[PATCH v2] 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.pm of platform_driver.

Signed-off-by: Hou Zhiqiang <b48...@freescale.com>
---
v2:
 - Replace .driver.suspend and .driver.resume with .driver.pm
 - Use CONFIG_PM_SLEEP instead of CONFIG_PM
 - Add spi_master_suspend and spi_master_resume

 drivers/spi/spi-fsl-espi.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 8106006..428dc7a 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -727,6 +727,66 @@ static int of_fsl_espi_remove(struct platform_device *dev)
        return mpc8xxx_spi_remove(&dev->dev);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int of_fsl_espi_suspend(struct device *dev)
+{
+       struct spi_master *master = dev_get_drvdata(dev);
+       struct mpc8xxx_spi *mpc8xxx_spi;
+       struct fsl_espi_reg *reg_base;
+       u32 regval;
+       int ret;
+
+       mpc8xxx_spi = spi_master_get_devdata(master);
+       reg_base = mpc8xxx_spi->reg_base;
+
+       ret = spi_master_suspend(master);
+       if (ret) {
+               dev_warn(dev, "cannot suspend master\n");
+               return ret;
+       }
+
+       regval = mpc8xxx_spi_read_reg(&reg_base->mode);
+       regval &= ~SPMODE_ENABLE;
+       mpc8xxx_spi_write_reg(&reg_base->mode, regval);
+
+       return 0;
+}
+
+static int of_fsl_espi_resume(struct device *dev)
+{
+       struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
+       struct spi_master *master = dev_get_drvdata(dev);
+       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 spi_master_resume(master);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops espi_pm = {
+       SET_SYSTEM_SLEEP_PM_OPS(of_fsl_espi_suspend, of_fsl_espi_resume)
+};
+
 static const struct of_device_id of_fsl_espi_match[] = {
        { .compatible = "fsl,mpc8536-espi" },
        {}
@@ -738,6 +798,7 @@ static struct platform_driver fsl_espi_driver = {
                .name = "fsl_espi",
                .owner = THIS_MODULE,
                .of_match_table = of_fsl_espi_match,
+               .pm = &espi_pm,
        },
        .probe          = of_fsl_espi_probe,
        .remove         = of_fsl_espi_remove,
-- 
1.8.4.1


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