Re: [PATCH v2 2/4] drm/panel: ilitek-ili9806e: split core and DSI logic

[Neil Armstrong <neil.armstrong@linaro.org>]

On 1/14/26 17:16, Dario Binacchi wrote:
> Split the driver to support multiple transport buses. The core logic
> (power, GPIO, backlight) is moved to a dedicated core module, while
> DSI-specific code is restricted to the DSI module.
> 
> Introduce DRM_PANEL_ILITEK_ILI9806E_CORE as a hidden Kconfig symbol
> selected by the bus-specific configuration.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> ---
> 
> (no changes since v1)
> 
>   MAINTAINERS                                   |   2 +-
>   drivers/gpu/drm/panel/Kconfig                 |   8 +-
>   drivers/gpu/drm/panel/Makefile                |   1 +
>   .../drm/panel/panel-ilitek-ili9806e-core.c    | 129 +++++++++++++++
>   .../drm/panel/panel-ilitek-ili9806e-core.h    |  15 ++
>   .../gpu/drm/panel/panel-ilitek-ili9806e-dsi.c | 151 +++++-------------
>   6 files changed, 195 insertions(+), 111 deletions(-)
>   create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c
>   create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 317e76cc99e5..67117d8cf483 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7913,7 +7913,7 @@ F:	drivers/gpu/drm/panel/panel-ilitek-ili9805.c
>   DRM DRIVER FOR ILITEK ILI9806E PANELS
>   M:	Michael Walle <mwalle@kernel.org>
>   S:	Maintained
> -F:	drivers/gpu/drm/panel/panel-ilitek-ili9806e-dsi.c
> +F:	drivers/gpu/drm/panel/panel-ilitek-ili9806e-*
>   
>   DRM DRIVER FOR JADARD JD9365DA-H3 MIPI-DSI LCD PANELS
>   M:	Jagan Teki <jagan@edgeble.ai>
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 692cd474910d..333e981eda96 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -257,11 +257,15 @@ config DRM_PANEL_ILITEK_ILI9805
>   	  Say Y if you want to enable support for panels based on the
>   	  Ilitek ILI9805 controller.
>   
> +config DRM_PANEL_ILITEK_ILI9806E_CORE
> +       tristate
> +       depends on OF
> +       depends on BACKLIGHT_CLASS_DEVICE
> +
>   config DRM_PANEL_ILITEK_ILI9806E_DSI
>   	tristate "Ilitek ILI9806E-based DSI panels"
> -	depends on OF
>   	depends on DRM_MIPI_DSI
> -	depends on BACKLIGHT_CLASS_DEVICE
> +	select DRM_PANEL_ILITEK_ILI9806E_CORE
>   	help
>   	  Say Y if you want to enable support for panels based on the
>   	  Ilitek ILI9806E controller using DSI.
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 00071a983242..13034cadb8d8 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_DRM_PANEL_HYDIS_HV101HD1) += panel-hydis-hv101hd1.o
>   obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
>   obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
>   obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9805) += panel-ilitek-ili9805.o
> +obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_CORE) += panel-ilitek-ili9806e-core.o
>   obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_DSI) += panel-ilitek-ili9806e-dsi.o
>   obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
>   obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9882T) += panel-ilitek-ili9882t.o
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c
> new file mode 100644
> index 000000000000..c088685d9d85
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c
> @@ -0,0 +1,129 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Ilitek ILI9806E core driver.
