diff options
author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-04-15 23:56:01 -0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-16 12:16:19 +0200 |
commit | d80b5005c5dd113442454b469752f0f95ac15645 (patch) | |
tree | 36450319ec6c345904bfb591fdd125af093db2b6 /Documentation/usb/gadget_hid.txt | |
parent | 5f9be5f3f89921de6e3961bedf3202a383f126c9 (diff) | |
download | linux-d80b5005c5dd113442454b469752f0f95ac15645.tar.bz2 |
docs: usb: convert documents to ReST
Convert USB documents to ReST, in order to prepare for adding it
to the kernel API book, as most of the stuff there are driver or
subsystem-related.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/usb/gadget_hid.txt')
-rw-r--r-- | Documentation/usb/gadget_hid.txt | 175 |
1 files changed, 90 insertions, 85 deletions
diff --git a/Documentation/usb/gadget_hid.txt b/Documentation/usb/gadget_hid.txt index 7a0fb8e16e27..098d563040cc 100644 --- a/Documentation/usb/gadget_hid.txt +++ b/Documentation/usb/gadget_hid.txt @@ -1,28 +1,31 @@ - - Linux USB HID gadget driver +=========================== +Linux USB HID gadget driver +=========================== Introduction +============ - The HID Gadget driver provides emulation of USB Human Interface - Devices (HID). The basic HID handling is done in the kernel, - and HID reports can be sent/received through I/O on the - /dev/hidgX character devices. +The HID Gadget driver provides emulation of USB Human Interface +Devices (HID). The basic HID handling is done in the kernel, +and HID reports can be sent/received through I/O on the +/dev/hidgX character devices. - For more details about HID, see the developer page on - http://www.usb.org/developers/hidpage/ +For more details about HID, see the developer page on +http://www.usb.org/developers/hidpage/ Configuration +============= - g_hid is a platform driver, so to use it you need to add - struct platform_device(s) to your platform code defining the - HID function descriptors you want to use - E.G. something - like: +g_hid is a platform driver, so to use it you need to add +struct platform_device(s) to your platform code defining the +HID function descriptors you want to use - E.G. something +like:: -#include <linux/platform_device.h> -#include <linux/usb/g_hid.h> + #include <linux/platform_device.h> + #include <linux/usb/g_hid.h> -/* hid descriptor for a keyboard */ -static struct hidg_func_descriptor my_hid_data = { + /* hid descriptor for a keyboard */ + static struct hidg_func_descriptor my_hid_data = { .subclass = 0, /* No subclass */ .protocol = 1, /* Keyboard */ .report_length = 8, @@ -61,85 +64,87 @@ static struct hidg_func_descriptor my_hid_data = { 0x81, 0x00, /* INPUT (Data,Ary,Abs) */ 0xc0 /* END_COLLECTION */ } -}; + }; -static struct platform_device my_hid = { + static struct platform_device my_hid = { .name = "hidg", .id = 0, .num_resources = 0, .resource = 0, .dev.platform_data = &my_hid_data, -}; + }; - You can add as many HID functions as you want, only limited by - the amount of interrupt endpoints your gadget driver supports. +You can add as many HID functions as you want, only limited by +the amount of interrupt endpoints your gadget driver supports. Configuration with configfs +=========================== - Instead of adding fake platform devices and drivers in order to pass - some data to the kernel, if HID is a part of a gadget composed with - configfs the hidg_func_descriptor.report_desc is passed to the kernel - by writing the appropriate stream of bytes to a configfs attribute. +Instead of adding fake platform devices and drivers in order to pass +some data to the kernel, if HID is a part of a gadget composed with +configfs the hidg_func_descriptor.report_desc is passed to the kernel +by writing the appropriate stream of bytes to a configfs attribute. Send and receive HID reports +============================ - HID reports can be sent/received using read/write on the - /dev/hidgX character devices. See below for an example program - to do this. +HID reports can be sent/received using read/write on the +/dev/hidgX character devices. See below for an example program +to do this. - hid_gadget_test is a small interactive program to test the HID - gadget driver. To use, point it at a hidg device and set the - device type (keyboard / mouse / joystick) - E.G.: +hid_gadget_test is a small interactive program to test the HID +gadget driver. To use, point it at a hidg device and set the +device type (keyboard / mouse / joystick) - E.G.:: - # hid_gadget_test /dev/hidg0 keyboard + # hid_gadget_test /dev/hidg0 keyboard - You are now in the prompt of hid_gadget_test. You can type any - combination of options and values. Available options and - values are listed at program start. In keyboard mode you can - send up to six values. +You are now in the prompt of hid_gadget_test. You can type any +combination of options and values. Available options and +values are listed at program start. In keyboard mode you can +send up to six values. - For example type: g i s t r --left-shift +For example type: g i s t r --left-shift - Hit return and the corresponding report will be sent by the - HID gadget. +Hit return and the corresponding report will be sent by the +HID gadget. - Another interesting example is the caps lock test. Type - --caps-lock and hit return. A report is then sent by the - gadget and you should receive the host answer, corresponding - to the caps lock LED status. +Another interesting example is the caps lock test. Type +--caps-lock and hit return. A report is then sent by the +gadget and you should receive the host answer, corresponding +to the caps lock LED status:: - --caps-lock - recv report:2 + --caps-lock + recv report:2 - With this command: +With this command:: - # hid_gadget_test /dev/hidg1 mouse + # hid_gadget_test /dev/hidg1 mouse - You can test the mouse emulation. Values are two signed numbers. +You can test the mouse emulation. Values are two signed numbers. -Sample code +Sample code:: -/* hid_gadget_test */ + /* hid_gadget_test */ -#include <pthread.h> -#include <string.h> -#include <stdio.h> -#include <ctype.h> -#include <fcntl.h> -#include <errno.h> -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> + #include <pthread.h> + #include <string.h> + #include <stdio.h> + #include <ctype.h> + #include <fcntl.h> + #include <errno.h> + #include <stdio.h> + #include <stdlib.h> + #include <unistd.h> -#define BUF_LEN 512 + #define BUF_LEN 512 -struct options { + struct options { const char *opt; unsigned char val; -}; + }; -static struct options kmod[] = { + static struct options kmod[] = { {.opt = "--left-ctrl", .val = 0x01}, {.opt = "--right-ctrl", .val = 0x10}, {.opt = "--left-shift", .val = 0x02}, @@ -149,9 +154,9 @@ static struct options kmod[] = { {.opt = "--left-meta", .val = 0x08}, {.opt = "--right-meta", .val = 0x80}, {.opt = NULL} -}; + }; -static struct options kval[] = { + static struct options kval[] = { {.opt = "--return", .val = 0x28}, {.opt = "--esc", .val = 0x29}, {.opt = "--bckspc", .val = 0x2a}, @@ -183,10 +188,10 @@ static struct options kval[] = { {.opt = "--up", .val = 0x52}, {.opt = "--num-lock", .val = 0x53}, {.opt = NULL} -}; + }; -int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold) -{ + int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold) + { char *tok = strtok(buf, " "); int key = 0; int i = 0; @@ -229,17 +234,17 @@ int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold) fprintf(stderr, "unknown option: %s\n", tok); } return 8; -} + } -static struct options mmod[] = { + static struct options mmod[] = { {.opt = "--b1", .val = 0x01}, {.opt = "--b2", .val = 0x02}, {.opt = "--b3", .val = 0x04}, {.opt = NULL} -}; + }; -int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold) -{ + int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold) + { char *tok = strtok(buf, " "); int mvt = 0; int i = 0; @@ -274,9 +279,9 @@ int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold) fprintf(stderr, "unknown option: %s\n", tok); } return 3; -} + } -static struct options jmod[] = { + static struct options jmod[] = { {.opt = "--b1", .val = 0x10}, {.opt = "--b2", .val = 0x20}, {.opt = "--b3", .val = 0x40}, @@ -287,10 +292,10 @@ static struct options jmod[] = { {.opt = "--hat4", .val = 0x03}, {.opt = "--hatneutral", .val = 0x04}, {.opt = NULL} -}; + }; -int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold) -{ + int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold) + { char *tok = strtok(buf, " "); int mvt = 0; int i = 0; @@ -326,10 +331,10 @@ int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold) fprintf(stderr, "unknown option: %s\n", tok); } return 4; -} + } -void print_options(char c) -{ + void print_options(char c) + { int i = 0; if (c == 'k') { @@ -358,10 +363,10 @@ void print_options(char c) " three signed numbers\n" "--quit to close\n"); } -} + } -int main(int argc, const char *argv[]) -{ + int main(int argc, const char *argv[]) + { const char *filename = NULL; int fd = 0; char buf[BUF_LEN]; @@ -449,4 +454,4 @@ int main(int argc, const char *argv[]) close(fd); return 0; -} + } |