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1 /*
2  * mostcore.h - Interface between MostCore,
3  *   Hardware Dependent Module (HDM) and Application Interface Module (AIM).
4  *
5  * Copyright (C) 2013-2015, Microchip Technology Germany II GmbH & Co. KG
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  *
12  * This file is licensed under GPLv2.
13  */
14 
15 /*
16  * Authors:
17  *   Andrey Shvetsov <andrey.shvetsov@k2l.de>
18  *   Christian Gromm <christian.gromm@microchip.com>
19  *   Sebastian Graf
20  */
21 
22 #ifndef __MOST_CORE_H__
23 #define __MOST_CORE_H__
24 
25 #include <linux/types.h>
26 
27 struct kobject;
28 struct module;
29 
30 /**
31  * Interface type
32  */
33 enum most_interface_type {
34 	ITYPE_LOOPBACK = 1,
35 	ITYPE_I2C,
36 	ITYPE_I2S,
37 	ITYPE_TSI,
38 	ITYPE_HBI,
39 	ITYPE_MEDIALB_DIM,
40 	ITYPE_MEDIALB_DIM2,
41 	ITYPE_USB,
42 	ITYPE_PCIE
43 };
44 
45 /**
46  * Channel direction.
47  */
48 enum most_channel_direction {
49 	MOST_CH_RX = 1 << 0,
50 	MOST_CH_TX = 1 << 1,
51 };
52 
53 /**
54  * Channel data type.
55  */
56 enum most_channel_data_type {
57 	MOST_CH_CONTROL = 1 << 0,
58 	MOST_CH_ASYNC = 1 << 1,
59 	MOST_CH_ISOC_AVP = 1 << 2,
60 	MOST_CH_SYNC = 1 << 5,
61 };
62 
63 
64 enum mbo_status_flags {
65 	/* MBO was processed successfully (data was send or received )*/
66 	MBO_SUCCESS = 0,
67 	/* The MBO contains wrong or missing information.  */
68 	MBO_E_INVAL,
69 	/* MBO was completed as HDM Channel will be closed */
70 	MBO_E_CLOSE,
71 };
72 
73 /**
74  * struct most_channel_capability - Channel capability
75  * @direction: Supported channel directions.
76  * The value is bitwise OR-combination of the values from the
77  * enumeration most_channel_direction. Zero is allowed value and means
78  * "channel may not be used".
79  * @data_type: Supported channel data types.
80  * The value is bitwise OR-combination of the values from the
81  * enumeration most_channel_data_type. Zero is allowed value and means
82  * "channel may not be used".
83  * @num_buffer_packet: Maximum number of buffers supported by this channel
84  * for packet data types (Async,Control,QoS)
85  * @buffer_size_packet: Maximum buffer size supported by this channel
86  * for packet data types (Async,Control,QoS)
87  * @num_buffer_streaming: Maximum number of buffers supported by this channel
88  * for streaming data types (Sync,AV Packetized)
89  * @buffer_size_streaming: Maximum buffer size supported by this channel
90  * for streaming data types (Sync,AV Packetized)
91  * @name_suffix: Optional suffix providean by an HDM that is attached to the
92  * regular channel name.
93  *
94  * Describes the capabilities of a MostCore channel like supported Data Types
95  * and directions. This information is provided by an HDM for the MostCore.
96  *
97  * The Core creates read only sysfs attribute files in
98  * /sys/devices/virtual/most/mostcore/devices/mdev-#/mdev#-ch#/ with the
99  * following attributes:
100  *	-available_directions
101  *	-available_datatypes
102  *	-number_of_packet_buffers
103  *	-number_of_stream_buffers
104  *	-size_of_packet_buffer
105  *	-size_of_stream_buffer
106  * where content of each file is a string with all supported properties of this
107  * very channel attribute.
108  */
109 struct most_channel_capability {
110 	u16 direction;
111 	u16 data_type;
112 	u16 num_buffers_packet;
113 	u16 buffer_size_packet;
114 	u16 num_buffers_streaming;
115 	u16 buffer_size_streaming;
116 	char *name_suffix;
117 };
118 
119 /**
120  * struct most_channel_config - stores channel configuration
121  * @direction: direction of the channel
122  * @data_type: data type travelling over this channel
123  * @num_buffers: number of buffers
124  * @buffer_size: size of a buffer for AIM.
