TCA6424A: Operating two TCA6424ARGJR connected to same I2C bus

Visweshwar Selvaraj

Part Number: TCA6424A
Other Parts Discussed in Thread: AM625-Q1, TPIC2810

Tool/software:

Greetings TI Community,

In our custom AM625-Q1 based board design we have connected two TCA6424ARGJR I/O Expanders onto the same I2C bus. As the SoC is operating on a Linux based environment we have also enabled the required device tree and kernel configurations for both the I/O expanders. However, we are only able to only able to utilize one I/O expander while the other is non-operational.

Kernel Configuration Settings

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#
# I2C GPIO expanders
#
# CONFIG_GPIO_ADNP is not set
# CONFIG_GPIO_GW_PLD is not set
# CONFIG_GPIO_MAX7300 is not set
CONFIG_GPIO_MAX732X=y
# CONFIG_GPIO_MAX732X_IRQ is not set
CONFIG_GPIO_PCA953X=y
CONFIG_GPIO_PCA953X_IRQ=y
# CONFIG_GPIO_PCA9570 is not set
# CONFIG_GPIO_PCF857X is not set
# CONFIG_GPIO_TPIC2810 is not set
# end of I2C GPIO expanders
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

#
# I2C GPIO expanders
#
# CONFIG_GPIO_ADNP is not set
# CONFIG_GPIO_GW_PLD is not set
# CONFIG_GPIO_MAX7300 is not set
CONFIG_GPIO_MAX732X=y
# CONFIG_GPIO_MAX732X_IRQ is not set
CONFIG_GPIO_PCA953X=y
CONFIG_GPIO_PCA953X_IRQ=y
# CONFIG_GPIO_PCA9570 is not set
# CONFIG_GPIO_PCF857X is not set
# CONFIG_GPIO_TPIC2810 is not set
# end of I2C GPIO expanders

DTS Settings

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&main_i2c3 {
    status = "okay";
    pinctrl-names = "default";
    pinctrl-0 = <&main_i2c3_pins_default>;
    clock-frequency = <100000>;
    exp1: gpio@23 {
        compatible = "ti,tca6424";
        reg = <0x23>;
        gpio-controller;
        #gpio-cells = <2>;
        gpio-line-names = "12V_GPI1_OUT", "12V_GPI2_OUT",
                   "12V_GPI3_OUT", "12V_GPI4_OUT",
                   "12V_GPI5_OUT", "12V_GPI6_OUT",
                   "12V_GPI7_OUT", "12V_GPI8_OUT",
                   "12V_GPI9_OUT", "12V_GPI10_OUT",
                   "12V_GPI11_OUT", "12V_GPI12_OUT",
                   "12V_GPO1_IN", "12V_GPO2_IN",
                   "12V_GPO3_IN", "12V_GPO4_IN",
                   "12V_GPO5678_FAULT2", "12V_GPO5678_FAULT1",
                   "12V_GPO1234_FAULT2", "12V_GPO1234_FAULT1",
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

&main_i2c3 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&main_i2c3_pins_default>;
	clock-frequency = <100000>;

	exp1: gpio@23 {
		compatible = "ti,tca6424";
		reg = <0x23>;
		gpio-controller;
		#gpio-cells = <2>;
		gpio-line-names = "12V_GPI1_OUT", "12V_GPI2_OUT",
				   "12V_GPI3_OUT", "12V_GPI4_OUT",
				   "12V_GPI5_OUT", "12V_GPI6_OUT",
				   "12V_GPI7_OUT", "12V_GPI8_OUT",
				   "12V_GPI9_OUT", "12V_GPI10_OUT",
				   "12V_GPI11_OUT", "12V_GPI12_OUT",
				   "12V_GPO1_IN", "12V_GPO2_IN",
				   "12V_GPO3_IN", "12V_GPO4_IN",
				   "12V_GPO5678_FAULT2", "12V_GPO5678_FAULT1",
				   "12V_GPO1234_FAULT2", "12V_GPO1234_FAULT1",
				   "12V_GPO8_IN", "12V_GPO7_IN",
				   "12V_GPO6_IN", "12V_GPO5_IN";

		pinctrl-names = "default";
		pinctrl-0 = <&main_gpio1_ioexp_intr_pins_default>;

		interrupt-parent = <&main_gpio1>;
		interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
		interrupt-controller;
		#interrupt-cells = <2>;
	};

