diff mbox

[v2,2/2] drm/bridge: Add PTN3460 bridge driver

Message ID 1376513258-25703-3-git-send-email-seanpaul@chromium.org
State Superseded
Headers show

Commit Message

Sean Paul Aug. 14, 2013, 8:47 p.m. UTC
This patch adds a drm_bridge driver for the PTN3460 DisplayPort to LVDS
bridge chip.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
---
 .../devicetree/bindings/drm/bridge/ptn3460.txt     |  27 ++
 drivers/gpu/drm/Kconfig                            |   2 +
 drivers/gpu/drm/Makefile                           |   1 +
 drivers/gpu/drm/bridge/Kconfig                     |   5 +
 drivers/gpu/drm/bridge/Makefile                    |   3 +
 drivers/gpu/drm/bridge/ptn3460.c                   | 349 +++++++++++++++++++++
 include/drm/bridge/ptn3460.h                       |  36 +++
 7 files changed, 423 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
 create mode 100644 drivers/gpu/drm/bridge/Kconfig
 create mode 100644 drivers/gpu/drm/bridge/Makefile
 create mode 100644 drivers/gpu/drm/bridge/ptn3460.c
 create mode 100644 include/drm/bridge/ptn3460.h

Comments

Thierry Reding Aug. 15, 2013, 3:28 p.m. UTC | #1
On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
[...]
> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
> +		struct i2c_client *client, struct device_node *node)
[...]
> +	ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);

of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
that in the driver that uses ptn3460_init(). Since you pass in an
initialized drm_device, you'd need to undo all of that in case of
-EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
but it makes things difficult to handle for drivers.

For instance on Tegra we pretty much delay DRM initialization until all
required subdevices (there are quite a few) have been probed, so if we
wanted to use this function we'd have to call it after all drivers have
been probed because only then do we have access to a struct drm_device.
That will cause other problems, however, because at that point we can't
defer probing anymore.

Thierry
Sean Paul Aug. 15, 2013, 7:32 p.m. UTC | #2
On Thu, Aug 15, 2013 at 11:28 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
> [...]
>> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
>> +             struct i2c_client *client, struct device_node *node)
> [...]
>> +     ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
>
> of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
> that in the driver that uses ptn3460_init(). Since you pass in an
> initialized drm_device, you'd need to undo all of that in case of
> -EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
> but it makes things difficult to handle for drivers.
>
> For instance on Tegra we pretty much delay DRM initialization until all
> required subdevices (there are quite a few) have been probed, so if we
> wanted to use this function we'd have to call it after all drivers have
> been probed because only then do we have access to a struct drm_device.
> That will cause other problems, however, because at that point we can't
> defer probing anymore.
>

I suppose I could add another init that performs the deferrable tasks
(ptn3460_init_deferrable or something). This would be called before
drm init has been started from one of the probe functions.
Alternatively, I could set this up as a standalone i2c driver and do
this stuff in the probe. Any other options?

Adding another init call adds yet another thing the drm driver has to
do to use this bridge. Making the ptn driver standalone requires you
to set things up such that drm init is dependent on ptn probe running
successfully. I'm not sure which is more desirable.

Practically speaking, do you expect to call drm_init before the gpio
is available?

Sean



> Thierry
Thierry Reding Aug. 15, 2013, 8:42 p.m. UTC | #3
On Thu, Aug 15, 2013 at 03:32:58PM -0400, Sean Paul wrote:
> On Thu, Aug 15, 2013 at 11:28 AM, Thierry Reding
> <thierry.reding@gmail.com> wrote:
> > On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
> > [...]
> >> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
> >> +             struct i2c_client *client, struct device_node *node)
> > [...]
> >> +     ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
> >
> > of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
> > that in the driver that uses ptn3460_init(). Since you pass in an
> > initialized drm_device, you'd need to undo all of that in case of
> > -EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
> > but it makes things difficult to handle for drivers.
> >
> > For instance on Tegra we pretty much delay DRM initialization until all
> > required subdevices (there are quite a few) have been probed, so if we
> > wanted to use this function we'd have to call it after all drivers have
> > been probed because only then do we have access to a struct drm_device.
> > That will cause other problems, however, because at that point we can't
> > defer probing anymore.
> >
> 
> I suppose I could add another init that performs the deferrable tasks
> (ptn3460_init_deferrable or something). This would be called before
> drm init has been started from one of the probe functions.
> Alternatively, I could set this up as a standalone i2c driver and do
> this stuff in the probe. Any other options?

