GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: core/src/ux_host_stack_bandwidth_release.c Lines: 40 40 100.0 %
Date: 2024-12-12 17:16:36 Branches: 24 24 100.0 %

Line Branch Exec Source
1
/***************************************************************************
2
 * Copyright (c) 2024 Microsoft Corporation
3
 *
4
 * This program and the accompanying materials are made available under the
5
 * terms of the MIT License which is available at
6
 * https://opensource.org/licenses/MIT.
7
 *
8
 * SPDX-License-Identifier: MIT
9
 **************************************************************************/
10
11
12
/**************************************************************************/
13
/**************************************************************************/
14
/**                                                                       */
15
/** USBX Component                                                        */
16
/**                                                                       */
17
/**   Host Stack                                                          */
18
/**                                                                       */
19
/**************************************************************************/
20
/**************************************************************************/
21
22
23
/* Include necessary system files.  */
24
25
#define UX_SOURCE_CODE
26
27
#include "ux_api.h"
28
#include "ux_host_stack.h"
29
30
31
#if UX_MAX_DEVICES > 1
32
/**************************************************************************/
33
/*                                                                        */
34
/*  FUNCTION                                               RELEASE        */
35
/*                                                                        */
36
/*    _ux_host_stack_bandwidth_release                    PORTABLE C      */
37
/*                                                           6.1          */
38
/*  AUTHOR                                                                */
39
/*                                                                        */
40
/*    Chaoqiong Xiao, Microsoft Corporation                               */
41
/*                                                                        */
42
/*  DESCRIPTION                                                           */
43
/*                                                                        */
44
/*    This function will release bandwidth for a periodic endpoint. The   */
45
/*    bandwidth requirement is calculated by the MaxPacketSize field of   */
46
/*    endpoint and the speed of the endpoint. If the device is on a 1.1   */
47
/*    bus or it is a 1.1 device behind a 2.0 hub on a 2.0 bus, the device */
48
/*    bandwidth must be multiplied by 8 on the 1.1 segment.               */
49
/*                                                                        */
50
/*    This algorithm takes into account both TT bandwidth and HCD         */
51
/*    bandwidth. The TTs are attached to the device structure and not the */
52
/*    hub structure in order to make the stack agnostic of the hub class. */
53
/*                                                                        */
54
/*  INPUT                                                                 */
55
/*                                                                        */
56
/*    HCD                                   Pointer to HCD                */
57
/*    endpoint                              Pointer to endpoint           */
58
/*                                                                        */
59
/*  OUTPUT                                                                */
60
/*                                                                        */
61
/*    None                                                                */
62
/*                                                                        */
63
/*  CALLS                                                                 */
64
/*                                                                        */
65
/*    None                                                                */
66
/*                                                                        */
67
/*  CALLED BY                                                             */
68
/*                                                                        */
69
/*    USBX Components                                                     */
70
/*                                                                        */
71
/*  RELEASE HISTORY                                                       */
72
/*                                                                        */
73
/*    DATE              NAME                      DESCRIPTION             */
74
/*                                                                        */
75
/*  05-19-2020     Chaoqiong Xiao           Initial Version 6.0           */
76
/*  09-30-2020     Chaoqiong Xiao           Modified comment(s),          */
77
/*                                            optimized based on compile  */
78
/*                                            definitions,                */
79
/*                                            resulting in version 6.1    */
80
/*                                                                        */
81
/**************************************************************************/
82
1139
VOID  _ux_host_stack_bandwidth_release(UX_HCD *hcd, UX_ENDPOINT *endpoint)
83
{
84
85
UX_DEVICE       *device;
86
UX_DEVICE       *parent_device;
87
USHORT          hcd_bandwidth_claimed;
88
USHORT          max_packet_size;
89
LONG            packet_size;
90
1139
USHORT          tt_bandwidth_claimed =  0;
91
ULONG           port_index;
92
ULONG           port_map;
93
ULONG           tt_index;
94
1139
const UCHAR     overheads[4][3] = {
95
/*   LS  FS   HS   */
96
    {63, 45, 173}, /* Control */
97
    { 0,  9,  38}, /* Isochronous */
98
    { 0, 13,  55}, /* Bulk */
99
    {19, 13,  55}  /* Interrupt */
100
};
101
102
    /* Get the pointer to the device.  */
103
1139
    device =  endpoint -> ux_endpoint_device;
104
105
    /* Calculate the bandwidth. From USB spec.
106
     *
107
     * The frame unit consumed per byte is like follow:
108
     *              Bytes/FrameUnit     FrameUnit/byte  FrameUnit/byte
109
     *              (Overhead included) (HS baseline)   (FS baseline)
110
     * Low Speed       187.5                40             8
111
     * Full Speed     1500                   5             1
112
     * High Speed     7500                   1            1/5
113
     *
114
     * The overhead is like follow:
115
     *               Control Isochronous Bulk Interrupt
116
     * bmAttribute     (0)       (1)     (2)     (3)
117
     * Low Speed        63       --      --      19
118
     * Full Speed       45        9      13      13
119
     * High Speed      173       38      55      55
120
     *
121
     * Worst case bit stuffing is calculated as 1.1667 (7/6) times the raw time.
