linux/drivers/net/irda/pxaficp_ir.c

/*
 * linux/drivers/net/irda/pxaficp_ir.c
 *
 * Based on sa1100_ir.c by Russell King
 *
 * Changes copyright (C) 2003-2005 MontaVista Software, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Infra-red driver (SIR/FIR) for the PXA2xx embedded microprocessor
 *
 */
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dma/pxa-dma.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/sched/clock.h>

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

#include <linux/platform_data/irda-pxaficp.h>
#undef __REG
#define __REG(x) ((x) & 0xffff)
#include <mach/regs-uart.h>

#define ICCR0		0x0000		/* ICP Control Register 0 */
#define ICCR1		0x0004		/* ICP Control Register 1 */
#define ICCR2		0x0008		/* ICP Control Register 2 */
#define ICDR		0x000c		/* ICP Data Register */
#define ICSR0		0x0014		/* ICP Status Register 0 */
#define ICSR1		0x0018		/* ICP Status Register 1 */

#define ICCR0_AME	(1 << 7)	/* Address match enable */
#define ICCR0_TIE	(1 << 6)	/* Transmit FIFO interrupt enable */
#define ICCR0_RIE	(1 << 5)	/* Receive FIFO interrupt enable */
#define ICCR0_RXE	(1 << 4)	/* Receive enable */
#define ICCR0_TXE	(1 << 3)	/* Transmit enable */
#define ICCR0_TUS	(1 << 2)	/* Transmit FIFO underrun select */
#define ICCR0_LBM	(1 << 1)	/* Loopback mode */
#define ICCR0_ITR	(1 << 0)	/* IrDA transmission */

#define ICCR2_RXP       (1 << 3)	/* Receive Pin Polarity select */
#define ICCR2_TXP       (1 << 2)	/* Transmit Pin Polarity select */
#define ICCR2_TRIG	(3 << 0)	/* Receive FIFO Trigger threshold */
#define ICCR2_TRIG_8    (0 << 0)	/* 	>= 8 bytes */
#define ICCR2_TRIG_16   (1 << 0)	/*	>= 16 bytes */
#define ICCR2_TRIG_32   (2 << 0)	/*	>= 32 bytes */

#define ICSR0_EOC	(1 << 6)	/* DMA End of Descriptor Chain */
#define ICSR0_FRE	(1 << 5)	/* Framing error */
#define ICSR0_RFS	(1 << 4)	/* Receive FIFO service request */
#define ICSR0_TFS	(1 << 3)	/* Transnit FIFO service request */
#define ICSR0_RAB	(1 << 2)	/* Receiver abort */
#define ICSR0_TUR	(1 << 1)	/* Trunsmit FIFO underun */
#define ICSR0_EIF	(1 << 0)	/* End/Error in FIFO */

#define ICSR1_ROR	(1 << 6)	/* Receiver FIFO underrun  */
#define ICSR1_CRE	(1 << 5)	/* CRC error */
#define ICSR1_EOF	(1 << 4)	/* End of frame */
#define ICSR1_TNF	(1 << 3)	/* Transmit FIFO not full */
#define ICSR1_RNE	(1 << 2)	/* Receive FIFO not empty */
#define ICSR1_TBY	(1 << 1)	/* Tramsmiter busy flag */
#define ICSR1_RSY	(1 << 0)	/* Recevier synchronized flag */

#define IrSR_RXPL_NEG_IS_ZERO (1<<4)
#define IrSR_RXPL_POS_IS_ZERO 0x0
#define IrSR_TXPL_NEG_IS_ZERO (1<<3)
#define IrSR_TXPL_POS_IS_ZERO 0x0
#define IrSR_XMODE_PULSE_1_6  (1<<2)
#define IrSR_XMODE_PULSE_3_16 0x0
#define IrSR_RCVEIR_IR_MODE   (1<<1)
#define IrSR_RCVEIR_UART_MODE 0x0
#define IrSR_XMITIR_IR_MODE   (1<<0)
#define IrSR_XMITIR_UART_MODE 0x0

#define IrSR_IR_RECEIVE_ON (\
                IrSR_RXPL_NEG_IS_ZERO | \
                IrSR_TXPL_POS_IS_ZERO | \
                IrSR_XMODE_PULSE_3_16 | \
                IrSR_RCVEIR_IR_MODE   | \
                IrSR_XMITIR_UART_MODE)

#define IrSR_IR_TRANSMIT_ON (\
                IrSR_RXPL_NEG_IS_ZERO | \
                IrSR_TXPL_POS_IS_ZERO | \
                IrSR_XMODE_PULSE_3_16 | \
                IrSR_RCVEIR_UART_MODE | \
                IrSR_XMITIR_IR_MODE)

