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products:sbc:common:applications:gpio:spi

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products:sbc:common:applications:gpio:spi [2022/07/13 05:23]
nick [Table] 		products:sbc:common:applications:gpio:spi [2023/11/07 05:07] (current)
nick [Enable SPI]
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-====== SPI ====== 
  
-===== Introduction =====+===== SPI Reference table =====
  
-This document mainly introduces the usage of SPI on [[products:sbc:common:applications:gpio:40pin-header|40-Pin Header]].+|           ^  SPI    ^ Pin  ^ Pin name     ^  GPIO name  ^  DT overlay node  ^  Device node     ^ 
 +^  VIM3/3L  |  SPI_B  |  15  | SPIB_SS      |  GPIOH_6    |  spi1             |  /dev/spidev1.1  | 
 +| :::       | :::     |  16  | SPIB_SCLK    |  GPIOH_7    | :::               | :::              | 
 +| :::       | :::     |  35  | SPIB_MISO    |  GPIOH_5    | :::               | :::              | 
 +| :::       | :::     |  37  | SPIB_MOSI    |  GPIOH_4    | :::               | :::              | 
 +^  VIM4     |  SPI_A  |  25  |  SPI_A_SCLK  |  GPIOT_20   |  spi0             |  /dev/spidev1.0  | 
 +| :::       | :::     |  26  |  SPI_A_SS0   |  GPIOT_21   | :::               | :::              | 
 +| :::       | :::     |  36  |  SPI_A_MOSI  |  GPIOT_18   | :::               | :::              | 
 +| :::       | :::     |  37  |  SPI_A_MISO  |  GPIOT_19   | :::               | :::              | 
 +^  VIM1S    |  SPI_A  |  29  |  SPI_A_MOSI  |  GPIOZ_1    | :::               | :::              | 
 +| :::       | :::     |  31  |  SPI_A_CLK   |  GPIOZ_2    | :::               | :::              | 
 +| :::       | :::     |  32  |  SPI_A_MISO  |  GPIOZ_0    | :::               | :::              | 
 +| :::       | :::     |  33  |  SPI_A_SS0   |  GPIOZ_3    | :::               | :::              |
  
-===== I2C Information =====+===== Enable SPI =====
  
-|           ^  SPI    ^  PIN & GPIO(#number)                                                                                                            ^  DT Overlays Node  ^  Bus Number  ^  Device Node  ^ +In order to use the SPI, you need to enable the SPI function via [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]].
-^  VIM3/3L  |  SPIB   |  SPIB_SS(15) - GPIOH_6 (#433)\\ SPIB_SCLK(16) - GPIOH_7 (#434)\\ SPIB_MISO(35) - GPIOH_5(#432)\\ SPIB_MOSI(37) - GPIOH_4(#431)  |  spi1              |  3           |  /dev/i2c-3   | +
-^  VIM4     | I2CM F  |  SCL(22) - GPIOY_17 (#501)\\ SDA (23) - GPIOY_18 (#502)                                                                         |  i2cm_f            |  5           |  /dev/i2c-5   |+
  
 +<tabbox VIM3/3L/Edge1>
  
-===== System Configuration =====+Edit ''/boot/env.txt'' to add the SPI node to ''overlays'' node if it doesn't exist. 
 + 
 +Take VIM3 as an example to enable ''SPI_B'', you need to add ''spi1'' node to ''overlays'' node if it doesn't exist.
  
-The default SPI is disabled. If you need to use SPI, you can enable it through the overlays function. 
 ```shell ```shell
-$ sudo vim /boot/env.txt+overlays=spi1
 ``` ```
-Modify the overlays part, remove ''pwm_f'' and ''uart3'', and open SPI. 
  
-```diff +<WRAP important > 
-- overlays=uart3 pwm_f i2c3 os08a10 +As SPI pins are also used for other function, e.g. UART_C, PWM_F, so that you also need to remove node ''uart3'' and ''pwm_f''.
-+ overlays=i2c3 os08a10 spi1 +
-``` +
- +
-Reboot to effect. +
- +
-<WRAP info > +
-For Overlays documentation, please refer to [[products:sbc:vim4:configurations:device-tree-overlay|Device Tree Overlay]].+
 </WRAP> </WRAP>
  
-SPI configures a loopback test device by default.+ 
 +After reboot, you will see the spi device node.
  
