1 | /* |
2 | * Public header for the MPC52xx processor BestComm driver |
3 | * |
4 | * |
5 | * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com> |
6 | * Copyright (C) 2005 Varma Electronics Oy, |
7 | * ( by Andrey Volkov <avolkov@varma-el.com> ) |
8 | * Copyright (C) 2003-2004 MontaVista, Software, Inc. |
9 | * ( by Dale Farnsworth <dfarnsworth@mvista.com> ) |
10 | * |
11 | * This file is licensed under the terms of the GNU General Public License |
12 | * version 2. This program is licensed "as is" without any warranty of any |
13 | * kind, whether express or implied. |
14 | */ |
15 | |
16 | #ifndef __BESTCOMM_H__ |
17 | #define __BESTCOMM_H__ |
18 | |
19 | /** |
20 | * struct bcom_bd - Structure describing a generic BestComm buffer descriptor |
21 | * @status: The current status of this buffer. Exact meaning depends on the |
22 | * task type |
23 | * @data: An array of u32 extra data. Size of array is task dependent. |
24 | * |
25 | * Note: Don't dereference a bcom_bd pointer as an array. The size of the |
26 | * bcom_bd is variable. Use bcom_get_bd() instead. |
27 | */ |
28 | struct bcom_bd { |
29 | u32 status; |
30 | u32 data[]; /* variable payload size */ |
31 | }; |
32 | |
33 | /* ======================================================================== */ |
34 | /* Generic task management */ |
35 | /* ======================================================================== */ |
36 | |
37 | /** |
38 | * struct bcom_task - Structure describing a loaded BestComm task |
39 | * |
40 | * This structure is never built by the driver it self. It's built and |
41 | * filled the intermediate layer of the BestComm API, the task dependent |
42 | * support code. |
43 | * |
44 | * Most likely you don't need to poke around inside this structure. The |
45 | * fields are exposed in the header just for the sake of inline functions |
46 | */ |
47 | struct bcom_task { |
48 | unsigned int tasknum; |
49 | unsigned int flags; |
50 | int irq; |
51 | |
52 | struct bcom_bd *bd; |
53 | phys_addr_t bd_pa; |
54 | void **cookie; |
55 | unsigned short index; |
56 | unsigned short outdex; |
57 | unsigned int num_bd; |
58 | unsigned int bd_size; |
59 | |
60 | void* priv; |
61 | }; |
62 | |
63 | #define BCOM_FLAGS_NONE 0x00000000ul |
64 | #define BCOM_FLAGS_ENABLE_TASK (1ul << 0) |
65 | |
66 | /** |
67 | * bcom_enable - Enable a BestComm task |
68 | * @tsk: The BestComm task structure |
69 | * |
70 | * This function makes sure the given task is enabled and can be run |
71 | * by the BestComm engine as needed |
72 | */ |
73 | extern void bcom_enable(struct bcom_task *tsk); |
74 | |
75 | /** |
76 | * bcom_disable - Disable a BestComm task |
77 | * @tsk: The BestComm task structure |
78 | * |
79 | * This function disable a given task, making sure it's not executed |
80 | * by the BestComm engine. |
81 | */ |
82 | extern void bcom_disable(struct bcom_task *tsk); |
83 | |
84 | |
85 | /** |
86 | * bcom_get_task_irq - Returns the irq number of a BestComm task |
87 | * @tsk: The BestComm task structure |
88 | */ |
89 | static inline int |
90 | bcom_get_task_irq(struct bcom_task *tsk) { |
91 | return tsk->irq; |
92 | } |
93 | |
94 | /* ======================================================================== */ |
95 | /* BD based tasks helpers */ |
96 | /* ======================================================================== */ |
97 | |
98 | #define BCOM_BD_READY 0x40000000ul |
99 | |
100 | /** _bcom_next_index - Get next input index. |
101 | * @tsk: pointer to task structure |