/* macros for registers read/write */
#define ficp_writel(irda, val, off)					\
	do {								\
		dev_vdbg(irda->dev,					\
			 "%s():%d ficp_writel(0x%x, %s)\n",		\
			 __func__, __LINE__, (val), #off);		\
		writel_relaxed((val), (irda)->irda_base + (off));	\
	} while (0)

#define ficp_readl(irda, off)						\
	({								\
		unsigned int _v;					\
		_v = readl_relaxed((irda)->irda_base + (off));		\
		dev_vdbg(irda->dev,					\
			 "%s():%d ficp_readl(%s): 0x%x\n",		\
			 __func__, __LINE__, #off, _v);			\
		_v;							\
	})

#define stuart_writel(irda, val, off)					\
	do {								\
		dev_vdbg(irda->dev,					\
			 "%s():%d stuart_writel(0x%x, %s)\n",		\
			 __func__, __LINE__, (val), #off);		\
		writel_relaxed((val), (irda)->stuart_base + (off));	\
	} while (0)

#define stuart_readl(irda, off)						\
	({								\
		unsigned int _v;					\
		_v = readl_relaxed((irda)->stuart_base + (off));	\
		dev_vdbg(irda->dev,					\
			 "%s():%d stuart_readl(%s): 0x%x\n",		\
			 __func__, __LINE__, #off, _v);			\
		_v;							\
	})

struct pxa_irda {
	int			speed;
	int			newspeed;
	unsigned long long	last_clk;

	void __iomem		*stuart_base;
	void __iomem		*irda_base;
	unsigned char		*dma_rx_buff;
	unsigned char		*dma_tx_buff;
	dma_addr_t		dma_rx_buff_phy;
	dma_addr_t		dma_tx_buff_phy;
	unsigned int		dma_tx_buff_len;
	struct dma_chan		*txdma;
	struct dma_chan		*rxdma;
	dma_cookie_t		rx_cookie;
	dma_cookie_t		tx_cookie;
	int			drcmr_rx;
	int			drcmr_tx;

	int			uart_irq;
	int			icp_irq;

	struct irlap_cb		*irlap;
	struct qos_info		qos;

	iobuff_t		tx_buff;
	iobuff_t		rx_buff;

	struct device		*dev;
	struct pxaficp_platform_data *pdata;
	struct clk		*fir_clk;
	struct clk		*sir_clk;
	struct clk		*cur_clk;
};

static int pxa_irda_set_speed(struct pxa_irda *si, int speed);

static inline void pxa_irda_disable_clk(struct pxa_irda *si)
{
	if (si->cur_clk)
		clk_disable_unprepare(si->cur_clk);
	si->cur_clk = NULL;
}

static inline void pxa_irda_enable_firclk(struct pxa_irda *si)
{
	si->cur_clk = si->fir_clk;
	clk_prepare_enable(si->fir_clk);
}

static inline void pxa_irda_enable_sirclk(struct pxa_irda *si)
{
	si->cur_clk = si->sir_clk;
	clk_prepare_enable(si->sir_clk);
}


#define IS_FIR(si)		((si)->speed >= 4000000)
#define IRDA_FRAME_SIZE_LIMIT	2047

static void pxa_irda_fir_dma_rx_irq(void *data);
static void pxa_irda_fir_dma_tx_irq(void *data);

inline static void pxa_irda_fir_dma_rx_start(struct pxa_irda *si)
{
	struct dma_async_tx_descriptor *tx;

	tx = dmaengine_prep_slave_single(si->rxdma, si->dma_rx_buff_phy,
					 IRDA_FRAME_SIZE_LIMIT, DMA_FROM_DEVICE,
					 DMA_PREP_INTERRUPT);
	if (!tx) {
		dev_err(si->dev, "prep_slave_sg() failed\n");
		return;
	}
	tx->callback = pxa_irda_fir_dma_rx_irq;
	tx->callback_param = si;
	si->rx_cookie = dmaengine_submit(tx);
	dma_async_issue_pending(si->rxdma);
}

inline static void pxa_irda_fir_dma_tx_start(struct pxa_irda *si)
{
	struct dma_async_tx_descriptor *tx;

	tx = dmaengine_prep_slave_single(si->txdma, si->dma_tx_buff_phy,
					 si->dma_tx_buff_len, DMA_TO_DEVICE,
					 DMA_PREP_INTERRUPT);
	if (!tx) {
		dev_err(si->dev, "prep_slave_sg() failed\n");
		return;
	}
	tx->callback = pxa_irda_fir_dma_tx_irq;
	tx->callback_param = si;
	si->tx_cookie = dmaengine_submit(tx);
	dma_async_issue_pending(si->rxdma);
}