	exp2: gpio@22 {
		compatible = "ti,tca6424";
		reg = <0x22>;
		gpio-controller;
		#gpio-cells = <2>;
		gpio-line-names = "MCU_12V_GPI1_OUT", "MCU_12V_GPI2_OUT",
				   "MCU_12V_GPI3_OUT", "MCU_12V_GPI4_OUT",
				   "MCU_12V_GPI5_OUT", "MCU_12V_GPI6_OUT",
				   "MCU_12V_GPI7_OUT", "MCU_12V_GPI8_OUT",
				   "MCU_12V_GPI9_OUT", "MCU_12V_GPI10_OUT",
				   "MCU_12V_GPI11_OUT", "MCU_12V_GPI12_OUT",
				   "MCU_12V_GPO1_IN", "MCU_12V_GPO2_IN",
				   "MCU_12V_GPO3_IN", "MCU_12V_GPO4_IN",
				   "MCU_12V_GPO5678_FAULT2", "MCU_12V_GPO5678_FAULT1",
				   "MCU_12V_GPO1234_FAULT2", "MCU_12V_GPO1234_FAULT1",
				   "MCU_12V_GPO8_IN", "MCU_12V_GPO7_IN",
				   "MCU_12V_GPO6_IN", "MCU_12V_GPO5_IN";

		pinctrl-names = "default";
		pinctrl-0 = <&main_gpio1_ioexp_intr_pins_default>;

		interrupt-parent = <&main_gpio1>;
		interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
		interrupt-controller;
		#interrupt-cells = <2>;
	};
};

I2C Address

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root@am62xx-evm:~# i2cdetect -r 3
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-3 using receive byte commands.
I will probe address range 0x08-0x77.
Continue? [Y/n] y
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- 22 UU -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
root@am62xx-evm:~#
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

root@am62xx-evm:~# i2cdetect -r 3
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-3 using receive byte commands.
I will probe address range 0x08-0x77.
Continue? [Y/n] y
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- 22 UU -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
root@am62xx-evm:~#

Linux GPIO Info

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root@am62xx-evm:~# gpioinfo
gpiochip0 - 92 lines:
        line   0:       unnamed                 input
        line   1:       unnamed                 input
        line   2:       unnamed                 input
        line   3:       unnamed                 input
        line   4:       unnamed                 input
        line   5:       unnamed                 input
        line   6:       unnamed                 input
        line   7:       unnamed                 input
        line   8:       unnamed                 input
        line   9:       unnamed                 input
        line  10:       unnamed                 input
        line  11:       unnamed                 input
        line  12:       unnamed                 input
        line  13:       unnamed                 input
        line  14:       unnamed                 input
        line  15:       unnamed                 input
        line  16:       unnamed                 input
        line  17:       unnamed                 input
        line  18:       unnamed                 input
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

