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[15/21] drm: sun4i: add support for HVCC regulator for DWC HDMI glue

Message ID 20180430114058.5061-16-jagan@amarulasolutions.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jagan Teki April 30, 2018, 11:40 a.m. UTC
From: Icenowy Zheng <icenowy@aosc.io>

Allwinner SoCs with DWC HDMI controller have a "HVCC" power pin for the
HDMI part, and on some boards it's connected to a dedicated regulator
rather than the main 3.3v.

Add support for optional HVCC regulator. For boards that doesn't use a
dedicated regulator to power it, the default dummy regulator is used.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 14 ++++++++++++++
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h |  2 ++
 2 files changed, 16 insertions(+)

Comments

Maxime Ripard May 2, 2018, 11:48 a.m. UTC | #1
On Mon, Apr 30, 2018 at 05:10:52PM +0530, Jagan Teki wrote:
> From: Icenowy Zheng <icenowy@aosc.io>
> 
> Allwinner SoCs with DWC HDMI controller have a "HVCC" power pin for the
> HDMI part, and on some boards it's connected to a dedicated regulator
> rather than the main 3.3v.
> 
> Add support for optional HVCC regulator. For boards that doesn't use a
> dedicated regulator to power it, the default dummy regulator is used.
>
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 14 ++++++++++++++
>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h |  2 ++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> index 9f40a44b456b..7c33faff7ad4 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> @@ -73,6 +73,12 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
>  	if (encoder->possible_crtcs == 0)
>  		return -EPROBE_DEFER;
>  
> +	hdmi->vcc_hdmi = devm_regulator_get(dev, "hvcc");
> +	if (IS_ERR(hdmi->vcc_hdmi)) {
> +		dev_err(dev, "Could not get HDMI power supply\n");
> +		return PTR_ERR(hdmi->vcc_hdmi);
> +	}
> +

You're not making it optional here, unlike what your commit log
says. Not that I'm fine with both, but we need to be consistent :)

>  	hdmi->rst_ctrl = devm_reset_control_get(dev, "ctrl");
>  	if (IS_ERR(hdmi->rst_ctrl)) {
>  		dev_err(dev, "Could not get ctrl reset control\n");
> @@ -91,6 +97,12 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
>  		return ret;
>  	}
>  
> +	ret = regulator_enable(hdmi->vcc_hdmi);
> +	if (ret) {
> +		dev_err(dev, "Cannot enable HDMI power supply\n");
> +		goto err_disable_vcc;
> +	}
> +
>  	ret = clk_prepare_enable(hdmi->clk_tmds);
>  	if (ret) {
>  		dev_err(dev, "Could not enable tmds clock\n");
> @@ -143,6 +155,8 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
>  	clk_disable_unprepare(hdmi->clk_tmds);
>  err_assert_ctrl_reset:
>  	reset_control_assert(hdmi->rst_ctrl);
> +err_disable_vcc:
> +	regulator_disable(hdmi->vcc_hdmi);


The err_disable_vcc label will disable the regulator, but if there's
an error in regulator_enable, it will disable it while it wasn't
enabled in the first place, which is not really something we want to
do.

Maxime
Icenowy Zheng May 2, 2018, 11:51 a.m. UTC | #2
于 2018年5月2日 GMT+08:00 下午7:48:43, Maxime Ripard <maxime.ripard@bootlin.com> 写到:
>On Mon, Apr 30, 2018 at 05:10:52PM +0530, Jagan Teki wrote:
>> From: Icenowy Zheng <icenowy@aosc.io>
>> 
>> Allwinner SoCs with DWC HDMI controller have a "HVCC" power pin for
>the
>> HDMI part, and on some boards it's connected to a dedicated regulator
>> rather than the main 3.3v.
>> 
>> Add support for optional HVCC regulator. For boards that doesn't use
>a
>> dedicated regulator to power it, the default dummy regulator is used.
>>
>> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
>> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
>> ---
>>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 14 ++++++++++++++
>>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h |  2 ++
>>  2 files changed, 16 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>> index 9f40a44b456b..7c33faff7ad4 100644
>> --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>> +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>> @@ -73,6 +73,12 @@ static int sun8i_dw_hdmi_bind(struct device *dev,
>struct device *master,
>>  	if (encoder->possible_crtcs == 0)
>>  		return -EPROBE_DEFER;
>>  
>> +	hdmi->vcc_hdmi = devm_regulator_get(dev, "hvcc");
>> +	if (IS_ERR(hdmi->vcc_hdmi)) {
>> +		dev_err(dev, "Could not get HDMI power supply\n");
>> +		return PTR_ERR(hdmi->vcc_hdmi);
>> +	}
>> +
>
>You're not making it optional here, unlike what your commit log
>says. Not that I'm fine with both, but we need to be consistent :)

If it's not set, regulator subsystem will generate a dummy
regulator as a spaceholder, except using the exclusive variant
of the function.

