Devicetree

* Re: [PATCH v4 3/4] drm/bridge: Add ti-tfp410 DVI transmitter driver
From: Jani Nikula @ 2016-11-23 11:08 UTC (permalink / raw)
  To: Jyri Sarha, dri-devel, devicetree
  Cc: khilman, tomi.valkeinen, laurent.pinchart, bgolaszewski
In-Reply-To: <b49e6517-2e44-c2b9-830c-ed71bb92b85b@ti.com>

On Wed, 23 Nov 2016, Jyri Sarha <jsarha@ti.com> wrote:
> On 11/22/16 16:49, Jyri Sarha wrote:
>> Add very basic ti-tfp410 DVI transmitter driver. The only feature
>> separating this from a completely dummy bridge is the EDID read
>> support trough DDC I2C. Even that functionality should be in a
>> separate generic connector driver. However, because of missing DRM
>> infrastructure support the connector is implemented within the bridge
>> driver. Some tfp410 HW specific features may be added later if needed,
>> because there is a set of registers behind i2c if it is connected.
>> 
>> This implementation is tested against my new tilcdc bridge support
>> and it works with BeagleBone DVI-D Cape Rev A3. A DT binding document
>> is also updated.
>> 
>> Signed-off-by: Jyri Sarha <jsarha@ti.com>
>> ---
>>  .../bindings/display/bridge/ti,tfp410.txt          |   9 +-
>>  drivers/gpu/drm/bridge/Kconfig                     |   7 +
>>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>>  drivers/gpu/drm/bridge/ti-tfp410.c                 | 311 +++++++++++++++++++++
>>  4 files changed, 326 insertions(+), 2 deletions(-)
>>  create mode 100644 drivers/gpu/drm/bridge/ti-tfp410.c
>> 
>> diff --git a/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt b/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt
>> index 2cbe32a..54d7e31 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt
>> @@ -6,10 +6,15 @@ Required properties:
>>  
>>  Optional properties:
>>  - powerdown-gpios: power-down gpio
>> +- reg: I2C address. If and only if present the device node
>> +       should be placed into the i2c controller node where the
>> +       tfp410 i2c is connected to.
>>  
>>  Required nodes:
>> -- Video port 0 for DPI input
>> -- Video port 1 for DVI output
>> +- Video port 0 for DPI input [1].
>> +- Video port 1 for DVI output [1].
>> +
>> +[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
>>  
>>  Example
>>  -------
>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>> index bd6acc8..a424e03 100644
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -81,6 +81,13 @@ config DRM_TOSHIBA_TC358767
>>  	---help---
>>  	  Toshiba TC358767 eDP bridge chip driver.
>>  
>> +config DRM_TI_TFP410
>> +	tristate "TI TFP410 DVI/HDMI bridge"
>> +	depends on OF
>> +	select DRM_KMS_HELPER
>> +	---help---
>> +	  Texas Instruments TFP410 DVI/HDMI Transmitter driver
>> +
>>  source "drivers/gpu/drm/bridge/analogix/Kconfig"
>>  
>>  source "drivers/gpu/drm/bridge/adv7511/Kconfig"
>> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
>> index 97ed1a5..8b065d9 100644
>> --- a/drivers/gpu/drm/bridge/Makefile
>> +++ b/drivers/gpu/drm/bridge/Makefile
>> @@ -11,3 +11,4 @@ obj-$(CONFIG_DRM_SII902X) += sii902x.o
>>  obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>>  obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix/
>>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
>> +obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>> diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
>> new file mode 100644
>> index 0000000..58e26cc
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/ti-tfp410.c
>> @@ -0,0 +1,311 @@
>> +/*
>> + * Copyright (C) 2016 Texas Instruments
>> + * Author: Jyri Sarha <jsarha@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of the GNU General Public License version 2 as published by
>> + * the Free Software Foundation.
>> + *
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/of_graph.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/i2c.h>
>> +
>> +#include <drm/drmP.h>
>> +#include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_crtc.h>
>> +#include <drm/drm_crtc_helper.h>
>> +
>> +struct tfp410 {
>> +	struct drm_bridge	bridge;
>> +	struct drm_connector	connector;
>> +
>> +	struct i2c_adapter	*ddc;
>> +
>> +	struct device *dev;
>> +};
>> +
>> +static inline struct tfp410 *
>> +drm_bridge_to_tfp410(struct drm_bridge *bridge)
>> +{
>> +	return container_of(bridge, struct tfp410, bridge);
>> +}
>> +
>> +static inline struct tfp410 *
>> +drm_connector_to_tfp410(struct drm_connector *connector)
>> +{
>> +	return container_of(connector, struct tfp410, connector);
>> +}
>> +
>> +static int tfp410_get_modes(struct drm_connector *connector)
>> +{
>> +	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