root@am62xx-evm:~# gpioinfo
gpiochip0 - 92 lines:
        line   0:       unnamed                 input
        line   1:       unnamed                 input
        line   2:       unnamed                 input
        line   3:       unnamed                 input
        line   4:       unnamed                 input
        line   5:       unnamed                 input
        line   6:       unnamed                 input
        line   7:       unnamed                 input
        line   8:       unnamed                 input
        line   9:       unnamed                 input
        line  10:       unnamed                 input
        line  11:       unnamed                 input
        line  12:       unnamed                 input
        line  13:       unnamed                 input
        line  14:       unnamed                 input
        line  15:       unnamed                 input
        line  16:       unnamed                 input
        line  17:       unnamed                 input
        line  18:       unnamed                 input
        line  19:       unnamed                 input
        line  20:       unnamed                 input
        line  21:       unnamed                 input
        line  22:       unnamed                 input
        line  23:       unnamed                 input
        line  24:       unnamed                 input
        line  25:       unnamed                 input
        line  26:       unnamed                 input
        line  27:       unnamed                 input
        line  28:       unnamed                 input
        line  29:       unnamed                 input
        line  30:       unnamed                 input
        line  31:       unnamed                 output consumer=regulator-6
        line  32:       unnamed                 input
        line  33:       unnamed                 input
        line  34:       unnamed                 input
        line  35:       unnamed                 input
        line  36:       unnamed                 output consumer=regulator-7
        line  37:       unnamed                 input
        line  38:       unnamed                 input
        line  39:       unnamed                 input
        line  40:       unnamed                 output consumer=tlv71033
        line  41:       unnamed                 input
        line  42:       unnamed                 input
        line  43:       unnamed                 input
        line  44:       unnamed                 input
        line  45:       unnamed                 input
        line  46:       unnamed                 input
        line  47:       unnamed                 input
        line  48:       unnamed                 input
        line  49:       unnamed                 input
        line  50:       unnamed                 input
        line  51:       unnamed                 input
        line  52:       unnamed                 input
        line  53:       unnamed                 input
        line  54:       unnamed                 input
        line  55:       unnamed                 input
        line  56:       unnamed                 input
        line  57:       unnamed                 input
        line  58:       unnamed                 input
        line  59:       unnamed                 input
        line  60:       unnamed                 input
        line  61:       unnamed                 input
        line  62:       unnamed                 input
        line  63:       unnamed                 input
        line  64:       unnamed                 input
        line  65:       unnamed                 input
        line  66:       unnamed                 input
        line  67:       unnamed                 input
        line  68:       unnamed                 input
        line  69:       unnamed                 input
        line  70:       unnamed                 input
        line  71:       unnamed                 input
        line  72:       unnamed                 input
        line  73:       unnamed                 output active-low consumer=reset
        line  74:       unnamed                 input
        line  75:       unnamed                 input
        line  76:       unnamed                 output consumer=regulator-3
        line  77:       unnamed                 input
        line  78:       unnamed                 input
        line  79:       unnamed                 input
        line  80:       unnamed                 input
        line  81:       unnamed                 input
        line  82:       unnamed                 input
        line  83:       unnamed                 input
        line  84:       unnamed                 input
        line  85:       unnamed                 input
        line  86:       unnamed                 input
        line  87:       unnamed                 input
        line  88:       unnamed                 input
        line  89:       unnamed                 input
        line  90:       unnamed                 output
        line  91:       unnamed                 input
gpiochip1 - 52 lines:
        line   0:       unnamed                 input
        line   1:       unnamed                 input
        line   2:       unnamed                 input
        line   3:       unnamed                 input
        line   4:       unnamed                 output
        line   5:       unnamed                 input
        line   6:       unnamed                 input
        line   7:       unnamed                 input
        line   8:       unnamed                 input
        line   9:       unnamed                 input
        line  10:       unnamed                 input
        line  11:       unnamed                 input
        line  12:       unnamed                 input
        line  13:       unnamed                 input
        line  14:       unnamed                 input
        line  15:       unnamed                 input
        line  16:       unnamed                 input
        line  17:       unnamed                 input
        line  18:       unnamed                 input
        line  19:       unnamed                 input
        line  20:       unnamed                 input
        line  21:       unnamed                 input
        line  22:       unnamed                 input
        line  23:       unnamed                 input
        line  24:       unnamed                 input
        line  25:       unnamed                 input
        line  26:       unnamed                 input
        line  27:       unnamed                 input
        line  28:       unnamed                 input
        line  29:       unnamed                 input
        line  30:       unnamed                 input
        line  31:       unnamed                 input
        line  32:       unnamed                 input
        line  33:       unnamed                 input
        line  34:       unnamed                 input
        line  35:       unnamed                 input
        line  36:       unnamed                 input
        line  37:       unnamed                 input
        line  38:       unnamed                 input
        line  39:       unnamed                 input
        line  40:       unnamed                 input
        line  41:       unnamed                 input
        line  42:       unnamed                 input
        line  43:       unnamed                 input
        line  44:       unnamed                 input
        line  45:       unnamed                 input
        line  46:       unnamed                 input
        line  47:       unnamed                 input
        line  48:       unnamed                 input
        line  49:       unnamed                 input
        line  50:       unnamed                 input
        line  51:       unnamed                 input
gpiochip2 - 24 lines:
        line   0:       "12V_GPI1_OUT"          input
        line   1:       "12V_GPI2_OUT"          input
        line   2:       "12V_GPI3_OUT"          input
        line   3:       "12V_GPI4_OUT"          input
        line   4:       "12V_GPI5_OUT"          input
        line   5:       "12V_GPI6_OUT"          input
        line   6:       "12V_GPI7_OUT"          input
        line   7:       "12V_GPI8_OUT"          input
        line   8:       "12V_GPI9_OUT"          input
        line   9:       "12V_GPI10_OUT"         input
        line  10:       "12V_GPI11_OUT"         input
        line  11:       "12V_GPI12_OUT"         input
        line  12:       "12V_GPO1_IN"           input
        line  13:       "12V_GPO2_IN"           input
        line  14:       "12V_GPO3_IN"           input
        line  15:       "12V_GPO4_IN"           input
        line  16:       "12V_GPO5678_FAULT2"    input
        line  17:       "12V_GPO5678_FAULT1"    input
        line  18:       "12V_GPO1234_FAULT2"    input
        line  19:       "12V_GPO1234_FAULT1"    input
        line  20:       "12V_GPO8_IN"           input
        line  21:       "12V_GPO7_IN"           input
        line  22:       "12V_GPO6_IN"           input
        line  23:       "12V_GPO5_IN"           input
root@am62xx-evm:~#

We are able to detect the I2C address of both the I/O expanders but only one is utilized or can be operated even though the kernel and dts configurations for both have been defined. We therefore need assistance to make both the I/O expanders operational.

