1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** USBX Component */
17 /** */
18 /** Host Stack */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23
24 /* Include necessary system files. */
25
26 #define UX_SOURCE_CODE
27
28 #include "ux_api.h"
29 #include "ux_host_stack.h"
30
31
32 #if UX_MAX_DEVICES > 1
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _ux_host_stack_bandwidth_check PORTABLE C */
38 /* 6.1 */
39 /* AUTHOR */
40 /* */
41 /* Chaoqiong Xiao, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function will check if there is enough bandwidth on the USB */
46 /* for the specified endpoint. The bandwidth requirement is calculated */
47 /* by the MaxPacketSize field of endpoint and the speed of the */
48 /* endpoint. If the device is on a 1.1 bus or it is a 1.1 device */
49 /* behind a 2.0 hub on a 2.0 bus, the device bandwidth must be */
50 /* multiplied by 8 on the 1.1 segment. */
51 /* */
52 /* This algorithm takes into account both TT bandwidth and HCD */
53 /* bandwidth. The TTs are attached to the device structure and not */
54 /* the hub structure in order to make the stack agnostic of the hub */
55 /* class. */
56 /* */
57 /* INPUT */
58 /* */
59 /* HCD Pointer to HCD */
60 /* endpoint Pointer to endpoint */
61 /* */
62 /* OUTPUT */
63 /* */
64 /* Completion Status */
65 /* */
66 /* CALLS */
67 /* */
68 /* None */
69 /* */
70 /* CALLED BY */
71 /* */
72 /* USBX Components */
73 /* */
74 /* RELEASE HISTORY */
75 /* */
76 /* DATE NAME DESCRIPTION */
77 /* */
78 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
79 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
80 /* optimized based on compile */
81 /* definitions, */
82 /* resulting in version 6.1 */
83 /* */
84 /**************************************************************************/
_ux_host_stack_bandwidth_check(UX_HCD * hcd,UX_ENDPOINT * endpoint)85 UINT _ux_host_stack_bandwidth_check(UX_HCD *hcd, UX_ENDPOINT *endpoint)
86 {
87
88 UX_DEVICE *device;
89 UX_DEVICE *parent_device;
90 USHORT hcd_bandwidth_claimed;
91 USHORT max_packet_size;
92 LONG packet_size;
93 USHORT tt_bandwidth_claimed = 0;
94 ULONG port_index;
95 ULONG port_map;
96 ULONG tt_index;
97 const UCHAR overheads[4][3] = {
98 /* LS FS HS */
99 {63, 45, 173}, /* Control */
100 { 0, 9, 38}, /* Isochronous */
101 { 0, 13, 55}, /* Bulk */
102 {19, 13, 55} /* Interrupt */
103 };
104
105 /* Get the pointer to the device. */
106 device = endpoint -> ux_endpoint_device;
107
108 /* Calculate the bandwidth. From USB spec.
109 *
110 * The frame unit consumed per byte is like follow:
111 * Bytes/FrameUnit FrameUnit/byte FrameUnit/byte
112 * (Overhead included) (HS baseline) (FS baseline)
113 * Low Speed 187.5 40 8
114 * Full Speed 1500 5 1
115 * High Speed 7500 1 1/5
116 *
117 * The overhead is like follow:
118 * Control Isochronous Bulk Interrupt
119 * bmAttribute (0) (1) (2) (3)
120 * Low Speed 63 -- -- 19
121 * Full Speed 45 9 13 13
122 * High Speed 173 38 55 55
123 *
124 * Worst case bit stuffing is calculated as 1.1667 (7/6) times the raw time.
