Qcom LCD commissioning

LCD DSI agreement
DSI Agreement ,0x29 and 0x39 difference ： stay Mipi Agreement , Both of them mean Long bag （Long Packet） data type .
Mipi DSI Of Spec The difference between the two is written in ： 0x29 Belong to Generic long write ,0x39 Belong to DCS long write.

DCS System read / write commands , With parameters , Commonly used in LCD Initialization parameter command .
Generic Is a read / write command , It is a command outside the protocol specification , Usually a few IC custom , Just make sure that the host and peripherals agree with these data formats , Usually and DCS Universal .

Various clk And its calculation method
DSI vdo mode Data rate under data_rate The approximate calculation formula is ：
  [Bitclk]Data rate= (Height+VSA+VBP+VFP) * (Width+HSA+HBP+HFP) * total_bit_per_pixel * frame_per_second / total_lane_num
  total_bit_per_pixel[bit per pixel]： Such as RGB888,24bit; RGB666,18bit  
  frame_per_second: How many frames per second
  total_lane_num: Use several routes lane To transmit data

With the following LCD give an example ：

720P: 1280*720 4lane
    <PanelWidth>720</PanelWidth>
    <PanelHeight>1280</PanelHeight>
    <HFrontPorch>100</HFrontPorch>
    <HBackPorch>100</HBackPorch>
    <HPulseWidth>33</HPulseWidth>
    <HSyncSkew>0</HSyncSkew>
    <VBackPorch>30</VBackPorch>
    <VFrontPorch>20</VFrontPorch>
    <VPulseWidth>2</VPulseWidth>
    <PanelFrameRate>60</PanelFrameRate>
H-total = HorizontalActive + HorizontalFrontPorch + HorizontalBackPorch + HorizontalSyncPulse + HorizontalSyncSkew

// 1280 + 100 + 100 + 33 + 0 = 1513

V-total = VerticalActive + VerticalFrontPorch + VerticalBackPorch + VerticalSyncPulse + VerticalSyncSkew

// 720 + 20 + 30 + 2 = 772

Total pixel = H-total * V-total * 60(Hz It's usually this , Of course it can change ).

// 1513 * 772 * 60 = 65,361,600

Bitclk = Total pixel * bpp(byte) *8/lane number( There are several ways mipi data lane).

// 65,361,600 * 3 * 8/4 = 392,169,600

Byteclk = bitclk/8

// 392,169,600/8 = 49,021,200

Dsipclk(Dsi pixel clock) = (Byteclk * lane number)/bpp(byte) = Total pixel * 8

// 49,021,200 * 4 / 3 = 65,361,600

LCD see LCD Resolution and DPI( Pixel density , Number of pixels per inch )
  adb root
  adb shell
  wm size             // Look at the resolution
  wm density        // see DPI
  wm size reset     // Restore the initial value
  wm density reset  // Restore the initial value

PPI and DPI
1. dpi yes dot per inch, How many dots per inch ,ppi yes Pixel per    inch, Pixels per inch , For the design of the display ,
  dpi=ppi.ppi The calculation method is the sum of the squares of the length and width , Divided by the diagonal length （ In inches ）. Principle can draw a rectangular Pythagorean theorem to calculate .
2. ppi Indicates the point density of the display device ,dpi Indicates the print point density .
3. dip or dp, It is the unit for Android development ,1dp Indicates that the density at the screen point is 160ppi when 1px length . Because Android devices have so many screens, it is impossible to develop each screen separately , So use the formula
 px=dp*(ppi/160) Calculate the number of pixels on different screens . give an example ：HVGA screen 320*480, It's usually 3.5 " , The calculated point density is
 √ (320^2 + 480^2) / 3.5 = 164, About equal to 160,1pd=1pxWVGA screen 480*800, Press 3.8 Inch screen calculation , Point density √ (480^2 + 800^2) / 3.8 = 245,
  About equal to 240,1dp=1.5px. There are more high-resolution screens, not to mention , All in all dp Is to facilitate the adaptation of different screen units , At different screen densities ,1dp The physical length of is the same .

link ：https://www.zhihu.com/question/21220154/answer/18584739

Modify the way ;
diff --git a/device/xxx/xxx/system.prop b/device/pri_name/system.prop
+# set lcd density
+ro.sf.lcd_density=180

ADB View the current LCD Of name -- Sl8521E
  adb root
  adb remount
  cd /sys/devices/platform/sprd-panel-if/display/panel0
  cat name