/*
 * Set the IrDA communications mode.
 */
static void pxa_irda_set_mode(struct pxa_irda *si, int mode)
{
	if (si->pdata->transceiver_mode)
		si->pdata->transceiver_mode(si->dev, mode);
	else {
		if (gpio_is_valid(si->pdata->gpio_pwdown))
			gpio_set_value(si->pdata->gpio_pwdown,
					!(mode & IR_OFF) ^
					!si->pdata->gpio_pwdown_inverted);
		pxa2xx_transceiver_mode(si->dev, mode);
	}
}

/*
 * Set the IrDA communications speed.
 */
static int pxa_irda_set_speed(struct pxa_irda *si, int speed)
{
	unsigned long flags;
	unsigned int divisor;

	switch (speed) {
	case 9600:	case 19200:	case 38400:
	case 57600:	case 115200:

		/* refer to PXA250/210 Developer's Manual 10-7 */
		/*  BaudRate = 14.7456 MHz / (16*Divisor) */
		divisor = 14745600 / (16 * speed);

		local_irq_save(flags);

		if (IS_FIR(si)) {
			/* stop RX DMA */
			dmaengine_terminate_all(si->rxdma);
			/* disable FICP */
			ficp_writel(si, 0, ICCR0);
			pxa_irda_disable_clk(si);

			/* set board transceiver to SIR mode */
			pxa_irda_set_mode(si, IR_SIRMODE);

			/* enable the STUART clock */
			pxa_irda_enable_sirclk(si);
		}

		/* disable STUART first */
		stuart_writel(si, 0, STIER);

		/* access DLL & DLH */
		stuart_writel(si, stuart_readl(si, STLCR) | LCR_DLAB, STLCR);
		stuart_writel(si, divisor & 0xff, STDLL);
		stuart_writel(si, divisor >> 8, STDLH);
		stuart_writel(si, stuart_readl(si, STLCR) & ~LCR_DLAB, STLCR);

		si->speed = speed;
		stuart_writel(si, IrSR_IR_RECEIVE_ON | IrSR_XMODE_PULSE_1_6,
			      STISR);
		stuart_writel(si, IER_UUE | IER_RLSE | IER_RAVIE | IER_RTIOE,
			      STIER);

		local_irq_restore(flags);
		break;

	case 4000000:
		local_irq_save(flags);

		/* disable STUART */
		stuart_writel(si, 0, STIER);
		stuart_writel(si, 0, STISR);
		pxa_irda_disable_clk(si);

		/* disable FICP first */
		ficp_writel(si, 0, ICCR0);

		/* set board transceiver to FIR mode */
		pxa_irda_set_mode(si, IR_FIRMODE);

		/* enable the FICP clock */
		pxa_irda_enable_firclk(si);

		si->speed = speed;
		pxa_irda_fir_dma_rx_start(si);
		ficp_writel(si, ICCR0_ITR | ICCR0_RXE, ICCR0);

		local_irq_restore(flags);
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

/* SIR interrupt service routine. */
static irqreturn_t pxa_irda_sir_irq(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct pxa_irda *si = netdev_priv(dev);
	int iir, lsr, data;

	iir = stuart_readl(si, STIIR);

	switch  (iir & 0x0F) {
	case 0x06: /* Receiver Line Status */
		lsr = stuart_readl(si, STLSR);
		while (lsr & LSR_FIFOE) {
			data = stuart_readl(si, STRBR);
			if (lsr & (LSR_OE | LSR_PE | LSR_FE | LSR_BI)) {
				printk(KERN_DEBUG "pxa_ir: sir receiving error\n");
				dev->stats.rx_errors++;
				if (lsr & LSR_FE)
					dev->stats.rx_frame_errors++;
				if (lsr & LSR_OE)
					dev->stats.rx_fifo_errors++;
			} else {
				dev->stats.rx_bytes++;
				async_unwrap_char(dev, &dev->stats,
						  &si->rx_buff, data);
			}
			lsr = stuart_readl(si, STLSR);
		}
		si->last_clk = sched_clock();
		break;

	case 0x04: /* Received Data Available */
	  	   /* forth through */

	case 0x0C: /* Character Timeout Indication */
	  	do  {
		    dev->stats.rx_bytes++;
		    async_unwrap_char(dev, &dev->stats, &si->rx_buff,
				      stuart_readl(si, STRBR));
		} while (stuart_readl(si, STLSR) & LSR_DR);
		si->last_clk = sched_clock();
	  	break;

	case 0x02: /* Transmit FIFO Data Request */
		while ((si->tx_buff.len) &&
		       (stuart_readl(si, STLSR) & LSR_TDRQ)) {
			stuart_writel(si, *si->tx_buff.data++, STTHR);
			si->tx_buff.len -= 1;
	    	}

		if (si->tx_buff.len == 0) {
			dev->stats.tx_packets++;
			dev->stats.tx_bytes += si->tx_buff.data - si->tx_buff.head;