122
     */
123
124
    /* Get maximum packet size.  */
125
1139
    max_packet_size  = endpoint -> ux_endpoint_descriptor.wMaxPacketSize & UX_MAX_PACKET_SIZE_MASK;
126
127
    /* Rough time for possible Bit Stuffing.  */
128
1139
    packet_size = (max_packet_size * 7 + 5) / 6;
129
130
    /* Add overhead.  */
131
1139
    packet_size += overheads[endpoint -> ux_endpoint_descriptor.bmAttributes & UX_MASK_ENDPOINT_TYPE][device -> ux_device_speed];
132
1139
    max_packet_size = (USHORT)packet_size;
133
134
    /* Check for high-speed endpoint.  */
135
1139
    if (device -> ux_device_speed == UX_HIGH_SPEED_DEVICE)
136
    {
137
138
        /* Get number of transactions.  */
139
119
        max_packet_size = (USHORT)(max_packet_size *
140
119
                    (((endpoint -> ux_endpoint_descriptor.wMaxPacketSize & UX_MAX_NUMBER_OF_TRANSACTIONS_MASK) >>
141
119
                        UX_MAX_NUMBER_OF_TRANSACTIONS_SHIFT) + 1));
142
    }
143
144
    /* Calculate the bandwidth claimed by this endpoint for the main bus.  */
145
1139
    if (hcd -> ux_hcd_version != 0x200)
146
    {
147
148
1109
        if (device -> ux_device_speed == UX_LOW_SPEED_DEVICE)
149
            /* Low speed transfer takes 40x more units than high speed. */
150
6
            hcd_bandwidth_claimed =  (USHORT)(max_packet_size * 8 * 5);
151
        else
152
        {
153
154
1103
            if (device -> ux_device_speed == UX_FULL_SPEED_DEVICE)
155
                /* Full speed transfer takes 5x more units than high speed. */
156
990
                hcd_bandwidth_claimed =  (USHORT)(max_packet_size * 5);
157
            else
158
                /* Use high speed timing as base for bus bandwidth calculation. */
159
113
                hcd_bandwidth_claimed =  (USHORT)max_packet_size;
160
        }
161
    }
162
    else
163
    {
164
165
30
        hcd_bandwidth_claimed =  (USHORT)max_packet_size;
166
30
        if (device -> ux_device_speed == UX_LOW_SPEED_DEVICE)
167
            /* Low speed transfer takes 8x more units than full speed. */
168
6
            tt_bandwidth_claimed =  (USHORT)(max_packet_size * 8);
169
        else
170
            /* Use full speed timing as base for TT bandwidth calculation. */
171
24
            tt_bandwidth_claimed =  (USHORT)max_packet_size;
172
    }
173
174
    /* Free the HCD bandwidth.  */
175
1139
    hcd -> ux_hcd_available_bandwidth +=  hcd_bandwidth_claimed;
176
177
    /* We need to take care of the case where the endpoint belongs to a USB 1.1
178
       device that sits behind a 2.0 hub. We ignore cases where the device
179
       is either high speed or the bus is 1.1.  */
180

1139
    if ((device -> ux_device_speed == UX_HIGH_SPEED_DEVICE) || (hcd -> ux_hcd_version != 0x200))
181
    {
182
183
        /* The device is high speed, therefore no need for TT.  */
184
1115
        return;
185
    }
186
187
    /* We have a 1.1 device, check if the parent is a 2.0 hub.  */
188
24
    parent_device =  device -> ux_device_parent;
189
24
    if (parent_device == UX_NULL)
190
    {
191
192
        /* We are at the root, must be a 1.1 controller then! */
193
13
        return;
194
    }
195
196
    /* We get here when the parent is a hub. The problem occurs when the hub is itself
197
       connected to a chain of hubs. We need to find the first 2.0 hub parent to this chain
198
       to check the TT. We need to remember the port on which the first 1.1 device is
199
       hooked to.  */
200
11
    port_index =  device -> ux_device_port_location - 1;
201
202
    /* Scan the chain of hubs upward.  */
203
34
    while (parent_device != UX_NULL)
204
    {
205
206
        /* Check for a high speed device.  */
207
33
        if (parent_device -> ux_device_speed == UX_HIGH_SPEED_DEVICE)
208
        {
209
210
            /* The device is a high speed hub, find the TT that manages the port.
211
               The first 1.1 device is connected to. First we calculate the port mapping bit.  */
212
10
            port_map =  (ULONG)(1 << port_index);
213
214
            /* Parse all the TTs attached to the hub.  */
215
55
            for (tt_index = 0; tt_index < UX_MAX_TT; tt_index++)
216
            {
217
218
                /* Check if this TT owns the port where the device is attached.  */
219
50
                if ((parent_device -> ux_device_hub_tt[tt_index].ux_hub_tt_port_mapping & port_map) != 0)
220
                {
221
222
                    /* We have found the port, check if the tt can give us the bandwidth
223
                       we want to claim.  */
224
5
                    parent_device -> ux_device_hub_tt[tt_index].ux_hub_tt_max_bandwidth +=  tt_bandwidth_claimed;
225
5
                    return;
226
                }
227
            }
228
229
            /* We should never get here!!!!! */
230
5
            return;
231
        }
232
233
        /* We now remember where this hub is located on the parent.  */
234
23
        port_index =  parent_device -> ux_device_port_location - 1;
235
236
        /* We go up one level in the hub chain.  */
237
23
        parent_device =  parent_device -> ux_device_parent;
238
    }
239
240
    /* We get here when we have not found a 2.0 hub in the list and we got
241
       to the root port.  */
242
1
    return;
243
}
244
#endif /* #if UX_MAX_DEVICES > 1 */