 ```shell ```shell
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 ``` ```
  
-===== Demo Source Code =====+<tabbox VIM3 with 5.15 kernel>
  
-Get test code+Edit ''/boot/dtb/amlogic/kvim3.dtb.overlay.env'' to add spi node to ''fdt_overlays'' node if it doesn't exist. 
 + 
 + 
 +e.g. Enable ''SPI_B'', you need to add ''spi1'' to node ''fdt_overlays'' if it doesn't exist. 
 + 
 +```shell 
 +fdt_overlays=spi1 
 + 
 +``` 
 + 
 +After reboot, you will see the SPI device node. 
 + 
 +<tabbox VIM3L with 5.15 kernel> 
 + 
 +Edit ''/boot/dtb/amlogic/kvim3l.dtb.overlay.env'' to add spi node to ''fdt_overlays'' node if it doesn't exist. 
 + 
 + 
 +e.g. Enable ''SPI_B'', you need to add ''spi1'' to node ''fdt_overlays'' if it doesn't exist. 
 + 
 +```shell 
 +fdt_overlays=spi1 
 + 
 +``` 
 + 
 +After reboot, you will see the SPI device node. 
 + 
 +<tabbox VIM4> 
 + 
 +Edit ''/boot/dtb/amlogic/kvim4.dtb.overlay.env'' to add spi node to ''fdt_overlays'' node if it doesn't exist. 
 + 
 + 
 +e.g. Enable ''SPI_A'', you need to add ''spi0'' to node ''fdt_overlays'' if it doesn't exist. 
 + 
 +```shell 
 +fdt_overlays=spi0 
 + 
 +``` 
 + 
 +After reboot, you will see the SPI device node. 
 + 
 +```shell 
 +$ ls /dev/spidev1.0  
 +/dev/spidev1.0 
 +``` 
 +<tabbox VIM1S> 
 + 
 +Edit ''/boot/dtb/amlogic/kvim1s.dtb.overlay.env'' to add spi node to ''fdt_overlays'' node if it doesn't exist. 
 + 
 + 
 +e.g. Enable ''SPI_A'', you need to add ''spi0'' to node ''fdt_overlays'' if it doesn't exist. 
 + 
 +```shell 
 +fdt_overlays=spi0 
 + 
 +``` 
 + 
 +After reboot, you will see the SPI device node. 
 + 
 +```shell 
 +$ ls /dev/spidev1.0  
 +/dev/spidev1.0 
 +``` 
 + 
 +</tabbox> 
 + 
 +===== Disable SPI ===== 
 + 
 +If you want to use normal GPIO instead of SPI, you can remove the SPI node in [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]].  
 + 
 + 
 +===== Demo Source Code =====
  
 ```c spidev_test.c ```c spidev_test.c
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 } }
  
-static const char *device = "/dev/spidev1.1";+static const char *device = "/dev/spidev1.0";
 static uint32_t mode; static uint32_t mode;
 static uint8_t bits = 8; static uint8_t bits = 8;
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 ``` ```
  
-Compile test code+Compile test code:
  
 ```shell ```shell
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 ``` ```
  
-===== Demonstrate =====+===== Test demonstration =====
  
- +Prepare input text file:
-Prepare a TST text file.+
  
 ```shell ```shell
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 ``` ```
  
-Run ''spidev_test''.+Connect PIN36(MOSI), PIN37(MISO) then run ''spidev_test'':
  
 ```shell ```shell
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 ``` ```
  
-Check output data.+Check output data: 
 ```shell ```shell
 $ cat ./spi_out.txt $ cat ./spi_out.txt
 Amazing Khadas! Amazing Khadas!
 ``` ```
Last modified: 2022/07/13 05:23 by nick

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