/*
 * Freescale SPI/eSPI controller driver library.
 *
 * Maintainer: Kumar Gala
 *
 * Copyright (C) 2006 Polycom, Inc.
 *
 * CPM SPI and QE buffer descriptors mode support:
 * Copyright (c) 2009  MontaVista Software, Inc.
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * Copyright 2010 Freescale Semiconductor, Inc.
 *
 * 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/kernel.h>
#include <linux/interrupt.h>
#include <linux/fsl_devices.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/of_platform.h>
#include <linux/spi/spi.h>
#ifdef CONFIG_FSL_SOC
#include <sysdev/fsl_soc.h>
#endif

#include "spi-fsl-lib.h"

#define MPC8XXX_SPI_RX_BUF(type) 					  \
void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
{									  \
	type *rx = mpc8xxx_spi->rx;					  \
	*rx++ = (type)(data >> mpc8xxx_spi->rx_shift);			  \
	mpc8xxx_spi->rx = rx;						  \
}

#define MPC8XXX_SPI_TX_BUF(type)				\
u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)	\
{								\
	u32 data;						\
	const type *tx = mpc8xxx_spi->tx;			\
	if (!tx)						\
		return 0;					\
	data = *tx++ << mpc8xxx_spi->tx_shift;			\
	mpc8xxx_spi->tx = tx;					\
	return data;						\
}

MPC8XXX_SPI_RX_BUF(u8)
MPC8XXX_SPI_RX_BUF(u16)
MPC8XXX_SPI_RX_BUF(u32)
MPC8XXX_SPI_TX_BUF(u8)
MPC8XXX_SPI_TX_BUF(u16)
MPC8XXX_SPI_TX_BUF(u32)

struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
{
	return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
}

static void mpc8xxx_spi_work(struct work_struct *work)
{
	struct mpc8xxx_spi *mpc8xxx_spi = container_of(work, struct mpc8xxx_spi,
						       work);

	spin_lock_irq(&mpc8xxx_spi->lock);
	while (!list_empty(&mpc8xxx_spi->queue)) {
		struct spi_message *m = container_of(mpc8xxx_spi->queue.next,
						   struct spi_message, queue);

		list_del_init(&m->queue);
		spin_unlock_irq(&mpc8xxx_spi->lock);

		if (mpc8xxx_spi->spi_do_one_msg)
			mpc8xxx_spi->spi_do_one_msg(m);

		spin_lock_irq(&mpc8xxx_spi->lock);
	}
	spin_unlock_irq(&mpc8xxx_spi->lock);
}

int mpc8xxx_spi_transfer(struct spi_device *spi,
				struct spi_message *m)
{
	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
	unsigned long flags;

	m->actual_length = 0;
	m->status = -EINPROGRESS;

	spin_lock_irqsave(&mpc8xxx_spi->lock, flags);
	list_add_tail(&m->queue, &mpc8xxx_spi->queue);
	queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work);
	spin_unlock_irqrestore(&mpc8xxx_spi->lock, flags);

	return 0;
}

void mpc8xxx_spi_cleanup(struct spi_device *spi)
{
	kfree(spi->controller_state);
}

const char *mpc8xxx_spi_strmode(unsigned int flags)
{
	if (flags & SPI_QE_CPU_MODE) {
		return "QE CPU";
	} else if (flags & SPI_CPM_MODE) {
		if (flags & SPI_QE)
			return "QE";
		else if (flags & SPI_CPM2)
			return "CPM2";
		else
			return "CPM1";
	}
	return "CPU";
}

int mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
			unsigned int irq)
{
	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
	struct spi_master *master;
	struct mpc8xxx_spi *mpc8xxx_spi;
	int ret = 0;

	master = dev_get_drvdata(dev);

	/* the spi->mode bits understood by this driver: */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
			| SPI_LSB_FIRST | SPI_LOOP;

	master->transfer = mpc8xxx_spi_transfer;
	master->cleanup = mpc8xxx_spi_cleanup;
	master->dev.of_node = dev->of_node;

	mpc8xxx_spi = spi_master_get_devdata(master);
	mpc8xxx_spi->dev = dev;
	mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
	mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
	mpc8xxx_spi->flags = pdata->flags;
	mpc8xxx_spi->spibrg = pdata->sysclk;
	mpc8xxx_spi->irq = irq;

	mpc8xxx_spi->rx_shift = 0;
	mpc8xxx_spi->tx_shift = 0;

	init_completion(&mpc8xxx_spi->done);

	master->bus_num = pdata->bus_num;
	master->num_chipselect = pdata->max_chipselect;

	spin_lock_init(&mpc8xxx_spi->lock);
	init_completion(&mpc8xxx_spi->done);
	INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
	INIT_LIST_HEAD(&mpc8xxx_spi->queue);

	mpc8xxx_spi->workqueue = create_singlethread_workqueue(
		dev_name(master->dev.parent));
	if (mpc8xxx_spi->workqueue == NULL) {
		ret = -EBUSY;
		goto err;
	}

	return 0;

err:
	return ret;
}

int mpc8xxx_spi_remove(struct device *dev)
{
	struct mpc8xxx_spi *mpc8xxx_spi;
	struct spi_master *master;

	master = dev_get_drvdata(dev);
	mpc8xxx_spi = spi_master_get_devdata(master);

	flush_workqueue(mpc8xxx_spi->workqueue);
	destroy_workqueue(mpc8xxx_spi->workqueue);
	spi_unregister_master(master);

	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);

	if (mpc8xxx_spi->spi_remove)
		mpc8xxx_spi->spi_remove(mpc8xxx_spi);

	return 0;
}

int of_mpc8xxx_spi_probe(struct platform_device *ofdev)
{
	struct device *dev = &ofdev->dev;
	struct device_node *np = ofdev->dev.of_node;
	struct mpc8xxx_spi_probe_info *pinfo;
	struct fsl_spi_platform_data *pdata;
	const void *prop;
	int ret = -ENOMEM;

	pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
	if (!pinfo)
		return -ENOMEM;

	pdata = &pinfo->pdata;
	dev->platform_data = pdata;

	/* Allocate bus num dynamically. */
	pdata->bus_num = -1;

#ifdef CONFIG_FSL_SOC
	/* SPI controller is either clocked from QE or SoC clock. */
	pdata->sysclk = get_brgfreq();
	if (pdata->sysclk == -1) {
		pdata->sysclk = fsl_get_sys_freq();
		if (pdata->sysclk == -1) {
			ret = -ENODEV;
			goto err;
		}
	}
#else
	ret = of_property_read_u32(np, "clock-frequency", &pdata->sysclk);
	if (ret)
		goto err;
#endif

	prop = of_get_property(np, "mode", NULL);
	if (prop && !strcmp(prop, "cpu-qe"))
		pdata->flags = SPI_QE_CPU_MODE;
	else if (prop && !strcmp(prop, "qe"))
		pdata->flags = SPI_CPM_MODE | SPI_QE;
	else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
		pdata->flags = SPI_CPM_MODE | SPI_CPM2;
	else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
		pdata->flags = SPI_CPM_MODE | SPI_CPM1;

	return 0;

err:
	kfree(pinfo);
	return ret;
}