Windows10 IoT Enterprise W21H2-1-4-1 How to support HID over I2C

[okuda]

Hi.

Currently, Windows is running on the NXP iMX8mp reference board with binaries created with Windows10 IoT Enterprise BSP W21H2-1-4-1.
Using the reference board's I2C port, HID over I2C
and want to use I2C devices via HID.

I'm reading the "hid-over-i2c-protocol-spec-v1-0.docx" document that I downloaded from the Microsoft homepage, but I can't really figure out what to do.

What steps should I take to use HID over I2C with the I2C port of the NXP reference board?

Best Regards,
Koji Okuda

[okuda]

Hi.

In order to realize HID over I2C, we have confirmed the operation of the current I2C driver alone.
I wanted to check using I2C5, but since it is CAN1 by default, I made the following modifications.

MX8M_PLUS_EVK.dsc
#
# Board configuration
#
giMX8TokenSpaceGuid.PcdCAN1InsteadOfI2C5|FALSE＜－－－－Change from TRUE to FALSE
giMX8TokenSpaceGuid.PcdCAN2InsteadOfPDMStream3|TRUE

After implementing the above modifications and starting the OS with the built version, I checked the device manager and it recognized I2C5.
However, when I tested it from the application, it did not work properly.

We reviewed the NXP porting again and made the following two corrections.

iMX8BoardInit.c
Added I2C5 daisy chain setting
VOID I2cInit()
{
IOMUXC_SW_MUX_CTL_PAD_I2C1_SCL = IOMUXC_MUX_ALT0 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_I2C1_SDA = IOMUXC_MUX_ALT0 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_I2C2_SCL = IOMUXC_MUX_ALT0 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_I2C2_SDA = IOMUXC_MUX_ALT0 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_I2C3_SCL = IOMUXC_MUX_ALT0 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_I2C3_SDA = IOMUXC_MUX_ALT0 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_SPDIF_TX = IOMUXC_MUX_ALT2 | IOMUXC_MUX_SION_ENABLED;
IOMUXC_SW_MUX_CTL_PAD_SPDIF_RX = IOMUXC_MUX_ALT2 | IOMUXC_MUX_SION_ENABLED;

/*** I2C5-CAN Debug for DMC 2023/10/23 Start ***/
IOMUXC_I2C5_SCL_IN_SELECT_INPUT = IOMUXC_MUX_ALT2;
IOMUXC_I2C5_SDA_IN_SELECT_INPUT = IOMUXC_MUX_ALT2;
/*** I2C5-CAN Debug for DMC 2023/10/23 End ***/

CAN1 initialization disabled when using I2C5
VOID CanInit(IN BOOLEAN UseCAN)
/*** I2C5-CAN Debug for DMC 2023/10/23 End ***/
{
// IOMUX CAN PINS
/*** I2C5-CAN Debug for DMC 2023/10/23 Start ***/
// IOMUXC_SW_MUX_CTL_PAD_SPDIF_TX = IOMUXC_MUX_ALT4; // CAN1_TX -> PAD_SPDIF_TX
// IOMUXC_SW_MUX_CTL_PAD_SPDIF_RX = IOMUXC_MUX_ALT4; // CAN1_RX -> CAN1_RX_SELECT_INPUT
// IOMUXC_CAN1_CANRX_SELECT_INPUT = IOMUXC_MUX_ALT2; // CAN1_RX_SELECT_INPUT -> PAD_SPDIF_RX
// IOMUXC_SW_PAD_CTL_PAD_SPDIF_TX = CAN_PAD_CTRL;
// IOMUXC_SW_PAD_CTL_PAD_SPDIF_RX = CAN_PAD_CTRL;

