imx7d how to transfer 32-bit data at a time

[864535720]

Hello everyone
my development board is IMX7DSABRE. Linux kernel version is 4.9.88
When I use SPI to transfer data on imx7d, my imx7d is the master device and my module is the slave device. My module receives 32bit data at a time. The driver I use is driver/spi/spidev.c. The test program I use is tools/spi/spidev_test.c.
If I transmit 8bit data each time, then there will be no problem, but if I transmit 32bit data each time, the program prompts: can't send spi message: Invalid argument
How can I transfer 32-bit data at a time.
By the way, I have achieved 16-bit half-duplex transmission through the read and write functions. But our SPI must work in full-duplex mode, that is, to use the spidev_message function area to transfer data.
Excuse me, how should I solve the problem I am facing now?

[weidong_sun]

Hi Qidong,

See below, please!

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1.The communication mode of SPI is originally full-duplex communication.

2. SPI allows 8bit and 16bit data transmission.

3. If you use 8bit mode, you need to send 4 times in a loop to achieve the purpose of transmitting 32bit data.

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Hope the information is helpful to you.

Have a nice day!

B.R,

Weidong

[864535720]

孙哥，你好。因为外设模块的特殊性，需要一次性传输32位。后面我通过参考driver / spi / spidev.c里面的代码，实现了一次传输32位的功能。可能还存在一些小的问题。后面我解决不了了再来请教你。

[weidong_sun]

你客气了，谈不上请教，一起讨论！

Weidong