i2c_transfer_dt issues

[o7-machinehum]

I'm using an ESP32 and having some issues using the i2c_transfer_dt function. When I do something like this...

struct i2c_msg msg[2] = {
        {
            .flags = I2C_MSG_WRITE,
            .len = 2,
            .buf = (uint8_t *)&addr,
        },
        {
            .flags = I2C_MSG_READ,
            .len = 7,
            .buf = (uint8_t *)&buf[1],
        },
    };
    ret = i2c_transfer_dt(&cfg->i2c, &msg, 1);

I get something like this, which looks reasonable. However I want to send msg[1] after msg[0], so I do something like this...

struct i2c_msg msg[2] = {
        {
            .flags = I2C_MSG_WRITE,
            .len = 2,
            .buf = (uint8_t *)&addr,
        },
        {
            .flags = I2C_MSG_READ,
            .len = 7,
            .buf = (uint8_t *)&buf[1],
        },
    };
    ret = i2c_transfer_dt(&cfg->i2c, &msg, 2);

However, absolutely nothing comes out on my logic analyzer. This is the serial output...

[machinehum@whitebox id01_fw]$ west espressif monitor
Serial port /dev/ttyUSB0
Connecting............
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting.....
Detecting chip type... ESP32
/home/machinehum/projects/id01-firmware/zephyr/../modules/hal/espressif/tools/idf_monitor.py:553: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
  if StrictVersion(serial.VERSION) < StrictVersion('3.3.0'):
--- idf_monitor on /dev/ttyUSB0 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:7132
ho 0 tail 12 room 4
load:0x40078000,len:14268
load:0x40080400,len:3716
entry 0x40080674
I (29) boot: ESP-IDF release/v4.3-198-g42ce90fa0 2nd stage bootloader
I (29) boot: compile time 17:05:12
I (30) boot: chip revision: 1
I (33) boot_comm: chip revision: 1, min. bootloader chip revision: 0
I (40) boot.esp32: SPI Speed      : 40MHz
I (45) boot.esp32: SPI Mode       : DIO
I (50) boot.esp32: SPI Flash Size : 4MB
I (54) boot: Enabling RNG early entropy source...
I (59) boot: Partition Table:
I (63) boot: ## Label            Usage          Type ST Offset   Length
I (70) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (78) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (85) boot:  2 factory          factory app      00 00 00010000 00100000
I (93) boot: End of partition table
I (97) boot_comm: chip revision: 1, min. application chip revision: 0
I (104) esp_image: segment 0: paddr=00010020 vaddr=00000020 size=0001ch (    28) 
I (112) esp_image: segment 1: paddr=00010044 vaddr=3ffb0000 size=0192ch (  6444) load
I (123) esp_image: segment 2: paddr=00011978 vaddr=3ffb192c size=00288h (   648) load
I (130) esp_image: segment 3: paddr=00011c08 vaddr=3ffb1bb8 size=0015ch (   348) load
I (138) esp_image: segment 4: paddr=00011d6c vaddr=40080000 size=0e050h ( 57424) load
I (171) esp_image: segment 5: paddr=0001fdc4 vaddr=00000000 size=00274h (   628) 
I (171) esp_image: segment 6: paddr=00020040 vaddr=3f400040 size=12bdch ( 76764) map
I (205) esp_image: segment 7: paddr=00032c24 vaddr=00000000 size=0d3f4h ( 54260) 
I (226) esp_image: segment 8: paddr=00040020 vaddr=400d0020 size=46d3ch (290108) map
I (343) boot: Loaded app from partition at offset 0x10000
I (343) boot: Disabling RNG early entropy source...
�*** Booting Zephyr OS build zephyr-v3.1.0-2460-g3f22a97c48bf  ***
[00:00:00.859,000] <inf> esp32_wifi: WIFI_EVENT_STA_START
[00:00:01.653,000] <inf> esp32_wifi: WIFI_EVENT_STA_CONNECTED
[00:00:05.866,000] <inf> net_dhcpv4: Received: 192.168.1.206
[00:00:05.866,000] <inf> esp32_wifi_sta: Your address: 192.168.1.206
[00:00:05.866,000] <inf> esp32_wifi_sta: Lease time: 43200 seconds
[00:00:05.867,000] <inf> esp32_wifi_sta: Subnet: 255.255.255.0
[00:00:05.867,000] <inf> esp32_wifi_sta: Router: 192.168.1.1

[EricNRS]

Have you configured the I2C output pins correctly? It would be something like this:

&pinctrl {
	i2c0_default: i2c0_default {
		group1 {
			pinmux = <I2C0_SDA_GPIO5>, <I2C0_SCL_GPIO4>;
			bias-pull-up;
			drive-open-drain;
			output-high;
		};
	};
}

Also, try enabling the I2C shell (CONFIG_I2C_SHELL) and then you can run i2c scan i2c@####### where #### is the name of your i2c controller.