Unverified Commit aadbff4a authored by Lad Prabhakar's avatar Lad Prabhakar Committed by Mark Brown
Browse files

spi: spi-rspi: Add support to deassert/assert reset line 



On RZ/G2L SoC we need to explicitly deassert the reset line
for the device to work, use this opportunity to deassert/assert
reset line in spi-rspi driver.

This patch adds support to read the "resets" property (if available)
from DT and perform deassert/assert when required.

Signed-off-by: default avatarLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: default avatarBiju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20211118031041.2312-3-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 5a8f8542

drivers/spi/spi-rspi.c

+25 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/dma-mapping.h>

#include <linux/of_device.h>

#include <linux/pm_runtime.h>

#include <linux/reset.h>

#include <linux/sh_dma.h>

#include <linux/spi/spi.h>

#include <linux/spi/rspi.h>
@@ -1225,8 +1226,14 @@ static const struct of_device_id rspi_of_match[] = { 


MODULE_DEVICE_TABLE(of, rspi_of_match);



static void rspi_reset_control_assert(void *data)

{

	reset_control_assert(data);

}



static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)

{

	struct reset_control *rstc;

	u32 num_cs;

	int error;
@@ -1238,6 +1245,24 @@ static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr) 
	}



	ctlr->num_chipselect = num_cs;



	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);

	if (IS_ERR(rstc))

		return dev_err_probe(dev, PTR_ERR(rstc),

					     "failed to get reset ctrl\n");



	error = reset_control_deassert(rstc);

	if (error) {

		dev_err(dev, "failed to deassert reset %d\n", error);

		return error;

	}



	error = devm_add_action_or_reset(dev, rspi_reset_control_assert, rstc);

	if (error) {

		dev_err(dev, "failed to register assert devm action, %d\n", error);

		return error;

	}



	return 0;

}

#else