spi: spi-fsl-dspi: Adding shutdown hook

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>

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 50e41f66a2d7077e6d5fe9e736e7e4b2b66d0b18..685afdf9e8078b1ce89f9aaeaa416c8b763e7dbb 100644 (file)
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 //
 // Copyright 2013 Freescale Semiconductor, Inc.
+// Copyright 2020 NXP
 //
 // Freescale DSPI driver
 // This file contains a driver for the Freescale DSPI
@@ -26,6 +27,9 @@
 #define SPI_MCR_CLR_TXF                        BIT(11)
 #define SPI_MCR_CLR_RXF                        BIT(10)
 #define SPI_MCR_XSPI                   BIT(3)
+#define SPI_MCR_DIS_TXF                        BIT(13)
+#define SPI_MCR_DIS_RXF                        BIT(12)
+#define SPI_MCR_HALT                   BIT(0)
 
 #define SPI_TCR                                0x08
 #define SPI_TCR_GET_TCNT(x)            (((x) & GENMASK(31, 16)) >> 16)
@@ -1417,6 +1421,24 @@ 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->ctlr);
+}
+
 static struct platform_driver fsl_dspi_driver = {
        .driver.name            = DRIVER_NAME,
        .driver.of_match_table  = fsl_dspi_dt_ids,
@@ -1424,6 +1446,7 @@ 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);