R-Car/Boards/Stout:CPLD

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This page contains information about hardware Stout board multiplexing. It allows to use same pins for on board connectors and different peripherals from a custom extension board and switching between them in the real time. There are several multiplexers under CPLD control, which connect SoC with on board peripherals and a 440-pin connector. It allows reuse SoC's busy pins.

Back to R-Car H2 ADAS Starter Kit (Stout board) page]

Hardware configurations

VIN0

Vin0 interface can be connected using CPLD in two different modes: BT656 and Full.

Hardware that is incompatible with VIN0 BT656 mode: SDHI2
Hardware that is incompatible with VIN0 Full mode: SDHI2, VIN2 (all modes) and AVB
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BT656 mode

In BT656 mode only VIN0_DATA<7..0> and VIN0_CLK pins are used. This functionality is enough for using cameras with itu-bt656 8bit interface. Pins VIN_DATA<7..0> are connected to pins 3-14 of the CN6 and pins C15-C20, C22-C23, D15-D18, D23 of the 440-pin connector. This pins are common for the VIN0 and SDHI2 subsystems, so using VIN0 and SDHI2 simultaneously is impossible.

Full mode

In Full mode all functionality of VIN0 subsystem is used. Cameras with ITU-R BT.601, ITU-R BT.656 interfaces can be connected to the CN6 or to the 440-pin connector.

VIN1

Stout board supports three modes of connection VIN1 subsystem to the 440-pin connector: BT656, 10 bits mode and 12 bits modes. VIN1_HSYNC, VIN1_VSYNC, VIN1_FIELD, VIN1_CLK and VIN1_CLKENB are connected directly to R-Car H2 SoC. SD0 pins of the 440-pin connector and MicroSD card slot are disconnected from SoC in all VIN1 modes.

Hardware that is incompatible with VIN1 BT656 mode: SDHI0
Hardware that is incompatible with VIN1 10 bits mode: SDHI0, I2C1, VIN3 (modes with FIELD line)
Hardware that is incompatible with VIN1 12 bits mode: SDHI0, I2C1, VIN3 (modes with FIELD line), SCIFA0
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BT656

In this mode VIN1 has ITU-R BT.656 functionality and can be used via the 440-pin connector (C27-C34 and D39 pins), but only with 8 bits data width.

10 bits mode

This mode allows using 10bit interfaces. In this mode using I2C1 and SD0 is impossible. Modes with FIELD line for VIN3 are blocked too.


12 bits mode

This mode allows using 12 bits data width. In this mode using I2C1, SD0, USB debug serial output (CN9) and debug serial via the 440-pin connector is impossible. Modes with FIELD line for VIN3 are blocked too.

VIN2

Stout board supports four modes of connection VIN2 subsystem: BT656, mode with SYNC lines, mode with FIELD line and mode with SYNC and FIELD lines. VIN2_CLK (440-pin connector D49 pin) is connected directly to R-Car H2 SoC. 440-pin connector provide only 8 pins for video data. Using VIN2 pins disallows using VIN0 in Full mode and Ethernet AVB.

Hardware that is incompatible with VIN2 BT656 mode: VIN0 in Full mode, Ethernet AVB
Hardware that is incompatible with VIN2 with SYNC lines: VIN0 in Full mode, Ethernet AVB, VIN3 (modes with FIELD line), I2C1, Serial debug port (all modes)
Hardware that is incompatible with VIN2 with FIELD line: VIN0 in Full mode, Ethernet AVB, QSPI (all modes)
Hardware that is incompatible with VIN2 with FIELD and SYNC lines: VIN0 in Full mode, Ethernet AVB, QSPI, I2C1, VIN3 (modes with FIELD line), Serial debug port (all modes)
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BT656

In this mode VIN2 has ITU-R BT.656 functionality and can be used via the 440-pin connector (C42-C49 and D49 pins), but only with 8 bits data width.


BT656 with SYNC lines

Setting this mode connects pins D47, D48 of the 440-pin connector to SoC's pins VIN2_HSYNC and VIN2_VSYNC. Switching to this mode blocks USB debug serial output (CN9), debug serial via the 440-pin connector and using I2C1. VIN3 modes with FIELD line are blocked too.

