Unverified Commit 6ecdb0aa authored by David Lechner's avatar David Lechner Committed by Mark Brown
Browse files

spi: axi-spi-engine: Add SPI_CS_HIGH support 



The AXI SPI Engine IP core v1.2 added support for SPI_CS_HIGH. This
provides the driver implementation to make use of this feature when
supported hardware is detected.

Signed-off-by: default avatarDavid Lechner <dlechner@baylibre.com>
Link: https://msgid.link/r/20240508-spi-axi-spi-engine-add-spi_cs_high-support-v1-1-695dd8e45f00@baylibre.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f44b3730

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

+34 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
#define SPI_ENGINE_INST_ASSERT			0x1

#define SPI_ENGINE_INST_WRITE			0x2

#define SPI_ENGINE_INST_MISC			0x3

#define SPI_ENGINE_INST_CS_INV			0x4



#define SPI_ENGINE_CMD_REG_CLK_DIV		0x0

#define SPI_ENGINE_CMD_REG_CONFIG		0x1
@@ -73,6 +74,8 @@ 
	SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SLEEP, (delay))

#define SPI_ENGINE_CMD_SYNC(id) \

	SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SYNC, (id))

#define SPI_ENGINE_CMD_CS_INV(flags) \

	SPI_ENGINE_CMD(SPI_ENGINE_INST_CS_INV, 0, (flags))



struct spi_engine_program {

	unsigned int length;
@@ -111,6 +114,8 @@ struct spi_engine { 
	struct spi_engine_message_state msg_state;

	struct completion msg_complete;

	unsigned int int_enable;

	/* shadows hardware CS inversion flag state */

	u8 cs_inv;

};



static void spi_engine_program_add_cmd(struct spi_engine_program *p,
@@ -530,6 +535,29 @@ static int spi_engine_unoptimize_message(struct spi_message *msg) 
	return 0;

}



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);



	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_CS_INV(spi_engine->cs_inv),

		       spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);



	/*

	 * In addition to setting the flags, we have to do a CS assert command

	 * to make the new setting actually take effect.

	 */

	writel_relaxed(SPI_ENGINE_CMD_ASSERT(0, 0xff),

		       spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);



	return 0;

}



static int spi_engine_transfer_one_message(struct spi_controller *host,

	struct spi_message *msg)

{
@@ -653,6 +681,12 @@ static int spi_engine_probe(struct platform_device *pdev) 
	host->unoptimize_message = spi_engine_unoptimize_message;

	host->num_chipselect = 8;



	/* Some features depend of the IP core version. */

	if (ADI_AXI_PCORE_VER_MINOR(version) >= 2) {

		host->mode_bits |= SPI_CS_HIGH;

		host->setup = spi_engine_setup;

	}



	if (host->max_speed_hz == 0)

		return dev_err_probe(&pdev->dev, -EINVAL, "spi_clk rate is 0");