[PATCH v4 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Guido Günther]

This allows us to shut down the mipi power domain on the imx8. The
alternative would be to drop the dphy from the mipi power domain in the
SOCs device tree and only have the DSI host controller visible there but
since the PD is mostly about the PHY that would defeat it's purpose.

This allows to shut off the power domain hen blanking the LCD panel:

pm_genpd_summary before:

domain                          status          slaves
    /device                                             runtime status
----------------------------------------------------------------------
mipi                            on
    /devices/platform/soc at 0/soc at 0:bus at 30800000/30a00300.dphy  unsupported
    /devices/platform/soc at 0/soc at 0:bus at 30800000/30a00000.mipi_dsi  suspended

after:

mipi                            off-0
    /devices/platform/soc at 0/soc at 0:bus at 30800000/30a00300.dphy  suspended
    /devices/platform/soc at 0/soc at 0:bus at 30800000/30a00000.mipi_dsi  suspended

Signed-off-by: Guido Günther <agx at sigxcpu.org>
---
 drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
index a95572b397ca..5de175695834 100644
--- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
+++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
@@ -14,6 +14,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 
 /* DPHY registers */
@@ -469,6 +470,8 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(dev, priv);
 
+	pm_runtime_enable(dev);
+
 	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
 	if (IS_ERR(phy)) {
 		dev_err(dev, "Failed to create phy %ld\n", PTR_ERR(phy));
@@ -481,8 +484,15 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	return PTR_ERR_OR_ZERO(phy_provider);
 }
 
+static int mixel_dphy_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+	return 0;
+}
+
 static struct platform_driver mixel_dphy_driver = {
 	.probe	= mixel_dphy_probe,
+	.remove = mixel_dphy_remove,
 	.driver = {
 		.name = "mixel-mipi-dphy",
 		.of_match_table	= mixel_dphy_of_match,
-- 
2.30.0