/*
   * Dmaengine driver base library for DMA controllers, found on SH-based SoCs
   *
   * extracted from shdma.c and headers
   *
   * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
   * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
   * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
   *
   * This is free software; you can redistribute it and/or modify
   * it under the terms of version 2 of the GNU General Public License as
   * published by the Free Software Foundation.
   */
  
  #ifndef SHDMA_BASE_H
  #define SHDMA_BASE_H
  
  #include <linux/dmaengine.h>
  #include <linux/interrupt.h>
  #include <linux/list.h>
  #include <linux/types.h>
  
  /**
   * shdma_pm_state - DMA channel PM state
   * SHDMA_PM_ESTABLISHED:	either idle or during data transfer
   * SHDMA_PM_BUSY:		during the transfer preparation, when we have to
   *				drop the lock temporarily
   * SHDMA_PM_PENDING:	transfers pending
   */
  enum shdma_pm_state {
  	SHDMA_PM_ESTABLISHED,
  	SHDMA_PM_BUSY,
  	SHDMA_PM_PENDING,
  };
  
  struct device;
  
  /*
   * Drivers, using this library are expected to embed struct shdma_dev,
   * struct shdma_chan, struct shdma_desc, and struct shdma_slave
   * in their respective device, channel, descriptor and slave objects.
   */
  
  struct shdma_slave {
  	int slave_id;
  };
  
  struct shdma_desc {
  	struct list_head node;
  	struct dma_async_tx_descriptor async_tx;
  	enum dma_transfer_direction direction;
  	size_t partial;
  	dma_cookie_t cookie;
  	int chunks;
  	int mark;
  };
  
  struct shdma_chan {
  	spinlock_t chan_lock;		/* Channel operation lock */
  	struct list_head ld_queue;	/* Link descriptors queue */
  	struct list_head ld_free;	/* Free link descriptors */
  	struct dma_chan dma_chan;	/* DMA channel */
  	struct device *dev;		/* Channel device */
  	void *desc;			/* buffer for descriptor array */
  	int desc_num;			/* desc count */
  	size_t max_xfer_len;		/* max transfer length */
  	int id;				/* Raw id of this channel */
  	int irq;			/* Channel IRQ */
  	int slave_id;			/* Client ID for slave DMA */
  	int hw_req;			/* DMA request line for slave DMA - same
  					 * as MID/RID, used with DT */
  	enum shdma_pm_state pm_state;
  };
  
  /**
   * struct shdma_ops - simple DMA driver operations
   * desc_completed:	return true, if this is the descriptor, that just has
   *			completed (atomic)
   * halt_channel:	stop DMA channel operation (atomic)
   * channel_busy:	return true, if the channel is busy (atomic)
   * slave_addr:		return slave DMA address
   * desc_setup:		set up the hardware specific descriptor portion (atomic)
   * set_slave:		bind channel to a slave
   * setup_xfer:		configure channel hardware for operation (atomic)
   * start_xfer:		start the DMA transfer (atomic)
   * embedded_desc:	return Nth struct shdma_desc pointer from the
   *			descriptor array
   * chan_irq:		process channel IRQ, return true if a transfer has
   *			completed (atomic)
   */
  struct shdma_ops {
  	bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
  	void (*halt_channel)(struct shdma_chan *);
  	bool (*channel_busy)(struct shdma_chan *);
  	dma_addr_t (*slave_addr)(struct shdma_chan *);
  	int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
  			  dma_addr_t, dma_addr_t, size_t *);
  	int (*set_slave)(struct shdma_chan *, int, dma_addr_t, bool);
  	void (*setup_xfer)(struct shdma_chan *, int);
  	void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
  	struct shdma_desc *(*embedded_desc)(void *, int);
  	bool (*chan_irq)(struct shdma_chan *, int);
  	size_t (*get_partial)(struct shdma_chan *, struct shdma_desc *);
  };
  
  struct shdma_dev {
  	struct dma_device dma_dev;
  	struct shdma_chan **schan;
  	const struct shdma_ops *ops;
  	size_t desc_size;
  };
  
  #define shdma_for_each_chan(c, d, i) for (i = 0, c = (d)->schan[0]; \
  				i < (d)->dma_dev.chancnt; c = (d)->schan[++i])
  
  int shdma_request_irq(struct shdma_chan *, int,
  			   unsigned long, const char *);
  bool shdma_reset(struct shdma_dev *sdev);
  void shdma_chan_probe(struct shdma_dev *sdev,
  			   struct shdma_chan *schan, int id);
  void shdma_chan_remove(struct shdma_chan *schan);
  int shdma_init(struct device *dev, struct shdma_dev *sdev,
  		    int chan_num);
  void shdma_cleanup(struct shdma_dev *sdev);
  #if IS_ENABLED(CONFIG_SH_DMAE_BASE)
  bool shdma_chan_filter(struct dma_chan *chan, void *arg);
  #else
  #define shdma_chan_filter NULL
  #endif
  
  #endif