path: root/drivers/net/irda/bfin_sir.c

/*
 * Blackfin Infra-red Driver
 *
 * Copyright 2006-2009 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 *
 */
#include "bfin_sir.h"

#ifdef CONFIG_SIR_BFIN_DMA
#define DMA_SIR_RX_XCNT        10
#define DMA_SIR_RX_YCNT        (PAGE_SIZE / DMA_SIR_RX_XCNT)
#define DMA_SIR_RX_FLUSH_JIFS  (HZ * 4 / 250)
#endif

#if ANOMALY_05000447
static int max_rate = 57600;
#else
static int max_rate = 115200;
#endif

static void turnaround_delay(unsigned long last_jif, int mtt)
{
	long ticks;

	mtt = mtt < 10000 ? 10000 : mtt;
	ticks = 1 + mtt / (USEC_PER_SEC / HZ);
	schedule_timeout_uninterruptible(ticks);
}

static void __devinit bfin_sir_init_ports(struct bfin_sir_port *sp, struct platform_device *pdev)
{
	int i;
	struct resource *res;

	for (i = 0; i < pdev->num_resources; i++) {
		res = &pdev->resource[i];
		switch (res->flags) {
		case IORESOURCE_MEM:
			sp->membase   = (void __iomem *)res->start;
			break;
		case IORESOURCE_IRQ:
			sp->irq = res->start;
			break;
		case IORESOURCE_DMA:
			sp->rx_dma_channel = res->start;
			sp->tx_dma_channel = res->end;
			break;
		default:
			break;
		}
	}

	sp->clk = get_sclk();
#ifdef CONFIG_SIR_BFIN_DMA
	sp->tx_done        = 1;
	init_timer(&(sp->rx_dma_timer));
#endif
}

static void bfin_sir_stop_tx(struct bfin_sir_port *port)
{
#ifdef CONFIG_SIR_BFIN_DMA
	disable_dma(port->tx_dma_channel);
#endif

	while (!(SIR_UART_GET_LSR(port) & THRE)) {
		cpu_relax();
		continue;
	}

	SIR_UART_STOP_TX(port);
}

static void bfin_sir_enable_tx(struct bfin_sir_port *port)
{
	SIR_UART_ENABLE_TX(port);
}

static void bfin_sir_stop_rx(struct bfin_sir_port *port)
{
	SIR_UART_STOP_RX(port);
}

static void bfin_sir_enable_rx(struct bfin_sir_port *port)
{
	SIR_UART_ENABLE_RX(port);
}

static int bfin_sir_set_speed(struct bfin_sir_port *port, int speed)
{
	int ret = -EINVAL;
	unsigned int quot;
	unsigned short val, lsr, lcr;
	static int utime;
	int count = 10;

	lcr = WLS(8);

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

		quot = (port->clk + (8 * speed)) / (16 * speed)\
						- ANOMALY_05000230;

		do {
			udelay(utime);
			lsr = SIR_UART_GET_LSR(port);
		} while (!(lsr & TEMT) && count--);

		/* The useconds for 1 bits to transmit */
		utime = 1000000 / speed + 1;

		/* Clear UCEN bit to reset the UART state machine
		 * and control registers
		 */
		val = SIR_UART_GET_GCTL(port);
		val &= ~UCEN;
		SIR_UART_PUT_GCTL(port, val);

		/* Set DLAB in LCR to Access THR RBR IER */
		SIR_UART_SET_DLAB(port);
		SSYNC();

		SIR_UART_PUT_DLL(port, quot & 0xFF);
		SIR_UART_PUT_DLH(port, (quot >> 8) & 0xFF);
		SSYNC();

		/* Clear DLAB in LCR */
		SIR_UART_CLEAR_DLAB(port);
		SSYNC();

		SIR_UART_PUT_LCR(port, lcr);

		val = SIR_UART_GET_GCTL(port);
		val |= UCEN;
		SIR_UART_PUT_GCTL(port, val);

		ret = 0;
		break;
	default:
		printk(KERN_WARNING "bfin_sir: Invalid speed %d\n", speed);
		break;
	}

	val = SIR_UART_GET_GCTL(port);
	/* If not add the 'RPOLC', we can't catch the receive interrupt.
	 * It's related with the HW layout and the IR transiver.
	 */
	val |= IREN | RPOLC;
	SIR_UART_PUT_GCTL(port, val);
	return ret;
}

static int bfin_sir_is_receiving(struct net_device *dev)
{
	struct bfin_sir_self *self = netdev_priv(dev);
	struct bfin_sir_port *port = self->sir_port;

	if (!(SIR_UART_GET_IER(port) & ERBFI))
		return 0;
	return self->rx_buff.state != OUTSIDE_FRAME;
}

#ifdef CONFIG_SIR_BFIN_PIO
static void bfin_sir_tx_chars(struct net_device *dev)
{
	unsigned int chr;
	struct bfin_sir_self *self = netdev_priv(dev);
	struct bfin_sir_port *port = self->sir_port;

	if (self->tx_buff.len != 0) {
		chr = *(self->tx_buff.data);
		SIR_UART_PUT_CHAR(port, chr);
		self->tx_buff.data++;
		self->tx_buff.len--;
	} else {
		self->stats.tx_packets++;
		self->stats.tx_bytes += self->tx_buff.data - self->tx_buff.head;
		if (self->newspeed) {
			bfin_sir_set_speed(port, self->newspeed);
			self->speed = self->newspeed;
			self->newspeed = 0;
		}
		bfin_sir_stop_tx(port);
		bfin_sir_enable_rx(port);
		/* I'm hungry! */
		netif_wake_queue(