Hello everyone,
I'm currently trying to enable the MIPI-DSI display based on the Imx8mp Variscite board.
Hoping that someone can help me.
I'm using the following setup :
- Driver : panel-rocktech-hx8394f.c updated regarding the TFT (based on a HX8394F controller)
- DST : imx8mp-var-dart-dt8mcustomboard.dts updated
Using a MIPI analyzer (LA5076 and oscilloscope) I'm able to check that the driver is correctly scheduled and the right behavior during the init phase (during the LP mode) :
The frame buffer device seems to be ok :
$ cat mode modes name virtual_size
U:720x1280p-0
imx-drmdrmfb
720,1280
My device tree blob configuration (MIPI DSI section):
/* MIPI-DSI */
&lcdif1 {
status = "okay";
};
&mipi_dsi {
status = "okay";
panel@0 {
compatible = "rocktech,hx8394f";
reg = <0>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_hx8394>;
himax,dsi-lanes = <2>;
enable-gpios = <&gpio4 0 GPIO_ACTIVE_HIGH>;
reset-gpios = <&gpio4 1 GPIO_ACTIVE_LOW>;
vcc-supply = <®_hx8394_vcc>;
iovcc-supply = <®_hx8394_iovcc>;
backlight = <&backlight>;
};
};
For information :
Kernel log :
0.078695] platform 32e80000.lcd-controller: Fixing up cyclic dependency with 32e60000.mipi_dsi
[ 2.135453] imx_sec_dsim_drv 32e60000.mipi_dsi: version number is 0x1060200
[ 2.143131] imx-drm display-subsystem: bound 32e60000.mipi_dsi (ops imx_sec_dsim_ops)
[ 2.394006] WARNING: CPU: 0 PID: 9 at drivers/gpu/drm/bridge/sec-dsim.c:1868 sec_mipi_dsim_irq_handler+0x194/0x214
[ 2.394060] pc : sec_mipi_dsim_irq_handler+0x194/0x214
[ 2.394219] sec_mipi_dsim_irq_handler+0x194/0x214
[ 2.394318] mipi_dsi_dcs_exit_sleep_mode+0x0/0x84
[ 2.394336] sec_mipi_dsim_bridge_atomic_enable+0x368/0x520
[ 2.394701] imx_sec_dsim_drv 32e60000.mipi_dsi: LP RX timeout
[ 2.653625] imx_sec_dsim_drv 32e60000.mipi_dsi: wait pkthdr tx done time out
[ 2.653631] imx_sec_dsim_drv 32e60000.mipi_dsi: panel enable failed: -16
$ fbset --info
mode "720x1280"
geometry 720 1280 720 1280 32
timings 0 0 0 0 0 0 0
accel true
rgba 8/16,8/8,8/0,0/0
endmode
Frame buffer device information:
Name : imx-drmdrmfb
Address : (nil)
Size : 3686400
Type : PACKED PIXELS
Visual : TRUECOLOR
XPanStep : 1
YPanStep : 1
YWrapStep : 0
LineLength : 2880
Accelerator : No
My question(s) :
I'm not checking a correctly displayed picture for now, I would like to proceed step by step and I need help to understand why I'm not able and how it would be possible to check the correct behavior in HS mode (after the init sequence)
- Even if the bandwidth of the MIPI analyzer or the oscilloscope is not high enough, why I'm not able to get any samples in HS mode (in order to see something living) ? Would it be due to the input impedance which collapses the signals ?
- Does someone have solution to measure / check that the frame buffer in correctly "connected" to the MIPI DSI interface ? From software or hardware (instrumental) point of view
I hope I have not forgotten any information. Let me know if you need more details.
I am thankful for any suggestions.
Best regards