ADB View boot animation
  adb shell setprop ctl.start bootanim

SC9820E ADB Set the backlight level  
 adb root
 adb shell
 cd sys/class/backlight/sprd_backlight # echo 50 > brightness 
 // Set the method directly  
 adb shell settings put system screen_brightness 150 
 // Get sleep time  
 adb shell settings get system screen_off_timeout 

ADB adjustment LCD Front and back shoulders // Zhan Rui SL8521E
  adb root
  adb shell
  cd sys/devices/platform/sprd-panel-if/display/panel0
  cat vporch
  cat hporch
  echo 80 54 8 > hporch // After the adjustment , Need to stop the screen , Then wake up again to take effect
  echo 12 16 2 > vporch // After the adjustment , Need to stop the screen , Then wake up again to take effect

ADB Screen capture command
  adb root
  adb wait-for-device
  adb shell screencap -p /data/screen.png
  adb pull /data/screen.png

ADB Recording screen
  adb shell screenrecord  --time-limit 10 /sdcard/demo.mp4

# ADB see fb0 Data on a node // It is equivalent to a screenshot
  take fb0 The data in is saved to the root directory of the memory card in the form of pictures , The name of the picture is fb0.png
  adb shell screencap -d /dev/graphics/fb0 sdcard/fb0.png

# ADB see lcd Information contain mipi-on off Wait for the order
【 The Qualcomm platform Android 9.0】

  sys/kernel/debug/mdss_panel_fb0/intf0/
  cd dsi_ctrl_pdata  // Some initialization data can be viewed inside
  cd lcdc                  // see lcd Front and rear shoulder values

KEY Android 5.1 Use KEY_F1 Key , The upper layer cannot receive the key value
【 Software configuration problem 】 It involves multiple documents ：
    Device tree configuration ：xxx_msm8909-pinctrl.dtsi  xxx_msm8909-qrd.dtsi These two files use KEY Relevant configurations shall be correct

    key_F1 {
        label = "key_f1";
        gpios = <&msm_gpio 95 0x1>;
        linux,input-type = <1>;
        linux,code = <59>;
        debounce-interval = <15>;
      };
 
  tlmm_gpio_key {
        qcom,pins = <&gp 90>, <&gp 91>, <&gp 92>, <&gp 95>;
        qcom,pin-func = <0>;
        qcom,num-grp-pins = <4>;
        label = "tlmm_gpio_key";
        gpio_key_active: gpio_key_active {
          drive-strength = <2>;
          bias-pull-up;
        };
        gpio_key_suspend: gpio_key_suspend {
          drive-strength = <2>;
          bias-disable;
        };
      };
  device\xxx\gpio-keys.kl   Modify this file , Increase your own KEY_F1 Key mapping .

  key 59  F1
  key 60  F2
  key 61  F3
  key 62  F4

  kernel\include\uapi\linux\input.h In this document , There are key value definitions for all available keys . After reading the key value defined in the device tree , The key value will be converted into the key name for uploading . Of course, after uploading ,JNI The layer does another conversion of the key value , Convert to the upper key value .
  File of upper key value frameworks\base\core\java\android\view\KeyEvent.java
  adb logcat –v time –b main –b system > d:/log.log  ( This catch log Don't stop , Will always catch )
  Then press the key , Search for interceptKeyTq If the submission is successful, the converted key value will be received .
  These items must be opened debug The switch can be caught on the upper floor log.

key_code // android9 Drive key definition
8953_APP_P\kernel\msm-4.9\include\uapi\linux\input-event-codes.h 

# LOG // user Version grabs all log
  adb bugreport > bugreport.log This command catches , The cache will stop automatically after reading
  ------ KERNEL LOG (dmesg) ------ // kernel log The beginning mark

# LOG kernel log node
  dmesg It's a Executable program , To read /proc/kmsg( This is a node )

# LOG Exhibition information platform framework crash Catch slog
  slog log
  adb pull /data/slog .
  /data/misc/hprofs/ Under the hprof file
  adb pull /data/misc/hprofs .
  Crash occurs If there is adb port Just use the command directly   without adb port Then restart and execute

  Grab the upper layer log: adb logcat -b main -b radio -b system -v time
  // Don't use ctrl+c end , Will always catch log