                        /* We need to ensure that the transmitter has finished. */
			while ((stuart_readl(si, STLSR) & LSR_TEMT) == 0)
				cpu_relax();
			si->last_clk = sched_clock();

			/*
		 	* Ok, we've finished transmitting.  Now enable
		 	* the receiver.  Sometimes we get a receive IRQ
		 	* immediately after a transmit...
		 	*/
			if (si->newspeed) {
				pxa_irda_set_speed(si, si->newspeed);
				si->newspeed = 0;
			} else {
				/* enable IR Receiver, disable IR Transmitter */
				stuart_writel(si, IrSR_IR_RECEIVE_ON |
					      IrSR_XMODE_PULSE_1_6, STISR);
				/* enable STUART and receive interrupts */
				stuart_writel(si, IER_UUE | IER_RLSE |
					      IER_RAVIE | IER_RTIOE, STIER);
			}
			/* I'm hungry! */
			netif_wake_queue(dev);
		}
		break;
	}

	return IRQ_HANDLED;
}

/* FIR Receive DMA interrupt handler */
static void pxa_irda_fir_dma_rx_irq(void *data)
{
	struct net_device *dev = data;
	struct pxa_irda *si = netdev_priv(dev);

	dmaengine_terminate_all(si->rxdma);
	netdev_dbg(dev, "pxa_ir: fir rx dma bus error\n");
}

/* FIR Transmit DMA interrupt handler */
static void pxa_irda_fir_dma_tx_irq(void *data)
{
	struct net_device *dev = data;
	struct pxa_irda *si = netdev_priv(dev);

	dmaengine_terminate_all(si->txdma);
	if (dmaengine_tx_status(si->txdma, si->tx_cookie, NULL) == DMA_ERROR) {
		dev->stats.tx_errors++;
	} else {
		dev->stats.tx_packets++;
		dev->stats.tx_bytes += si->dma_tx_buff_len;
	}

	while (ficp_readl(si, ICSR1) & ICSR1_TBY)
		cpu_relax();
	si->last_clk = sched_clock();

	/*
	 * HACK: It looks like the TBY bit is dropped too soon.
	 * Without this delay things break.
	 */
	udelay(120);

	if (si->newspeed) {
		pxa_irda_set_speed(si, si->newspeed);
		si->newspeed = 0;
	} else {
		int i = 64;

		ficp_writel(si, 0, ICCR0);
		pxa_irda_fir_dma_rx_start(si);
		while ((ficp_readl(si, ICSR1) & ICSR1_RNE) && i--)
			ficp_readl(si, ICDR);
		ficp_writel(si, ICCR0_ITR | ICCR0_RXE, ICCR0);

		if (i < 0)
			printk(KERN_ERR "pxa_ir: cannot clear Rx FIFO!\n");
	}
	netif_wake_queue(dev);
}

/* EIF(Error in FIFO/End in Frame) handler for FIR */
static void pxa_irda_fir_irq_eif(struct pxa_irda *si, struct net_device *dev, int icsr0)
{
	unsigned int len, stat, data;
	struct dma_tx_state state;

	/* Get the current data position. */

	dmaengine_tx_status(si->rxdma, si->rx_cookie, &state);
	len = IRDA_FRAME_SIZE_LIMIT - state.residue;

	do {
		/* Read Status, and then Data. 	 */
		stat = ficp_readl(si, ICSR1);
		rmb();
		data = ficp_readl(si, ICDR);

		if (stat & (ICSR1_CRE | ICSR1_ROR)) {
			dev->stats.rx_errors++;
			if (stat & ICSR1_CRE) {
				printk(KERN_DEBUG "pxa_ir: fir receive CRC error\n");
				dev->stats.rx_crc_errors++;
			}
			if (stat & ICSR1_ROR) {
				printk(KERN_DEBUG "pxa_ir: fir receive overrun\n");
				dev->stats.rx_over_errors++;
			}
		} else	{
			si->dma_rx_buff[len++] = data;
		}
		/* If we hit the end of frame, there's no point in continuing. */
		if (stat & ICSR1_EOF)
			break;
	} while (ficp_readl(si, ICSR0) & ICSR0_EIF);

	if (stat & ICSR1_EOF) {
		/* end of frame. */
		struct sk_buff *skb;

		if (icsr0 & ICSR0_FRE) {
			printk(KERN_ERR "pxa_ir: dropping erroneous frame\n");
			dev->stats.rx_dropped++;
			return;
		}

		skb = alloc_skb(len+1,GFP_ATOMIC);
		if (!skb)  {
			printk(KERN_ERR "pxa_ir: fir out of memory for receive skb\n");
			dev->stats.rx_dropped++;
			return;
		}

