From a1f0161eadbd7941c09b5f4c6a210c390d2b86d6 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Fri, 10 Jun 2022 15:44:59 +0800 Subject: [PATCH] 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 Reviewed-by: Greentime Hu Link: https://lore.kernel.org/r/20220610074459.3261383-2-andy.chiu@sifive.com Signed-off-by: Mark Brown --- drivers/spi/spi-sifive.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c index f7c1e20432e0..e29e85cee88a 100644 --- a/drivers/spi/spi-sifive.c +++ b/drivers/spi/spi-sifive.c @@ -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, }, };