DUMP MSM8953 Explain 【kernel dump】
  1. After the machine crashes , Pull out usb, prevent usb Wake up and restart again
  2. open QPST software Download Software , Plug in USB, stay SB3.0 On , open Browse, You can see dump Has started crawling
  3. C:\ProgramData\Qualcomm\QPST\Sahara // This is generated dumo File path , Find the file you just grabbed
  4. find out\target\product\prj_name\obj\KERNEL_OBJ\vmlinux file , Copy it out and put it in a file
  5. open dump Website https://cap.qti.qualcomm.com/default.aspx perhaps Desktop QCAP Software
  6. Login solution dump Websites or tools , Select corresponding platform (msm953),AP(kernel Of course. ap Side )
  7. Select the one just I caught it dump Document and vmlinux, Start parsing dump
  8. Click on Summary, View reasons .
  example ： Empty pointer causes kernel crash
  APPS Crash - Page fault Execute error: PC = pinctrl_select_state+0x1c/0x50 LR = adv7533_probe

notes ：Log Location:C:\ProgramData\Qualcomm\QPST\Sahara\Port_COM611        // QPST software Download Caught dead file
notes ： Select the lower sub option APPS, Then select file prj_name\dump  // vmlinux file

# Catch dump step -- Must use IE browser
  1. After the crash , open QPST config Software , Waiting to catch dump end ,900E Until it disappears
  2. dump In the following path ,C:\ProgramData\Qualcomm\QPST\Sahara\
  3. In the compiled code path , find vmlinux(kernel Of elf file , For other parts, please find the corresponding elf file )

Simulation system enters dump state
【(dump The function needs to be on , General version dump It's all off )】

 adb shell
 echo c > /proc/sysrq-trigger
 adb shell "echo c > /proc/sysrq-trigger"

Check to see if... Is turned on dump function
adb shell "cat /sys/module/msm_poweroff/parameters/download_mode"

Settings on dump function
adb shell "echo 1 > /sys/module/msm_poweroff/parameters/download_mode"

LOG Trace print function call relationships
  dump_stack(); // Print function call relationships

LCD Show direction ( modify memory Scanning direction )
  General modifications 0x36 register , For detailed modification, please refer to specific datasheet

KEY SL8521E The key refers to the table
  frameworks/native/include/android/keycodes.h
  adb shell input keyevent 26 // Power   Key   26 The value of is taken from here
  adb shell input keyevent 23 // center Key
  adb shell input keyevent 17 // * key
  adb shell input keyevent 18 // # key

  kernel keycode Key value definition table
  kernel\include\uapi\linux\input-event-codes.h

SL8521E Unlock
  adb shell input keyevent 23  // center Key
  adb shell input keyevent 17  // # key

# LCD Determine the number of pixels
  // see lcd Specifications
  Color Depth  16.7M
  2^24 = 16777216 About equal to 16.7M That is, each pixel is 24bit RGB888

ADB see android Version number
  adb shell getprop ro.build.version.release
  8.1.0

# LED // Android9 MSM8953
1. Turn on the flash

  adb shell
  cd sys/class/leds
  cd led:flash_0
  echo 255 > brightness // Perform before brightness for 0
  cd ../led:switch_0
  echo 255 > brightness // Perform before brightness for 0
  // After executing this sentence, it flashes , A flash

2. Turn on the lights

  adb shell
  cd sys/class/leds
  cd led:torch_0
  echo 255 > brightness // Perform before brightness for 0
  cd ../led:switch_0
  echo 255 > brightness // Perform before brightness for 0
  // After executing this sentence, it will light up , Changliang

Boot animation modification (Android Power on animation of the word )
  Just change the picture
  frameworks\base\core\res\assets\images\android-logo-mask.png

ADB SElinux // adb see selinux Whether to open
  adb shell getenforce // adb see selinux state
  Enforcing  // Indicates that it is currently open
  Permissive // Indicates that it is currently closed

  adb shell setenforce 0 // adb close selinux
  adb shell setenforce 1 // adb open selinux

ADB android How to judge the mobile phone CPU yes 32 A still 64 Bit ？
 adb shell getprop ro.product.cpu.abi
 arm64-v8a

PMIC-bootreason
[msm8909、Android8.1]

//adb Method to obtain the startup reason
adb shell
cd /d/spmi/spmi-0/
echo 0x808 > address
echo 0x1 > count
cat data

kernel API Interface
kernel/drivers/platform/msm/qpnp-power-on.c
static int qpnp_pon_probe(struct spmi_device *spmi)
{...
/* PON reason */
rc = spmi_ext_register_readl(pon->spmi->ctrl, pon->spmi->sid, QPNP_PON_REASON1(pon->base), &pon_sts, 1);
...}

Link to the original text ：https://blog.csdn.net/FANG_YISHAO/article/details/120654883