This is the latest (main) BeagleBoard documentation. If you are looking for stable releases, use the drop-down menu on the bottom-left and select the desired version.

BeagleBone cape interface spec

This page is a fork of BeagleBone cape interface spec page on elinux. This is the new official home.

Background and overview

Note

Below, when mentioning “Black”, this is true for all AM3358-based BeagleBone boards. “AI” is AM5729-based. “AI-64” is TDA4VM-based.

The device tree symbols for the BeagleBone Cape Compatibility Layer are provided in BeagleBoard-DeviceTrees at:

The udev rules used to create the userspace symlinks for the BeagleBone Cape Compatibility Layer are provided in usr-customizations at:

More details can be found in Methodology.

Note

Legend

  • D: Digital general purpose input and output (GPIO)

  • I: Inter-integrated circuit bus (I2C) ports

  • S: Serial peripheral interface (SPI) ports

  • U: Universal asynchronous reciever/transmitter (UART) serial ports

  • C: CAN

  • A: Analog inputs

  • E: PWM

  • Q: Capture/EQEP

  • M: MMC/SD/SDIO

  • B: I2S/audio serial ports

  • L: LCD

  • P: PRU

  • Y: ECAP

Table 53 Overall

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

USB D+

E1

E2

USB D-

5V OUT

E3

E4

GND

GND

1

2

GND

GND

1

2

GND

3V3 OUT

3

4

3V3 OUT

D M

3

4

D M

5V IN

5

6

5V IN

D M C

5

6

D M C

5V OUT

7

8

5V OUT

D C

7

8

D C

PWR BUT

9

10

RESET

D C

9

10

D C

D U

11

12

D

D P

11

12

D Q P

D U

13

14

D E

D E

13

14

D

D

15

16

D E

D P

15

16

D P

D I S

17

18

D I S

D

17

18

D

D I C

19

20

D I C

D E

19

20

D M P

D E S U

21

22

D E S U

D M P

21

22

D M Q

D S

23

24

D I U C

D M

23

24

D M

D P

25

26

D I U C

D M

25

26

D

D P Q

27

28

D S P

D L P

27

28

D L P U

D E S P

29

30

D S P

D L P U

29

30

D L P

D E S P

31

32

ADC VDD REF OUT

D L

31

32

D L

A

33

34

ADC GND

D L Q

33

34

D E L

A

35

36

A

D L Q

35

36

D E L

A

37

38

A

D L U

37

38

D L U

A

39

40

A

D L P

39

40

D L P

D P

41

42

D Q S U P

D L P

41

42

D L P

GND

43

44

GND

D L P

43

44

D L P

GND

45

46

GND

D E L P

45

46

D E L P

Digital GPIO

The compatibility layer comes with simple reference nodes for attaching the Linuuux gpio-leds or gpio-keys to any cape header GPIO pin. This provides simple userspace general purpose input or output with various trigger modes.

The format followed for the gpio-leds nodes is bone_led_P8_## / bone_led_P9_##. The gpio-leds driver is used by these reference nodes internally and allows users to easily create compatible led nodes in overlays for Black, AI and AI-64.

Listing 1 Example device tree overlay to enable LED driver on header P8 pin 3
1/dts-v1/;
2/plugin/;
3
4&bone_led_P8_03 {
5    status = "okay";
6}

In Example device tree overlay to enable LED driver on header P8 pin 3, it is possible to redefine the default label and other properties defined in the gpio-leds schema.

