Hi,
On 11/15/2016 08:29 AM, Chen-Yu Tsai wrote:
Hi,
On Wed, Nov 2, 2016 at 9:33 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
On Mon, Oct 31, 2016 at 2:28 PM, Rob Herring <robh@xxxxxxxxxx> wrote:
On Sat, Oct 29, 2016 at 07:06:10PM +0800, Chen-Yu Tsai wrote:
Some dumb VGA DACs are active components which require external power.
Add support for specifying a regulator as its power supply.
Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
---
.../bindings/display/bridge/dumb-vga-dac.txt | 2 ++
For the binding,
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Any comments on this patch from the DRM people?
A comment below.
ChenYu
One code comment below...
drivers/gpu/drm/bridge/dumb-vga-dac.c | 35 ++++++++++++++++++++++
2 files changed, 37 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
index 003bc246a270..164cbb15f04c 100644
--- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
+++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
@@ -16,6 +16,8 @@ graph bindings specified in Documentation/devicetree/bindings/graph.txt.
- Video port 0 for RGB input
- Video port 1 for VGA output
+Optional properties:
+- vdd-supply: Power supply for DAC
Example
-------
diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c b/drivers/gpu/drm/bridge/dumb-vga-dac.c
index afec232185a7..59781e031220 100644
--- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
+++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
#include <drm/drmP.h>
#include <drm/drm_atomic_helper.h>
@@ -23,6 +24,7 @@ struct dumb_vga {
struct drm_connector connector;
struct i2c_adapter *ddc;
+ struct regulator *vdd;
};
static inline struct dumb_vga *
@@ -124,8 +126,33 @@ static int dumb_vga_attach(struct drm_bridge *bridge)
return 0;
}
+static void dumb_vga_enable(struct drm_bridge *bridge)
+{
+ struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
+ int ret;
+
+ if (!IS_ERR(vga->vdd)) {
if (IS_ERR())
return;
...will save some intentation.
I thought about that, though if someone were to add more stuff to
this, such as an enable GPIO, they might have to rework it. A standalone
block of code would be easier to work with. I'm OK either way though.
ChenYu
+ ret = regulator_enable(vga->vdd);
+
+ if (ret) {
+ DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
+ return;
+ }
+ }
+}
+
+static void dumb_vga_disable(struct drm_bridge *bridge)
+{
+ struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
+
+ if (!IS_ERR(vga->vdd))
+ regulator_disable(vga->vdd);
+}
+
static const struct drm_bridge_funcs dumb_vga_bridge_funcs = {
.attach = dumb_vga_attach,
+ .enable = dumb_vga_enable,
+ .disable = dumb_vga_disable,
};
static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
@@ -169,6 +196,14 @@ static int dumb_vga_probe(struct platform_device *pdev)
return -ENOMEM;
platform_set_drvdata(pdev, vga);
+ vga->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
+ if (IS_ERR(vga->vdd)) {
+ ret = PTR_ERR(vga->vdd);
+ if (ret == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
A cleaner way would be to set vga->vdd to NULL here, and do:
int ret = 0;
if (vga->vdd)
ret = regulator_enable(vga->vdd);
if (ret) {
...
return;
}
/* if a gpio is added later */
if (vga->gpio)
ret = gpiod_set_value_cansleep(vga->gpio, 1);
if (ret) {
...
return;
}
...
We don't really care what error code is contained in vga->vdd once we have
identified whether we got a regulator or not.
The same thing can be done for ddc too, but that can done left for later.
If you're okay with the suggestion, can you re-spin a patch?
Thanks,
Archit
+ }
+
vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev);
if (IS_ERR(vga->ddc)) {
if (PTR_ERR(vga->ddc) == -ENODEV) {
--
2.9.3
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