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Diffstat (limited to 'drivers/usb/musb/musb_dma.h')
| -rw-r--r-- | drivers/usb/musb/musb_dma.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/usb/musb/musb_dma.h b/drivers/usb/musb/musb_dma.h new file mode 100644 index 000000000000..0a2c4e3602c1 --- /dev/null +++ b/drivers/usb/musb/musb_dma.h @@ -0,0 +1,172 @@ +/* + * MUSB OTG driver DMA controller abstraction + * + * Copyright 2005 Mentor Graphics Corporation + * Copyright (C) 2005-2006 by Texas Instruments + * Copyright (C) 2006-2007 Nokia Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + * + * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN + * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#ifndef __MUSB_DMA_H__ +#define __MUSB_DMA_H__ + +struct musb_hw_ep; + +/* + * DMA Controller Abstraction + * + * DMA Controllers are abstracted to allow use of a variety of different + * implementations of DMA, as allowed by the Inventra USB cores. On the + * host side, usbcore sets up the DMA mappings and flushes caches; on the + * peripheral side, the gadget controller driver does. Responsibilities + * of a DMA controller driver include: + * + * - Handling the details of moving multiple USB packets + * in cooperation with the Inventra USB core, including especially + * the correct RX side treatment of short packets and buffer-full + * states (both of which terminate transfers). + * + * - Knowing the correlation between dma channels and the + * Inventra core's local endpoint resources and data direction. + * + * - Maintaining a list of allocated/available channels. + * + * - Updating channel status on interrupts, + * whether shared with the Inventra core or separate. + */ + +#define DMA_ADDR_INVALID (~(dma_addr_t)0) + +#ifndef CONFIG_MUSB_PIO_ONLY +#define is_dma_capable() (1) +#else +#define is_dma_capable() (0) +#endif + +#ifdef CONFIG_USB_TI_CPPI_DMA +#define is_cppi_enabled() 1 +#else +#define is_cppi_enabled() 0 +#endif + +#ifdef CONFIG_USB_TUSB_OMAP_DMA +#define tusb_dma_omap() 1 +#else +#define tusb_dma_omap() 0 +#endif + +/* + * DMA channel status ... updated by the dma controller driver whenever that + * status changes, and protected by the overall controller spinlock. + */ +enum dma_channel_status { + /* unallocated */ + MUSB_DMA_STATUS_UNKNOWN, + /* allocated ... but not busy, no errors */ + MUSB_DMA_STATUS_FREE, + /* busy ... transactions are active */ + MUSB_DMA_STATUS_BUSY, + /* transaction(s) aborted due to ... dma or memory bus error */ + MUSB_DMA_STATUS_BUS_ABORT, + /* transaction(s) aborted due to ... core error or USB fault */ + MUSB_DMA_STATUS_CORE_ABORT +}; + +struct dma_controller; + +/** + * struct dma_channel - A DMA channel. + * @private_data: channel-private data + * @max_len: the maximum number of bytes the channel can move in one + * transaction (typically representing many USB maximum-sized packets) + * @actual_len: how many bytes have been transferred + * @status: current channel status (updated e.g. on interrupt) + * @desired_mode: true if mode 1 is desired; false if mode 0 is desired + * + * channels are associated with an endpoint for the duration of at least + * one usb transfer. + */ +struct dma_channel { + void *private_data; + /* FIXME not void* private_data, but a dma_controller * */ + size_t max_len; + size_t actual_len; + enum dma_channel_status status; + bool desired_mode; +}; + +/* + * dma_channel_status - return status of dma channel + * @c: the channel + * + * Returns the software's view of the channel status. If that status is BUSY + * then it's possible that the hardware has completed (or aborted) a transfer, + * so the driver needs to update that status. + */ +static inline enum dma_channel_status +dma_channel_status(struct dma_channel *c) +{ + return (is_dma_capable() && c) ? c->status : MUSB_DMA_STATUS_UNKNOWN; +} + +/** + * struct dma_controller - A DMA Controller. + * @start: call this to start a DMA controller; + * return 0 on success, else negative errno + * @stop: call this to stop a DMA controller + * return 0 on success, else negative errno + * @channel_alloc: call this to allocate a DMA channel + * @channel_release: call this to release a DMA channel + * @channel_abort: call this to abort a pending DMA transaction, + * returning it to FREE (but allocated) state + * + * Controllers manage dma channels. + */ +struct dma_controller { + int (*start)(struct dma_controller *); + int (*stop)(struct dma_controller *); + struct dma_channel *(*channel_alloc)(struct dma_controller *, + struct musb_hw_ep *, u8 is_tx); + void (*channel_release)(struct dma_channel *); + int (*channel_program)(struct dma_channel *channel, + u16 maxpacket, u8 mode, + dma_addr_t dma_addr, + u32 length); + int (*channel_abort)(struct dma_channel *); +}; + +/* called after channel_program(), may indicate a fault */ +extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit); + + +extern struct dma_controller *__init +dma_controller_create(struct musb *, void __iomem *); + +extern void dma_controller_destroy(struct dma_controller *); + +#endif /* __MUSB_DMA_H__ */ |