		/* Align IP header to 20 bytes  */
		skb_reserve(skb, 1);
		skb_copy_to_linear_data(skb, si->dma_rx_buff, len);
		skb_put(skb, len);

		/* Feed it to IrLAP  */
		skb->dev = dev;
		skb_reset_mac_header(skb);
		skb->protocol = htons(ETH_P_IRDA);
		netif_rx(skb);

		dev->stats.rx_packets++;
		dev->stats.rx_bytes += len;
	}
}

/* FIR interrupt handler */
static irqreturn_t pxa_irda_fir_irq(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct pxa_irda *si = netdev_priv(dev);
	int icsr0, i = 64;

	/* stop RX DMA */
	dmaengine_terminate_all(si->rxdma);
	si->last_clk = sched_clock();
	icsr0 = ficp_readl(si, ICSR0);

	if (icsr0 & (ICSR0_FRE | ICSR0_RAB)) {
		if (icsr0 & ICSR0_FRE) {
		        printk(KERN_DEBUG "pxa_ir: fir receive frame error\n");
			dev->stats.rx_frame_errors++;
		} else {
			printk(KERN_DEBUG "pxa_ir: fir receive abort\n");
			dev->stats.rx_errors++;
		}
		ficp_writel(si, icsr0 & (ICSR0_FRE | ICSR0_RAB), ICSR0);
	}

	if (icsr0 & ICSR0_EIF) {
		/* An error in FIFO occurred, or there is a end of frame */
		pxa_irda_fir_irq_eif(si, dev, icsr0);
	}

	ficp_writel(si, 0, ICCR0);
	pxa_irda_fir_dma_rx_start(si);
	while ((ficp_readl(si, ICSR1) & ICSR1_RNE) && i--)
		ficp_readl(si, ICDR);
	ficp_writel(si, ICCR0_ITR | ICCR0_RXE, ICCR0);

	if (i < 0)
		printk(KERN_ERR "pxa_ir: cannot clear Rx FIFO!\n");

	return IRQ_HANDLED;
}

/* hard_xmit interface of irda device */
static int pxa_irda_hard_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct pxa_irda *si = netdev_priv(dev);
	int speed = irda_get_next_speed(skb);

	/*
	 * Does this packet contain a request to change the interface
	 * speed?  If so, remember it until we complete the transmission
	 * of this frame.
	 */
	if (speed != si->speed && speed != -1)
		si->newspeed = speed;

	/*
	 * If this is an empty frame, we can bypass a lot.
	 */
	if (skb->len == 0) {
		if (si->newspeed) {
			si->newspeed = 0;
			pxa_irda_set_speed(si, speed);
		}
		dev_kfree_skb(skb);
		return NETDEV_TX_OK;
	}

	netif_stop_queue(dev);

	if (!IS_FIR(si)) {
		si->tx_buff.data = si->tx_buff.head;
		si->tx_buff.len  = async_wrap_skb(skb, si->tx_buff.data, si->tx_buff.truesize);

		/* Disable STUART interrupts and switch to transmit mode. */
		stuart_writel(si, 0, STIER);
		stuart_writel(si, IrSR_IR_TRANSMIT_ON | IrSR_XMODE_PULSE_1_6,
			      STISR);

		/* enable STUART and transmit interrupts */
		stuart_writel(si, IER_UUE | IER_TIE, STIER);
	} else {
		unsigned long mtt = irda_get_mtt(skb);

		si->dma_tx_buff_len = skb->len;
		skb_copy_from_linear_data(skb, si->dma_tx_buff, skb->len);

		if (mtt)
			while ((sched_clock() - si->last_clk) * 1000 < mtt)
				cpu_relax();

