path: root/drivers/net/wireless/libertas/if_spi.c

/*
 *	linux/drivers/net/wireless/libertas/if_spi.c
 *
 *	Driver for Marvell SPI WLAN cards.
 *
 *	Copyright 2008 Analog Devices Inc.
 *
 *	Authors:
 *	Andrey Yurovsky <andrey@cozybit.com>
 *	Colin McCabe <colin@cozybit.com>
 *
 *	Inspired by if_sdio.c, Copyright 2007-2008 Pierre Ossman
 *
 * 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.
 */

#include <linux/moduleparam.h>
#include <linux/firmware.h>
#include <linux/jiffies.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/semaphore.h>
#include <linux/spi/libertas_spi.h>
#include <linux/spi/spi.h>

#include "host.h"
#include "decl.h"
#include "defs.h"
#include "dev.h"
#include "if_spi.h"

struct if_spi_card {
	struct spi_device		*spi;
	struct lbs_private		*priv;
	struct libertas_spi_platform_data *pdata;

	char				helper_fw_name[IF_SPI_FW_NAME_MAX];
	char				main_fw_name[IF_SPI_FW_NAME_MAX];

	/* The card ID and card revision, as reported by the hardware. */
	u16				card_id;
	u8				card_rev;

	/* The last time that we initiated an SPU operation */
	unsigned long			prev_xfer_time;

	int				use_dummy_writes;
	unsigned long			spu_port_delay;
	unsigned long			spu_reg_delay;

	/* Handles all SPI communication (except for FW load) */
	struct task_struct		*spi_thread;
	int				run_thread;

	/* Used to wake up the spi_thread */
	struct semaphore		spi_ready;
	struct semaphore		spi_thread_terminated;

	u8				cmd_buffer[IF_SPI_CMD_BUF_SIZE];
};

static void free_if_spi_card(struct if_spi_card *card)
{
	spi_set_drvdata(card->spi, NULL);
	kfree(card);
}

static struct chip_ident chip_id_to_device_name[] = {
	{ .chip_id = 0x04, .name = 8385 },
	{ .chip_id = 0x0b, .name = 8686 },
};

/*
 * SPI Interface Unit Routines
 *
 * The SPU sits between the host and the WLAN module.
 * All communication with the firmware is through SPU transactions.
 *
 * First we have to put a SPU register name on the bus. Then we can
 * either read from or write to that register.
 *
 */

static void spu_transaction_init(struct if_spi_card *card)
{
	if (!time_after(jiffies, card->prev_xfer_time + 1)) {
		/* Unfortunately, the SPU requires a delay between successive
		 * transactions. If our last transaction was more than a jiffy
		 * ago, we have obviously already delayed enough.
		 * If not, we have to busy-wait to be on the safe side. */
		ndelay(400);
	}
}

static void spu_transaction_finish(struct if_spi_card *card)
{
	card->prev_xfer_time = jiffies;
}

/* Write out a byte buffer to an SPI register,
 * using a series of 16-bit transfers. */
static int spu_write(struct if_spi_card *card, u16 reg, const u8 *buf, int len)
{
	int err = 0;
	__le16 reg_out = cpu_to_le16(reg | IF_SPI_WRITE_OPERATION_MASK);
	struct spi_message m;
	struct spi_transfer reg_trans;
	struct spi_transfer data_trans;

	spi_message_init(&m);
	memset(&reg_trans, 0, sizeof(reg_trans));
	memset(&data_trans, 0, sizeof(data_trans));

	/* You must give an even number of bytes to the SPU, even if it
	 * doesn't care about the last one.  */
	BUG_ON(len & 0x1);

	spu_transaction_init(card);

	/* write SPU register index */
	reg_trans.tx_buf = &reg_out;
	reg_trans.len = sizeof(reg_out);

	data_trans.tx_buf = buf;
	data_trans.len = len;

	spi_message_add_tail(&reg_trans, &m);
	spi_message_add_tail(&data_trans, &m);

	err = spi_sync(card->spi, &m);
	spu_transaction_finish(card);
	return err;
}

static inline int spu_write_u16(struct if_spi_card *card, u16 reg, u16 val)
{
	__le16 buff;

	buff = cpu_to_le16(val);
	return spu_write(card, reg, (u8 *)&buff, sizeof(u16));
}

static inline int spu_reg_is_port_reg(u16 reg)
{