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