My point was that in those cases you don't have access to the DRM device
yet since you haven't called drm_init() yet.

> Adding another init call adds yet another thing the drm driver has to
> do to use this bridge. Making the ptn driver standalone requires you
> to set things up such that drm init is dependent on ptn probe running
> successfully. I'm not sure which is more desirable.
> 
> Practically speaking, do you expect to call drm_init before the gpio
> is available?

No, not really, but I won't know that the GPIO is available until I
actually call of_get_named_gpio_flags().

But perhaps we should cross that bridge when we get to it.

Thierry
Sean Paul Aug. 15, 2013, 8:51 p.m. UTC | #4
On Thu, Aug 15, 2013 at 4:42 PM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Thu, Aug 15, 2013 at 03:32:58PM -0400, Sean Paul wrote:
>> On Thu, Aug 15, 2013 at 11:28 AM, Thierry Reding
>> <thierry.reding@gmail.com> wrote:
>> > On Wed, Aug 14, 2013 at 04:47:38PM -0400, Sean Paul wrote:
>> > [...]
>> >> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
>> >> +             struct i2c_client *client, struct device_node *node)
>> > [...]
>> >> +     ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
>> >
>> > of_get_named_gpio() can return -EPROBE_DEFER and I wonder how you handle
>> > that in the driver that uses ptn3460_init(). Since you pass in an
>> > initialized drm_device, you'd need to undo all of that in case of
>> > -EPROBE_DEFER. Well I guess you'd have to do that in case of any error,
>> > but it makes things difficult to handle for drivers.
>> >
>> > For instance on Tegra we pretty much delay DRM initialization until all
>> > required subdevices (there are quite a few) have been probed, so if we
>> > wanted to use this function we'd have to call it after all drivers have
>> > been probed because only then do we have access to a struct drm_device.
>> > That will cause other problems, however, because at that point we can't
>> > defer probing anymore.
>> >
>>
>> I suppose I could add another init that performs the deferrable tasks
>> (ptn3460_init_deferrable or something). This would be called before
>> drm init has been started from one of the probe functions.
>> Alternatively, I could set this up as a standalone i2c driver and do
>> this stuff in the probe. Any other options?
>
> My point was that in those cases you don't have access to the DRM device
> yet since you haven't called drm_init() yet.
>

Yep, I got that. I meant to say we could parse the dt and save the
gpio number for later use when ptn3460_init is called with a
drm_device (thus separating the deferable parts into a place that's
easier to defer). I'm not sure this is worth fixing, TBH.


>> Adding another init call adds yet another thing the drm driver has to
>> do to use this bridge. Making the ptn driver standalone requires you
>> to set things up such that drm init is dependent on ptn probe running
>> successfully. I'm not sure which is more desirable.
>>
>> Practically speaking, do you expect to call drm_init before the gpio
>> is available?
>
> No, not really, but I won't know that the GPIO is available until I
> actually call of_get_named_gpio_flags().
>
> But perhaps we should cross that bridge when we get to it.
>

Pun intended? ;-)

