xref: /openbmc/linux/drivers/usb/host/ehci-sysfs.c (revision 8fdff1dc)
1 /*
2  * Copyright (C) 2007 by Alan Stern
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 /* this file is part of ehci-hcd.c */
20 
21 
22 /* Display the ports dedicated to the companion controller */
23 static ssize_t show_companion(struct device *dev,
24 			      struct device_attribute *attr,
25 			      char *buf)
26 {
27 	struct ehci_hcd		*ehci;
28 	int			nports, index, n;
29 	int			count = PAGE_SIZE;
30 	char			*ptr = buf;
31 
32 	ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
33 	nports = HCS_N_PORTS(ehci->hcs_params);
34 
35 	for (index = 0; index < nports; ++index) {
36 		if (test_bit(index, &ehci->companion_ports)) {
37 			n = scnprintf(ptr, count, "%d\n", index + 1);
38 			ptr += n;
39 			count -= n;
40 		}
41 	}
42 	return ptr - buf;
43 }
44 
45 /*
46  * Dedicate or undedicate a port to the companion controller.
47  * Syntax is "[-]portnum", where a leading '-' sign means
48  * return control of the port to the EHCI controller.
49  */
50 static ssize_t store_companion(struct device *dev,
51 			       struct device_attribute *attr,
52 			       const char *buf, size_t count)
53 {
54 	struct ehci_hcd		*ehci;
55 	int			portnum, new_owner;
56 
57 	ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
58 	new_owner = PORT_OWNER;		/* Owned by companion */
59 	if (sscanf(buf, "%d", &portnum) != 1)
60 		return -EINVAL;
61 	if (portnum < 0) {
62 		portnum = - portnum;
63 		new_owner = 0;		/* Owned by EHCI */
64 	}
65 	if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
66 		return -ENOENT;
67 	portnum--;
68 	if (new_owner)
69 		set_bit(portnum, &ehci->companion_ports);
70 	else
71 		clear_bit(portnum, &ehci->companion_ports);
72 	set_owner(ehci, portnum, new_owner);
73 	return count;
74 }
75 static DEVICE_ATTR(companion, 0644, show_companion, store_companion);
76 
77 
78 /*
79  * Display / Set uframe_periodic_max
80  */
81 static ssize_t show_uframe_periodic_max(struct device *dev,
82 					struct device_attribute *attr,
83 					char *buf)
84 {
85 	struct ehci_hcd		*ehci;
86 	int			n;
87 
88 	ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
89 	n = scnprintf(buf, PAGE_SIZE, "%d\n", ehci->uframe_periodic_max);
90 	return n;
91 }
92 
93 
94 static ssize_t store_uframe_periodic_max(struct device *dev,
95 					struct device_attribute *attr,
96 					const char *buf, size_t count)
97 {
98 	struct ehci_hcd		*ehci;
99 	unsigned		uframe_periodic_max;
100 	unsigned		frame, uframe;
101 	unsigned short		allocated_max;
102 	unsigned long		flags;
103 	ssize_t			ret;
104 
105 	ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
106 	if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
107 		return -EINVAL;
108 
109 	if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
110 		ehci_info(ehci, "rejecting invalid request for "
111 				"uframe_periodic_max=%u\n", uframe_periodic_max);
112 		return -EINVAL;
113 	}
114 
115 	ret = -EINVAL;
116 
117 	/*
118 	 * lock, so that our checking does not race with possible periodic
119 	 * bandwidth allocation through submitting new urbs.
120 	 */
121 	spin_lock_irqsave (&ehci->lock, flags);
122 
123 	/*
124 	 * for request to decrease max periodic bandwidth, we have to check
125 	 * every microframe in the schedule to see whether the decrease is
126 	 * possible.
127 	 */
128 	if (uframe_periodic_max < ehci->uframe_periodic_max) {
129 		allocated_max = 0;
130 
131 		for (frame = 0; frame < ehci->periodic_size; ++frame)
132 			for (uframe = 0; uframe < 7; ++uframe)
133 				allocated_max = max(allocated_max,
134 						    periodic_usecs (ehci, frame, uframe));
135 
136 		if (allocated_max > uframe_periodic_max) {
137 			ehci_info(ehci,
138 				"cannot decrease uframe_periodic_max becase "
139 				"periodic bandwidth is already allocated "
140 				"(%u > %u)\n",
141 				allocated_max, uframe_periodic_max);
142 			goto out_unlock;
143 		}
144 	}
145 
146 	/* increasing is always ok */
147 
148 	ehci_info(ehci, "setting max periodic bandwidth to %u%% "
149 			"(== %u usec/uframe)\n",
150 			100*uframe_periodic_max/125, uframe_periodic_max);
151 
152 	if (uframe_periodic_max != 100)
153 		ehci_warn(ehci, "max periodic bandwidth set is non-standard\n");
154 
155 	ehci->uframe_periodic_max = uframe_periodic_max;
156 	ret = count;
157 
158 out_unlock:
159 	spin_unlock_irqrestore (&ehci->lock, flags);
160 	return ret;
161 }
162 static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max, store_uframe_periodic_max);
163 
164 
165 static inline int create_sysfs_files(struct ehci_hcd *ehci)
166 {
167 	struct device	*controller = ehci_to_hcd(ehci)->self.controller;
168 	int	i = 0;
169 
170 	/* with integrated TT there is no companion! */
171 	if (!ehci_is_TDI(ehci))
172 		i = device_create_file(controller, &dev_attr_companion);
173 	if (i)
174 		goto out;
175 
176 	i = device_create_file(controller, &dev_attr_uframe_periodic_max);
177 out:
178 	return i;
179 }
180 
181 static inline void remove_sysfs_files(struct ehci_hcd *ehci)
182 {
183 	struct device	*controller = ehci_to_hcd(ehci)->self.controller;
184 
185 	/* with integrated TT there is no companion! */
186 	if (!ehci_is_TDI(ehci))
187 		device_remove_file(controller, &dev_attr_companion);
188 
189 	device_remove_file(controller, &dev_attr_uframe_periodic_max);
190 }
191