/*
   * 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;
  }