1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2007 by Alan Stern
4 */
5
6/* this file is part of ehci-hcd.c */
7
8
9/* Display the ports dedicated to the companion controller */
10static ssize_t companion_show(struct device *dev,
11 struct device_attribute *attr,
12 char *buf)
13{
14 struct ehci_hcd *ehci;
15 int nports, index, n;
16 int count = PAGE_SIZE;
17 char *ptr = buf;
18
19 ehci = hcd_to_ehci(hcd: dev_get_drvdata(dev));
20 nports = HCS_N_PORTS(ehci->hcs_params);
21
22 for (index = 0; index < nports; ++index) {
23 if (test_bit(index, &ehci->companion_ports)) {
24 n = scnprintf(buf: ptr, size: count, fmt: "%d\n", index + 1);
25 ptr += n;
26 count -= n;
27 }
28 }
29 return ptr - buf;
30}
31
32/*
33 * Dedicate or undedicate a port to the companion controller.
34 * Syntax is "[-]portnum", where a leading '-' sign means
35 * return control of the port to the EHCI controller.
36 */
37static ssize_t companion_store(struct device *dev,
38 struct device_attribute *attr,
39 const char *buf, size_t count)
40{
41 struct ehci_hcd *ehci;
42 int portnum, new_owner;
43
44 ehci = hcd_to_ehci(hcd: dev_get_drvdata(dev));
45 new_owner = PORT_OWNER; /* Owned by companion */
46 if (sscanf(buf, "%d", &portnum) != 1)
47 return -EINVAL;
48 if (portnum < 0) {
49 portnum = - portnum;
50 new_owner = 0; /* Owned by EHCI */
51 }
52 if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
53 return -ENOENT;
54 portnum--;
55 if (new_owner)
56 set_bit(nr: portnum, addr: &ehci->companion_ports);
57 else
58 clear_bit(nr: portnum, addr: &ehci->companion_ports);
59 set_owner(ehci, portnum, new_owner);
60 return count;
61}
62static DEVICE_ATTR_RW(companion);
63
64
65/*
66 * Display / Set uframe_periodic_max
67 */
68static ssize_t uframe_periodic_max_show(struct device *dev,
69 struct device_attribute *attr,
70 char *buf)
71{
72 struct ehci_hcd *ehci;
73 int n;
74
75 ehci = hcd_to_ehci(hcd: dev_get_drvdata(dev));
76 n = scnprintf(buf, PAGE_SIZE, fmt: "%d\n", ehci->uframe_periodic_max);
77 return n;
78}
79
80
81static ssize_t uframe_periodic_max_store(struct device *dev,
82 struct device_attribute *attr,
83 const char *buf, size_t count)
84{
85 struct ehci_hcd *ehci;
86 unsigned uframe_periodic_max;
87 unsigned uframe;
88 unsigned long flags;
89 ssize_t ret;
90
91 ehci = hcd_to_ehci(hcd: dev_get_drvdata(dev));
92 if (kstrtouint(s: buf, base: 0, res: &uframe_periodic_max) < 0)
93 return -EINVAL;
94
95 if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
96 ehci_info(ehci, "rejecting invalid request for "
97 "uframe_periodic_max=%u\n", uframe_periodic_max);
98 return -EINVAL;
99 }
100
101 ret = -EINVAL;
102
103 /*
104 * lock, so that our checking does not race with possible periodic
105 * bandwidth allocation through submitting new urbs.
106 */
107 spin_lock_irqsave (&ehci->lock, flags);
108
109 /*
110 * for request to decrease max periodic bandwidth, we have to check
111 * to see whether the decrease is possible.
112 */
113 if (uframe_periodic_max < ehci->uframe_periodic_max) {
114 u8 allocated_max = 0;
115
116 for (uframe = 0; uframe < EHCI_BANDWIDTH_SIZE; ++uframe)
117 allocated_max = max(allocated_max,
118 ehci->bandwidth[uframe]);
119
120 if (allocated_max > uframe_periodic_max) {
121 ehci_info(ehci,
122 "cannot decrease uframe_periodic_max because "
123 "periodic bandwidth is already allocated "
124 "(%u > %u)\n",
125 allocated_max, uframe_periodic_max);
126 goto out_unlock;
127 }
128 }
129
130 /* increasing is always ok */
131
132 ehci_info(ehci, "setting max periodic bandwidth to %u%% "
133 "(== %u usec/uframe)\n",
134 100*uframe_periodic_max/125, uframe_periodic_max);
135
136 if (uframe_periodic_max != 100)
137 ehci_warn(ehci, "max periodic bandwidth set is non-standard\n");
138
139 ehci->uframe_periodic_max = uframe_periodic_max;
140 ret = count;
141
142out_unlock:
143 spin_unlock_irqrestore (lock: &ehci->lock, flags);
144 return ret;
145}
146static DEVICE_ATTR_RW(uframe_periodic_max);
147
148
149static inline int create_sysfs_files(struct ehci_hcd *ehci)
150{
151 struct device *controller = ehci_to_hcd(ehci)->self.controller;
152 int i = 0;
153
154 /* with integrated TT there is no companion! */
155 if (!ehci_is_TDI(ehci))
156 i = device_create_file(device: controller, entry: &dev_attr_companion);
157 if (i)
158 goto out;
159
160 i = device_create_file(device: controller, entry: &dev_attr_uframe_periodic_max);
161out:
162 return i;
163}
164
165static inline void remove_sysfs_files(struct ehci_hcd *ehci)
166{
167 struct device *controller = ehci_to_hcd(ehci)->self.controller;
168
169 /* with integrated TT there is no companion! */
170 if (!ehci_is_TDI(ehci))
171 device_remove_file(dev: controller, attr: &dev_attr_companion);
172
173 device_remove_file(dev: controller, attr: &dev_attr_uframe_periodic_max);
174}
175

source code of linux/drivers/usb/host/ehci-sysfs.c