Sean


> Thierry
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt b/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
new file mode 100644
index 0000000..c1cd329
--- /dev/null
+++ b/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt
@@ -0,0 +1,27 @@ 
+ptn3460-bridge bindings
+
+Required properties:
+	- compatible: "nxp,ptn3460"
+	- reg: i2c address of the bridge
+	- powerdown-gpio: OF device-tree gpio specification
+	- reset-gpio: OF device-tree gpio specification
+	- edid-emulation: The EDID emulation entry to use
+		+-------+------------+------------------+
+		| Value | Resolution | Description      |
+		|   0   |  1024x768  | NXP Generic      |
+		|   1   |  1920x1080 | NXP Generic      |
+		|   2   |  1920x1080 | NXP Generic      |
+		|   3   |  1600x900  | Samsung LTM200KT |
+		|   4   |  1920x1080 | Samsung LTM230HT |
+		|   5   |  1366x768  | NXP Generic      |
+		|   6   |  1600x900  | ChiMei M215HGE   |
+		+-------+------------+------------------+
+
+Example:
+	ptn3460-bridge@20 {
+		compatible = "nxp,ptn3460";
+		reg = <0x20>;
+		powerdown-gpio = <&gpy2 5 1 0 0>;
+		reset-gpio = <&gpx1 5 1 0 0>;
+		edid-emulation = <5>;
+	};
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index a7c54c8..6105a34 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -223,3 +223,5 @@  source "drivers/gpu/drm/omapdrm/Kconfig"
 source "drivers/gpu/drm/tilcdc/Kconfig"
 
