Re: [PATCH 3/5] drm/bridge: Add PTN3460 bridge driver

From: Sean Paul
Date: Thu Oct 03 2013 - 14:32:39 EST

On Thu, Oct 3, 2013 at 2:23 PM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote:
> 2013/10/4 Sean Paul <seanpaul@xxxxxxxxxxxx>:
>> On Thu, Oct 3, 2013 at 1:39 PM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote:
>>> 2013/10/3 Sean Paul <seanpaul@xxxxxxxxxxxx>:
>>>> On Thu, Oct 3, 2013 at 9:55 AM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote:
>>>>> Hi, thank you for your contribution and the below is my short comments,
>>>>>
>>>>> 2013/10/2 Sean Paul <seanpaul@xxxxxxxxxxxx>:
>>>>>> This patch adds a drm_bridge driver for the PTN3460 DisplayPort to LVDS
>>>>>> bridge chip.
>>>>>>
>>>>>> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
>>>>>> ---
>>>>>> .../devicetree/bindings/drm/bridge/ptn3460.txt | 27 ++
>>>>>> drivers/gpu/drm/Kconfig | 2 +
>>>>>> drivers/gpu/drm/Makefile | 1 +
>>>>>> drivers/gpu/drm/bridge/Kconfig | 4 +
>>>>>> drivers/gpu/drm/bridge/Makefile | 3 +
>>>>>> drivers/gpu/drm/bridge/ptn3460.c | 349 +++++++++++++++++++++
>>>>>> include/drm/bridge/ptn3460.h | 36 +++
>>>>>> 7 files changed, 422 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
>>>>>>
>>>>>> 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
>>>>>
>>>>> Can a regulator be used instead of gpio in other board case?
>>>>>
>>>>
>>>> No, not to my knowledge.
>>>>
>>>
>>> Hm.. plz check it out again. the gpio pin is specific to board, and
>>> the the gpio be used as power source trigger could be replaced with a
>>> regulator according to board design. So you should consider all
>>> possibilities even though there are no other cases yet: other board
>>> could use a regulator instead.
>>>
>>>>
>>>>>> + - 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 955555d..cd7bfb3 100644
>>>>>> --- a/drivers/gpu/drm/Kconfig
>>>>>> +++ b/drivers/gpu/drm/Kconfig
>>>>>> @@ -236,3 +236,5 @@ source "drivers/gpu/drm/tilcdc/Kconfig"
>>>>>> source "drivers/gpu/drm/qxl/Kconfig"
>>>>>>
>>>>>> source "drivers/gpu/drm/msm/Kconfig"
>>>>>> +
>>>>>> +source "drivers/gpu/drm/bridge/Kconfig"
>>>>>> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
>>>>>> index f089adf..9234253 100644
>>>>>> --- a/drivers/gpu/drm/Makefile
>>>>>> +++ b/drivers/gpu/drm/Makefile
>>>>>> @@ -56,3 +56,4 @@ obj-$(CONFIG_DRM_TILCDC) += tilcdc/
>>>>>> obj-$(CONFIG_DRM_QXL) += qxl/
>>>>>> obj-$(CONFIG_DRM_MSM) += msm/
>>>>>> obj-y += i2c/
>>>>>> +obj-y += bridge/
>>>>>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>>>>>> new file mode 100644
>>>>>> index 0000000..f8db069
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/gpu/drm/bridge/Kconfig
>>>>>> @@ -0,0 +1,4 @@
>>>>>> +config DRM_PTN3460
>>>>>> + tristate "PTN3460 DP/LVDS bridge"
>>>>>> + depends on DRM && I2C
>>>>>> + ---help---
>>>>>> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
>>>>>> new file mode 100644
>>>>>> index 0000000..b4733e1
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/gpu/drm/bridge/Makefile
>>>>>> @@ -0,0 +1,3 @@
>>>>>> +ccflags-y := -Iinclude/drm
>>>>>> +
>>>>>> +obj-$(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);
>>>>>
>>>>> Ditto.
>>>>>
>>>>>> +
>>>>>> + 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);
>>>>>
>>>>> Ditto.
>>>>>
>>>>>> +}
>>>>>> +
>>>>>> +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);
>>>>>
>>>>> Ditto.
>>>>>
>>>>>> + 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,
>>>>>> +};
>>>>>
>>>>> Why do you try to add a new connector here? We already have the
>>>>> connector for LCD, and also provides some callbacks for it. For this,
>>>>> please see exynos_drm_display_ops of exynos_drm_fimd driver, and you
>>>>> can add new callbacks to there such as init callback for bridge device
>>>>> initialization if needed.
>>>>>
>>>>
>>>> We add a new connector for 2 reasons:
>>>>
>>>> 1) We need to override the drm detect() callback to always return true
>>>> since the DP driver will presumably return its hotplug status which
>>>> will always be low when the ptn chip is turned off.
>>>> 2) We want the ability to control the result of get_modes().
>>>>
>>>> I've got a patch set almost ready to tear the display ops out of fimd
>>>> and put them in the DP driver.
>>>
>>> Really? if so, that is ideal something we want and we should go. But
>>> isn't the DP driver placed in drivers/video/exynos? How did you take
>>> care of that?
>>
>> git mv :)
>>
>
> :)
>
>
>>> Actually, for this, we planned to use CDF(Common Display
>>> Framework) if the framework is merged to mainline somehow.
>>>
>>
>> Right. I think CDF will end up being a series of improvements to drm,
>> as opposed to its own framework (at least this was the conclusion I
>> came to after speaking with Laurent at the plumbers conference). I
>> don't think it makes sense to have the DP driver outside of drm. The
>> HDMI driver is already inside drm, the DP driver should be too.
>
> See the below,
>
> Application
> --------------------------------------------------------------
> v4l2 drm kms
> hdmi driver hdmi driver
> -------------------------------------------------------------
> hdmi hw
>
> HDMI is a controller can be controlled by user application, and for
> this some frameworks such as v4l2 and drm kms interfaces are used. But
> DP, MIPI-DSI, LVDS, and so on aren't controlled by user application.
> These are just display bus between scanout devices(hdmi, fimd) and lcd
> panel. So the above your example doesn't make sense.
>