		/* stop RX DMA,  disable FICP */
		dmaengine_terminate_all(si->rxdma);
		ficp_writel(si, 0, ICCR0);

		pxa_irda_fir_dma_tx_start(si);
		ficp_writel(si, ICCR0_ITR | ICCR0_TXE, ICCR0);
	}

	dev_kfree_skb(skb);
	return NETDEV_TX_OK;
}

static int pxa_irda_ioctl(struct net_device *dev, struct ifreq *ifreq, int cmd)
{
	struct if_irda_req *rq = (struct if_irda_req *)ifreq;
	struct pxa_irda *si = netdev_priv(dev);
	int ret;

	switch (cmd) {
	case SIOCSBANDWIDTH:
		ret = -EPERM;
		if (capable(CAP_NET_ADMIN)) {
			/*
			 * We are unable to set the speed if the
			 * device is not running.
			 */
			if (netif_running(dev)) {
				ret = pxa_irda_set_speed(si,
						rq->ifr_baudrate);
			} else {
				printk(KERN_INFO "pxa_ir: SIOCSBANDWIDTH: !netif_running\n");
				ret = 0;
			}
		}
		break;

	case SIOCSMEDIABUSY:
		ret = -EPERM;
		if (capable(CAP_NET_ADMIN)) {
			irda_device_set_media_busy(dev, TRUE);
			ret = 0;
		}
		break;

	case SIOCGRECEIVING:
		ret = 0;
		rq->ifr_receiving = IS_FIR(si) ? 0
					: si->rx_buff.state != OUTSIDE_FRAME;
		break;

	default:
		ret = -EOPNOTSUPP;
		break;
	}

	return ret;
}

static void pxa_irda_startup(struct pxa_irda *si)
{
	/* Disable STUART interrupts */
	stuart_writel(si, 0, STIER);
	/* enable STUART interrupt to the processor */
	stuart_writel(si, MCR_OUT2, STMCR);
	/* configure SIR frame format: StartBit - Data 7 ... Data 0 - Stop Bit */
	stuart_writel(si, LCR_WLS0 | LCR_WLS1, STLCR);
	/* enable FIFO, we use FIFO to improve performance */
	stuart_writel(si, FCR_TRFIFOE | FCR_ITL_32, STFCR);

	/* disable FICP */
	ficp_writel(si, 0, ICCR0);
	/* configure FICP ICCR2 */
	ficp_writel(si, ICCR2_TXP | ICCR2_TRIG_32, ICCR2);

	/* force SIR reinitialization */
	si->speed = 4000000;
	pxa_irda_set_speed(si, 9600);

	printk(KERN_DEBUG "pxa_ir: irda startup\n");
}

static void pxa_irda_shutdown(struct pxa_irda *si)
{
	unsigned long flags;

	local_irq_save(flags);

	/* disable STUART and interrupt */
	stuart_writel(si, 0, STIER);
	/* disable STUART SIR mode */
	stuart_writel(si, 0, STISR);

	/* disable DMA */
	dmaengine_terminate_all(si->rxdma);
	dmaengine_terminate_all(si->txdma);
	/* disable FICP */
	ficp_writel(si, 0, ICCR0);

	/* disable the STUART or FICP clocks */
	pxa_irda_disable_clk(si);

	local_irq_restore(flags);

	/* power off board transceiver */
	pxa_irda_set_mode(si, IR_OFF);

	printk(KERN_DEBUG "pxa_ir: irda shutdown\n");
}

static int pxa_irda_start(struct net_device *dev)
{
	struct pxa_irda *si = netdev_priv(dev);
	dma_cap_mask_t mask;
	struct dma_slave_config	config;
	struct pxad_param param;
	int err;

	si->speed = 9600;

	err = request_irq(si->uart_irq, pxa_irda_sir_irq, 0, dev->name, dev);
	if (err)
		goto err_irq1;

	err = request_irq(si->icp_irq, pxa_irda_fir_irq, 0, dev->name, dev);
	if (err)
		goto err_irq2;

	/*
	 * The interrupt must remain disabled for now.
	 */
	disable_irq(si->uart_irq);
	disable_irq(si->icp_irq);

	err = -EBUSY;
	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);
	param.prio = PXAD_PRIO_LOWEST;

	memset(&config, 0, sizeof(config));
	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	config.src_addr = (dma_addr_t)si->irda_base + ICDR;
	config.dst_addr = (dma_addr_t)si->irda_base + ICDR;
	config.src_maxburst = 32;
	config.dst_maxburst = 32;

	param.drcmr = si->drcmr_rx;
	si->rxdma = dma_request_slave_channel_compat(mask, pxad_filter_fn,
						     &param, &dev->dev, "rx");
	if (!si->rxdma)
		goto err_rx_dma;

	param.drcmr = si->drcmr_tx;
	si->txdma = dma_request_slave_channel_compat(mask, pxad_filter_fn,
						     &param, &dev->dev, "tx");
	if (!si->txdma)
		goto err_tx_dma;

