xref: /linux/drivers/usb/musb/cppi_dma.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /* Copyright (C) 2005-2006 by Texas Instruments */
2 
3 #ifndef _CPPI_DMA_H_
4 #define _CPPI_DMA_H_
5 
6 #include <linux/slab.h>
7 #include <linux/list.h>
8 #include <linux/errno.h>
9 #include <linux/dmapool.h>
10 
11 #include "musb_dma.h"
12 #include "musb_core.h"
13 
14 
15 /* FIXME fully isolate CPPI from DaVinci ... the "CPPI generic" registers
16  * would seem to be shared with the TUSB6020 (over VLYNQ).
17  */
18 
19 #include "davinci.h"
20 
21 
22 /* CPPI RX/TX state RAM */
23 
24 struct cppi_tx_stateram {
25 	u32 tx_head;			/* "DMA packet" head descriptor */
26 	u32 tx_buf;
27 	u32 tx_current;			/* current descriptor */
28 	u32 tx_buf_current;
29 	u32 tx_info;			/* flags, remaining buflen */
30 	u32 tx_rem_len;
31 	u32 tx_dummy;			/* unused */
32 	u32 tx_complete;
33 };
34 
35 struct cppi_rx_stateram {
36 	u32 rx_skipbytes;
37 	u32 rx_head;
38 	u32 rx_sop;			/* "DMA packet" head descriptor */
39 	u32 rx_current;			/* current descriptor */
40 	u32 rx_buf_current;
41 	u32 rx_len_len;
42 	u32 rx_cnt_cnt;
43 	u32 rx_complete;
44 };
45 
46 /* hw_options bits in CPPI buffer descriptors */
47 #define CPPI_SOP_SET	((u32)(1 << 31))
48 #define CPPI_EOP_SET	((u32)(1 << 30))
49 #define CPPI_OWN_SET	((u32)(1 << 29))	/* owned by cppi */
50 #define CPPI_EOQ_MASK	((u32)(1 << 28))
51 #define CPPI_ZERO_SET	((u32)(1 << 23))	/* rx saw zlp; tx issues one */
52 #define CPPI_RXABT_MASK	((u32)(1 << 19))	/* need more rx buffers */
53 
54 #define CPPI_RECV_PKTLEN_MASK 0xFFFF
55 #define CPPI_BUFFER_LEN_MASK 0xFFFF
56 
57 #define CPPI_TEAR_READY ((u32)(1 << 31))
58 
59 /* CPPI data structure definitions */
60 
61 #define	CPPI_DESCRIPTOR_ALIGN	16	/* bytes; 5-dec docs say 4-byte align */
62 
63 struct cppi_descriptor {
64 	/* hardware overlay */
65 	u32		hw_next;	/* next buffer descriptor Pointer */
66 	u32		hw_bufp;	/* i/o buffer pointer */
67 	u32		hw_off_len;	/* buffer_offset16, buffer_length16 */
68 	u32		hw_options;	/* flags:  SOP, EOP etc*/
69 
70 	struct cppi_descriptor *next;
71 	dma_addr_t	dma;		/* address of this descriptor */
72 	u32		buflen;		/* for RX: original buffer length */
73 } __attribute__ ((aligned(CPPI_DESCRIPTOR_ALIGN)));
74 
75 
76 struct cppi;
77 
78 /* CPPI  Channel Control structure */
79 struct cppi_channel {
80 	struct dma_channel	channel;
81 
82 	/* back pointer to the DMA controller structure */
83 	struct cppi		*controller;
84 
85 	/* which direction of which endpoint? */
86 	struct musb_hw_ep	*hw_ep;
87 	bool			transmit;
88 	u8			index;
89 
90 	/* DMA modes:  RNDIS or "transparent" */
91 	u8			is_rndis;
92 
93 	/* book keeping for current transfer request */
94 	dma_addr_t		buf_dma;
95 	u32			buf_len;
96 	u32			maxpacket;
97 	u32			offset;		/* dma requested */
98 
99 	void __iomem		*state_ram;	/* CPPI state */
100 
101 	struct cppi_descriptor	*freelist;
102 
103 	/* BD management fields */
104 	struct cppi_descriptor	*head;
105 	struct cppi_descriptor	*tail;
106 	struct cppi_descriptor	*last_processed;
107 
108 	/* use tx_complete in host role to track endpoints waiting for
109 	 * FIFONOTEMPTY to clear.
110 	 */
111 	struct list_head	tx_complete;
112 };
113 
114 /* CPPI DMA controller object */
115 struct cppi {
116 	struct dma_controller		controller;
117 	struct musb			*musb;
118 	void __iomem			*mregs;		/* Mentor regs */
119 	void __iomem			*tibase;	/* TI/CPPI regs */
120 
121 	int				irq;
122 
123 	struct cppi_channel		tx[4];
124 	struct cppi_channel		rx[4];
125 
126 	struct dma_pool			*pool;
127 
128 	struct list_head		tx_complete;
129 };
130 
131 /* CPPI IRQ handler */
132 extern irqreturn_t cppi_interrupt(int, void *);
133 
134 #endif				/* end of ifndef _CPPI_DMA_H_ */
135