BT656 with FIELD line

Setting this mode connects pins D45, D46 of the 440-pin connector to SoC's pins VIN2_CLKENB, VIN2_FIELD. Switching to this mode blocks QSPI interface (on board and external).


BT656 with FIELD and SYNC lines

Setting this mode connects pins D45, D46, D47, D48 of the 440-pin connector to SoC's pins VIN2_CLKENB, VIN2_FIELD, VIN2_HSYNC and VIN2_VSYNC. Switching to this mode blocks USB debug serial output (CN9) debug serial via the 440-pin connector, QSPI interface (on board and external) and use of I2C1. VIN3's lines FIELD and SYNC are blocked too.

VIN3

Stout board supports three modes of connection VIN3 subsystem to the 440-pin connector: BT656, mode with FIELD line and mode with SYNC and FIELD lines. VIN3<7..0> bus is connected directly to R-Car H2 SoC. 440-pin connector provides only 8 pins for video data. Using VIN3 pins disallows use of IRQ3 pin.

Hardware that is incompatible with VIN3 BT656 mode: IRQ3
Hardware that is incompatible with VIN3 with FIELD line: IRQ3, VIN1 (modes 10 bit and 12 bit), VIN2 (modes with SYNC lines)
Hardware that is incompatible with VIN3 with FIELD and SYNC lines: IRQ3, VIN1 (modes 10 bit and 12 bit), VIN2 (modes with SYNC lines), I2C1
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BT656

In this mode VIN3 has ITU-R BT.656 functionality and can be used via the 440-pin connector (C52-C59 and D49 pins), but only with 8 bits data width. Pin VIN3_CLK is multiplexed with IRQ3 line.


BT656 with FIELD line

Setting this mode connects pins D55, D56 of the 440-pin connector to SoC's pins VIN3_CLKENB, VIN3_FIELD. Switching to this mode also blocks VIN1 (modes 10 bit and 12 bit) and VIN2 (modes with SYNC lines).


BT656 with FIELD and SYNC lines

Setting this mode connects pins D55, D56, D57, D58 of the 440-pin connector to SoC's pins VIN3_CLKENB, VIN2_FIELD, VIN3_HSYNC and VIN3_VSYNC. Switching to this mode also blocks VIN1 (modes 10 bit and 12 bit) and VIN2 (modes with SYNC lines) and I2C.

Ethernet AVB

Setting this mode disconnects VIN0 and VIN2 pins of 440-pin connector and connects this SoC's pins to Altera MAX V, which converts ETH_GMII into the ETH_RGMII.

Hardware that is incompatible with Ethernet AVB mode: VIN0 (Full mode), VIN2 (all modes)


QSPI

QSPI can be connected to the on board QSPI Flash or to the external one. It can be selected using QSPI_ONBOARD mode or QSPI_COM_EXPRESS mode. Using QSPI blocks VIN2 (modes with FIELD line).

Hardware that is incompatible with Ethernet QSPI modes: VIN2 (modes with FIELD)


I2C

I2C subsystem can be connected to 440-pin connector and to PMIC using mode I2C1.

Incompatible modes: VIN1 (10 bits, 12 bits), VIN2 (with SYNC lines), VIN3 (with FIELD and SYNC lines)


IRQ3

Setting this mode connects IRQ3 line of SoC to the HDMI transmitter.

Incompatible modes: VIN3 (all modes)


SCIFA0 (Serial debug port)

SCIFA channel 0 can be connected to the on board ftdi UART to USB converter and then to the CN9 (mode SCIFA0_USB) or to the 440-pin connector (mode SCIFA0_COM_EXPRESS) directly.

Incompatible modes: VIN1 (12bits mode), VIN2 (modes with SYNC lines)

SCIFA2

SCIFA channel 2 and PWM have common pins. This pins can be connected to 440-pin as UART or as PWM.

Incompatible modes: PWM210


SD0

Setting CPLD in this mode connects R-Car H2 SoC to the MicroSD socket. This pins are also available in the 440-pin connector.

Incompatible modes: VIN1 (all modes)


SD2

Setting CPLD in this mode connects SDHI2 subsystem to the 440-pin connector.

