Unverified Commit a1f0161e authored by Andy Chiu's avatar Andy Chiu Committed by Mark Brown
Browse files

spi: sifive: add PM callbacks to support suspend/resume 



The patch has been tested on Unmatched using pm_test. The Unmatched board
uses SD over SPI and it was tested by initiating S2RAM cycles for all
devices while reading/writing files at the same time. We found no dropped
connection to the card or corrupted filesystem during test cycles.

Signed-off-by: default avatarAndy Chiu <andy.chiu@sifive.com>
Reviewed-by: default avatarGreentime Hu <greentime.hu@sifive.com>
Link: https://lore.kernel.org/r/20220610074459.3261383-2-andy.chiu@sifive.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 0356163e

drivers/spi/spi-sifive.c

+39 −0
Original line number Diff line number Diff line
@@ -427,6 +427,44 @@ static int sifive_spi_remove(struct platform_device *pdev) 
	return 0;

}



static int sifive_spi_suspend(struct device *dev)

{

	struct spi_master *master = dev_get_drvdata(dev);

	struct sifive_spi *spi = spi_master_get_devdata(master);

	int ret;



	ret = spi_master_suspend(master);

	if (ret)

		return ret;



	/* Disable all the interrupts just in case */

	sifive_spi_write(spi, SIFIVE_SPI_REG_IE, 0);



	clk_disable_unprepare(spi->clk);



	return ret;

}



static int sifive_spi_resume(struct device *dev)

{

	struct spi_master *master = dev_get_drvdata(dev);

	struct sifive_spi *spi = spi_master_get_devdata(master);

	int ret;



	ret = clk_prepare_enable(spi->clk);

	if (ret)

		return ret;

	ret = spi_master_resume(master);

	if (ret)

		clk_disable_unprepare(spi->clk);



	return ret;

}



static DEFINE_SIMPLE_DEV_PM_OPS(sifive_spi_pm_ops,

				sifive_spi_suspend, sifive_spi_resume);





static const struct of_device_id sifive_spi_of_match[] = {

	{ .compatible = "sifive,spi0", },

	{}
@@ -438,6 +476,7 @@ static struct platform_driver sifive_spi_driver = { 
	.remove = sifive_spi_remove,

	.driver = {

		.name = SIFIVE_SPI_DRIVER_NAME,

		.pm = &sifive_spi_pm_ops,

		.of_match_table = sifive_spi_of_match,

	},

};