Table 54 GPIO pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

GND

1

2

GND

GND

1

2

GND

3V3 OUT

3

4

3V3 OUT

D M

3

4

D M

5V IN

5

6

5V IN

D M C4t

5

6

D M C4r

5V OUT

7

8

5V OUT

D C2r

7

8

D C2t

PWR BUT

9

10

RESET

D C3r

9

10

D C3t

D U4r

11

12

D

D P0o

11

12

D Q2a P0o

D U4t

13

14

D E1a

D E2b

13

14

D

D

15

16

D E1b

D P0i

15

16

D P0i

D I1c S00

17

18

D I1d S0o

D

17

18

D

C0r D I2c

19

20

C0t D I2d

D E2a

19

20

D M P1

D E0b S0i U2t

21

22

D E0a S0c U2r

D M P1

21

22

D M Q2b

D S01

23

24

C1r D I3c U1t

D M

23

24

D M

D P0

25

26

C1t D I3d U1r

D M

25

26

D

D P0 Q0b

27

28

D P0 S10

D L P1

27

28

D L P1 U6r

D E S1i P0

29

30

D P0 S1o

D L P1 U6t

29

30

D L P1

D E S1c P0

31

32

ADC VDD

D L

31

32

D L

A 4

33

34

ADC GND

D L Q1b

33

34

D E L

A 6

35

36

A 5

D L Q1a

35

36

D E L

A 2

37

38

A 3

D L U5t

37

38

D L U5r

A 0

39

40

A 1

D L P1

39

40

D L P1

D P0

41

42

D Q0a S11 U3t P0

D L P1

41

42

D L P1

GND

43

44

GND

D L P1

43

44

D L P1

GND

45

46

GND

D E L P1

45

46

D E L P1

Table 55 Bone GPIO LEDs interface

LED SYSFS

Header pin

Black

AI

AI-64

/sys/class/leds/P8_03

P8_03

gpio1_6

gpio1_24

gpio0_20

/sys/class/leds/P8_04

P8_04

gpio1_7

gpio1_25

gpio0_48

/sys/class/leds/P8_05

P8_05

gpio1_2

gpio7_1

gpio0_33

/sys/class/leds/P8_06

P8_06

gpio1_3

gpio7_2

gpio0_34

/sys/class/leds/P8_07

P8_07

gpio2_2

gpio6_5

gpio0_15

/sys/class/leds/P8_08

P8_08

gpio2_3

gpio6_6

gpio0_14

/sys/class/leds/P8_09

P8_09

gpio2_5

gpio6_18

gpio0_17

/sys/class/leds/P8_10

P8_10

gpio2_4

gpio6_4

gpio0_16

/sys/class/leds/P8_11

P8_11

gpio1_13

gpio3_11

gpio0_60

/sys/class/leds/P8_12

P8_12

gpio1_12

gpio3_10

gpio0_59

/sys/class/leds/P8_13

P8_13

gpio0_23

gpio4_11

gpio0_89

/sys/class/leds/P8_14

P8_14

gpio0_26

gpio4_13

gpio0_75

/sys/class/leds/P8_15

P8_15

gpio1_15

gpio4_3

gpio0_61

/sys/class/leds/P8_16

P8_16

gpio1_14

gpio4_29

gpio0_62

/sys/class/leds/P8_17

P8_17

gpio0_27

gpio8_18

gpio0_3

/sys/class/leds/P8_18

P8_18

gpio2_1

gpio4_9

gpio0_4

/sys/class/leds/P8_19

P8_19

gpio0_22

gpio4_10

gpio0_88

/sys/class/leds/P8_20

P8_20

gpio1_31

gpio6_30

gpio0_76

/sys/class/leds/P8_21

P8_21

gpio1_30

gpio6_29

gpio0_30

/sys/class/leds/P8_22

P8_22

gpio1_5

gpio1_23

gpio0_5

/sys/class/leds/P8_23

P8_23

gpio1_4

gpio1_22

gpio0_31

/sys/class/leds/P8_24

P8_24

gpio1_1

gpio7_0

gpio0_6

/sys/class/leds/P8_25

P8_25

gpio1_0

gpio6_31

gpio0_35

/sys/class/leds/P8_26

P8_26

gpio1_29

gpio4_28

gpio0_51

/sys/class/leds/P8_27

P8_27

gpio2_22

gpio4_23

gpio0_71

/sys/class/leds/P8_28

P8_28

gpio2_24

gpio4_19

gpio0_72

/sys/class/leds/P8_29

P8_29

gpio2_23

gpio4_22

gpio0_73

/sys/class/leds/P8_30

P8_30

gpio2_25

gpio4_20

gpio0_74

/sys/class/leds/P8_31

P8_31

gpio0_10

gpio8_14

gpio0_32

/sys/class/leds/P8_32

P8_32

gpio0_11

gpio8_15

gpio0_26

/sys/class/leds/P8_33

P8_33

gpio0_9

gpio8_13

gpio0_25

/sys/class/leds/P8_34

P8_34

gpio2_17

gpio8_11

gpio0_7

/sys/class/leds/P8_35

P8_35

gpio0_8

gpio8_12

gpio0_24

/sys/class/leds/P8_36

P8_36

gpio2_16

gpio8_10

gpio0_8

/sys/class/leds/P8_37

P8_37

gpio2_14

gpio8_8

gpio0_106

/sys/class/leds/P8_38

P8_38

gpio2_15

gpio8_9

gpio0_105

/sys/class/leds/P8_39

P8_39

gpio2_12

gpio8_6

gpio0_69

/sys/class/leds/P8_40

P8_40

gpio2_13

gpio8_7

gpio0_70

/sys/class/leds/P8_41

