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authorBen Dooks <ben-linux@fluff.org>2005-08-10 11:45:14 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2005-08-10 11:45:14 -0400
commitc59d071d4a32e1c45cac6d47f5b59ec36a9a997b (patch)
tree671909f7778b7ec30bfe821c85b5c4802e7f2479 /Documentation/arm
parent8d3722667762af1490db18ba927386d3be89a32b (diff)
[PATCH] ARM: 2847/1: S3C24XX - Documentation for USB OHCI host
Patch from Ben Dooks Documentation for the in-built OHCI host controller and the support for it in Linux. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'Documentation/arm')
-rw-r--r--Documentation/arm/Samsung-S3C24XX/USB-Host.txt93
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1 S3C24XX USB Host support
2 ========================
3
4
5
6Introduction
7------------
8
9 This document details the S3C2410/S3C2440 in-built OHCI USB host support.
10
11Configuration
12-------------
13
14 Enable at least the following kernel options:
15
16 menuconfig:
17
18 Device Drivers --->
19 USB support --->
20 <*> Support for Host-side USB
21 <*> OHCI HCD support
22
23
24 .config:
25 CONFIG_USB
26 CONFIG_USB_OHCI_HCD
27
28
29 Once these options are configured, the standard set of USB device
30 drivers can be configured and used.
31
32
33Board Support
34-------------
35
36 The driver attaches to a platform device, which will need to be
37 added by the board specific support file in linux/arch/arm/mach-s3c2410,
38 such as mach-bast.c or mach-smdk2410.c
39
40 The platform device's platform_data field is only needed if the
41 board implements extra power control or over-current monitoring.
42
43 The OHCI driver does not ensure the state of the S3C2410's MISCCTRL
44 register, so if both ports are to be used for the host, then it is
45 the board support file's responsibility to ensure that the second
46 port is configured to be connected to the OHCI core.
47
48
49Platform Data
50-------------
51
52 See linux/include/asm-arm/arch-s3c2410/usb-control.h for the
53 descriptions of the platform device data. An implementation
54 can be found in linux/arch/arm/mach-s3c2410/usb-simtec.c .
55
56 The `struct s3c2410_hcd_info` contains a pair of functions
57 that get called to enable over-current detection, and to
58 control the port power status.
59
60 The ports are numbered 0 and 1.
61
62 power_control:
63
64 Called to enable or disable the power on the port.
65
66 enable_oc:
67
68 Called to enable or disable the over-current monitoring.
69 This should claim or release the resources being used to
70 check the power condition on the port, such as an IRQ.
71
72 report_oc:
73
74 The OHCI driver fills this field in for the over-current code
75 to call when there is a change to the over-current state on
76 an port. The ports argument is a bitmask of 1 bit per port,
77 with bit X being 1 for an over-current on port X.
78
79 The function s3c2410_usb_report_oc() has been provided to
80 ensure this is called correctly.
81
82 port[x]:
83
84 This is struct describes each port, 0 or 1. The platform driver
85 should set the flags field of each port to S3C_HCDFLG_USED if
86 the port is enabled.
87
88
89
90Document Author
91---------------
92
93Ben Dooks, (c) 2005 Simtec Electronics