125 */
126
127 /* Get maximum packet size. */
128 max_packet_size = endpoint -> ux_endpoint_descriptor.wMaxPacketSize & UX_MAX_PACKET_SIZE_MASK;
129
130 /* Rough time for possible Bit Stuffing. */
131 packet_size = (max_packet_size * 7 + 5) / 6;
132
133 /* Add overhead. */
134 packet_size += overheads[endpoint -> ux_endpoint_descriptor.bmAttributes & UX_MASK_ENDPOINT_TYPE][device -> ux_device_speed];
135 max_packet_size = (USHORT)packet_size;
136
137 /* Check for high-speed endpoint. */
138 if (device -> ux_device_speed == UX_HIGH_SPEED_DEVICE)
139 {
140
141 /* Get number of transactions. */
142 max_packet_size = (USHORT)(max_packet_size *
143 (((endpoint -> ux_endpoint_descriptor.wMaxPacketSize & UX_MAX_NUMBER_OF_TRANSACTIONS_MASK) >>
144 UX_MAX_NUMBER_OF_TRANSACTIONS_SHIFT) + 1));
145 }
146
147 /* Calculate the bandwidth claimed by this endpoint for the main bus. */
148 if (hcd -> ux_hcd_version != 0x200)
149 {
150
151 if (device -> ux_device_speed == UX_LOW_SPEED_DEVICE)
152 /* Low speed transfer takes 40x more units than high speed. */
153 hcd_bandwidth_claimed = (USHORT)(max_packet_size * 8 * 5);
154 else
155 {
156
157 if (device -> ux_device_speed == UX_FULL_SPEED_DEVICE)
158 /* Full speed transfer takes 5x more units than high speed. */
159 hcd_bandwidth_claimed = (USHORT)(max_packet_size * 5);
160 else
161 /* Use high speed timing as base for bus bandwidth calculation. */
162 hcd_bandwidth_claimed = (USHORT)max_packet_size;
163 }
164 }
165 else
166 {
167
168 hcd_bandwidth_claimed = (USHORT)max_packet_size;
169 if (device -> ux_device_speed == UX_LOW_SPEED_DEVICE)
170 /* Low speed transfer takes 8x more units than full speed. */
171 tt_bandwidth_claimed = (USHORT)(max_packet_size * 8);
172 else
173 /* Use full speed timing as base for TT bandwidth calculation. */
174 tt_bandwidth_claimed = (USHORT)max_packet_size;
175 }
176
177 /* Do we have enough on the bus for this new endpoint? */
178 if (hcd -> ux_hcd_available_bandwidth < hcd_bandwidth_claimed)
179 {
180
181 /* If trace is enabled, insert this event into the trace buffer. */
182 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_NO_BANDWIDTH_AVAILABLE, endpoint, 0, 0, UX_TRACE_ERRORS, 0, 0)
183
184 /* Error trap. */
185 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_ENUMERATOR, UX_NO_BANDWIDTH_AVAILABLE);
186
187 return(UX_NO_BANDWIDTH_AVAILABLE);
188 }
189
190 /* We need to take care of the case where the endpoint belongs to a USB 1.1
191 device that sits behind a 2.0 hub. We ignore cases where the device
192 is either high speed or the bus is 1.1. */
193 if ((device -> ux_device_speed == UX_HIGH_SPEED_DEVICE) || (hcd -> ux_hcd_version != 0x200))
194 {
195
196 /* The device is high speed, therefore no need for TT. */
197 return(UX_SUCCESS);
198 }
199
200 /* We have a 1.1 device, check if the parent is a 2.0 hub. */
201 parent_device = device -> ux_device_parent;
202 if (parent_device == UX_NULL)
203 {
204
205 /* We are at the root, this controller must support 1.1 then! */
206 return(UX_SUCCESS);
207 }
208
209 /* We get here when the parent is a hub. The problem occurs when the hub is itself
210 connected to a chain of hubs. We need to find the first 2.0 hub parent to this
211 chain to check the TT. We need to remember the port on which the first 1.1
212 device is hooked to. */
213 port_index = device -> ux_device_port_location - 1;
214
215 /* Scan the chain of hubs upward. */
216 while (parent_device != UX_NULL)
217 {
218
219 /* Determine if the device is high speed. */
220 if (parent_device -> ux_device_speed == UX_HIGH_SPEED_DEVICE)
221 {
222
223 /* The device is a high speed hub, find the TT that manages the port.
224 The first 1.1 device is connected to. First we calculate the port
225 mapping bit. */
226 port_map = (ULONG)(1 << port_index);
227
228 /* Parse all the TTs attached to the hub. */
229 for (tt_index = 0; tt_index < UX_MAX_TT; tt_index++)
230 {
231
232 /* Check if this TT owns the port where the device is attached. */
233 if ((parent_device -> ux_device_hub_tt[tt_index].ux_hub_tt_port_mapping & port_map) != 0)
234 {
235
236 /* We have found the port, check if the tt can give us the bandwidth
237 we want to claim. */
238 if (parent_device -> ux_device_hub_tt[tt_index].ux_hub_tt_max_bandwidth < tt_bandwidth_claimed)
239 {
240
241 /* If trace is enabled, insert this event into the trace buffer. */
242 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_NO_BANDWIDTH_AVAILABLE, endpoint, 0, 0, UX_TRACE_ERRORS, 0, 0)
243
244 /* Error trap. */
245 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_ENUMERATOR, UX_NO_BANDWIDTH_AVAILABLE);
246
247 return(UX_NO_BANDWIDTH_AVAILABLE);
248 }
249
250 else
251 return(UX_SUCCESS);
252 }
253 }
254
255 /* If trace is enabled, insert this event into the trace buffer. */
256 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_NO_BANDWIDTH_AVAILABLE, endpoint, 0, 0, UX_TRACE_ERRORS, 0, 0)
257
258 /* Error trap. */
259 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_ENUMERATOR, UX_NO_BANDWIDTH_AVAILABLE);
260
261 /* We should never get here !!!!! */
262 return(UX_NO_BANDWIDTH_AVAILABLE);
263 }
264
265 /* We now remember where this hub is located on the parent. */
266 port_index = parent_device -> ux_device_port_location - 1;
267
268 /* We go up one level in the hub chain. */
269 parent_device = parent_device -> ux_device_parent;
270 }
271
272 /* We get here when we have not found a 2.0 hub in the list and we got to the root port. */
273 return(UX_SUCCESS);
274 }
275 #endif /* #if UX_MAX_DEVICES > 1 */
276
