1/* 2 * MUSB OTG driver DMA controller abstraction 3 * 4 * Copyright 2005 Mentor Graphics Corporation 5 * Copyright (C) 2005-2006 by Texas Instruments 6 * Copyright (C) 2006-2007 Nokia Corporation 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * version 2 as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 20 * 02110-1301 USA 21 * 22 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 25 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 28 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 29 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 * 33 */ 34 35#ifndef __MUSB_DMA_H__ 36#define __MUSB_DMA_H__ 37 38struct musb_hw_ep; 39 40/* 41 * DMA Controller Abstraction 42 * 43 * DMA Controllers are abstracted to allow use of a variety of different 44 * implementations of DMA, as allowed by the Inventra USB cores. On the 45 * host side, usbcore sets up the DMA mappings and flushes caches; on the 46 * peripheral side, the gadget controller driver does. Responsibilities 47 * of a DMA controller driver include: 48 * 49 * - Handling the details of moving multiple USB packets 50 * in cooperation with the Inventra USB core, including especially 51 * the correct RX side treatment of short packets and buffer-full 52 * states (both of which terminate transfers). 53 * 54 * - Knowing the correlation between dma channels and the 55 * Inventra core's local endpoint resources and data direction. 56 * 57 * - Maintaining a list of allocated/available channels. 58 * 59 * - Updating channel status on interrupts, 60 * whether shared with the Inventra core or separate. 61 */ 62 63#define DMA_ADDR_INVALID (~(dma_addr_t)0) 64 65#ifndef CONFIG_MUSB_PIO_ONLY 66#define is_dma_capable() (1) 67#else 68#define is_dma_capable() (0) 69#endif 70 71#ifdef CONFIG_USB_TI_CPPI_DMA 72#define is_cppi_enabled() 1 73#else 74#define is_cppi_enabled() 0 75#endif 76 77#ifdef CONFIG_USB_TUSB_OMAP_DMA 78#define tusb_dma_omap() 1 79#else 80#define tusb_dma_omap() 0 81#endif 82 83/* 84 * DMA channel status ... updated by the dma controller driver whenever that 85 * status changes, and protected by the overall controller spinlock. 86 */ 87enum dma_channel_status { 88 /* unallocated */ 89 MUSB_DMA_STATUS_UNKNOWN, 90 /* allocated ... but not busy, no errors */ 91 MUSB_DMA_STATUS_FREE, 92 /* busy ... transactions are active */ 93 MUSB_DMA_STATUS_BUSY, 94 /* transaction(s) aborted due to ... dma or memory bus error */ 95 MUSB_DMA_STATUS_BUS_ABORT, 96 /* transaction(s) aborted due to ... core error or USB fault */ 97 MUSB_DMA_STATUS_CORE_ABORT 98}; 99 100struct dma_controller; 101 102/** 103 * struct dma_channel - A DMA channel. 104 * @private_data: channel-private data 105 * @max_len: the maximum number of bytes the channel can move in one 106 * transaction (typically representing many USB maximum-sized packets) 107 * @actual_len: how many bytes have been transferred 108 * @status: current channel status (updated e.g. on interrupt) 109 * @desired_mode: true if mode 1 is desired; false if mode 0 is desired 110 * 111 * channels are associated with an endpoint for the duration of at least 112 * one usb transfer. 113 */ 114struct dma_channel { 115 void *private_data; 116 /* FIXME not void* private_data, but a dma_controller * */ 117 size_t max_len; 118 size_t actual_len; 119 enum dma_channel_status status; 120 bool desired_mode; 121}; 122 123/* 124 * dma_channel_status - return status of dma channel 125 * @c: the channel 126 * 127 * Returns the software's view of the channel status. If that status is BUSY 128 * then it's possible that the hardware has completed (or aborted) a transfer, 129 * so the driver needs to update that status. 130 */ 131static inline enum dma_channel_status 132dma_channel_status(struct dma_channel *c) 133{ 134 return (is_dma_capable() && c) ? c->status : MUSB_DMA_STATUS_UNKNOWN; 135} 136 137/** 138 * struct dma_controller - A DMA Controller. 139 * @start: call this to start a DMA controller; 140 * return 0 on success, else negative errno 141 * @stop: call this to stop a DMA controller 142 * return 0 on success, else negative errno 143 * @channel_alloc: call this to allocate a DMA channel 144 * @channel_release: call this to release a DMA channel 145 * @channel_abort: call this to abort a pending DMA transaction, 146 * returning it to FREE (but allocated) state 147 * 148 * Controllers manage dma channels. 149 */ 150struct dma_controller { 151 int (*start)(struct dma_controller *); 152 int (*stop)(struct dma_controller *); 153 struct dma_channel *(*channel_alloc)(struct dma_controller *, 154 struct musb_hw_ep *, u8 is_tx); 155 void (*channel_release)(struct dma_channel *); 156 int (*channel_program)(struct dma_channel *channel, 157 u16 maxpacket, u8 mode, 158 dma_addr_t dma_addr, 159 u32 length); 160 int (*channel_abort)(struct dma_channel *); 161}; 162 163/* called after channel_program(), may indicate a fault */ 164extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit); 165 166 167extern struct dma_controller *__init 168dma_controller_create(struct musb *, void __iomem *); 169 170extern void dma_controller_destroy(struct dma_controller *); 171 172#endif /* __MUSB_DMA_H__ */ 173