LXR linux/drivers/usb/musb/musb

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * MUSB OTG driver DMA controller abstraction
   4 *
   5 * Copyright 2005 Mentor Graphics Corporation
   6 * Copyright (C) 2005-2006 by Texas Instruments
   7 * Copyright (C) 2006-2007 Nokia Corporation
   8 */
   9
  10#ifndef __MUSB_DMA_H__
  11#define __MUSB_DMA_H__
  12
  13struct musb_hw_ep;
  14
  15/*
  16 * DMA Controller Abstraction
  17 *
  18 * DMA Controllers are abstracted to allow use of a variety of different
  19 * implementations of DMA, as allowed by the Inventra USB cores.  On the
  20 * host side, usbcore sets up the DMA mappings and flushes caches; on the
  21 * peripheral side, the gadget controller driver does.  Responsibilities
  22 * of a DMA controller driver include:
  23 *
  24 *  - Handling the details of moving multiple USB packets
  25 *    in cooperation with the Inventra USB core, including especially
  26 *    the correct RX side treatment of short packets and buffer-full
  27 *    states (both of which terminate transfers).
  28 *
  29 *  - Knowing the correlation between dma channels and the
  30 *    Inventra core's local endpoint resources and data direction.
  31 *
  32 *  - Maintaining a list of allocated/available channels.
  33 *
  34 *  - Updating channel status on interrupts,
  35 *    whether shared with the Inventra core or separate.
  36 */
  37
  38#define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  39
  40#ifdef CONFIG_MUSB_PIO_ONLY
  41#define is_dma_capable()        (0)
  42#else
  43#define is_dma_capable()        (1)
  44#endif
  45
  46#ifdef CONFIG_USB_UX500_DMA
  47#define musb_dma_ux500(musb)            (musb->ops->quirks & MUSB_DMA_UX500)
  48#else
  49#define musb_dma_ux500(musb)            0
  50#endif
  51
  52#ifdef CONFIG_USB_TI_CPPI41_DMA
  53#define musb_dma_cppi41(musb)           (musb->ops->quirks & MUSB_DMA_CPPI41)
  54#else
  55#define musb_dma_cppi41(musb)           0
  56#endif
  57
  58#ifdef CONFIG_USB_TI_CPPI_DMA
  59#define musb_dma_cppi(musb)             (musb->ops->quirks & MUSB_DMA_CPPI)
  60#else
  61#define musb_dma_cppi(musb)             0
  62#endif
  63
  64#ifdef CONFIG_USB_TUSB_OMAP_DMA
  65#define tusb_dma_omap(musb)             (musb->ops->quirks & MUSB_DMA_TUSB_OMAP)
  66#else
  67#define tusb_dma_omap(musb)             0
  68#endif
  69
  70#ifdef CONFIG_USB_INVENTRA_DMA
  71#define musb_dma_inventra(musb)         (musb->ops->quirks & MUSB_DMA_INVENTRA)
  72#else
  73#define musb_dma_inventra(musb)         0
  74#endif
  75
  76#if defined(CONFIG_USB_TI_CPPI_DMA) || defined(CONFIG_USB_TI_CPPI41_DMA)
  77#define is_cppi_enabled(musb)           \
  78        (musb_dma_cppi(musb) || musb_dma_cppi41(musb))
  79#else
  80#define is_cppi_enabled(musb)   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        bool                    rx_packet_done;
 122};
 123
 124/*
 125 * dma_channel_status - return status of dma channel
 126 * @c: the channel
 127 *
 128 * Returns the software's view of the channel status.  If that status is BUSY
 129 * then it's possible that the hardware has completed (or aborted) a transfer,
 130 * so the driver needs to update that status.
 131 */
 132static inline enum dma_channel_status
 133dma_channel_status(struct dma_channel *c)
 134{
 135        return (is_dma_capable() && c) ? c->status : MUSB_DMA_STATUS_UNKNOWN;
 136}
 137
 138/**
 139 * struct dma_controller - A DMA Controller.
 140 * @musb: the usb controller
 141 * @start: call this to start a DMA controller;
 142 *      return 0 on success, else negative errno
 143 * @stop: call this to stop a DMA controller
 144 *      return 0 on success, else negative errno
 145 * @channel_alloc: call this to allocate a DMA channel
 146 * @channel_release: call this to release a DMA channel
 147 * @channel_abort: call this to abort a pending DMA transaction,
 148 *      returning it to FREE (but allocated) state
 149 * @dma_callback: invoked on DMA completion, useful to run platform
 150 *      code such IRQ acknowledgment.
 151 *
 152 * Controllers manage dma channels.
 153 */
 154struct dma_controller {
 155        struct musb *musb;
 156        struct dma_channel      *(*channel_alloc)(struct dma_controller *,
 157                                        struct musb_hw_ep *, u8 is_tx);
 158        void                    (*channel_release)(struct dma_channel *);
 159        int                     (*channel_program)(struct dma_channel *channel,
 160                                                        u16 maxpacket, u8 mode,
 161                                                        dma_addr_t dma_addr,
 162                                                        u32 length);
 163        int                     (*channel_abort)(struct dma_channel *);
 164        int                     (*is_compatible)(struct dma_channel *channel,
 165                                                        u16 maxpacket,
 166                                                        void *buf, u32 length);
 167        void                    (*dma_callback)(struct dma_controller *);
 168};
 169
 170/* called after channel_program(), may indicate a fault */
 171extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit);
 172
 173#ifdef CONFIG_MUSB_PIO_ONLY
 174static inline struct dma_controller *
 175musb_dma_controller_create(struct musb *m, void __iomem *io)
 176{
 177        return NULL;
 178}
 179
 180static inline void musb_dma_controller_destroy(struct dma_controller *d) { }
 181
 182#else
 183
 184extern struct dma_controller *
 185(*musb_dma_controller_create)(struct musb *, void __iomem *);
 186
 187extern void (*musb_dma_controller_destroy)(struct dma_controller *);
 188#endif
 189
 190/* Platform specific DMA functions */
 191extern struct dma_controller *
 192musbhs_dma_controller_create(struct musb *musb, void __iomem *base);
 193extern void musbhs_dma_controller_destroy(struct dma_controller *c);
 194
 195extern struct dma_controller *
 196tusb_dma_controller_create(struct musb *musb, void __iomem *base);
 197extern void tusb_dma_controller_destroy(struct dma_controller *c);
 198
 199extern struct dma_controller *
 200cppi_dma_controller_create(struct musb *musb, void __iomem *base);
 201extern void cppi_dma_controller_destroy(struct dma_controller *c);
 202
 203extern struct dma_controller *
 204cppi41_dma_controller_create(struct musb *musb, void __iomem *base);
 205extern void cppi41_dma_controller_destroy(struct dma_controller *c);
 206
 207extern struct dma_controller *
 208ux500_dma_controller_create(struct musb *musb, void __iomem *base);
 209extern void ux500_dma_controller_destroy(struct dma_controller *c);
 210
 211#endif  /* __MUSB_DMA_H__ */
 212