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: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Link: https://lore.kernel.org/r/20220610074459.3261383-2-andy.chiu@sifive.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Andy Chiu 2022-06-10 15:44:59 +08:00 committed by Mark Brown
parent 0356163e58
commit a1f0161ead
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@ -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,
},
};