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 MUSB_HSDMA_BASE 0x200
39#define MUSB_HSDMA_INTR (MUSB_HSDMA_BASE + 0)
40#define MUSB_HSDMA_CONTROL 0x4
41#define MUSB_HSDMA_ADDRESS 0x8
42#define MUSB_HSDMA_COUNT 0xc
43
44#define DMA_ADDR_INVALID (~(dma_addr_t)0)
45
46#ifdef CONFIG_MUSB_PIO_ONLY
47#define is_dma_capable() (0)
48#else
49#define is_dma_capable() (1)
50#endif
51
52#ifdef CONFIG_USB_UX500_DMA
53#define musb_dma_ux500(musb) (musb->ops->quirks & MUSB_DMA_UX500)
54#else
55#define musb_dma_ux500(musb) 0
56#endif
57
58#ifdef CONFIG_USB_TI_CPPI41_DMA
59#define musb_dma_cppi41(musb) (musb->ops->quirks & MUSB_DMA_CPPI41)
60#else
61#define musb_dma_cppi41(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_CPPI41_DMA)
77#define is_cppi_enabled(musb) musb_dma_cppi41(musb)
78#else
79#define is_cppi_enabled(musb) 0
80#endif
81
82/*
83 * DMA channel status ... updated by the dma controller driver whenever that
84 * status changes, and protected by the overall controller spinlock.
85 */
86enum dma_channel_status {
87 /* unallocated */
88 MUSB_DMA_STATUS_UNKNOWN,
89 /* allocated ... but not busy, no errors */
90 MUSB_DMA_STATUS_FREE,
91 /* busy ... transactions are active */
92 MUSB_DMA_STATUS_BUSY,
93 /* transaction(s) aborted due to ... dma or memory bus error */
94 MUSB_DMA_STATUS_BUS_ABORT,
95 /* transaction(s) aborted due to ... core error or USB fault */
96 MUSB_DMA_STATUS_CORE_ABORT
97};
98
99struct dma_controller;
100
101/**
102 * struct dma_channel - A DMA channel.
103 * @private_data: channel-private data
104 * @max_len: the maximum number of bytes the channel can move in one
105 * transaction (typically representing many USB maximum-sized packets)
106 * @actual_len: how many bytes have been transferred
107 * @status: current channel status (updated e.g. on interrupt)
108 * @desired_mode: true if mode 1 is desired; false if mode 0 is desired
109 *
110 * channels are associated with an endpoint for the duration of at least
111 * one usb transfer.
112 */
113struct dma_channel {
114 void *private_data;
115 /* FIXME not void* private_data, but a dma_controller * */
116 size_t max_len;
117 size_t actual_len;
118 enum dma_channel_status status;
119 bool desired_mode;
120 bool rx_packet_done;
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 * @musb: the usb controller
140 * @start: call this to start a DMA controller;
141 * return 0 on success, else negative errno
142 * @stop: call this to stop a DMA controller
143 * return 0 on success, else negative errno
144 * @channel_alloc: call this to allocate a DMA channel
145 * @channel_release: call this to release a DMA channel
146 * @channel_abort: call this to abort a pending DMA transaction,
147 * returning it to FREE (but allocated) state
148 * @dma_callback: invoked on DMA completion, useful to run platform
149 * code such IRQ acknowledgment.
150 *
151 * Controllers manage dma channels.
152 */
153struct dma_controller {
154 struct musb *musb;
155 struct dma_channel *(*channel_alloc)(struct dma_controller *,
156 struct musb_hw_ep *, u8 is_tx);
157 void (*channel_release)(struct dma_channel *);
158 int (*channel_program)(struct dma_channel *channel,
159 u16 maxpacket, u8 mode,
160 dma_addr_t dma_addr,
161 u32 length);
162 int (*channel_abort)(struct dma_channel *);
163 int (*is_compatible)(struct dma_channel *channel,
164 u16 maxpacket,
165 void *buf, u32 length);
166 void (*dma_callback)(struct dma_controller *);
167};
168
169/* called after channel_program(), may indicate a fault */
170extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit);
171
172#ifdef CONFIG_MUSB_PIO_ONLY
173static inline struct dma_controller *
174musb_dma_controller_create(struct musb *m, void __iomem *io)
175{
176 return NULL;
177}
178
179static inline void musb_dma_controller_destroy(struct dma_controller *d) { }
180
181#else
182
183extern struct dma_controller *
184(*musb_dma_controller_create)(struct musb *, void __iomem *);
185
186extern void (*musb_dma_controller_destroy)(struct dma_controller *);
187#endif
188
189/* Platform specific DMA functions */
190extern struct dma_controller *
191musbhs_dma_controller_create(struct musb *musb, void __iomem *base);
192extern void musbhs_dma_controller_destroy(struct dma_controller *c);
193extern struct dma_controller *
194musbhs_dma_controller_create_noirq(struct musb *musb, void __iomem *base);
195extern irqreturn_t dma_controller_irq(int irq, void *private_data);
196
197extern struct dma_controller *
198tusb_dma_controller_create(struct musb *musb, void __iomem *base);
199extern void tusb_dma_controller_destroy(struct dma_controller *c);
200
201extern struct dma_controller *
202cppi41_dma_controller_create(struct musb *musb, void __iomem *base);
203extern void cppi41_dma_controller_destroy(struct dma_controller *c);
204
205extern struct dma_controller *
206ux500_dma_controller_create(struct musb *musb, void __iomem *base);
207extern void ux500_dma_controller_destroy(struct dma_controller *c);
208
209#endif /* __MUSB_DMA_H__ */
210

source code of linux/drivers/usb/musb/musb_dma.h