102 | * |
103 | * Support function; Device drivers should not call this |
104 | */ |
105 | static inline int |
106 | _bcom_next_index(struct bcom_task *tsk) |
107 | { |
108 | return ((tsk->index + 1) == tsk->num_bd) ? 0 : tsk->index + 1; |
109 | } |
110 | |
111 | /** _bcom_next_outdex - Get next output index. |
112 | * @tsk: pointer to task structure |
113 | * |
114 | * Support function; Device drivers should not call this |
115 | */ |
116 | static inline int |
117 | _bcom_next_outdex(struct bcom_task *tsk) |
118 | { |
119 | return ((tsk->outdex + 1) == tsk->num_bd) ? 0 : tsk->outdex + 1; |
120 | } |
121 | |
122 | /** |
123 | * bcom_queue_empty - Checks if a BestComm task BD queue is empty |
124 | * @tsk: The BestComm task structure |
125 | */ |
126 | static inline int |
127 | bcom_queue_empty(struct bcom_task *tsk) |
128 | { |
129 | return tsk->index == tsk->outdex; |
130 | } |
131 | |
132 | /** |
133 | * bcom_queue_full - Checks if a BestComm task BD queue is full |
134 | * @tsk: The BestComm task structure |
135 | */ |
136 | static inline int |
137 | bcom_queue_full(struct bcom_task *tsk) |
138 | { |
139 | return tsk->outdex == _bcom_next_index(tsk); |
140 | } |
141 | |
142 | /** |
143 | * bcom_get_bd - Get a BD from the queue |
144 | * @tsk: The BestComm task structure |
145 | * index: Index of the BD to fetch |
146 | */ |
147 | static inline struct bcom_bd |
148 | *bcom_get_bd(struct bcom_task *tsk, unsigned int index) |
149 | { |
150 | /* A cast to (void*) so the address can be incremented by the |
151 | * real size instead of by sizeof(struct bcom_bd) */ |
152 | return ((void *)tsk->bd) + (index * tsk->bd_size); |
153 | } |
154 | |
155 | /** |
156 | * bcom_buffer_done - Checks if a BestComm |
157 | * @tsk: The BestComm task structure |
158 | */ |
159 | static inline int |
160 | bcom_buffer_done(struct bcom_task *tsk) |
161 | { |
162 | struct bcom_bd *bd; |
163 | if (bcom_queue_empty(tsk)) |
164 | return 0; |
165 | |
166 | bd = bcom_get_bd(tsk, index: tsk->outdex); |
167 | return !(bd->status & BCOM_BD_READY); |
168 | } |
169 | |
170 | /** |
171 | * bcom_prepare_next_buffer - clear status of next available buffer. |
172 | * @tsk: The BestComm task structure |
173 | * |
174 | * Returns pointer to next buffer descriptor |
175 | */ |
176 | static inline struct bcom_bd * |
177 | bcom_prepare_next_buffer(struct bcom_task *tsk) |
178 | { |
179 | struct bcom_bd *bd; |
180 | |
181 | bd = bcom_get_bd(tsk, index: tsk->index); |
182 | bd->status = 0; /* cleanup last status */ |
183 | return bd; |
184 | } |
185 | |
186 | static inline void |
187 | bcom_submit_next_buffer(struct bcom_task *tsk, void *cookie) |
188 | { |
189 | struct bcom_bd *bd = bcom_get_bd(tsk, index: tsk->index); |
190 | |
191 | tsk->cookie[tsk->index] = cookie; |
192 | mb(); /* ensure the bd is really up-to-date */ |
193 | bd->status |= BCOM_BD_READY; |
194 | tsk->index = _bcom_next_index(tsk); |
195 | if (tsk->flags & BCOM_FLAGS_ENABLE_TASK) |
196 | bcom_enable(tsk); |
197 | } |
198 | |
199 | static inline void * |
200 | bcom_retrieve_buffer(struct bcom_task *tsk, u32 *p_status, struct bcom_bd **p_bd) |
201 | { |
202 | void *cookie = tsk->cookie[tsk->outdex]; |
203 | struct bcom_bd *bd = bcom_get_bd(tsk, index: tsk->outdex); |
204 | |
205 | if (p_status) |
206 | *p_status = bd->status; |
207 | if (p_bd) |
208 | *p_bd = bd; |
209 | tsk->outdex = _bcom_next_outdex(tsk); |
210 | return cookie; |
211 | } |
212 | |
213 | #endif /* __BESTCOMM_H__ */ |
214 | |