Re: [PATCH v1 2/2] spi: fsl-spi: Implement trailing clock mode

On Sun, Feb 27, 2022 at 11:00:35AM +0100, Christophe Leroy wrote:

+	if (!status && spi->mode & SPI_TRAILING) {
+		struct spi_transfer t = {
+			.len = 1,
+			.tx_buf = "",
+			.bits_per_word = 4
+		};
+
+		status = fsl_spi_setup_transfer(spi, &t);
+		if (!status)
+			status = fsl_spi_bufs(spi, &t, 0);
+	}
+	m->status = status;

This seems to be begging for a generic implementation in the core rather
than being driver specific - drivers would for the most part need
updating to advertise less than 8 bit per word transfers but the basic
operation isn't really device specific and it pretty much fits with the
existing interfaces.