[PATCH v7 12/23] drm/sun4i: sun6i_mipi_dsi: Add support for VCC-DSI voltage regulator

[Jagan Teki <jagan-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org>]

Allwinner MIPI DSI controllers are supplied with SoC DSI power rails
via VCC-DSI pin.

Add support for this supply pin by adding voltage regulator handling
code to MIPI DSI driver.

Signed-off-by: Jagan Teki <jagan-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org>
Tested-by: Merlijn Wajer <merlijn-tF0PIh4TN3odnm+yROfE0A@public.gmane.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 14 ++++++++++++++
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  3 +++
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 3d7c03161954..9be414131460 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -1107,6 +1107,12 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
 		return PTR_ERR(base);
 	}
 
+	dsi->regulator = devm_regulator_get(dev, "vcc-dsi");
+	if (IS_ERR(dsi->regulator)) {
+		dev_err(dev, "Couldn't get VCC-DSI supply\n");
+		return PTR_ERR(dsi->regulator);
+	}
+
 	dsi->regs = devm_regmap_init_mmio_clk(dev, "bus", base,
 					      &sun6i_dsi_regmap_config);
 	if (IS_ERR(dsi->regs)) {
@@ -1183,6 +1189,13 @@ static int sun6i_dsi_remove(struct platform_device *pdev)
 static int __maybe_unused sun6i_dsi_runtime_resume(struct device *dev)
 {
 	struct sun6i_dsi *dsi = dev_get_drvdata(dev);
+	int err;
+
+	err = regulator_enable(dsi->regulator);
+	if (err) {
+		dev_err(dsi->dev, "failed to enable VCC-DSI supply: %d\n", err);
+		return err;
+	}
 
 	reset_control_deassert(dsi->reset);
 	clk_prepare_enable(dsi->mod_clk);
@@ -1215,6 +1228,7 @@ static int __maybe_unused sun6i_dsi_runtime_suspend(struct device *dev)
 
 	clk_disable_unprepare(dsi->mod_clk);
 	reset_control_assert(dsi->reset);
+	regulator_disable(dsi->regulator);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
index 257cca660da0..06cce0d0d3ad 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
@@ -13,6 +13,8 @@
 #include <drm/drm_encoder.h>
 #include <drm/drm_mipi_dsi.h>
 
+#include <linux/regulator/consumer.h>
+
 struct sun6i_dphy {
 	struct clk		*bus_clk;
 	struct clk		*mod_clk;
@@ -28,6 +30,7 @@ struct sun6i_dsi {
 	struct clk		*bus_clk;
 	struct clk		*mod_clk;
 	struct regmap		*regs;
+	struct regulator	*regulator;
 	struct reset_control	*reset;
 	struct sun6i_dphy	*dphy;
 
-- 
2.18.0.321.gffc6fa0e3