On 11/18/16 07:00, Christopher Spinrath wrote:
> Hi Jyri,
>
> On 11/17/2016 02:28 PM, Jyri Sarha wrote:
>> Add very basic ti-ftp410 DVI transmitter driver. The only feature
>
> s/ftp/tfp ?
>
My fingers just want type these three letter is that order, wonder why :).
>> 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 added.
>>
>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
>
> Thanks for working on this. I have tested the driver on my Utilite Pro
> which is based on the imx6q SoC and has a tfp410 chip hooked up to its
> parallel rgb24 interface. So you can add my
>
> Tested-By: Christopher Spinrath <christopher.spinrath at rwth-aachen.de>
>
Thanks, I'll address these comments and resend the corrected patches
before sending a pull request.
> However, I have two more comments below.
>
>> ---
>> .../bindings/display/bridge/ti,tfp410.txt | 40 +++
>> drivers/gpu/drm/bridge/Kconfig | 7 +
>> drivers/gpu/drm/bridge/Makefile | 1 +
>> drivers/gpu/drm/bridge/ti-tfp410.c | 287
>> +++++++++++++++++++++
>> 4 files changed, 335 insertions(+)
>> create mode 100644
>> Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt
>> 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
>> new file mode 100644
>> index 0000000..6174b18
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt
>
> There already is a binding documentation for the tfp410 in
>
> Documentation/devicetree/bindings/display/ti/ti,tfp410.txt .
>
> It is used by the omap drm driver. IMHO you should extend, move or
> deprecate that one. Note that it describes an optional powerdown-gpios
> property.
>
Good that you noticed that. Guess we need to unify those. Probably to
the new location under bridge directory.
>> @@ -0,0 +1,40 @@
>> +TFP410 DVI bridge bindings
>> +
>> +Required properties:
>> + - compatible: "ti,tfp410"
>> +
>> +Optional properties
>> + - 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 subnodes:
>> + - port at 0: Video input port node to connect the bridge to a
>> + display controller output [1].
>> + - port at 1: Video output port node to connect the bridge to a
>> + connector input [1].
>> +
>> +[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
>> +
>> +Example:
>> + hdmi-bridge {
>> + compatible = "ti,tfp410";
>> + ports {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + port at 0 {
>> + reg = <0>;
>> + bridge_in: endpoint {
>> + remote-endpoint = <&dc_out>;
>> + };
>> + };
>> +
>> + port at 1 {
>> + reg = <1>;
>> + bridge_out: endpoint {
>> + remote-endpoint = <&hdmi_in>;
>> + };
>> + };
>> + };
>> + };
>> 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..64f54e4
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/ti-tfp410.c
>> @@ -0,0 +1,287 @@
>> +/*
>> + * Copyright (C) 2016 Texas Instruments
>> + * Author: Jyri Sarha <jsarha at 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;
>> + }
>
> I wonder what happens if a display with none or defect ddc/edid is
> attached? The dumb-vga-dac bridge driver reports
> connector_status_unknown in the case drm_probe_ddc fails.
>
If there is such a problem with DVI/HDMI device, then the device is
clearly broken. In such a case one can hack a custom dtd file without
ddc-i2c-bus. The situation with VGA is slightly different. There may
still be some perfectly legitimate legacy VGA devices that do not
support ddc.
I do not have a strong opinion about this, but would like to wait if
anybody is bothered about this behaviour and fix it only if there is a
problem.
> Cheers,
> Christopher
>
>> +
>> + 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 at 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);
>> +}
>> +
>> +/* 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", ®)) {
>> + 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 int __init tfp410_module_init(void)
>> +{
>> + i2c_add_driver(&tfp410_i2c_driver);
>> + platform_driver_register(&tfp410_platform_driver);
>> +
>> + return 0;
>> +}
>> +module_init(tfp410_module_init);
>> +
>> +static void __exit tfp410_module_exit(void)
>> +{
>> + i2c_del_driver(&tfp410_i2c_driver);
>> + platform_driver_unregister(&tfp410_platform_driver);
>> +}
>> +module_exit(tfp410_module_exit);
>> +
>> +MODULE_AUTHOR("Jyri Sarha <jsarha at ti.com>");
>> +MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
>> +MODULE_LICENSE("GPL");
>>
>>