Regards,

Visweshwar Selvaraj

6 months ago

0 Clemens Ladisch 6 months ago

Guru 297210 points

Any messages regarding pca953x or gpio/pinctrl in the kernel log?

0 Visweshwar Selvaraj 6 months ago in reply to Clemens Ladisch

Prodigy 70 points

Greetings Clemens,

Yes, in the kernel log we do get messages regarding pca953x and gpio/pinctrl.

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root@am62xx-evm:~# dmesg | grep pca953
[    1.339365] pca953x 3-0023: supply vcc not found, using dummy regulator
[    1.346211] pca953x 3-0023: using AI
[    1.409957] pca953x 3-0022: Error applying setting, reverse things back
root@am62xx-evm:~# dmesg | grep gpio
[    1.396798] pinctrl-single f4000.pinctrl: could not request pin 97 (PIN97) from group main-gpio1-ioexp-intr-pins-default  on device pinctrl-single
root@am62xx-evm:~# dmesg | grep pinctrl
[    0.213068] pinctrl core: initialized pinctrl subsystem
[    0.756962] pinctrl-single 4084000.pinctrl: 34 pins, size 136
[    0.763644] pinctrl-single f4000.pinctrl: 171 pins, size 684
[    1.373652] pinctrl-single f4000.pinctrl: pin PIN97 already requested by 3-0023; cannot claim for 3-0022
[    1.390306] pinctrl-single f4000.pinctrl: pin-97 (3-0022) status -22
[    1.396798] pinctrl-single f4000.pinctrl: could not request pin 97 (PIN97) from group main-gpio1-ioexp-intr-pins-default  on device pinctrl-single
root@am62xx-evm:~#
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

root@am62xx-evm:~# dmesg | grep pca953
[    1.339365] pca953x 3-0023: supply vcc not found, using dummy regulator
[    1.346211] pca953x 3-0023: using AI
[    1.409957] pca953x 3-0022: Error applying setting, reverse things back
root@am62xx-evm:~# dmesg | grep gpio
[    1.396798] pinctrl-single f4000.pinctrl: could not request pin 97 (PIN97) from group main-gpio1-ioexp-intr-pins-default  on device pinctrl-single
root@am62xx-evm:~# dmesg | grep pinctrl
[    0.213068] pinctrl core: initialized pinctrl subsystem
[    0.756962] pinctrl-single 4084000.pinctrl: 34 pins, size 136
[    0.763644] pinctrl-single f4000.pinctrl: 171 pins, size 684
[    1.373652] pinctrl-single f4000.pinctrl: pin PIN97 already requested by 3-0023; cannot claim for 3-0022
[    1.390306] pinctrl-single f4000.pinctrl: pin-97 (3-0022) status -22
[    1.396798] pinctrl-single f4000.pinctrl: could not request pin 97 (PIN97) from group main-gpio1-ioexp-intr-pins-default  on device pinctrl-single
root@am62xx-evm:~#

0 Clemens Ladisch 6 months ago in reply to Visweshwar Selvaraj

Guru 297210 points

Apparently, you are using main_gpio1_ioexp_intr_pins_default for both devices.

0 Tyler Townsend 6 months ago in reply to Visweshwar Selvaraj

TI__Mastermind 37293 points

Visweshwar,

Did the latest reply from Clemens fix the issue?

Have you confirmed this setup on a hardware level? Were you able to verify that both devices are ACK'ing to your commands?

Regards,

Tyler

0 Visweshwar Selvaraj 6 months ago in reply to Clemens Ladisch

Prodigy 70 points

Hi Clemens,

Yes, we are using the main_gpio1_ioexp_intr_pins_default for both devices. We removed the DTS definition of main_gpio1_ioexp_intr_pins_default for the second device and the I/O expander was detected in the gpio info.

0 Visweshwar Selvaraj 6 months ago in reply to Tyler Townsend

Prodigy 70 points

Greetings Tyler,

The reply from Clemens helped us fix the issue. We have confirmed the results of the setup on the hardware level. Yes, both the devices are acknowledging our commands

Regards,
Visweshwar Selvaraj

0 Tyler Townsend 6 months ago in reply to Visweshwar Selvaraj

TI__Mastermind 37293 points

Hi Visweshwar,

Please let me know if you have any more questions.

Regards,

Tyler

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TCA6424A: Operating two TCA6424ARGJR connected to same I2C bus