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(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(ptr, count, "%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(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(portnum, &ehci->companion_ports);
57	else
58		clear_bit(portnum, &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(dev_get_drvdata(dev));
76	n = scnprintf(buf, PAGE_SIZE, "%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(dev_get_drvdata(dev));
92	if (kstrtouint(buf, 0, &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 (&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(controller, &dev_attr_companion);
157	if (i)
158		goto out;
159
160	i = device_create_file(controller, &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(controller, &dev_attr_companion);
172
173	device_remove_file(controller, &dev_attr_uframe_periodic_max);
174}
175