xref: /OK3568_Linux_fs/kernel/Documentation/arm/samsung-s3c24xx/usb-host.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun========================
2*4882a593SmuzhiyunS3C24XX USB Host support
3*4882a593Smuzhiyun========================
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun
7*4882a593SmuzhiyunIntroduction
8*4882a593Smuzhiyun------------
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun  This document details the S3C2410/S3C2440 in-built OHCI USB host support.
11*4882a593Smuzhiyun
12*4882a593SmuzhiyunConfiguration
13*4882a593Smuzhiyun-------------
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun  Enable at least the following kernel options:
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun  menuconfig::
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun   Device Drivers  --->
20*4882a593Smuzhiyun     USB support  --->
21*4882a593Smuzhiyun       <*> Support for Host-side USB
22*4882a593Smuzhiyun       <*>   OHCI HCD support
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun  .config:
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun    - CONFIG_USB
28*4882a593Smuzhiyun    - CONFIG_USB_OHCI_HCD
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun  Once these options are configured, the standard set of USB device
32*4882a593Smuzhiyun  drivers can be configured and used.
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun
35*4882a593SmuzhiyunBoard Support
36*4882a593Smuzhiyun-------------
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun  The driver attaches to a platform device, which will need to be
39*4882a593Smuzhiyun  added by the board specific support file in linux/arch/arm/mach-s3c2410,
40*4882a593Smuzhiyun  such as mach-bast.c or mach-smdk2410.c
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun  The platform device's platform_data field is only needed if the
43*4882a593Smuzhiyun  board implements extra power control or over-current monitoring.
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun  The OHCI driver does not ensure the state of the S3C2410's MISCCTRL
46*4882a593Smuzhiyun  register, so if both ports are to be used for the host, then it is
47*4882a593Smuzhiyun  the board support file's responsibility to ensure that the second
48*4882a593Smuzhiyun  port is configured to be connected to the OHCI core.
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun
51*4882a593SmuzhiyunPlatform Data
52*4882a593Smuzhiyun-------------
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun  See arch/arm/mach-s3c2410/include/mach/usb-control.h for the
55*4882a593Smuzhiyun  descriptions of the platform device data. An implementation
56*4882a593Smuzhiyun  can be found in linux/arch/arm/mach-s3c2410/usb-simtec.c .
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun  The `struct s3c2410_hcd_info` contains a pair of functions
59*4882a593Smuzhiyun  that get called to enable over-current detection, and to
60*4882a593Smuzhiyun  control the port power status.
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun  The ports are numbered 0 and 1.
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun  power_control:
65*4882a593Smuzhiyun    Called to enable or disable the power on the port.
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun  enable_oc:
68*4882a593Smuzhiyun    Called to enable or disable the over-current monitoring.
69*4882a593Smuzhiyun    This should claim or release the resources being used to
70*4882a593Smuzhiyun    check the power condition on the port, such as an IRQ.
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun  report_oc:
73*4882a593Smuzhiyun    The OHCI driver fills this field in for the over-current code
74*4882a593Smuzhiyun    to call when there is a change to the over-current state on
75*4882a593Smuzhiyun    an port. The ports argument is a bitmask of 1 bit per port,
76*4882a593Smuzhiyun    with bit X being 1 for an over-current on port X.
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun    The function s3c2410_usb_report_oc() has been provided to
79*4882a593Smuzhiyun    ensure this is called correctly.
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun  port[x]:
82*4882a593Smuzhiyun    This is struct describes each port, 0 or 1. The platform driver
83*4882a593Smuzhiyun    should set the flags field of each port to S3C_HCDFLG_USED if
84*4882a593Smuzhiyun    the port is enabled.
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun
88*4882a593SmuzhiyunDocument Author
89*4882a593Smuzhiyun---------------
90*4882a593Smuzhiyun
91*4882a593SmuzhiyunBen Dooks, Copyright 2005 Simtec Electronics
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