>> +	struct edid *edid;
>> +	int ret;
>> +
>> +	if (!dvi->ddc)
>> +		goto fallback;
>> +
>> +	edid = drm_get_edid(connector, dvi->ddc);
>> +	if (!edid) {
>> +		DRM_INFO("EDID read failed. Fallback to standard modes\n");
>> +		goto fallback;
>> +	}
>> +
>> +	drm_mode_connector_update_edid_property(connector, edid);
>> +
>> +	return drm_add_edid_modes(connector, edid);
>> +fallback:
>> +	/* No EDID, fallback on the XGA standard modes */
>> +	ret = drm_add_modes_noedid(connector, 1920, 1200);
>> +
>> +	/* And prefer a mode pretty much anything can handle */
>> +	drm_set_preferred_mode(connector, 1024, 768);
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
>> +	.get_modes	= tfp410_get_modes,
>> +};
>> +
>> +static enum drm_connector_status
>> +tfp410_connector_detect(struct drm_connector *connector, bool force)
>> +{
>> +	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
>> +
>> +	if (dvi->ddc) {
>> +		if (drm_probe_ddc(dvi->ddc))
>> +			return connector_status_connected;
>> +		else
>> +			return connector_status_disconnected;
>> +	}
>> +
>> +	return connector_status_unknown;
>> +}
>> +
>> +static const struct drm_connector_funcs tfp410_con_funcs = {
>> +	.dpms			= drm_atomic_helper_connector_dpms,
>> +	.detect			= tfp410_connector_detect,
>> +	.fill_modes		= drm_helper_probe_single_connector_modes,
>> +	.destroy		= drm_connector_cleanup,
>> +	.reset			= drm_atomic_helper_connector_reset,
>> +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
>> +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
>> +};
>> +
>> +static int tfp410_attach(struct drm_bridge *bridge)
>> +{
>> +	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
>> +	int ret;
>> +
>> +	if (!bridge->encoder) {
>> +		dev_err(dvi->dev, "Missing encoder\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	drm_connector_helper_add(&dvi->connector,
>> +				 &tfp410_con_helper_funcs);
>> +	ret = drm_connector_init(bridge->dev, &dvi->connector,
>> +				 &tfp410_con_funcs, DRM_MODE_CONNECTOR_HDMIA);
>> +	if (ret) {
>> +		dev_err(dvi->dev, "drm_connector_init() failed: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	drm_mode_connector_attach_encoder(&dvi->connector,
>> +					  bridge->encoder);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct drm_bridge_funcs tfp410_bridge_funcs = {
>> +	.attach		= tfp410_attach,
>> +};
>> +
>> +static int tfp410_get_connector_ddc(struct tfp410 *dvi)
>> +{
>> +	struct device_node *ep = NULL, *connector_node = NULL;
>> +	struct device_node *ddc_phandle = NULL;
>> +	int ret = 0;
>> +
>> +	/* port@1 is the connector node */
>> +	ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 1, -1);
>> +	if (!ep)
>> +		goto fail;
>> +
>> +	connector_node = of_graph_get_remote_port_parent(ep);
>> +	if (!connector_node)
>> +		goto fail;
>> +
>> +	ddc_phandle = of_parse_phandle(connector_node, "ddc-i2c-bus", 0);
>> +	if (!ddc_phandle)
>> +		goto fail;
>> +
>> +	dvi->ddc = of_get_i2c_adapter_by_node(ddc_phandle);
>> +	if (dvi->ddc)
>> +		dev_info(dvi->dev, "Connector's ddc i2c bus found\n");
>> +	else
>> +		ret = -EPROBE_DEFER;
>> +
>> +fail:
>> +	of_node_put(ep);
>> +	of_node_put(connector_node);
>> +	of_node_put(ddc_phandle);
>> +	return ret;
>> +}
>> +
>> +static int tfp410_init(struct device *dev)
>> +{
>> +	struct tfp410 *dvi;
>> +	int ret;
>> +
>> +	if (!dev->of_node) {
>> +		dev_err(dev, "device-tree data is missing\n");
>> +		return -ENXIO;
>> +	}
>> +
>> +	dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
>> +	if (!dvi)
>> +		return -ENOMEM;
>> +	dev_set_drvdata(dev, dvi);
>> +
>> +	dvi->bridge.funcs = &tfp410_bridge_funcs;
>> +	dvi->bridge.of_node = dev->of_node;
>> +	dvi->dev = dev;
>> +
>> +	ret = tfp410_get_connector_ddc(dvi);
>> +	if (ret)
>> +		goto fail;
>> +
>> +	ret = drm_bridge_add(&dvi->bridge);
>> +	if (ret) {
>> +		dev_err(dev, "drm_bridge_add() failed: %d\n", ret);
>> +		goto fail;
>> +	}
>> +
>> +	return 0;
>> +fail:
>> +	i2c_put_adapter(dvi->ddc);
>> +	return ret;
>> +}
>> +
>> +static int tfp410_fini(struct device *dev)
>> +{
>> +	struct tfp410 *dvi = dev_get_drvdata(dev);
>> +
>> +	drm_bridge_remove(&dvi->bridge);
>> +
>> +	if (dvi->ddc)
>> +		i2c_put_adapter(dvi->ddc);
>> +
>> +	return 0;
>> +}
>> +
>> +static int tfp410_probe(struct platform_device *pdev)
>> +{
>> +	return tfp410_init(&pdev->dev);
>> +}
>> +
>> +static int tfp410_remove(struct platform_device *pdev)
>> +{
>> +	return tfp410_fini(&pdev->dev);
>> +}
>> +
>
> Argh... I think I should still put all i2c code between
> #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)