I think we've probably gone far enough off-topic. Let's discuss this
when you've had an opportunity to see the patchset. I hope the code
will speak for itself.

Aside from Olof's suggestion about changing the dts binding to
lvds-bridge (which I'll upload a new patch for), do you have any
suggestions for this patch?

Sean


>> Regardless, this conversation is only tangentially related to this
>> patch and can probably be deferred.
>>
>> Sean
>>
>>>> The display ops are better suited
>>>> there, since it's the actual encoder/connector. I hope to get that
>>>> posted this week.
>>>>
>>>
>>> I will look forward to that posting. :)
>>>
>>>>
>>>>>> +
>>>>>> +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);
>>>>>
>>>>> Also, if a regulator is used instead?
>>>>>
>>>>>> + 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);
>>>>>
>>>>> So it seems that here's not right place to call drm_connector_init function.
>>>>>
>>>>> Display pipeline path could be one of,
>>>>> Display Controller Display bus
>>>>> ---------------------------------------------------------------------------
>>>>> FIMD---------------------LVDS--------------------LCD,
>>>>> or
>>>>> FIMD----------------------eDP---------------------LCD,
>>>>> or
>>>>> FIMD------------------MIPI-DSI------------------LCD,
>>>>> or
>>>>> FIMD-------------------------------------------------LCD
>>>>>
>>>>> And also in case using image enhancement chip,
>>>>> mDNIe-------------FIMD-LITE between Display Controller and Display
>>>>> bus.
>>>>>
>>>>> So, wouldn't the right place below FIMD driver? :)
>>>>>
>>>>
>>>> Well, this driver should be considered outside of exynos context since
>>>> it could be used by any drm driver.
>>>>
>>>> In the exynos context, the right place to implement it would be in the
>>>> dp driver, actually. However, the exynos driver has a level of
>>>> abstraction on top of the crtcs/encoders such that we need to
>>>> initialize it in the exynos_drm_core. The patchset I mentioned above
>>>> should help move things in a direction where fimd/mixer implement
>>>> drm_crtc directly and hdmi/dp implement drm_encoder/drm_connector
>>>> directly. In that world, DP would initialize the ptn driver.
>>>>
>>>>>
>>>>>> + 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
>>>>>> --
>>>>>> 1.8.4
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> linux-arm-kernel mailing list
>>>>>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>>>>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>> _______________________________________________
>>>> dri-devel mailing list
>>>> dri-devel@xxxxxxxxxxxxxxxxxxxxx
>>>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@xxxxxxxxxxxxxxxxxxxxx
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
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