SYSFS

The FBTFT drivers exposes some files in the sysfs filesystem.

/sys/class/graphics/fb1

FBTFT

gamma Driver specific, see Gamma

0005 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0001 0002 0002 0001 0001 0001 0002 0002 0002 0002 0002 0003 0003 0003 0003 0003 0003 0003 0003 0003 0003 0003 0004 0004 0004 0004 0004 0004 0004 0004 0004 0004 0004 0004 0005 0005 0005 0005 0005 0005 0005 0005 0005 0005 0005 0005

Framebuffer subsystem

http://lxr.free-electrons.com/source/drivers/video/fbsysfs.c

bits_per_pixel Read: fb_info->var.bits_per_pixel 16 Write: not supported by FBTFT

blank Read: (can be read, but returns nothing) Write: Currently only supported by ssd1351fb

# blank display
echo "4" | sudo tee blank

# unblank display
echo "0" | sudo tee blank

bl_curve Only works with drivers that have registered a backlight device. Not used by FBTFT, as it doesn't support PWM.

console (does nothing)

cursor (does nothing)

mode Read: If set: fb_info->mode (nothing) Write: does not apply to FBTFT

modes Read: fb_info->modelist U:128x128p-0 Write: does not apply to FBTFT

name Read: fb_info->fix.id (driver name) ssd1351fb

pan 0,0

rotate Read: fb_info->var.rotate 0 Write: not supported by FBTFT

state Read: fb_info->state 0 Write: don't know

stride Read: fb_info->fix.line_length 256

virtual_size Read: fb_info->var.xres_virtual, fb_info->var.yres_virtual 128,128 Write: not supported by FBTFT

OTHER

dev 29:1

device -> ../../../spi0.0

power/ (empty directory)

subsystem -> ../../../../../../../../class/graphics

uevent

MAJOR=29
MINOR=1
DEVNAME=fb1

Backlight

Many FBTFT drivers have backlight support

/sys/backlight//

https://www.kernel.org/doc/Documentation/ABI/stable/sysfs-class-backlight

pi@raspberrypi /sys/class/graphics/fb1 $ ls -l
total 0
-rw-r--r-- 1 root root 4096 Jul  2 23:15 bits_per_pixel
-rw-r--r-- 1 root root 4096 Jul  2 23:15 blank
-rw-r--r-- 1 root root 4096 Jul  2 23:15 bl_curve
-rw-r--r-- 1 root root 4096 Jul  2 23:15 console
-rw-r--r-- 1 root root 4096 Jul  2 23:15 cursor
-r--r--r-- 1 root root 4096 Jul  2 23:15 dev
lrwxrwxrwx 1 root root    0 Jul  2 23:15 device -> ../../../spi0.0
-rw-rw-rw- 1 root root 4096 Jul  2 23:15 gamma
-rw-r--r-- 1 root root 4096 Jul  2 23:15 mode
-rw-r--r-- 1 root root 4096 Jul  2 23:15 modes
-r--r--r-- 1 root root 4096 Jul  2 23:15 name
-rw-r--r-- 1 root root 4096 Jul  2 23:15 pan
drwxr-xr-x 2 root root    0 Jul  2 23:15 power
-rw-r--r-- 1 root root 4096 Jul  2 23:15 rotate
-rw-r--r-- 1 root root 4096 Jul  2 23:15 state
-r--r--r-- 1 root root 4096 Jul  2 23:15 stride
lrwxrwxrwx 1 root root    0 Jul  2 23:15 subsystem -> ../../../../../../../../class/graphics
-rw-r--r-- 1 root root 4096 Jul  2 23:15 uevent
-rw-r--r-- 1 root root 4096 Jul  2 23:15 virtual_size