	err = dmaengine_slave_config(si->rxdma, &config);
	if (err)
		goto err_dma_rx_buff;
	err = dmaengine_slave_config(si->txdma, &config);
	if (err)
		goto err_dma_rx_buff;

	err = -ENOMEM;
	si->dma_rx_buff = dma_alloc_coherent(si->dev, IRDA_FRAME_SIZE_LIMIT,
					     &si->dma_rx_buff_phy, GFP_KERNEL);
	if (!si->dma_rx_buff)
		goto err_dma_rx_buff;

	si->dma_tx_buff = dma_alloc_coherent(si->dev, IRDA_FRAME_SIZE_LIMIT,
					     &si->dma_tx_buff_phy, GFP_KERNEL);
	if (!si->dma_tx_buff)
		goto err_dma_tx_buff;

	/* Setup the serial port for the initial speed. */
	pxa_irda_startup(si);

	/*
	 * Open a new IrLAP layer instance.
	 */
	si->irlap = irlap_open(dev, &si->qos, "pxa");
	err = -ENOMEM;
	if (!si->irlap)
		goto err_irlap;

	/*
	 * Now enable the interrupt and start the queue
	 */
	enable_irq(si->uart_irq);
	enable_irq(si->icp_irq);
	netif_start_queue(dev);

	printk(KERN_DEBUG "pxa_ir: irda driver opened\n");

	return 0;

err_irlap:
	pxa_irda_shutdown(si);
	dma_free_coherent(si->dev, IRDA_FRAME_SIZE_LIMIT, si->dma_tx_buff, si->dma_tx_buff_phy);
err_dma_tx_buff:
	dma_free_coherent(si->dev, IRDA_FRAME_SIZE_LIMIT, si->dma_rx_buff, si->dma_rx_buff_phy);
err_dma_rx_buff:
	dma_release_channel(si->txdma);
err_tx_dma:
	dma_release_channel(si->rxdma);
err_rx_dma:
	free_irq(si->icp_irq, dev);
err_irq2:
	free_irq(si->uart_irq, dev);
err_irq1:

	return err;
}

static int pxa_irda_stop(struct net_device *dev)
{
	struct pxa_irda *si = netdev_priv(dev);

	netif_stop_queue(dev);

	pxa_irda_shutdown(si);

	/* Stop IrLAP */
	if (si->irlap) {
		irlap_close(si->irlap);
		si->irlap = NULL;
	}

	free_irq(si->uart_irq, dev);
	free_irq(si->icp_irq, dev);

	dmaengine_terminate_all(si->rxdma);
	dmaengine_terminate_all(si->txdma);
	dma_release_channel(si->rxdma);
	dma_release_channel(si->txdma);

	if (si->dma_rx_buff)
		dma_free_coherent(si->dev, IRDA_FRAME_SIZE_LIMIT, si->dma_tx_buff, si->dma_tx_buff_phy);
	if (si->dma_tx_buff)
		dma_free_coherent(si->dev, IRDA_FRAME_SIZE_LIMIT, si->dma_rx_buff, si->dma_rx_buff_phy);

	printk(KERN_DEBUG "pxa_ir: irda driver closed\n");
	return 0;
}

static int pxa_irda_suspend(struct platform_device *_dev, pm_message_t state)
{
	struct net_device *dev = platform_get_drvdata(_dev);
	struct pxa_irda *si;

	if (dev && netif_running(dev)) {
		si = netdev_priv(dev);
		netif_device_detach(dev);
		pxa_irda_shutdown(si);
	}

	return 0;
}

static int pxa_irda_resume(struct platform_device *_dev)
{
	struct net_device *dev = platform_get_drvdata(_dev);
	struct pxa_irda *si;

	if (dev && netif_running(dev)) {
		si = netdev_priv(dev);
		pxa_irda_startup(si);
		netif_device_attach(dev);
		netif_wake_queue(dev);
	}

	return 0;
}


static int pxa_irda_init_iobuf(iobuff_t *io, int size)
{
	io->head = kmalloc(size, GFP_KERNEL | GFP_DMA);
	if (io->head != NULL) {
		io->truesize = size;
		io->in_frame = FALSE;
		io->state    = OUTSIDE_FRAME;
		io->data     = io->head;
	}
	return io->head ? 0 : -ENOMEM;
}

static const struct net_device_ops pxa_irda_netdev_ops = {
	.ndo_open		= pxa_irda_start,
	.ndo_stop		= pxa_irda_stop,
	.ndo_start_xmit		= pxa_irda_hard_xmit,
	.ndo_do_ioctl		= pxa_irda_ioctl,
};