P8_41

gpio2_10

gpio8_4

gpio0_67

/sys/class/leds/P8_42

P8_42

gpio2_11

gpio8_5

gpio0_68

/sys/class/leds/P8_43

P8_43

gpio2_8

gpio8_2

gpio0_65

/sys/class/leds/P8_44

P8_44

gpio2_9

gpio8_3

gpio0_66

/sys/class/leds/P8_45

P8_45

gpio2_6

gpio8_0

gpio0_79

/sys/class/leds/P8_46

P8_46

gpio2_7

gpio8_1

gpio0_80

/sys/class/leds/P9_11

P9_11

gpio0_30

gpio8_17

gpio0_1

/sys/class/leds/P9_12

P9_12

gpio1_28

gpio5_0

gpio0_45

/sys/class/leds/P9_13

P9_13

gpio0_31

gpio6_12

gpio0_2

/sys/class/leds/P9_14

P9_14

gpio1_18

gpio4_25

gpio0_93

/sys/class/leds/P9_15

P9_15

gpio1_16

gpio3_12

gpio0_47

/sys/class/leds/P9_16

P9_16

gpio1_19

gpio4_26

gpio0_94

/sys/class/leds/P9_17

P9_17

gpio0_5

gpio7_17

gpio0_28

/sys/class/leds/P9_18

P9_18

gpio0_4

gpio7_16

gpio0_40

/sys/class/leds/P9_19

P9_19

gpio0_13

gpio7_3

gpio0_78

/sys/class/leds/P9_20

P9_20

gpio0_12

gpio7_4

gpio0_77

/sys/class/leds/P9_21

P9_21

gpio0_3

gpio3_3

gpio0_39

/sys/class/leds/P9_22

P9_22

gpio0_2

gpio6_19

gpio0_38

/sys/class/leds/P9_23

P9_23

gpio1_17

gpio7_11

gpio0_10

/sys/class/leds/P9_24

P9_24

gpio0_15

gpio6_15

gpio0_13

/sys/class/leds/P9_25

P9_25

gpio3_21

gpio6_17

gpio0_127

/sys/class/leds/P9_26

P9_26

gpio0_14

gpio6_14

gpio0_12

/sys/class/leds/P9_27

P9_27

gpio3_19

gpio4_15

gpio0_46

/sys/class/leds/P9_28

P9_28

gpio3_17

gpio4_17

gpio1_11

/sys/class/leds/P9_29

P9_29

gpio3_15

gpio5_11

gpio0_53

/sys/class/leds/P9_30

P9_30

gpio3_16

gpio5_12

gpio0_44

/sys/class/leds/P9_31

P9_31

gpio3_14

gpio5_10

gpio0_52

/sys/class/leds/P9_33

P9_33

n/a

n/a

gpio0_50

/sys/class/leds/P9_35

P9_35

n/a

n/a

gpio0_55

/sys/class/leds/P9_36

P9_36

n/a

n/a

gpio0_56

/sys/class/leds/P9_37

P9_37

n/a

n/a

gpio0_57

/sys/class/leds/P9_38

P9_38

n/a

n/a

gpio0_58

/sys/class/leds/P9_39

P9_39

n/a

n/a

gpio0_54

/sys/class/leds/P9_40

P9_40

n/a

n/a

gpio0_81

/sys/class/leds/P9_41

P9_41

gpio0_20

gpio6_20

gpio1_0

/sys/class/leds/P9_42

P9_42

gpio0_7

gpio4_18

gpio0_123

/sys/class/leds/A15

A15

gpio0_19

NA

NA

I2C

Compatibility layer provides simple I2C bone bus nodes for creating compatible overlays for Black, AI and AI-64. The format followed for these nodes is bone_i2c_#.

Table 56 I2C pins

P9

Functions

odd

even

Functions

1 SCL

17

18

1 SDA

2 SCL

19

20

2 SDA

4 SCL 4 5

21

22

4 SDA 4 5

23

24

3 SCL 3

25

26

3 SDA 3

3(1,2)

Mutually exclusive with port 1 on Black

4(1,2)

Mutually exclusive with port 2 on Black

5(1,2)

On Black and AI-64 only

Table 57 I2C port mapping

SYSFS

DT symbol

Black

AI

AI-64

SCL

SDA

Overlay

/dev/bone/i2c/0

bone_i2c_0

I2C0

I2C1

TBD

On-board

/dev/bone/i2c/1

bone_i2c_1

I2C1

I2C5

MAIN_I2C6

P9.17

P9.18

BONE-I2C1

/dev/bone/i2c/2

bone_i2c_2

I2C2

I2C4

MAIN_I2C3

P9.19

P9.20

BONE-I2C2

/dev/bone/i2c/3

bone_i2c_3

I2C1

I2C3

MAIN_I2C4

P9.24

P9.26

BONE-I2C3

/dev/bone/i2c/4

bone_i2c_4

I2C2

n/a

MAIN_I2C3

P9.21

P9.22

BONE-I2C4

Important

In the case the same controller is used for 2 different bone bus nodes, usage of those nodes is mutually-exclusive.

Note

The provided pre-compiled overlays enable the I2C bus driver only, not a specific device driver. Either a custom overlay is required to load the device driver or usermode device driver loading can be performed, depending on the driver. See Using I2C with Linux drivers for information on loading I2C drivers from userspace.

