diff options
Diffstat (limited to 'include/linux/shdma-base.h')
| -rw-r--r-- | include/linux/shdma-base.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h new file mode 100644 index 00000000000..93f9821554b --- /dev/null +++ b/include/linux/shdma-base.h @@ -0,0 +1,124 @@ +/* + * 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; + 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 */ + 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, 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); +}; + +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 *); +void shdma_free_irq(struct shdma_chan *); +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); + +#endif |