125  * Buffer size may be cutted down by HDM in a configure callback
126  * to match to a given interface and channel type.
127  * @extra_len: additional buffer space for internal HDM purposes like padding.
128  * May be set by HDM in a configure callback if needed.
129  * @subbuffer_size: size of a subbuffer
130  * @packets_per_xact: number of MOST frames that are packet inside one USB
131  *		      packet. This is USB specific
132  *
133  * Describes the configuration for a MostCore channel. This information is
134  * provided from the MostCore to a HDM (like the Medusa PCIe Interface) as a
135  * parameter of the "configure" function call.
136  */
137 struct most_channel_config {
138 	enum most_channel_direction direction;
139 	enum most_channel_data_type data_type;
140 	u16 num_buffers;
141 	u16 buffer_size;
142 	u16 extra_len;
143 	u16 subbuffer_size;
144 	u16 packets_per_xact;
145 };
146 
147 /*
148  * struct mbo - MOST Buffer Object.
149  * @context: context for core completion handler
150  * @priv: private data for HDM
151  *
152  *	public: documented fields that are used for the communications
153  *	between MostCore and HDMs
154  *
155  * @list: list head for use by the mbo's current owner
156  * @ifp: (in) associated interface instance
157  * @hdm_channel_id: (in) HDM channel instance
158  * @virt_address: (in) kernel virtual address of the buffer
159  * @bus_address: (in) bus address of the buffer
160  * @buffer_length: (in) buffer payload length
161  * @processed_length: (out) processed length
162  * @status: (out) transfer status
163  * @complete: (in) completion routine
164  *
165  * The MostCore allocates and initializes the MBO.
166  *
167  * The HDM receives MBO for transfer from MostCore with the call to enqueue().
168  * The HDM copies the data to- or from the buffer depending on configured
169  * channel direction, set "processed_length" and "status" and completes
170  * the transfer procedure by calling the completion routine.
171  *
172  * At the end the MostCore deallocates the MBO or recycles it for further
173  * transfers for the same or different HDM.
174  *
175  * Directions of usage:
176  * The core driver should never access any MBO fields (even if marked
177  * as "public") while the MBO is owned by an HDM. The ownership starts with
178  * the call of enqueue() and ends with the call of its complete() routine.
179  *
180  *					II.
181  * Every HDM attached to the core driver _must_ ensure that it returns any MBO
182  * it owns (due to a previous call to enqueue() by the core driver) before it
183  * de-registers an interface or gets unloaded from the kernel. If this direction
184  * is violated memory leaks will occur, since the core driver does _not_ track
185  * MBOs it is currently not in control of.
186  *
187  */
188 struct mbo {
189 	void *context;
190 	void *priv;
191 	struct list_head list;
192 	struct most_interface *ifp;
193 	int *num_buffers_ptr;
194 	u16 hdm_channel_id;
195 	void *virt_address;
196 	dma_addr_t bus_address;
197 	u16 buffer_length;
198 	u16 processed_length;
199 	enum mbo_status_flags status;
200 	void (*complete)(struct mbo *);
201 };
202 
203 /**
204  * Interface instance description.
205  *
206  * Describes one instance of an interface like Medusa PCIe or Vantage USB.
207  * This structure is allocated and initialized in the HDM. MostCore may not
208  * modify this structure.
209  *
210  * @interface Interface type. \sa most_interface_type.
211  * @description PRELIMINARY.
212  *   Unique description of the device instance from point of view of the
213  *   interface in free text form (ASCII).
214  *   It may be a hexadecimal presentation of the memory address for the MediaLB
215  *   IP or USB device ID with USB properties for USB interface, etc.
216  * @num_channels Number of channels and size of the channel_vector.
217  * @channel_vector Properties of the channels.
218  *   Array index represents channel ID by the driver.
219  * @configure Callback to change data type for the channel of the
220  *   interface instance. May be zero if the instance of the interface is not
221  *   configurable. Parameter channel_config describes direction and data
222  *   type for the channel, configured by the higher level. The content of
223  * @enqueue Delivers MBO to the HDM for processing.
