[PATCH v3 2/7] drm/bridge: Repurpose lvds-encoder.c
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Nov 7 20:34:54 UTC 2019
Hi Fabrizio,
Thank you for the patch.
On Thu, Nov 07, 2019 at 08:10:58PM +0000, Fabrizio Castro wrote:
> lvds-encoder.c implementation is also suitable for LVDS decoders,
> not just LVDS encoders.
> Instead of creating a new driver for addressing support for
> transparent LVDS decoders, repurpose lvds-encoder.c for the greater
> good.
>
> Signed-off-by: Fabrizio Castro <fabrizio.castro at bp.renesas.com>
>
> ---
> v2->v3:
> * No change
> v1->v2:
> * No change
> ---
> drivers/gpu/drm/bridge/Kconfig | 8 +-
> drivers/gpu/drm/bridge/Makefile | 2 +-
> drivers/gpu/drm/bridge/lvds-codec.c | 131 ++++++++++++++++++++++++++++
> drivers/gpu/drm/bridge/lvds-encoder.c | 155 ----------------------------------
> 4 files changed, 136 insertions(+), 160 deletions(-)
It would help if you added the -M1 option to git-format-patch to detect
the rename, the result would be easier to review.
> create mode 100644 drivers/gpu/drm/bridge/lvds-codec.c
> delete mode 100644 drivers/gpu/drm/bridge/lvds-encoder.c
>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 3436297..9e75ca4e 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -45,14 +45,14 @@ config DRM_DUMB_VGA_DAC
> Support for non-programmable RGB to VGA DAC bridges, such as ADI
> ADV7123, TI THS8134 and THS8135 or passive resistor ladder DACs.
>
> -config DRM_LVDS_ENCODER
> - tristate "Transparent parallel to LVDS encoder support"
> +config DRM_LVDS_CODEC
> + tristate "Transparent LVDS encoders and decoders support"
> depends on OF
> select DRM_KMS_HELPER
> select DRM_PANEL_BRIDGE
> help
> - Support for transparent parallel to LVDS encoders that don't require
> - any configuration.
> + Support for transparent LVDS encoders and LVDS decoders that don't
> + require any configuration.
>
> config DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW
> tristate "MegaChips stdp4028-ge-b850v3-fw and stdp2690-ge-b850v3-fw"
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 4934fcf..8a9178a 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -2,7 +2,7 @@
> obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
> obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
> -obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
> +obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
> obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
> obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> new file mode 100644
> index 0000000..d57a8eb
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -0,0 +1,131 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2019 Renesas Electronics Corporation
> + * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_panel.h>
> +
> +struct lvds_codec {
> + struct drm_bridge bridge;
> + struct drm_bridge *panel_bridge;
> + struct gpio_desc *powerdown_gpio;
> +};
> +
> +static int lvds_codec_attach(struct drm_bridge *bridge)
> +{
> + struct lvds_codec *lvds_codec = container_of(bridge,
> + struct lvds_codec, bridge);
> +
> + return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
> + bridge);
> +}
> +
> +static void lvds_codec_enable(struct drm_bridge *bridge)
> +{
> + struct lvds_codec *lvds_codec = container_of(bridge,
> + struct lvds_codec, bridge);
> +
> + if (lvds_codec->powerdown_gpio)
> + gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
> +}
> +
> +static void lvds_codec_disable(struct drm_bridge *bridge)
> +{
> + struct lvds_codec *lvds_codec = container_of(bridge,
> + struct lvds_codec, bridge);
> +
> + if (lvds_codec->powerdown_gpio)
> + gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
> +}
> +
> +static struct drm_bridge_funcs funcs = {
> + .attach = lvds_codec_attach,
> + .enable = lvds_codec_enable,
> + .disable = lvds_codec_disable,
> +};
> +
> +static int lvds_codec_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *panel_node;
> + struct drm_panel *panel;
> + struct lvds_codec *lvds_codec;
> +
> + lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
> + if (!lvds_codec)
> + return -ENOMEM;
> +
> + lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(lvds_codec->powerdown_gpio))
> + return PTR_ERR(lvds_codec->powerdown_gpio);
The driver had an error message here, any reason it got removed ?
> +
> + panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
> + if (!panel_node) {
> + dev_dbg(dev, "panel DT node not found\n");
> + return -ENXIO;
> + }
> +
> + panel = of_drm_find_panel(panel_node);
> + of_node_put(panel_node);
> + if (IS_ERR(panel)) {
> + dev_dbg(dev, "panel not found, deferring probe\n");
> + return PTR_ERR(panel);
> + }
> +
> + lvds_codec->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
This was devm_drm_panel_bridge_add_typed(), do you think there's a risk
of breaking userspace ? Of course as noted in the documentation of
devm_drm_panel_bridge_add_typed() the right solution is to fix panel
drivers, but I'm still slightly worried.
Actually, could you split this patch in two, with a patch that only
renames the driver (and the symbols internally) without any functional
change, and another patch that performs the modifications ? That would
be much easier to review and discuss.
> + if (IS_ERR(lvds_codec->panel_bridge))
> + return PTR_ERR(lvds_codec->panel_bridge);
> +
> + /* The panel_bridge bridge is attached to the panel's of_node,
> + * but we need a bridge attached to our of_node for our user
> + * to look up.
> + */
> + lvds_codec->bridge.of_node = dev->of_node;
> + lvds_codec->bridge.funcs = &funcs;
> + drm_bridge_add(&lvds_codec->bridge);
> +
> + platform_set_drvdata(pdev, lvds_codec);
> +
> + return 0;
> +}
> +
> +static int lvds_codec_remove(struct platform_device *pdev)
> +{
> + struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
> +
> + drm_bridge_remove(&lvds_codec->bridge);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id lvds_codec_match[] = {
> + { .compatible = "lvds-encoder" },
> + { .compatible = "thine,thc63lvdm83d" },
> + { .compatible = "lvds-decoder" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, lvds_codec_match);
> +
> +static struct platform_driver lvds_codec_driver = {
> + .probe = lvds_codec_probe,
> + .remove = lvds_codec_remove,
> + .driver = {
> + .name = "lvds-codec",
> + .of_match_table = lvds_codec_match,
> + },
> +};
> +module_platform_driver(lvds_codec_driver);
> +
> +MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart at ideasonboard.com>");
> +MODULE_DESCRIPTION("Driver for transparent LVDS encoders and LVDS decoders");
Maybe "LVDS encoders and decoders" ?
> +MODULE_LICENSE("GPL");
[snip]
--
Regards,
Laurent Pinchart
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