path: root/drivers/net/irda/sa1100_ir.c

/*
 *  linux/drivers/net/irda/sa1100_ir.c
 *
 *  Copyright (C) 2000-2001 Russell King
 *
 * 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 for the StrongARM SA1100 embedded microprocessor
 *
 *  Note that we don't have to worry about the SA1111's DMA bugs in here,
 *  so we use the straight forward dma_map_* functions with a null pointer.
 *
 *  This driver takes one kernel command line parameter, sa1100ir=, with
 *  the following options:
 *	max_rate:baudrate	- set the maximum baud rate
 *	power_level:level	- set the transmitter power level
 *	tx_lpm:0|1		- set transmit low power mode
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/rtnetlink.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/sa11x0-dma.h>

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

#include <mach/hardware.h>
#include <asm/mach/irda.h>

static int power_level = 3;
static int tx_lpm;
static int max_rate = 4000000;

struct sa1100_buf {
	struct device		*dev;
	struct sk_buff		*skb;
	struct scatterlist	sg;
	struct dma_chan		*chan;
	dma_cookie_t		cookie;
};

struct sa1100_irda {
	unsigned char		utcr4;
	unsigned char		power;
	unsigned char		open;

	int			speed;
	int			newspeed;

	struct sa1100_buf	dma_rx;
	struct sa1100_buf	dma_tx;

	struct device		*dev;
	struct irda_platform_data *pdata;
	struct irlap_cb		*irlap;
	struct qos_info		qos;

	iobuff_t		tx_buff;
	iobuff_t		rx_buff;

	int (*tx_start)(struct sk_buff *, struct net_device *, struct sa1100_irda *);
	irqreturn_t (*irq)(struct net_device *, struct sa1100_irda *);
};

static int sa1100_irda_set_speed(struct sa1100_irda *, int);

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

#define HPSIR_MAX_RXLEN		2047

static struct dma_slave_config sa1100_irda_sir_tx = {
	.direction	= DMA_TO_DEVICE,
	.dst_addr	= __PREG(Ser2UTDR),
	.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE,
	.dst_maxburst	= 4,
};

static struct dma_slave_config sa1100_irda_fir_rx = {
	.direction	= DMA_FROM_DEVICE,
	.src_addr	= __PREG(Ser2HSDR),
	.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE,
	.src_maxburst	= 8,
};

static struct dma_slave_config sa1100_irda_fir_tx = {
	.direction	= DMA_TO_DEVICE,
	.dst_addr	= __PREG(Ser2HSDR),
	.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE,
	.dst_maxburst	= 8,
};

static unsigned sa1100_irda_dma_xferred(struct sa1100_buf *buf)
{
	struct dma_chan *chan = buf->chan;
	struct dma_tx_state state;
	enum dma_status status;

	status = chan->device->device_tx_status(chan, buf->cookie, &state);
	if (status != DMA_PAUSED)
		return 0;

	return sg_dma_len(&buf->sg) - state.residue;
}

static int sa1100_irda_dma_request(struct device *dev, struct sa1100_buf *buf,
	const char *name, struct dma_slave_config *cfg)
{
	dma_cap_mask_t m;
	int ret;

	dma_cap_zero(m);
	dma_cap_set(DMA_SLAVE, m);

	buf->chan = dma_request_channel(m