94 строки
2.4 KiB
Plaintext
94 строки
2.4 KiB
Plaintext
S3C24XX USB Host support
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Introduction
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------------
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This document details the S3C2410/S3C2440 in-built OHCI USB host support.
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Configuration
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-------------
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Enable at least the following kernel options:
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menuconfig:
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Device Drivers --->
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USB support --->
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<*> Support for Host-side USB
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<*> OHCI HCD support
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.config:
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CONFIG_USB
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CONFIG_USB_OHCI_HCD
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Once these options are configured, the standard set of USB device
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drivers can be configured and used.
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Board Support
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-------------
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The driver attaches to a platform device, which will need to be
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added by the board specific support file in linux/arch/arm/mach-s3c2410,
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such as mach-bast.c or mach-smdk2410.c
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The platform device's platform_data field is only needed if the
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board implements extra power control or over-current monitoring.
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The OHCI driver does not ensure the state of the S3C2410's MISCCTRL
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register, so if both ports are to be used for the host, then it is
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the board support file's responsibility to ensure that the second
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port is configured to be connected to the OHCI core.
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Platform Data
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-------------
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See arch/arm/mach-s3c2410/include/mach/usb-control.h for the
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descriptions of the platform device data. An implementation
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can be found in linux/arch/arm/mach-s3c2410/usb-simtec.c .
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The `struct s3c2410_hcd_info` contains a pair of functions
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that get called to enable over-current detection, and to
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control the port power status.
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The ports are numbered 0 and 1.
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power_control:
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Called to enable or disable the power on the port.
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enable_oc:
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Called to enable or disable the over-current monitoring.
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This should claim or release the resources being used to
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check the power condition on the port, such as an IRQ.
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report_oc:
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The OHCI driver fills this field in for the over-current code
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to call when there is a change to the over-current state on
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an port. The ports argument is a bitmask of 1 bit per port,
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with bit X being 1 for an over-current on port X.
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The function s3c2410_usb_report_oc() has been provided to
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ensure this is called correctly.
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port[x]:
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This is struct describes each port, 0 or 1. The platform driver
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should set the flags field of each port to S3C_HCDFLG_USED if
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the port is enabled.
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Document Author
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---------------
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Ben Dooks, (c) 2005 Simtec Electronics
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