[PATCH v6 13/22] drm/sun4i: sun6i_mipi_dsi: Add support for VCC-DSI voltage regulator

[Jagan Teki]

Some boards have VCC-DSI pin connected to voltage regulator which may
not be turned on by default.

Add support for such boards by adding voltage regulator handling code to
MIPI DSI driver.

Signed-off-by: Jagan Teki <ja...@amarulasolutions.com>
---
 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