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

From: Otto Pflüger
Date: Sun Nov 27 2022 - 14:17:19 EST


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.pflueger@xxxxxxxxx>
---
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