224  *   After HDM completes Rx- or Tx- operation the processed MBO shall
225  *   be returned back to the MostCore using completion routine.
226  *   The reason to get the MBO delivered from the MostCore after the channel
227  *   is poisoned is the re-opening of the channel by the application.
228  *   In this case the HDM shall hold MBOs and service the channel as usual.
229  *   The HDM must be able to hold at least one MBO for each channel.
230  *   The callback returns a negative value on error, otherwise 0.
231  * @poison_channel Informs HDM about closing the channel. The HDM shall
232  *   cancel all transfers and synchronously or asynchronously return
233  *   all enqueued for this channel MBOs using the completion routine.
234  *   The callback returns a negative value on error, otherwise 0.
235  * @request_netinfo: triggers retrieving of network info from the HDM by
236  *   means of "Message exchange over MDP/MEP"
237  * @priv Private field used by mostcore to store context information.
238  */
239 struct most_interface {
240 	struct module *mod;
241 	enum most_interface_type interface;
242 	const char *description;
243 	int num_channels;
244 	struct most_channel_capability *channel_vector;
245 	int (*configure)(struct most_interface *iface, int channel_idx,
246 			 struct most_channel_config *channel_config);
247 	int (*enqueue)(struct most_interface *iface, int channel_idx,
248 		       struct mbo *mbo);
249 	int (*poison_channel)(struct most_interface *iface, int channel_idx);
250 	void (*request_netinfo)(struct most_interface *iface, int channel_idx);
251 	void *priv;
252 };
253 
254 /**
255  * struct most_aim - identifies MOST device driver to mostcore
256  * @name: Driver name
257  * @probe_channel: function for core to notify driver about channel connection
258  * @disconnect_channel: callback function to disconnect a certain channel
259  * @rx_completion: completion handler for received packets
260  * @tx_completion: completion handler for transmitted packets
261  * @context: context pointer to be used by mostcore
262  */
263 struct most_aim {
264 	const char *name;
265 	int (*probe_channel)(struct most_interface *iface, int channel_idx,
266 			     struct most_channel_config *cfg,
267 			     struct kobject *parent, char *name);
268 	int (*disconnect_channel)(struct most_interface *iface,
269 				  int channel_idx);
270 	int (*rx_completion)(struct mbo *mbo);
271 	int (*tx_completion)(struct most_interface *iface, int channel_idx);
272 	void *context;
273 };
274 
275 /**
276  * most_register_interface - Registers instance of the interface.
277  * @iface: Pointer to the interface instance description.
278  *
279  * Returns a pointer to the kobject of the generated instance.
280  *
281  * Note: HDM has to ensure that any reference held on the kobj is
282  * released before deregistering the interface.
283  */
284 struct kobject *most_register_interface(struct most_interface *iface);
285 
286 /**
287  * Deregisters instance of the interface.
288  * @intf_instance Pointer to the interface instance description.
289  */
290 void most_deregister_interface(struct most_interface *iface);
291 int most_submit_mbo(struct mbo *mbo);
292 
293 /**
294  * most_stop_enqueue - prevents core from enqueing MBOs
295  * @iface: pointer to interface
296  * @channel_idx: channel index
297  */
298 void most_stop_enqueue(struct most_interface *iface, int channel_idx);
299 
300 /**
301  * most_resume_enqueue - allow core to enqueue MBOs again
302  * @iface: pointer to interface
303  * @channel_idx: channel index
304  *
305  * This clears the enqueue halt flag and enqueues all MBOs currently
306  * in wait fifo.
307  */
308 void most_resume_enqueue(struct most_interface *iface, int channel_idx);
309 int most_register_aim(struct most_aim *aim);
310 int most_deregister_aim(struct most_aim *aim);
311 struct mbo *most_get_mbo(struct most_interface *iface, int channel_idx,
312 			 struct most_aim *);
313 void most_put_mbo(struct mbo *mbo);
314 int channel_has_mbo(struct most_interface *iface, int channel_idx);
315 int most_start_channel(struct most_interface *iface, int channel_idx,
316 		       struct most_aim *);
317 int most_stop_channel(struct most_interface *iface, int channel_idx,
318 		      struct most_aim *);
319 
320 
321 #endif /* MOST_CORE_H_ */
322