diff options
| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-18 23:05:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-20 14:28:36 +0200 |
| commit | ecefae6db042283bf88ef3777f2381b18df8ed46 (patch) | |
| tree | 5177129d720add73008eeadd6581fab7c27f5233 /Documentation/usb/misc_usbsevseg.rst | |
| parent | usb: renesas_usbhs: Use struct assignment instead of memcpy() (diff) | |
| download | linux-ecefae6db042283bf88ef3777f2381b18df8ed46.tar.xz linux-ecefae6db042283bf88ef3777f2381b18df8ed46.zip | |
docs: usb: rename files to .rst and add them to drivers-api
While there are a mix of things here, most of the stuff
were written from Kernel developer's PoV. So, add them to
the driver-api book.
A follow up for this patch would be to move documents from
there that are specific to sysadmins, adding them to the
admin-guide.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/usb/misc_usbsevseg.rst')
| -rw-r--r-- | Documentation/usb/misc_usbsevseg.rst | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/Documentation/usb/misc_usbsevseg.rst b/Documentation/usb/misc_usbsevseg.rst new file mode 100644 index 000000000000..6274aee083ed --- /dev/null +++ b/Documentation/usb/misc_usbsevseg.rst @@ -0,0 +1,51 @@ +============================= +USB 7-Segment Numeric Display +============================= + +Manufactured by Delcom Engineering + +Device Information +------------------ +USB VENDOR_ID 0x0fc5 +USB PRODUCT_ID 0x1227 +Both the 6 character and 8 character displays have PRODUCT_ID, +and according to Delcom Engineering no queryable information +can be obtained from the device to tell them apart. + +Device Modes +------------ +By default, the driver assumes the display is only 6 characters +The mode for 6 characters is: + + MSB 0x06; LSB 0x3f + +For the 8 character display: + + MSB 0x08; LSB 0xff + +The device can accept "text" either in raw, hex, or ascii textmode. +raw controls each segment manually, +hex expects a value between 0-15 per character, +ascii expects a value between '0'-'9' and 'A'-'F'. +The default is ascii. + +Device Operation +---------------- +1. Turn on the device: + echo 1 > /sys/bus/usb/.../powered +2. Set the device's mode: + echo $mode_msb > /sys/bus/usb/.../mode_msb + echo $mode_lsb > /sys/bus/usb/.../mode_lsb +3. Set the textmode: + echo $textmode > /sys/bus/usb/.../textmode +4. set the text (for example): + echo "123ABC" > /sys/bus/usb/.../text (ascii) + echo "A1B2" > /sys/bus/usb/.../text (ascii) + echo -ne "\x01\x02\x03" > /sys/bus/usb/.../text (hex) +5. Set the decimal places. + The device has either 6 or 8 decimal points. + to set the nth decimal place calculate 10 ** n + and echo it in to /sys/bus/usb/.../decimals + To set multiple decimals points sum up each power. + For example, to set the 0th and 3rd decimal place + echo 1001 > /sys/bus/usb/.../decimals |