 source "drivers/gpu/drm/qxl/Kconfig"
+
+source "drivers/gpu/drm/bridge/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index d943b94..c2ae293 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -55,3 +55,4 @@  obj-$(CONFIG_DRM_OMAP)	+= omapdrm/
 obj-$(CONFIG_DRM_TILCDC)	+= tilcdc/
 obj-$(CONFIG_DRM_QXL) += qxl/
 obj-y			+= i2c/
+obj-y			+= bridge/
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
new file mode 100644
index 0000000..27a83b5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -0,0 +1,5 @@ 
+config DRM_PTN3460
+	tristate "PTN3460 DP/LVDS bridge"
+	depends on DRM && I2C
+	---help---
+	  Adds the driver for the NXP PTN3460 DP/LVDS bridge chip.
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
new file mode 100644
index 0000000..b4733e1
--- /dev/null
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -0,0 +1,3 @@ 
+ccflags-y := -Iinclude/drm
+
+obj-$(CONFIG_DRM_PTN3460) += ptn3460.o
diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c
new file mode 100644
index 0000000..a9e5c1a
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ptn3460.c
@@ -0,0 +1,349 @@ 
+/*
+ * NXP PTN3460 DP/LVDS bridge driver
+ *
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+
+#include "drmP.h"
+#include "drm_edid.h"
+#include "drm_crtc.h"
+#include "drm_crtc_helper.h"
+
+#include "bridge/ptn3460.h"
+
+#define PTN3460_EDID_ADDR			0x0
+#define PTN3460_EDID_EMULATION_ADDR		0x84
+#define PTN3460_EDID_ENABLE_EMULATION		0
+#define PTN3460_EDID_EMULATION_SELECTION	1
+#define PTN3460_EDID_SRAM_LOAD_ADDR		0x85
+
+struct ptn3460_bridge {
+	struct drm_connector connector;
+	struct i2c_client *client;
+	struct drm_encoder *encoder;
+	struct drm_bridge *bridge;
+	struct edid *edid;
+	int gpio_pd_n;
+	int gpio_rst_n;
+	u32 edid_emulation;
+	bool enabled;
+};
+
+static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
+		u8 *buf, int len)
+{
+	int ret;
+
+	ret = i2c_master_send(ptn_bridge->client, &addr, 1);
+	if (ret <= 0) {
+		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
+		return ret;
+	}
+
+	ret = i2c_master_recv(ptn_bridge->client, buf, len);
+	if (ret <= 0) {
+		DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
+		char val)
+{
+	int ret;
+	char buf[2];
+
+	buf[0] = addr;
+	buf[1] = val;
+
+	ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
+	if (ret <= 0) {
+		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
+{
+	int ret;
+	char val;
+
+	/* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
+	ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
+			ptn_bridge->edid_emulation);
+	if (ret) {
+		DRM_ERROR("Failed to transfer edid to sram, ret=%d\n", ret);
+		return ret;
+	}
+
+	/* Enable EDID emulation and select the desired EDID */
+	val = 1 << PTN3460_EDID_ENABLE_EMULATION |
+		ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
+
+	ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
+	if (ret) {
+		DRM_ERROR("Failed to write edid value, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void ptn3460_pre_enable(struct drm_bridge *bridge)
+{
+	struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+	int ret;
+
+	if (ptn_bridge->enabled)
+		return;
+
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_set_value(ptn_bridge->gpio_pd_n, 1);
+
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n)) {
+		gpio_set_value(ptn_bridge->gpio_rst_n, 0);
+		udelay(10);
+		gpio_set_value(ptn_bridge->gpio_rst_n, 1);
+	}
+
+	/*
+	 * There's a bug in the PTN chip where it falsely asserts hotplug before
+	 * it is fully functional. We're forced to wait for the maximum start up
+	 * time specified in the chip's datasheet to make sure we're really up.
+	 */
+	msleep(90);
+
+	ret = ptn3460_select_edid(ptn_bridge);
+	if (ret)
+		DRM_ERROR("Select edid failed ret=%d\n", ret);
+
+	ptn_bridge->enabled = true;
+}
+
+static void ptn3460_enable(struct drm_bridge *bridge)
+{
+}
+
+static void ptn3460_disable(struct drm_bridge *bridge)
+{
+	struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+
+	if (!ptn_bridge->enabled)
+		return;
+
+	ptn_bridge->enabled = false;
+
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+		gpio_set_value(ptn_bridge->gpio_rst_n, 1);
+
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_set_value(ptn_bridge->gpio_pd_n, 0);
+}
+
+static void ptn3460_post_disable(struct drm_bridge *bridge)
+{
+}
+
+void ptn3460_bridge_destroy(struct drm_bridge *bridge)
+{
+	struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+
+	drm_bridge_cleanup(bridge);
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_free(ptn_bridge->gpio_pd_n);
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+		gpio_free(ptn_bridge->gpio_rst_n);
+	/* Nothing else to free, we've got devm allocated memory */
+}
+
+struct drm_bridge_funcs ptn3460_bridge_funcs = {
+	.pre_enable = ptn3460_pre_enable,
+	.enable = ptn3460_enable,
+	.disable = ptn3460_disable,
