
		}
		self->stats.tx_packets++;