Listing 2 Example device tree overlay to enable I2C driver
 1/dts-v1/;
 2/plugin/;
 3
 4&bone_i2c_1 {
 5    status = "okay";
 6    accel@1c {
 7        compatible = "fsl,mma8453";
 8        reg = <0x1c>;
 9    };
10}

In Example device tree overlay to enable I2C driver, you can specify what driver you want to load and provide any properties it might need.

SPI

SPI bone bus nodes allow creating compatible overlays for Black, AI and AI-64.

Table 58 SPI pins

P9

Functions

odd

even

Functions

0 CS0

17

18

0 SDO

19

20

0 SDI

21

22

0 CLK

0 CS1

23

24

25

26

27

28

1 CS0

1 SDI

29

30

1 SDO

1 CLK

31

32

33

34

35

36

37

38

39

40

41

42

1 CS1 2

Table 59 SPI port mapping

Bone bus

DT symbol

Black

AI

AI-64

SDO

SDI

CLK

CS

Overlay

/dev/bone/spi/0.0

bone_spi_0

SPI0

SPI2

MAIN_SPI6

P9.18

P9.21

P9.22

P9.17 (CS0)

BONE-SPI0_0

/dev/bone/spi/0.1

P9.23 (CS1) 2

BONE-SPI0_1

/dev/bone/spi/1.0

bone_spi_1

SPI1

SPI3

MAIN_SPI7

P9.30

P9.29

P9.31

P9.28 (CS0)

BONE-SPI1_0

/dev/bone/spi/1.1

P9.42 (CS1)

BONE-SPI1_1

2(1,2)

Only available on AI and AI-64

Note

The provided pre-compiled overlays enable the “spidev” driver using the “rohm,dh2228fv” compatible string. See https://stackoverflow.com/questions/53634892/linux-spidev-why-it-shouldnt-be-directly-in-devicetree for more background. A custom overlay is required to overload the compatible string to load a non-spidev driver.

Note

#TODO# figure out if BONE-SPI0_0 and BONE-SPI0_1 can be loaded at the same time

Listing 3 Example device tree overlay to enable SPI driver
 1/dts-v1/;
 2/plugin/;
 3
 4&bone_spi_0 {
 5    status = "okay";
 6     pressure@0 {
 7         compatible = "bosch,bmp280";
 8         reg = <0>;      /* CS0 */
 9         spi-max-frequency = <5000000>;
10     };
11}

In Example device tree overlay to enable SPI driver, you can specify what driver you want to load and provide any properties it might need.

UART

UART bone bus nodes allow creating compatible overlays for Black, AI and AI-64.

Table 60 UART pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

4 RX 6

11

12

11

12

4 TX 6

13

14

13

14

15

16

15

16

17

18

17

18

19

20

19

20

2 TX

21

22

2 RX

21

22

23

24

1 TX

23

24

25

26

1 RX

25

26

27

28

27

28

6 RX

29

30

6 TX

29

30

31

32

31

32

33

34

33

34

7 TX

35

36

35

36

37

38

5 TX

37

38

5 RX

39

40

39

40

41

42

3 TX

41

42

Important

RTSn and CTSn mappings are not compatible across boards in the family and are therefore not part of the cape specification.

Table 61 UART port mapping

Bone bus

DT symbol

Black

AI

AI-64

TX

RX

Overlay

/dev/bone/uart/0

bone_uart_0

UART0

UART1

MAIN_UART0

Console debug header pins

/dev/bone/uart/1

bone_uart_1

UART1

UART10

MAIN_UART2

P9.24

P9.26

BONE-UART1

/dev/bone/uart/2

bone_uart_2

UART2

UART3

n/a

P9.21

P9.22

BONE-UART2

/dev/bone/uart/3

bone_uart_3

UART3

n/a

n/a

P9.42

n/a

BONE-UART3

/dev/bone/uart/4

bone_uart_4

UART4

UART5

MAIN_UART0 6

P9.13

P9.11

BONE-UART4

/dev/bone/uart/5

bone_uart_5

UART5

UART8

MAIN_UART5

P8.37

P8.38

BONE-UART5

/dev/bone/uart/6

bone_uart_6

n/a

n/a

MAIN_UART8

P8.29

P8.28

BONE-UART6

/dev/bone/uart/7

bone_uart_7

n/a

n/a

MAIN_UART2

P8.34

P8.22

BONE-UART7

6(1,2,3)

This port is shared with the console UART on AI-64

Important

In the case the same controller is used for 2 different bone bus nodes, usage of those nodes is mutually-exclusive.

CAN

CAN bone bus nodes allow creating compatible overlays for Black, AI and AI-64.

