diff options
author | Ben Dooks <ben-linux@fluff.org> | 2005-08-10 11:45:14 -0400 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2005-08-10 11:45:14 -0400 |
commit | c59d071d4a32e1c45cac6d47f5b59ec36a9a997b (patch) | |
tree | 671909f7778b7ec30bfe821c85b5c4802e7f2479 | |
parent | 8d3722667762af1490db18ba927386d3be89a32b (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>
-rw-r--r-- | Documentation/arm/Samsung-S3C24XX/USB-Host.txt | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/Documentation/arm/Samsung-S3C24XX/USB-Host.txt b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt new file mode 100644 index 000000000000..b93b68e2b143 --- /dev/null +++ b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt | |||
@@ -0,0 +1,93 @@ | |||
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 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 | |||
90 | Document Author | ||
91 | --------------- | ||
92 | |||
93 | Ben Dooks, (c) 2005 Simtec Electronics | ||