Unverified Commit 1d0ee0c9 authored by David Lechner's avatar David Lechner Committed by Mark Brown
Browse files

spi: axi-spi-engine: wait for completion in setup 



Add a polling wait for SPI instruction execution to complete in the
spi_engine_setup() function. In practice, these instructions complete
in a few 10s of nanoseconds, so we never ran into any race conditions,
but it is good practice to wait for the completion of the SPI engine
instructions before returning from the setup function.

Signed-off-by: default avatarDavid Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250428-adi-main-v1-1-4b8a1b88a212@baylibre.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b4432656

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

+10 −1
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/fpga/adi-axi-common.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/iopoll.h>

#include <linux/of.h>

#include <linux/module.h>

#include <linux/overflow.h>
@@ -739,12 +740,16 @@ static int spi_engine_setup(struct spi_device *device) 
{

	struct spi_controller *host = device->controller;

	struct spi_engine *spi_engine = spi_controller_get_devdata(host);

	unsigned int reg;



	if (device->mode & SPI_CS_HIGH)

		spi_engine->cs_inv |= BIT(spi_get_chipselect(device, 0));

	else

		spi_engine->cs_inv &= ~BIT(spi_get_chipselect(device, 0));



	writel_relaxed(SPI_ENGINE_CMD_SYNC(0),

		       spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);



	writel_relaxed(SPI_ENGINE_CMD_CS_INV(spi_engine->cs_inv),

		       spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
@@ -755,7 +760,11 @@ static int spi_engine_setup(struct spi_device *device) 
	writel_relaxed(SPI_ENGINE_CMD_ASSERT(0, 0xff),

		       spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);



	return 0;

	writel_relaxed(SPI_ENGINE_CMD_SYNC(1),

		       spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);



	return readl_relaxed_poll_timeout(spi_engine->base + SPI_ENGINE_REG_SYNC_ID,

					  reg, reg == 1, 1, 1000);

}



static int spi_engine_transfer_one_message(struct spi_controller *host,