Table 62 CAN pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

5

6

4 TX

5

6

4 RX

7

8

2 RX

7

8

2 TX

9

10

3 RX

9

10

3 TX

11

12

11

12

13

14

13

14

15

16

15

16

17

18

17

18

0 RX

19

20

0 TX

19

20

21

22

21

22

23

24

1 RX

23

24

25

26

1 TX

25

26

Table 63 CAN port mapping

Bone bus

Black

AI

AI-64

TX

RX

Overlays

/dev/bone/can/0

CAN0

n/a

MAIN_MCAN0

P9.20

P9.19

BONE-CAN0

/dev/bone/can/1

CAN1

CAN2

MAIN_MCAN4

P9.26

P9.24

BONE-CAN1

/dev/bone/can/2

n/a

CAN1 1

MAIN_MCAN5

P8.08

P8.07

BONE-CAN2

/dev/bone/can/3

n/a

n/a

MAIN_MCAN6

P8.10

P8.09

BONE-CAN3

/dev/bone/can/4

n/a

n/a

MAIN_MCAN7

P8.05

P8.06

BONE-CAN4

1

BeagleBone AI rev A2 and later only

ADC

  • TODO: We need a udev rule to make sure the ADC shows up at /dev/bone/adc! There’s nothing for sure that IIO devices will show up in the same place.

  • TODO: I think we can also create symlinks for each channel based on which device is there, such that we can do /dev/bone/adc/Px_y

Table 64 ADC pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

USB D+

E1

E2

USB D-

5V OUT

E3

E4

GND

GND

1

2

GND

GND

1

2

GND

3V3 OUT

3

4

3V3 OUT

D M

3

4

D M

5V IN

5

6

5V IN

D M C4t

5

6

D M C4r

5V OUT

7

8

5V OUT

D C2r

7

8

D C2t

PWR BUT

9

10

RESET

D C3r

9

10

D C3t

D U4r

11

12

D

D P0o

11

12

D Q2a P0o

D U4t

13

14

D E1a

D E2b

13

14

D

D

15

16

D E1b

D P0i

15

16

D P0i

D I1c S00

17

18

D I1d S0o

D

17

18

D

C0r D I2c

19

20

C0t D I2d

D E2a

19

20

D M P1

D E0b S0i U2t

21

22

D E0a S0c U2r

D M P1

21

22

D M Q2b

D S01

23

24

C1r D I3c U1t

D M

23

24

D M

D P0

25

26

C1t D I3d U1r

D M

25

26

D

D P0 Q0b

27

28

D P0 S10

D L P1

27

28

D L P1 U6r

D E S1i P0

29

30

D P0 S1o

D L P1 U6t

29

30

D L P1

D E S1c P0

31

32

ADC VDD

D L

31

32

D L

A 4

33

34

ADC GND

D L Q1b

33

34

D E L

A 6

35

36

A 5

D L Q1a

35

36

D E L

A 2

37

38

A 3

D L U5t

37

38

D L U5r

A 0

39

40

A 1

D L P1

39

40

D L P1

D P0

41

42

D Q0a S11 U3t P0

D L P1

41

42

D L P1

GND

43

44

GND

D L P1

43

44

D L P1

GND

45

46

GND

D E L P1

45

46

D E L P1

Table 65 Bone ADC

Index

Header pin

Black/AI-64

AI

0

P9_39

in_voltage0_raw

in_voltage0_raw

1

P9_40

in_voltage1_raw

in_voltage1_raw

2

P9_37

in_voltage2_raw

in_voltage3_raw

3

P9_38

in_voltage3_raw

in_voltage2_raw

4

P9_33

in_voltage4_raw

in_voltage7_raw

5

P9_36

in_voltage5_raw

in_voltage6_raw

6

P9_35

in_voltage6_raw

in_voltage4_raw

Table 66 Bone ADC Overlay

Black

AI

AI-64

overlay

Internal

External (STMPE811)

TBD

BONE-ADC.dts

PWM

PWM bone bus nodes allow creating compatible overlays for Black, AI and AI-64. For the definitions, you can see bbai-bone-buses.dtsi#L415 & bbb-bone-buses.dtsi#L432

