[PATCH] spi/fsl-espi: Add Power Management support for eSPI controller

[Hou Zhiqiang]

Add PM support for eSPI controller using callback function suspend
and resume in .driver of platform_driver.

Signed-off-by: Hou Zhiqiang <b48...@freescale.com>
---
 drivers/spi/spi-fsl-espi.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 8106006..9c3fe70 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -727,6 +727,59 @@ static int of_fsl_espi_remove(struct platform_device *dev)
        return mpc8xxx_spi_remove(&dev->dev);
 }
 
+#ifdef CONFIG_PM
+static int of_fsl_espi_suspend(struct device *dev, pm_message_t state)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct spi_master *master = platform_get_drvdata(pdev);
+       struct mpc8xxx_spi *mpc8xxx_spi;
+       struct fsl_espi_reg *reg_base;
+       u32 regval;
+
+       mpc8xxx_spi = spi_master_get_devdata(master);
+       reg_base = mpc8xxx_spi->reg_base;
+
+       regval = mpc8xxx_spi_read_reg(&reg_base->mode);
+       regval &= ~(SPMODE_ENABLE);
+       mpc8xxx_spi_write_reg(&reg_base->mode, regval);
+
+       regval = mpc8xxx_spi_read_reg(&reg_base->mode);
+
+       return 0;
+}
+
+static int of_fsl_espi_resume(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
+       struct spi_master *master = platform_get_drvdata(pdev);
+       struct mpc8xxx_spi *mpc8xxx_spi;
+       struct fsl_espi_reg *reg_base;
+       u32 regval;
+       int i;
+
+       mpc8xxx_spi = spi_master_get_devdata(master);
+       reg_base = mpc8xxx_spi->reg_base;
+
+       /* SPI controller initializations */
+       mpc8xxx_spi_write_reg(&reg_base->mode, 0);
+       mpc8xxx_spi_write_reg(&reg_base->mask, 0);
+       mpc8xxx_spi_write_reg(&reg_base->command, 0);
+       mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
+
+       /* Init eSPI CS mode register */
+       for (i = 0; i < pdata->max_chipselect; i++)
+               mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
+
+       /* Enable SPI interface */
+       regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
+
+       mpc8xxx_spi_write_reg(&reg_base->mode, regval);
+
+       return 0;
+}
+#endif /* CONFIG_PM */
+
 static const struct of_device_id of_fsl_espi_match[] = {
        { .compatible = "fsl,mpc8536-espi" },
        {}
@@ -738,6 +791,10 @@ static struct platform_driver fsl_espi_driver = {
                .name = "fsl_espi",
                .owner = THIS_MODULE,
                .of_match_table = of_fsl_espi_match,
+#ifdef CONFIG_PM
+               .suspend        = of_fsl_espi_suspend,
+               .resume         = of_fsl_espi_resume,
+#endif
        },
        .probe          = of_fsl_espi_probe,
        .remove         = of_fsl_espi_remove,
-- 
1.8.4.1


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