[PATCH 1/4] drm/mipi-dbi: Support separate I/O regulator

[Otto Pflüger]

The MIPI DBI specification defines separate vdd (panel power) and
vddi (I/O voltage) supplies. Displays that require different voltages
for the different supplies do exist, so the supplies cannot be
combined into one as they are now. Add a new io_regulator property to
the mipi_dbi_dev struct which can be set by the panel driver along
with the regulator property.

Signed-off-by: Otto Pflüger <otto.pflue...@abscue.de>
---
 drivers/gpu/drm/drm_mipi_dbi.c | 14 ++++++++++++++
 include/drm/drm_mipi_dbi.h     |  7 ++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c
index a6ac56580876..047cab93a041 100644
--- a/drivers/gpu/drm/drm_mipi_dbi.c
+++ b/drivers/gpu/drm/drm_mipi_dbi.c
@@ -427,6 +427,8 @@ void mipi_dbi_pipe_disable(struct drm_simple_display_pipe 
*pipe)
 
        if (dbidev->regulator)
                regulator_disable(dbidev->regulator);
+       if (dbidev->io_regulator)
+               regulator_disable(dbidev->io_regulator);
 }
 EXPORT_SYMBOL(mipi_dbi_pipe_disable);
 
@@ -652,6 +654,16 @@ static int mipi_dbi_poweron_reset_conditional(struct 
mipi_dbi_dev *dbidev, bool
                }
        }
 
+       if (dbidev->io_regulator) {
+               ret = regulator_enable(dbidev->io_regulator);
+               if (ret) {
+                       DRM_DEV_ERROR(dev, "Failed to enable I/O regulator 
(%d)\n", ret);
+                       if (dbidev->regulator)
+                               regulator_disable(dbidev->regulator);
+                       return ret;
+               }
+       }
+
        if (cond && mipi_dbi_display_is_on(dbi))
                return 1;
 
@@ -661,6 +673,8 @@ static int mipi_dbi_poweron_reset_conditional(struct 
mipi_dbi_dev *dbidev, bool
                DRM_DEV_ERROR(dev, "Failed to send reset command (%d)\n", ret);
                if (dbidev->regulator)
                        regulator_disable(dbidev->regulator);
+               if (dbidev->io_regulator)
+                       regulator_disable(dbidev->io_regulator);
                return ret;
        }
 
diff --git a/include/drm/drm_mipi_dbi.h b/include/drm/drm_mipi_dbi.h
index 14eaecb1825c..e4efbd8ffc9d 100644
--- a/include/drm/drm_mipi_dbi.h
+++ b/include/drm/drm_mipi_dbi.h
@@ -122,10 +122,15 @@ struct mipi_dbi_dev {
        struct backlight_device *backlight;
 
        /**
-        * @regulator: power regulator (optional)
+        * @regulator: power regulator (Vdd) (optional)
         */
        struct regulator *regulator;
 
+       /**
+        * @io_regulator: I/O power regulator (Vddi) (optional)
+        */
+       struct regulator *io_regulator;
+
        /**
         * @dbi: MIPI DBI interface
         */
-- 
2.30.2