Unverified Commit 145bb2ae authored by David Lechner's avatar David Lechner Committed by Mark Brown
Browse files

spi: axi-spi-engine: add support for cs_off 



This adds support for the spi_transfer::cs_off flag to the AXI SPI
Engine driver.

The logic is copied from the generic spi_transfer_one_message() in
spi.c.

Signed-off-by: default avatarDavid Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20231117-axi-spi-engine-series-1-v1-13-cc59db999b87@baylibre.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 4e991445

drivers/spi/spi-axi-spi-engine.c

+21 −10
Original line number Diff line number Diff line
@@ -216,7 +216,7 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine, 
	struct spi_device *spi = msg->spi;

	struct spi_transfer *xfer;

	int clk_div, new_clk_div;

	bool cs_change = true;

	bool keep_cs = false;



	clk_div = -1;
@@ -224,6 +224,9 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine, 
		SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,

			spi_engine_get_config(spi)));



	xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);

	spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);



	list_for_each_entry(xfer, &msg->transfers, transfer_list) {

		new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer);

		if (new_clk_div != clk_div) {
@@ -233,20 +236,28 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine, 
					clk_div));

		}



		if (cs_change)

			spi_engine_gen_cs(p, dry, spi, true);



		spi_engine_gen_xfer(p, dry, xfer);

		spi_engine_gen_sleep(p, dry, spi_engine, clk_div, xfer);



		cs_change = xfer->cs_change;

		if (list_is_last(&xfer->transfer_list, &msg->transfers))

			cs_change = !cs_change;



		if (cs_change)

		if (xfer->cs_change) {

			if (list_is_last(&xfer->transfer_list, &msg->transfers)) {

				keep_cs = true;

			} else {

				if (!xfer->cs_off)

					spi_engine_gen_cs(p, dry, spi, false);



				if (!list_next_entry(xfer, transfer_list)->cs_off)

					spi_engine_gen_cs(p, dry, spi, true);

			}

		} else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&

			   xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {

			spi_engine_gen_cs(p, dry, spi, xfer->cs_off);

		}

	}



	if (!keep_cs)

		spi_engine_gen_cs(p, dry, spi, false);



	return 0;

}