path: root/drivers/spi/spi-fsl-spi.c

/*
 * Freescale SPI controller driver.
 *
 * Maintainer: Kumar Gala
 *
 * Copyright (C) 2006 Polycom, Inc.
 * Copyright 2010 Freescale Semiconductor, Inc.
 *
 * CPM SPI and QE buffer descriptors mode support:
 * Copyright (c) 2009  MontaVista Software, Inc.
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * GRLIB support:
 * Copyright (c) 2012 Aeroflex Gaisler AB.
 * Author: Andreas Larsson <andreas@gaisler.com>
 *
 * 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/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/platform_device.h>
#include <linux/fsl_devices.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>

#include "spi-fsl-lib.h"
#include "spi-fsl-cpm.h"
#include "spi-fsl-spi.h"

#define TYPE_FSL	0
#define TYPE_GRLIB	1

struct fsl_spi_match_data {
	int type;
};

static struct fsl_spi_match_data of_fsl_spi_fsl_config = {
	.type = TYPE_FSL,
};

static struct fsl_spi_match_data of_fsl_spi_grlib_config = {
	.type = TYPE_GRLIB,
};

static struct of_device_id of_fsl_spi_match[] = {
	{
		.compatible = "fsl,spi",
		.data = &of_fsl_spi_fsl_config,
	},
	{
		.compatible = "aeroflexgaisler,spictrl",
		.data = &of_fsl_spi_grlib_config,
	},
	{}
};
MODULE_DEVICE_TABLE(of, of_fsl_spi_match);

static int fsl_spi_get_type(struct device *dev)
{
	const struct of_device_id *match;

	if (dev->of_node) {
		match = of_match_node(of_fsl_spi_match, dev->of_node);
		if (match && match->data)
			return ((struct fsl_spi_match_data *)match->data)->type;
	}
	return TYPE_FSL;
}

static void fsl_spi_change_mode(struct spi_device *spi)
{
	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
	struct spi_mpc8xxx_cs *cs = spi->controller_state;
	struct fsl_spi_reg *reg_base = mspi->reg_base;
	__be32 __iomem *mode = &reg_base->mode;
	unsigned long flags;

	if (cs->hw_mode == mpc8xxx_spi_read_reg(mode))
		return;

	/* Turn off IRQs locally to minimize time that SPI is disabled. */
	local_irq_save(flags);

	/* Turn off SPI unit prior changing mode */
	mpc8xxx_spi_write_reg(mode, cs->hw_mode & ~SPMODE_ENABLE);

	/* When in CPM mode, we need to reinit tx and rx. */
	if (mspi->flags & SPI_CPM_MODE) {
		fsl_spi_cpm_reinit_txrx(mspi);
	}
	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
	local_irq_restore(flags);
}

static void fsl_spi_chipselect(struct spi_device *spi, int value)
{
	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
	struct fsl_spi_platform_data *pdata;
	bool pol = spi->mode & SPI_CS_HIGH;
	struct spi_mpc8xxx_cs	*cs = spi->controller_state;

	pdata = spi->dev.parent->parent->platform_data;

	if (value == BITBANG_CS_INACTIVE) {
		if (pdata->cs_control)
			pdata->cs_control(spi, !pol);
	}

	if (value == BITBANG_CS_ACTIVE) {
		mpc8xxx_spi->rx_shift = cs->rx_shift;
		mpc8xxx_spi->tx_shift = cs->tx_shift;
		mpc8xxx_spi->get_rx = cs->get_rx;
		mpc8xxx_spi->get_tx = cs->get_tx;

		fsl_spi_change_mode(spi);

		if (pdata->cs_control)
			pdata->cs_control(spi, pol);
	}
}

static void fsl_spi_qe_cpu_set_shifts(u32 *rx_shift, u32 *tx_shift,
				      int bits_per_word, int msb_first)
{
	*rx_shift = 0;
	*tx_shift = 0;
	if (msb_first) {
		if (bits_per_word <= 8) {
			*rx_shift = 16;
			*tx_shift = 24;
		} else if (bits_per_word <= 16) {
			*rx_shift = 16;
			*tx_shift = 16;
		}
	} else {
		if (bits_per_word <= 8)
			*rx_shift = 8;
	}
}

static void fsl_spi_grlib_set_shifts(u32 *rx_shift, u32 *tx_shift,
				     int bits_per_word, int msb_first)
{
	*rx_shift = 0;
	*tx_shift = 0;
	if (bits_per_word <= 16) {
		if (msb_first) {
			*rx_shift = 16; /* LSB in bit 16 */
			*tx_shift = 32 - bits_per_word; /* MSB in bit 31 */