+	.post_disable = ptn3460_post_disable,
+	.destroy = ptn3460_bridge_destroy,
+};
+
+int ptn3460_get_modes(struct drm_connector *connector)
+{
+	struct ptn3460_bridge *ptn_bridge;
+	u8 *edid;
+	int ret, num_modes;
+	bool power_off;
+
+	ptn_bridge = container_of(connector, struct ptn3460_bridge, connector);
+
+	if (ptn_bridge->edid)
+		return drm_add_edid_modes(connector, ptn_bridge->edid);
+
+	power_off = !ptn_bridge->enabled;
+	ptn3460_pre_enable(ptn_bridge->bridge);
+
+	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
+	if (!edid) {
+		DRM_ERROR("Failed to allocate edid\n");
+		return 0;
+	}
+
+	ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
+			EDID_LENGTH);
+	if (ret) {
+		kfree(edid);
+		num_modes = 0;
+		goto out;
+	}
+
+	ptn_bridge->edid = (struct edid *)edid;
+	drm_mode_connector_update_edid_property(connector, ptn_bridge->edid);
+
+	num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
+
+out:
+	if (power_off)
+		ptn3460_disable(ptn_bridge->bridge);
+
+	return num_modes;
+}
+
+static int ptn3460_mode_valid(struct drm_connector *connector,
+		struct drm_display_mode *mode)
+{
+	return MODE_OK;
+}
+
+struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
+{
+	struct ptn3460_bridge *ptn_bridge;
+
+	ptn_bridge = container_of(connector, struct ptn3460_bridge, connector);
+
+	return ptn_bridge->encoder;
+}
+
+struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
+	.get_modes = ptn3460_get_modes,
+	.mode_valid = ptn3460_mode_valid,
+	.best_encoder = ptn3460_best_encoder,
+};
+
+enum drm_connector_status ptn3460_detect(struct drm_connector *connector,
+		bool force)
+{
+	return connector_status_connected;
+}
+
+void ptn3460_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_cleanup(connector);
+}
+
+struct drm_connector_funcs ptn3460_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ptn3460_detect,
+	.destroy = ptn3460_connector_destroy,
+};
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+		struct i2c_client *client, struct device_node *node)
+{
+	int ret;
+	struct drm_bridge *bridge;
+	struct ptn3460_bridge *ptn_bridge;
+
+	bridge = devm_kzalloc(dev->dev, sizeof(*bridge), GFP_KERNEL);
+	if (!bridge) {
+		DRM_ERROR("Failed to allocate drm bridge\n");
+		return -ENOMEM;
+	}
+
+	ptn_bridge = devm_kzalloc(dev->dev, sizeof(*ptn_bridge), GFP_KERNEL);
+	if (!ptn_bridge) {
+		DRM_ERROR("Failed to allocate ptn bridge\n");
+		return -ENOMEM;
+	}
+
+	ptn_bridge->client = client;
+	ptn_bridge->encoder = encoder;
+	ptn_bridge->bridge = bridge;
+	ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n)) {
+		ret = gpio_request_one(ptn_bridge->gpio_pd_n,
+				GPIOF_OUT_INIT_HIGH, "PTN3460_PD_N");
+		if (ret) {
+			DRM_ERROR("Request powerdown-gpio failed (%d)\n", ret);
+			return ret;
+		}
+	}
+
+	ptn_bridge->gpio_rst_n = of_get_named_gpio(node, "reset-gpio", 0);
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n)) {
+		/*
+		 * Request the reset pin low to avoid the bridge being
+		 * initialized prematurely
+		 */
+		ret = gpio_request_one(ptn_bridge->gpio_rst_n,
+				GPIOF_OUT_INIT_LOW, "PTN3460_RST_N");
+		if (ret) {
+			DRM_ERROR("Request reset-gpio failed (%d)\n", ret);
+			gpio_free(ptn_bridge->gpio_pd_n);
+			return ret;
+		}
+	}
+
+	ret = of_property_read_u32(node, "edid-emulation",
+			&ptn_bridge->edid_emulation);
+	if (ret) {
+		DRM_ERROR("Can't read edid emulation value\n");
+		goto err;
+	}
+
+	ret = drm_bridge_init(dev, bridge, &ptn3460_bridge_funcs);
+	if (ret) {
+		DRM_ERROR("Failed to initialize bridge with drm\n");
+		goto err;
+	}
+
+	bridge->driver_private = ptn_bridge;
+	encoder->bridge = bridge;
+
+	ret = drm_connector_init(dev, &ptn_bridge->connector,
+			&ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector with drm\n");
+		goto err;
+	}
+	drm_connector_helper_add(&ptn_bridge->connector,
+			&ptn3460_connector_helper_funcs);
+	drm_sysfs_connector_add(&ptn_bridge->connector);
+	drm_mode_connector_attach_encoder(&ptn_bridge->connector, encoder);
+
+	return 0;
+
+err:
+	if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+		gpio_free(ptn_bridge->gpio_pd_n);
+	if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+		gpio_free(ptn_bridge->gpio_rst_n);
+	return ret;
+}
diff --git a/include/drm/bridge/ptn3460.h b/include/drm/bridge/ptn3460.h
new file mode 100644
index 0000000..157ffa1
--- /dev/null
+++ b/include/drm/bridge/ptn3460.h
@@ -0,0 +1,36 @@ 
+/*
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _DRM_BRIDGE_PTN3460_H_
+#define _DRM_BRIDGE_PTN3460_H_
+
+struct drm_device;
+struct drm_encoder;
+struct i2c_client;
+struct device_node;
+
+#ifdef CONFIG_DRM_PTN3460
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+		struct i2c_client *client, struct device_node *node);
+#else
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+		struct i2c_client *client, struct device_node *node)
+{
+	return 0;
+}
+
+#endif
+
+#endif