The word "optional" is from DT perspectove, as it's possible that
it's bound to some critical regulators.

>
>>  	hdmi->rst_ctrl = devm_reset_control_get(dev, "ctrl");
>>  	if (IS_ERR(hdmi->rst_ctrl)) {
>>  		dev_err(dev, "Could not get ctrl reset control\n");
>> @@ -91,6 +97,12 @@ static int sun8i_dw_hdmi_bind(struct device *dev,
>struct device *master,
>>  		return ret;
>>  	}
>>  
>> +	ret = regulator_enable(hdmi->vcc_hdmi);
>> +	if (ret) {
>> +		dev_err(dev, "Cannot enable HDMI power supply\n");
>> +		goto err_disable_vcc;
>> +	}
>> +
>>  	ret = clk_prepare_enable(hdmi->clk_tmds);
>>  	if (ret) {
>>  		dev_err(dev, "Could not enable tmds clock\n");
>> @@ -143,6 +155,8 @@ static int sun8i_dw_hdmi_bind(struct device *dev,
>struct device *master,
>>  	clk_disable_unprepare(hdmi->clk_tmds);
>>  err_assert_ctrl_reset:
>>  	reset_control_assert(hdmi->rst_ctrl);
>> +err_disable_vcc:
>> +	regulator_disable(hdmi->vcc_hdmi);
>
>
>The err_disable_vcc label will disable the regulator, but if there's
>an error in regulator_enable, it will disable it while it wasn't
>enabled in the first place, which is not really something we want to
>do.
>
>Maxime
diff mbox

Patch

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 9f40a44b456b..7c33faff7ad4 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -73,6 +73,12 @@  static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
 	if (encoder->possible_crtcs == 0)
 		return -EPROBE_DEFER;
 
+	hdmi->vcc_hdmi = devm_regulator_get(dev, "hvcc");
+	if (IS_ERR(hdmi->vcc_hdmi)) {
+		dev_err(dev, "Could not get HDMI power supply\n");
+		return PTR_ERR(hdmi->vcc_hdmi);
+	}
+
 	hdmi->rst_ctrl = devm_reset_control_get(dev, "ctrl");
 	if (IS_ERR(hdmi->rst_ctrl)) {
 		dev_err(dev, "Could not get ctrl reset control\n");
@@ -91,6 +97,12 @@  static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
 		return ret;
 	}
 
+	ret = regulator_enable(hdmi->vcc_hdmi);
+	if (ret) {
+		dev_err(dev, "Cannot enable HDMI power supply\n");
+		goto err_disable_vcc;
+	}
+
 	ret = clk_prepare_enable(hdmi->clk_tmds);
 	if (ret) {
 		dev_err(dev, "Could not enable tmds clock\n");
@@ -143,6 +155,8 @@  static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
 	clk_disable_unprepare(hdmi->clk_tmds);
 err_assert_ctrl_reset:
 	reset_control_assert(hdmi->rst_ctrl);
+err_disable_vcc:
+	regulator_disable(hdmi->vcc_hdmi);
 
 	return ret;
 }
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
index 79154f0f674a..c25d75ef9303 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -10,6 +10,7 @@ 
 #include <drm/drm_encoder.h>
 #include <linux/clk.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 
 #define SUN8I_HDMI_PHY_DBG_CTRL_REG	0x0000
@@ -173,6 +174,7 @@  struct sun8i_dw_hdmi {
 	struct drm_encoder		encoder;
 	struct sun8i_hdmi_phy		*phy;
 	struct dw_hdmi_plat_data	plat_data;
+	struct regulator		*vcc_hdmi;
 	struct reset_control		*rst_ctrl;
 };