Table 67 PWM pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

USB D+

E1

E2

USB D-

5V OUT

E3

E4

GND

GND

1

2

GND

GND

1

2

GND

3V3 OUT

3

4

3V3 OUT

D M

3

4

D M

5V IN

5

6

5V IN

D M C4t

5

6

D M C4r

5V OUT

7

8

5V OUT

D C2r

7

8

D C2t

PWR BUT

9

10

RESET

D C3r

9

10

D C3t

D U4r

11

12

D

D P0o

11

12

D Q2a P0o

D U4t

13

14

D E1a

D E2b

13

14

D

D

15

16

D E1b

D P0i

15

16

D P0i

D I1c S00

17

18

D I1d S0o

D

17

18

D

C0r D I2c

19

20

C0t D I2d

D E2a

19

20

D M P1

D E0b S0i U2t

21

22

D E0a S0c U2r

D M P1

21

22

D M Q2b

D S01

23

24

C1r D I3c U1t

D M

23

24

D M

D P0

25

26

C1t D I3d U1r

D M

25

26

D

D P0 Q0b

27

28

D P0 S10

D L P1

27

28

D L P1 U6r

D E S1i P0

29

30

D P0 S1o

D L P1 U6t

29

30

D L P1

D E S1c P0

31

32

ADC VDD

D L

31

32

D L

A 4

33

34

ADC GND

D L Q1b

33

34

D E L

A 6

35

36

A 5

D L Q1a

35

36

D E L

A 2

37

38

A 3

D L U5t

37

38

D L U5r

A 0

39

40

A 1

D L P1

39

40

D L P1

D P0

41

42

D Q0a S11 U3t P0

D L P1

41

42

D L P1

GND

43

44

GND

D L P1

43

44

D L P1

GND

45

46

GND

D E L P1

45

46

D E L P1

Table 68 Bone bus PWM

Bone bus

Black

AI

AI-64

A

B

Overlay

/dev/bone/pwm/0

PWM0

PWM1

P9.22

P9.21

BONE-PWM0.dts

/dev/bone/pwm/1

PWM1

PWM3

PWM2

P9.14

P9.16

BONE-PWM1.dts

/dev/bone/pwm/2

PWM2

PWM2

PWM0

P8.19

P8.13

BONE-PWM2.dts

TIMER PWM

TIMER PWM bone bus uses ti,omap-dmtimer-pwm driver, and timer nodes that allow creating compatible overlays for Black, AI and AI-64. For the timer node definitions, you can see bbai-bone-buses.dtsi#L449 & bbb-bone-buses.dtsi#L466.

Table 69 Bone TIMER PWMs

Bone bus

Header pin

Black

AI

overlay

/sys/bus/platform/devices/bone_timer_pwm_0/

P8.10

timer6

timer10

BONE-TIMER_PWM_0.dts

/sys/bus/platform/devices/bone_timer_pwm_1/

P8.07

timer4

timer11

BONE-TIMER_PWM_1.dts

/sys/bus/platform/devices/bone_timer_pwm_2/

P8.08

timer7

timer12

BONE-TIMER_PWM_2.dts

/sys/bus/platform/devices/bone_timer_pwm_3/

P9.21

timer13

BONE-TIMER_PWM_3.dts

/sys/bus/platform/devices/bone_timer_pwm_4/

P8.09

timer5

timer14

BONE-TIMER_PWM_4.dts

/sys/bus/platform/devices/bone_timer_pwm_5/

P9.22

timer15

BONE-TIMER_PWM_5.dts

eQEP

Table 70 eQEP pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

USB D+

E1

E2

USB D-

5V OUT

E3

E4

GND

GND

1

2

GND

GND

1

2

GND

3V3 OUT

3

4

3V3 OUT

D M

3

4

D M

5V IN

5

6

5V IN

D M C4t

5

6

D M C4r

5V OUT

7

8

5V OUT

D C2r

7

8

D C2t

PWR BUT

9

10

RESET

D C3r

9

10

D C3t

D U4r

11

12

D

D P0o

11

12

D Q2a P0o

D U4t

13

14

D E1a

D E2b

13

14

D

D

15

16

D E1b

D P0i

15

16

D P0i

D I1c S00

17

18

D I1d S0o

D

17

18

D

C0r D I2c

19

20

C0t D I2d

D E2a

19

20

D M P1

D E0b S0i U2t

21

22

D E0a S0c U2r

D M P1

21

22

D M Q2b

D S01

23

24

C1r D I3c U1t

D M

23

24

D M

D P0

25

26

C1t D I3d U1r

D M

25

26

D

D P0 Q0b

27

28

D P0 S10

D L P1

27

28

D L P1 U6r

D E S1i P0

29

30

D P0 S1o

D L P1 U6t

29

30

D L P1

D E S1c P0

31

32

ADC VDD

D L

31

32

D L

A 4

33

34

ADC GND

D L Q1b

33

34

D E L

A 6

35

36

A 5

D L Q1a

35

36

D E L

A 2

37

38

A 3

D L U5t

37

38

D L U5r

A 0

39

40

A 1

D L P1

39

40

D L P1

D P0

41

42

D Q0a S11 U3t P0

D L P1

41

42

D L P1

GND

43

44

GND

D L P1

43

44

D L P1

GND

45

46

GND

D E L P1

45

46

D E L P1

On BeagleBone’s without an eQEP on specific pins, consider using the PRU to perform a software counter function.

Table 71 Bone eQEP

Bone bus

Black

AI

AI-64

A

B

strobe

index

overlay

/dev/bone/counter/0

eQEP0

eQEP2

eQEP0

P9.42

P9.27

  • Black/AI-64: P9.25

  • AI: P8.06

  • Black/AI-64: P9.41

  • AI: P8.05

/dev/bone/counter/1

eQEP1

eQEP0

eQEP1

P8.35

P8.33

  • Black/AI-64: P8.32

  • AI: P9.21

  • Black/AI-64: P8.31

  • AI: ‒

/dev/bone/counter/2

eQEP2

eQEP1

P8.12

P8.22

  • Black: P8.15

  • AI: P8.18

  • Black: P8.16

  • AI: P9.15

eCAP

#TODO: This doesn’t include any abstraction yet.

