Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.
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, Copyright 2005 Simtec Electronics