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 38 struct 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_USB_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 /* Anomaly 05000456 - USB Receive Interrupt Is Not Generated in DMA Mode 1 84 * Only allow DMA mode 1 to be used when the USB will actually generate the 85 * interrupts we expect. 86 */ 87 #ifdef CONFIG_BLACKFIN 88 # undef USE_MODE1 89 # if !ANOMALY_05000456 90 # define USE_MODE1 91 # endif 92 #endif 93 94 /* 95 * DMA channel status ... updated by the dma controller driver whenever that 96 * status changes, and protected by the overall controller spinlock. 97 */ 98 enum dma_channel_status { 99 /* unallocated */ 100 MUSB_DMA_STATUS_UNKNOWN, 101 /* allocated ... but not busy, no errors */ 102 MUSB_DMA_STATUS_FREE, 103 /* busy ... transactions are active */ 104 MUSB_DMA_STATUS_BUSY, 105 /* transaction(s) aborted due to ... dma or memory bus error */ 106 MUSB_DMA_STATUS_BUS_ABORT, 107 /* transaction(s) aborted due to ... core error or USB fault */ 108 MUSB_DMA_STATUS_CORE_ABORT 109 }; 110 111 struct dma_controller; 112 113 /** 114 * struct dma_channel - A DMA channel. 115 * @private_data: channel-private data 116 * @max_len: the maximum number of bytes the channel can move in one 117 * transaction (typically representing many USB maximum-sized packets) 118 * @actual_len: how many bytes have been transferred 119 * @status: current channel status (updated e.g. on interrupt) 120 * @desired_mode: true if mode 1 is desired; false if mode 0 is desired 121 * 122 * channels are associated with an endpoint for the duration of at least 123 * one usb transfer. 124 */ 125 struct dma_channel { 126 void *private_data; 127 /* FIXME not void* private_data, but a dma_controller * */ 128 size_t max_len; 129 size_t actual_len; 130 enum dma_channel_status status; 131 bool desired_mode; 132 }; 133 134 /* 135 * dma_channel_status - return status of dma channel 136 * @c: the channel 137 * 138 * Returns the software's view of the channel status. If that status is BUSY 139 * then it's possible that the hardware has completed (or aborted) a transfer, 140 * so the driver needs to update that status. 141 */ 142 static inline enum dma_channel_status 143 dma_channel_status(struct dma_channel *c) 144 { 145 return (is_dma_capable() && c) ? c->status : MUSB_DMA_STATUS_UNKNOWN; 146 } 147 148 /** 149 * struct dma_controller - A DMA Controller. 150 * @start: call this to start a DMA controller; 151 * return 0 on success, else negative errno 152 * @stop: call this to stop a DMA controller 153 * return 0 on success, else negative errno 154 * @channel_alloc: call this to allocate a DMA channel 155 * @channel_release: call this to release a DMA channel 156 * @channel_abort: call this to abort a pending DMA transaction, 157 * returning it to FREE (but allocated) state 158 * 159 * Controllers manage dma channels. 160 */ 161 struct dma_controller { 162 int (*start)(struct dma_controller *); 163 int (*stop)(struct dma_controller *); 164 struct dma_channel *(*channel_alloc)(struct dma_controller *, 165 struct musb_hw_ep *, u8 is_tx); 166 void (*channel_release)(struct dma_channel *); 167 int (*channel_program)(struct dma_channel *channel, 168 u16 maxpacket, u8 mode, 169 dma_addr_t dma_addr, 170 u32 length); 171 int (*channel_abort)(struct dma_channel *); 172 int (*is_compatible)(struct dma_channel *channel, 173 u16 maxpacket, 174 void *buf, u32 length); 175 }; 176 177 /* called after channel_program(), may indicate a fault */ 178 extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit); 179 180 181 extern struct dma_controller *__init 182 dma_controller_create(struct musb *, void __iomem *); 183 184 extern void dma_controller_destroy(struct dma_controller *); 185 186 #endif /* __MUSB_DMA_H__ */ 187