Documentation/arm/Samsung-S3C24XX/USB-Host.txt

   1                         S3C24XX USB Host support
   2                         ========================
   3
   4
   5
   6 Introduction
   7 ------------
   8
   9   This document details the S3C2410/S3C2440 in-built OHCI USB host support.
  10
  11 Configuration
  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
  33 Board 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
  49 Platform Data
  50 -------------
  51
  52   See arch/arm/mach-s3c2410/include/mach/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
  90 Document Author
  91 ---------------
  92
  93 Ben Dooks, (c) 2005 Simtec Electronics