if( UseCAN ){
IOMUXC_SW_MUX_CTL_PAD_SPDIF_TX = IOMUXC_MUX_ALT4; // CAN1_TX -> PAD_SPDIF_TX
IOMUXC_SW_MUX_CTL_PAD_SPDIF_RX = IOMUXC_MUX_ALT4; // CAN1_RX -> CAN1_RX_SELECT_INPUT
IOMUXC_CAN1_CANRX_SELECT_INPUT = IOMUXC_MUX_ALT2; // CAN1_RX_SELECT_INPUT -> PAD_SPDIF_RX
IOMUXC_SW_PAD_CTL_PAD_SPDIF_TX = CAN_PAD_CTRL;
IOMUXC_SW_PAD_CTL_PAD_SPDIF_RX = CAN_PAD_CTRL;
}else{
SerialPortWrite( (UINT8 *)("---- MUX_CTRL not Init for CAN1 not Use\r\n"), (UINTN)sizeof("---- MUX_CTRL not Init for CAN1 not Use\r\n") );
}
/*** I2C5-CAN Debug for DMC 2023/10/23 End ***/

IOMUXC_SW_MUX_CTL_PAD_SAI5_RXD3 = IOMUXC_MUX_ALT6; // CAN2_TX -> PAD_SAI5_RXD3
IOMUXC_SW_MUX_CTL_PAD_SAI5_MCLK = IOMUXC_MUX_ALT6; // CAN2_RX -> CAN2_RX_SELECT_INPUT
IOMUXC_CAN2_CANRX_SELECT_INPUT = IOMUXC_MUX_ALT0; // CAN2_RX_SELECT_INPUT -> PAD_SAI5_MCLK
IOMUXC_SW_PAD_CTL_PAD_SAI5_RXD3 = CAN_PAD_CTRL;
IOMUXC_SW_PAD_CTL_PAD_SAI5_MCLK = CAN_PAD_CTRL;

// Configures GPIO5_IO05 as output with "1". This signal is connected to the STBN1 pin of the TJA1048T chip.
// The goal is for the CAN transceiver TJA1048T to leave standby mode
/*** I2C5-CAN Debug for DMC 2023/10/23 Start ***/
// IOMUXC_SW_MUX_CTL_PAD_SPDIF_EXT_CLK = IOMUXC_MUX_ALT5; // GPIO5_IO5 -> PAD_SPDIF_EXT_CLK
// IOMUXC_SW_PAD_CTL_PAD_SPDIF_EXT_CLK = CAN_PAD_CTRL;
// GPIO5_DR |= (0x01 << 5); // Set the pad to the high level
// GPIO5_GDIR |= (0x01 << 5);
if( UseCAN ){
IOMUXC_SW_MUX_CTL_PAD_SPDIF_EXT_CLK = IOMUXC_MUX_ALT5; // GPIO5_IO5 -> PAD_SPDIF_EXT_CLK
IOMUXC_SW_PAD_CTL_PAD_SPDIF_EXT_CLK = CAN_PAD_CTRL;
GPIO5_DR |= (0x01 << 5); // Set the pad to the high level
GPIO5_GDIR |= (0x01 << 5);
}else{
SerialPortWrite( (UINT8 *)("---- PAD_CTRL not Init for CAN1 not Use\r\n"), (UINTN)sizeof("---- PAD_CTRL not Init for CAN1 not Use\r\n") );
}
/*** I2C5-CAN Debug for DMC 2023/10/23 End ***/

// Configures GPIO4_IO27 as output with "1". This signal is connected to the STBN2 pin of the TJA1048T chip.
IOMUXC_SW_MUX_CTL_PAD_SAI2_MCLK = IOMUXC_MUX_ALT5; // GPIO4_IO27 -> PAD_SAI2_MCLK
IOMUXC_SW_PAD_CTL_PAD_SAI2_MCLK = CAN_PAD_CTRL;
GPIO4_DR |= (0x01 << 27); // Set the pad to the high level
GPIO4_GDIR |= (0x01 << 27);