ITYM

#if IS_ENABLED(CONFIG_I2C)

BR,
Jani.

>
> #endif
>
> Otherwise I think this is now finally ready.
>
>> +/* There is currently no i2c functionality. */
>> +static int tfp410_i2c_probe(struct i2c_client *client,
>> +			    const struct i2c_device_id *id)
>> +{
>> +	int reg;
>> +
>> +	if (!client->dev.of_node ||
>> +	    of_property_read_u32(client->dev.of_node, "reg", &reg)) {
>> +		dev_err(&client->dev,
>> +			"Can't get i2c reg property from device-tree\n");
>> +		return -ENXIO;
>> +	}
>> +
>> +	return tfp410_init(&client->dev);
>> +}
>> +
>> +static int tfp410_i2c_remove(struct i2c_client *client)
>> +{
>> +	return tfp410_fini(&client->dev);
>> +}
>> +
>> +static const struct of_device_id tfp410_match[] = {
>> +	{ .compatible = "ti,tfp410" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, tfp410_match);
>> +
>> +struct platform_driver tfp410_platform_driver = {
>> +	.probe	= tfp410_probe,
>> +	.remove	= tfp410_remove,
>> +	.driver	= {
>> +		.name		= "tfp410-bridge",
>> +		.of_match_table	= tfp410_match,
>> +	},
>> +};
>> +
>> +static const struct i2c_device_id tfp410_i2c_ids[] = {
>> +	{ "tfp410", 0 },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
>> +
>> +static struct i2c_driver tfp410_i2c_driver = {
>> +	.driver = {
>> +		.name	= "tfp410",
>> +		.of_match_table = of_match_ptr(tfp410_match),
>> +	},
>> +	.id_table	= tfp410_i2c_ids,
>> +	.probe		= tfp410_i2c_probe,
>> +	.remove		= tfp410_i2c_remove,
>> +};
>> +
>> +static struct {
>> +	uint i2c:1;
>> +	uint platform:1;
>> +}  tfp410_registered_driver;
>> +
>> +static int __init tfp410_module_init(void)
>> +{
>> +	int ret;
>> +
>> +	ret = i2c_add_driver(&tfp410_i2c_driver);
>> +	if (ret)
>> +		pr_err("%s: registering i2c driver failed: %d",
>> +		       __func__, ret);
>> +	else
>> +		tfp410_registered_driver.i2c = 1;
>> +
>> +	ret = platform_driver_register(&tfp410_platform_driver);
>> +	if (ret)
>> +		pr_err("%s: registering platform driver failed: %d",
>> +		       __func__, ret);
>> +	else
>> +		tfp410_registered_driver.platform = 1;
>> +
>> +	if (tfp410_registered_driver.i2c ||
>> +	    tfp410_registered_driver.platform)
>> +		return 0;
>> +
>> +	return ret;
>> +}
>> +module_init(tfp410_module_init);
>> +
>> +static void __exit tfp410_module_exit(void)
>> +{
>> +	if (tfp410_registered_driver.i2c)
>> +		i2c_del_driver(&tfp410_i2c_driver);
>> +	if (tfp410_registered_driver.platform)
>> +		platform_driver_unregister(&tfp410_platform_driver);
>> +}
>> +module_exit(tfp410_module_exit);
>> +
>> +MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
>> +MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
>> +MODULE_LICENSE("GPL");
>> 
>
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> dri-devel@lists.freedesktop.org
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-- 
Jani Nikula, Intel Open Source Technology Center
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