spi: spi-fsl-dspi: Adding shutdown hook

[ Upstream commit dc234825997ec6ff05980ca9e2204f4ac3f8d695 ]

We need to ensure dspi controller could be stopped in order for kexec
to start the next kernel.
So add the shutdown operation support.

Signed-off-by: Peng Ma <peng.ma@nxp.com>
Link: https://lore.kernel.org/r/20200424061216.27445-1-peng.ma@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index ca013dd4ff6bb19d410ae522fe1f91b27d5f7ace..d5b56b7814fe32499ecde65e9c82f0d934449f3e 100644 (file)
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -49,6 +49,9 @@
 #define SPI_MCR_PCSIS          (0x3F << 16)
 #define SPI_MCR_CLR_TXF        (1 << 11)
 #define SPI_MCR_CLR_RXF        (1 << 10)
+#define SPI_MCR_DIS_TXF                (1 << 13)
+#define SPI_MCR_DIS_RXF                (1 << 12)
+#define SPI_MCR_HALT           (1 << 0)
 
 #define SPI_TCR                        0x08
 #define SPI_TCR_GET_TCNT(x)    (((x) & 0xffff0000) >> 16)
@@ -1074,6 +1077,24 @@ static int dspi_remove(struct platform_device *pdev)
        return 0;
 }
 
+static void dspi_shutdown(struct platform_device *pdev)
+{
+       struct spi_controller *ctlr = platform_get_drvdata(pdev);
+       struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);
+
+       /* Disable RX and TX */
+       regmap_update_bits(dspi->regmap, SPI_MCR,
+                          SPI_MCR_DIS_TXF | SPI_MCR_DIS_RXF,
+                          SPI_MCR_DIS_TXF | SPI_MCR_DIS_RXF);
+
+       /* Stop Running */
+       regmap_update_bits(dspi->regmap, SPI_MCR, SPI_MCR_HALT, SPI_MCR_HALT);
+
+       dspi_release_dma(dspi);
+       clk_disable_unprepare(dspi->clk);
+       spi_unregister_controller(dspi->master);
+}
+
 static struct platform_driver fsl_dspi_driver = {
        .driver.name    = DRIVER_NAME,
        .driver.of_match_table = fsl_dspi_dt_ids,
@@ -1081,6 +1102,7 @@ static struct platform_driver fsl_dspi_driver = {
        .driver.pm = &dspi_pm,
        .probe          = dspi_probe,
        .remove         = dspi_remove,
+       .shutdown       = dspi_shutdown,
 };
 module_platform_driver(fsl_dspi_driver);