static int pxa_irda_probe(struct platform_device *pdev)
{
	struct net_device *dev;
	struct resource *res;
	struct pxa_irda *si;
	void __iomem *ficp, *stuart;
	unsigned int baudrate_mask;
	int err;

	if (!pdev->dev.platform_data)
		return -ENODEV;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ficp = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(ficp)) {
		dev_err(&pdev->dev, "resource ficp not defined\n");
		return PTR_ERR(ficp);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	stuart = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(stuart)) {
		dev_err(&pdev->dev, "resource stuart not defined\n");
		return PTR_ERR(stuart);
	}

	dev = alloc_irdadev(sizeof(struct pxa_irda));
	if (!dev) {
		err = -ENOMEM;
		goto err_mem_1;
	}

	SET_NETDEV_DEV(dev, &pdev->dev);
	si = netdev_priv(dev);
	si->dev = &pdev->dev;
	si->pdata = pdev->dev.platform_data;

	si->irda_base = ficp;
	si->stuart_base = stuart;
	si->uart_irq = platform_get_irq(pdev, 0);
	si->icp_irq = platform_get_irq(pdev, 1);

	si->sir_clk = devm_clk_get(&pdev->dev, "UARTCLK");
	si->fir_clk = devm_clk_get(&pdev->dev, "FICPCLK");
	if (IS_ERR(si->sir_clk) || IS_ERR(si->fir_clk)) {
		err = PTR_ERR(IS_ERR(si->sir_clk) ? si->sir_clk : si->fir_clk);
		goto err_mem_4;
	}

	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	if (res)
		si->drcmr_rx = res->start;
	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
	if (res)
		si->drcmr_tx = res->start;

	/*
	 * Initialise the SIR buffers
	 */
	err = pxa_irda_init_iobuf(&si->rx_buff, 14384);
	if (err)
		goto err_mem_4;
	err = pxa_irda_init_iobuf(&si->tx_buff, 4000);
	if (err)
		goto err_mem_5;

	if (gpio_is_valid(si->pdata->gpio_pwdown)) {
		err = gpio_request(si->pdata->gpio_pwdown, "IrDA switch");
		if (err)
			goto err_startup;
		err = gpio_direction_output(si->pdata->gpio_pwdown,
					!si->pdata->gpio_pwdown_inverted);
		if (err) {
			gpio_free(si->pdata->gpio_pwdown);
			goto err_startup;
		}
	}

	if (si->pdata->startup) {
		err = si->pdata->startup(si->dev);
		if (err)
			goto err_startup;
	}

	if (gpio_is_valid(si->pdata->gpio_pwdown) && si->pdata->startup)
		dev_warn(si->dev, "gpio_pwdown and startup() both defined!\n");

	dev->netdev_ops = &pxa_irda_netdev_ops;

	irda_init_max_qos_capabilies(&si->qos);

	baudrate_mask = 0;
	if (si->pdata->transceiver_cap & IR_SIRMODE)
		baudrate_mask |= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
	if (si->pdata->transceiver_cap & IR_FIRMODE)
		baudrate_mask |= IR_4000000 << 8;

	si->qos.baud_rate.bits &= baudrate_mask;
	si->qos.min_turn_time.bits = 7;  /* 1ms or more */

	irda_qos_bits_to_value(&si->qos);

	err = register_netdev(dev);

	if (err == 0)
		platform_set_drvdata(pdev, dev);

	if (err) {
		if (si->pdata->shutdown)
			si->pdata->shutdown(si->dev);
err_startup:
		kfree(si->tx_buff.head);
err_mem_5:
		kfree(si->rx_buff.head);
err_mem_4:
		free_netdev(dev);
	}
err_mem_1:
	return err;
}

static int pxa_irda_remove(struct platform_device *_dev)
{
	struct net_device *dev = platform_get_drvdata(_dev);

	if (dev) {
		struct pxa_irda *si = netdev_priv(dev);
		unregister_netdev(dev);
		if (gpio_is_valid(si->pdata->gpio_pwdown))
			gpio_free(si->pdata->gpio_pwdown);
		if (si->pdata->shutdown)
			si->pdata->shutdown(si->dev);
		kfree(si->tx_buff.head);
		kfree(si->rx_buff.head);
		free_netdev(dev);
	}

	return 0;
}

static struct platform_driver pxa_ir_driver = {
	.driver         = {
		.name   = "pxa2xx-ir",
	},
	.probe		= pxa_irda_probe,
	.remove		= pxa_irda_remove,
	.suspend	= pxa_irda_suspend,
	.resume		= pxa_irda_resume,
};

module_platform_driver(pxa_ir_driver);

MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pxa2xx-ir");