Table 72 ECAP pins

P9

P8

Functions

odd

even

Functions

Functions

odd

even

Functions

USB D+

E1

E2

USB D-

5V OUT

E3

E4

GND

GND

1

2

GND

GND

1

2

GND

3V3 OUT

3

4

3V3 OUT

D M

3

4

D M

5V IN

5

6

5V IN

D M C4t

5

6

D M C4r

5V OUT

7

8

5V OUT

D C2r

7

8

D C2t

PWR BUT

9

10

RESET

D C3r

9

10

D C3t

D U4r

11

12

D

D P0o

11

12

D Q2a P0o

D U4t

13

14

D E1a

D E2b

13

14

D

D

15

16

D E1b

D P0i

15

16

D P0i

D I1c S00

17

18

D I1d S0o

D

17

18

D

C0r D I2c

19

20

C0t D I2d

D E2a

19

20

D M P1

D E0b S0i U2t

21

22

D E0a S0c U2r

D M P1

21

22

D M Q2b

D S01

23

24

C1r D I3c U1t

D M

23

24

D M

D P0

25

26

C1t D I3d U1r

D M

25

26

D

D P0 Q0b

27

28

D P0 S10

D L P1

27

28

D L P1 U6r

D E S1i P0

29

30

D P0 S1o

D L P1 U6t

29

30

D L P1

D E S1c P0

31

32

ADC VDD

D L

31

32

D L

A 4

33

34

ADC GND

D L Q1b

33

34

D E L

A 6

35

36

A 5

D L Q1a

35

36

D E L

A 2

37

38

A 3

D L U5t

37

38

D L U5r

A 0

39

40

A 1

D L P1

39

40

D L P1

D P0

41

42

D Q0a S11 U3t P0

D L P1

41

42

D L P1

GND

43

44

GND

D L P1

43

44

D L P1

GND

45

46

GND

D E L P1

45

46

D E L P1

Table 73 Black eCAP PWMs

Bone bus

Header pin

peripheral

overlay

/sys/bus/platform/drivers/ecap/48302100.ecap

P9.42

eCAP0_in_PWM0_out

BBB-ECAP0.dts

/sys/bus/platform/drivers/ecap/48304100.ecap

P9.28

eCAP2_in_PWM2_out

BBB-ECAP2.dts

Table 74 AI eCAP PWMs

Bone bus

Header pin

peripheral

overlay

/sys/bus/platform/drivers/ecap/4843e100.ecap

P8.15

eCAP1_in_PWM1_out

BBAI-ECAP1.dts

/sys/bus/platform/drivers/ecap/48440100.ecap

P8.14

eCAP2_in_PWM2_out

BBAI-ECAP2.dts

/sys/bus/platform/drivers/ecap/48440100.ecap

P8.20

eCAP2_in_PWM2_out

BBAI-ECAP2A.dts

/sys/bus/platform/drivers/ecap/48442100.ecap

P8.04

eCAP3_in_PWM3_out

BBAI-ECAP3.dts

/sys/bus/platform/drivers/ecap/48442100.ecap

P8.26

eCAP3_in_PWM3_out

BBAI-ECAP3A.dts

eMMC

Table 75 Bone eMMC

Header pin

Description

P8.3

DAT6

P8.4

DAT7

P8.5

DAT2

P8.6

DAT3

P8.20

CMD

P8.21

CLK

P8.22

DAT5

P8.23

DAT4

P8.24

DAT1

P8.25

DAT0

Table 76 Bone eMMC Overlay

Black

AI

overlay

MMC2

MMC3

BONE-eMMC.dts

LCD

Table 77 16bit LCD interface

Header pin

Description

P8_45

lcd_data0

P8_46

lcd_data1

P8_43

lcd_data2

P8_44

lcd_data3

P8_41

lcd_data4

P8_42

lcd_data5

P8_39

lcd_data6

P8_40

lcd_data7

P8_37

lcd_data8

P8_38

lcd_data9

P8_36

lcd_data10

P8_34

lcd_data11

P8_35

lcd_data12

P8_33

lcd_data13

P8_31

lcd_data14

P8_32

lcd_data15

P8_27

lcd_vsync

P8_29

lcd_hsync

P8_28

lcd_pclk

P8_30

lcd_ac_bias_en

Table 78 16bit LCD interface Overlay

Black

AI

overlay

lcdc

dss

McASP

Table 79 Bone McASP0

Header pin

Description

P9.12

aclkr

P9.25

ahclkx

P9.27

fsr

P9.28

Black: axr2 AI: axr9

P9.29

fsx

P9.30

Black: axr0 AI: axr10

P9.31

aclkx

Table 80 Bone McASP0 Overlay

Black

AI

overlay

McASP0

McASP1

PRU

The overlay situation for PRUs is a bit more complex than with other peripherals. The mechanism for loading, starting and stopping the PRUs can go through either [https://www.kernel.org/doc/html/latest/driver-api/uio-howto.html UIO] or [https://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components/PRU-ICSS/Linux_Drivers/RemoteProc_and_RPMsg.html RemoteProc].