// CAN clock
CCM_CCGR_CAN1 = 0x00;
CCM_CCGR_CAN2 = 0x00;
/*** I2C5-CAN Debug for DMC 2023/10/23 Start ***/
//#if FixedPcdGet32(PcdCAN1XTALEnable)
// Configure CAN1 Clksrc=24M_REF_CLK (24 MHz), PreDiv = 1, PostDiv = 1, Fout = 24 MHz
// CCM_TARGET_ROOT_CAN1 = CCM_TARGET_ROOT_MUX(0) | CCM_TARGET_ROOT_PRE_PODF(0) | CCM_TARGET_ROOT_POST_PODF(0) | CCM_TARGET_ROOT_ENABLE_MASK;
//#else
// Configure CAN1 Clksrc=SYSTEM_PLL1_DIV20 (40 MHz, PLL1 = 800 MHz), PreDiv = 1, PostDiv = 1, Fout = 40 MHz
// CCM_TARGET_ROOT_CAN1 = CCM_TARGET_ROOT_MUX(2) | CCM_TARGET_ROOT_PRE_PODF(0) | CCM_TARGET_ROOT_POST_PODF(0) | CCM_TARGET_ROOT_ENABLE_MASK;
//#endif
if( UseCAN ){
#if FixedPcdGet32(PcdCAN1XTALEnable)
// Configure CAN1 Clksrc=24M_REF_CLK (24 MHz), PreDiv = 1, PostDiv = 1, Fout = 24 MHz
CCM_TARGET_ROOT_CAN1 = CCM_TARGET_ROOT_MUX(0) | CCM_TARGET_ROOT_PRE_PODF(0) | CCM_TARGET_ROOT_POST_PODF(0) | CCM_TARGET_ROOT_ENABLE_MASK;
#else
// Configure CAN1 Clksrc=SYSTEM_PLL1_DIV20 (40 MHz, PLL1 = 800 MHz), PreDiv = 1, PostDiv = 1, Fout = 40 MHz
CCM_TARGET_ROOT_CAN1 = CCM_TARGET_ROOT_MUX(2) | CCM_TARGET_ROOT_PRE_PODF(0) | CCM_TARGET_ROOT_POST_PODF(0) | CCM_TARGET_ROOT_ENABLE_MASK;
#endif
}else{
SerialPortWrite( (UINT8 *)("---- XTAL not Init for CAN1 not Use\r\n"), (UINTN)sizeof("---- XTAL not Init for CAN1 not Use\r\n") );
}
/*** I2C5-CAN Debug for DMC 2023/10/23 End ***/
#if FixedPcdGet32(PcdCAN2XTALEnable)
// Configure CAN2 Clksrc=24M_REF_CLK (24 MHz), PreDiv = 1, PostDiv = 1, Fout = 24 MHz
CCM_TARGET_ROOT_CAN2 = CCM_TARGET_ROOT_MUX(0) | CCM_TARGET_ROOT_PRE_PODF(0) | CCM_TARGET_ROOT_POST_PODF(0) | CCM_TARGET_ROOT_ENABLE_MASK;
#else
// Configure CAN2 Clksrc=SYSTEM_PLL1_DIV20 (40 MHz, PLL1 = 800 MHz), PreDiv = 1, PostDiv = 1, Fout = 40 MHz
CCM_TARGET_ROOT_CAN2 = CCM_TARGET_ROOT_MUX(2) | CCM_TARGET_ROOT_PRE_PODF(0) | CCM_TARGET_ROOT_POST_PODF(0) | CCM_TARGET_ROOT_ENABLE_MASK;
#endif
/*** I2C5-CAN Debug for DMC 2023/10/23 Start ***/
// CCM_CCGR_CAN1 = 0x03;
if( UseCAN ){
CCM_CCGR_CAN1 = 0x03;
}else{
SerialPortWrite( (UINT8 *)("---- CLK not Init for CAN1 not Use\r\n"), (UINTN)sizeof("---- CLK not Init for CAN1 not Use\r\n") );
}
/*** I2C5-CAN Debug for DMC 2023/10/23 End ***/
CCM_CCGR_CAN2 = 0x03;
}

By implementing the above modifications, I2C5 can now be accessed normally from the application.
Is the above fix the right way to fix it to use I2C5?

Best Regards,
Koji Okuda

[Bio_TICFSL]

Could  @MichalMinarcik  help here?

Regards

[okuda]

Hello Bio_TICFSL

Thank you for your reply.
@MichalMinarcik seems to have replied about LCD, but I don't understand how it has anything to do with HID over I2C.

It would be helpful if you could explain a little more.

Best Regards,
Koji Okuda