Incompatible modes: VIN0 (all modes)


PWM 2,1,0

Setting this mode connects PWM subsystem (channels 0-2) to the 440-pin connector.

Incompatible modes: SCIFA2


signal multiplexing table

This table describes the possible setups of CPLD.

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Software driver

Protocol part describes CPLD as a register with address 0x1 for loading configuration code. There are sysfs interface in yocto for access and special commands in U-Boot. Correct values can be calculated using this formula 

value = (current_value & (~mode_mask)) | mode_value

Table with mode masks and mode values

mode mask mode value
VIN0 BT656 0x00001001 0x00000000
VIN0 Full 0x00001007 0x00000002
VIN1 BT656 0x00000801 0x00000800
VIN1 10bit 0x00000821 0x00000800
VIN1 12bit 0x000008A1 0x00000880
VIN2 BT656 0x00000007 0x00000006
VIN2 with SYNC 0x000000A7 0x00000086
VIN2 with FIELD 0x0000000F 0x0000000E
VIN2 with SYNC and FIELD 0x000000AF 0x0000008E
VIN3 BT656 0x00000101 0x00000100
VIN3 with FIELD 0x00000121 0x00000120
VIN3 with SYNC and FIELD 0x00000161 0x00000120
Ethernet AVB 0x00000003 0x00000000
QSPI onboard 0x00000019 0x00000000
QSPI external 0x00000019 0x00000010
I2C1 0x00000061 0x00000060
IRQ3 0x00000101 0x00000000
SCIFA0 via USB 0x00004081 0x00004000
SCIFA0 via 440-pin connector 0x00004081 0x00000000
SCIFA2 0x00002001 0x00000000
SD0 0x00000801 0x00000000
SD2 0x00001001 0x00001000
PWM 2,1,0 0x00002001 0x00002000

U-Boot

There is a special command in U-Boot for working with CPLD: 

cpld read <adr=0x01>

for reading value from register 

cpld write  <adr=0x01> val

for writing value to the register

The write cpld command can be added to the bootcmd environment variable. 

=> set bootcmd 'cpld write 1 4842; tftp 0x40007fc0 uImage; tftp 0x40f00000 r8a7790-stout.dtb; bootm 0x40007fc0 - 0x40f00000'

During start up U-Boot prints current configuration. U-Boot output should looks like this:

DRAM: 1 GiB
CPLD version: 0x20150427
H2 Mode setting (MD0..28): 0x09e32028
Multiplexer settings:      0x00004062
HDMI setting: 0x00000007
DIPSW (SW3): 0x00000000

Where 0x00004062 means that modes SCFIA0 via USB, I2C1 and VIN0 Full modes are set.


Yocto

Yocto provides access to the CPLD via sysfs. It is possible to use hex numbers to manage configurations, similar to U-Boot. There are two files for it: /sys/devices/cpld.8/adr and /sys/devices/cpld.8/val. adr should be set to 0x1. 

echo -n "0x1" > /sys/devices/cpld.8/adr

Read current mode 

cat /sys/devices/cpld.8/val

Set new mode 

echo -n val > /sys/devices/cpld.8/val

There are also four pseudo multiplexers for named access:

  • /sys/devices/mux.9/
  • /sys/devices/mux.10/
  • /sys/devices/mux.11/
  • /sys/devices/mux.12/

All possible modes for this multiplexers can be read from states files. Reading states for mux.9 

cat /sys/devices/mux.9/states

Table with possible states

mux states default state
mux.9 VIN0_bt656_state,

VIN0_bt601_state, sdhi2_state,

sdhi2_state
mux.10 VIN1_bt656_state,

VIN1_bt601_state, sdhi0_state

sdhi0_state
mux.11 VIN2_bt656_state,

VIN2_bt601_state, avb_state

-
mux.12 VIN3_bt656_state,

VIN3_bt601_state, irq3_state

irq3_state

Reading and setting can be done via /sys/devices/mux.x/state file:

Reading
cat /sys/devices/mux.9/state
sdhi2_state
Setting
echo -n sdhi2_state > /sys/devices/mux.9/state

Unbind of current driver that uses pinmux is not necessary but desirable.

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