  • /dev/remoteproc/prussX-coreY (AM3358 X = “”, other x = “1|2”)

Table 81 Bone PRU eCAP

Header Pin

Black

AI

P8.15

pr1_ecap0

pr1_ecap0

P8.32

pr2_ecap0

P9.42

pr1_ecap0

Table 82 AI PRU UART

UART

TX

RX

RTSn

CTSn

Overlays

PRU1 UART0

P8_31

P8_33

P8_34

P8_35

PRU2 UART0

P8_43

P8_44

P8_45

P8_46

Table 83 Bone PRU

Header Pin

Black

AI

P8.03

pr2_pru0 10

P8.04

pr2_pru0 11

P8.05

pr2_pru0 06

P8.06

pr2_pru0 07

P8.07

pr2_pru1 16

P8.08

pr2_pru0 20

P8.09

pr2_pru1 06

P8.10

pr2_pru1 15

P8.11

pr1_pru0 15 (Out)

pr1_pru0 04

P8.12

pr1_pru0 14 (Out)

pr1_pru0 03

P8.13

pr1_pru1 07

P8.14

pr1_pru1 09

P8.15

pr1_pru0 15 (In)

pr1_pru1 16

P8.16

pr1_pru0 14 (In)

pr1_pru1 18

P8.17

pr2_pru0 15

P8.18

pr1_pru1 05

P8.19

pr1_pru1 06

P8.20

pr2_pru0 03

P8.21

pr2_pru0 02

P8.22

pr2_pru0 09

P8.23

pr2_pru0 08

P8.24

pr2_pru0 05

P8.25

pr2_pru0 04

P8.26

pr1_pru1 17

P8.27

pr2_pru1 17

P8.28

pr2_pru0 17

P8.29

pr2_pru0 18

P8.30

pr2_pru0 19

P8.31

pr2_pru0 11

P8.32

pr2_pru1 00

P8.33

pr2_pru0 10

P8.34

pr2_pru0 08

P8.35

pr2_pru0 09

P8.36

pr2_pru0 07

P8.37

pr2_pru0 05

P8.38

pr2_pru0 06

P8.39

pr2_pru0 03

P8.40

pr2_pru0 04

P8.41

pr2_pru0 01

P8.42

pr2_pru0 02

P8.43

pr2_pru1 20

P8.44

pr2_pru0 00

P8.45

pr2_pru1 18

P8.46

pr2_pru1 19

P9.11

pr2_pru0 14

P9.13

pr2_pru0 15

P9.14

pr1_pru1 14

P9.15

pr1_pru0 5

P9.16

pr1_pru1 15

P9.17

pr2_pru1 09

P9.18

pr2_pru1 08

P9.19

pr1_pru1 02

P9.20

pr1_pru1 01

P9.24

pr1_pru0 16 (In)

P9.25

pr1_pru0 07

pr2_pru1 05

P9.26

pr1_pru1 16 (In)

pr1_pru0 17

P9.27

pr1_pru0 05

pr1_pru1 11

P9.28

pr1_pru0 03

pr2_pru1 13

P9.29

pr1_pru0 01

pr2_pru1 11

P9.30

pr1_pru0 02

pr2_pru1 12

P9.31

pr1_pru0 00

pr2_pru1 10

P9.41

pr1_pru0 06

pr1_pru1 03

P9.42

pr1_pru0 04

pr1_pru1 10

GPIO

TODO<br> For each of the pins with a GPIO, there should be a symlink that comes from the names *

Methodology

The methodology for applied in the kernel and software images to expose the software interfaces is to be documented here. The most fundamental elements are the device tree entries, including overlays, and udev rules.

TBD

# Also courtesy of mvduin
# create symlinks for gpios exported to sysfs by DT
SUBSYSTEM=="gpio", ACTION=="add", TEST=="value", ATTR{label}!="sysfs", \
                RUN+="/bin/mkdir -p /dev/bone/gpio", \
                RUN+="/bin/ln -sT '/sys/class/gpio/%k' /dev/bone/gpio/%s{label}"

Verification

TODO: The steps used to verify all of these configurations is to be documented here. It will serve to document what has been tested, how to reproduce the configurations, and how to verify each major triannual release. All faults will be documented in the issue tracker.

References