> + *
> + * Copyright (c) 2026 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>
> + */
> +
> +#include <drm/drm_panel.h>
> +
> +#include <linux/delay.h>
> +#include <linux/export.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include "panel-ilitek-ili9806e-core.h"
> +
> +struct ili9806e {
> +	void *transport;
> +	struct drm_panel panel;
> +
> +	struct regulator_bulk_data supplies[2];
> +	struct gpio_desc *reset_gpio;
> +};
> +
> +static const char * const regulator_names[] = {
> +	"vdd",
> +	"vccio",
> +};
> +
> +void *ili9806e_get_transport(struct drm_panel *panel)
> +{
> +	struct ili9806e *ctx = container_of(panel, struct ili9806e, panel);
> +
> +	return ctx->transport;
> +}
> +EXPORT_SYMBOL_GPL(ili9806e_get_transport);
> +
> +int ili9806e_power_on(struct device *dev)
> +{
> +	struct ili9806e *ctx = dev_get_drvdata(dev);
> +	int ret;
> +
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret) {
> +		dev_err(dev, "regulator bulk enable failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(10000, 20000);
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(10000, 20000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ili9806e_power_on);
> +
> +int ili9806e_power_off(struct device *dev)
> +{
> +	struct ili9806e *ctx = dev_get_drvdata(dev);
> +	int ret;
> +
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret)
> +		dev_err(dev, "regulator bulk disable failed: %d\n", ret);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(ili9806e_power_off);
> +
> +int ili9806e_probe(struct device *dev, void *transport,
> +		  const struct drm_panel_funcs *funcs,
> +		  int connector_type)
> +{
> +	struct ili9806e *ctx;
> +	int i, ret;
> +
> +	ctx = devm_kzalloc(dev, sizeof(struct ili9806e), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	dev_set_drvdata(dev, ctx);
> +	ctx->transport = transport;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
> +		ctx->supplies[i].supply = regulator_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
> +				      ctx->supplies);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to get regulators\n");
> +
> +	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
> +				     "Failed to get reset-gpios\n");
> +
> +	drm_panel_init(&ctx->panel, dev, funcs, connector_type);
> +
> +	ret = drm_panel_of_backlight(&ctx->panel);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get backlight\n");
> +
> +	ctx->panel.prepare_prev_first = true;
> +	drm_panel_add(&ctx->panel);
> +
> +	return 0;
> +
> +}
> +EXPORT_SYMBOL_GPL(ili9806e_probe);
> +
> +void ili9806e_remove(struct device *dev)
> +{
> +	struct ili9806e *ctx = dev_get_drvdata(dev);
> +
> +	drm_panel_remove(&ctx->panel);
> +}
> +EXPORT_SYMBOL_GPL(ili9806e_remove);
> +
> +MODULE_AUTHOR("Dario Binacchi <dario.binacchi@amarulasolutions.com>");
> +MODULE_AUTHOR("Gunnar Dibbern <gunnar.dibbern@lht.dlh.de>");
> +MODULE_AUTHOR("Michael Walle <mwalle@kernel.org>");
> +MODULE_DESCRIPTION("Ilitek ILI9806E Controller Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.h b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.h
> new file mode 100644
> index 000000000000..dddece62cf42
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef _PANEL_ILITEK_ILI9806E_CORE_H
> +#define _PANEL_ILITEK_ILI9806E_CORE_H
> +
> +void *ili9806e_get_transport(struct drm_panel *panel);
> +int ili9806e_power_off(struct device *dev);
> +int ili9806e_power_on(struct device *dev);
> +
> +int ili9806e_probe(struct device *dev, void *transport,
> +		   const struct drm_panel_funcs *funcs,
> +		   int connector_type);
> +void ili9806e_remove(struct device *dev);
> +
> +#endif /* _PANEL_ILITEK_ILI9806E_CORE_H */
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-dsi.c b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-dsi.c
> index c337c4f1a1c7..ecdbed8d4a3a 100644
> --- a/drivers/gpu/drm/panel/panel-ilitek-ili9806e-dsi.c
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9806e-dsi.c
> @@ -1,15 +1,12 @@
>   // SPDX-License-Identifier: GPL-2.0
>   
> -#include <linux/delay.h>
>   #include <linux/device.h>
>   #include <linux/err.h>
>   #include <linux/errno.h>
> -#include <linux/gpio/consumer.h>
>   #include <linux/kernel.h>
>   #include <linux/mod_devicetable.h>
>   #include <linux/module.h>
>   #include <linux/property.h>
> -#include <linux/regulator/consumer.h>
>   
>   #include <drm/drm_mipi_dsi.h>
>   #include <drm/drm_modes.h>
> @@ -18,7 +15,9 @@
>   
>   #include <video/mipi_display.h>
>   
> -struct panel_desc {
> +#include "panel-ilitek-ili9806e-core.h"
> +
> +struct ili9806e_dsi_panel_desc {
>   	const struct drm_display_mode *display_mode;
>   	unsigned long mode_flags;
>   	enum mipi_dsi_pixel_format format;
> @@ -26,60 +25,13 @@ struct panel_desc {
>   	void (*init_sequence)(struct mipi_dsi_multi_context *ctx);
>   };
>   
> -struct ili9806e_panel {
> -	struct drm_panel panel;
> +struct ili9806e_dsi_panel {
>   	struct mipi_dsi_device *dsi;
> -	struct gpio_desc *reset_gpio;
> -	struct regulator_bulk_data supplies[2];
> -	const struct panel_desc *desc;
> +	const struct ili9806e_dsi_panel_desc *desc;
>   	enum drm_panel_orientation orientation;
>   };
>   
> -static const char * const regulator_names[] = {
> -	"vdd",
> -	"vccio",
> -};
> -
> -static inline struct ili9806e_panel *to_ili9806e_panel(struct drm_panel *panel)
> -{
> -	return container_of(panel, struct ili9806e_panel, panel);
> -}
> -
> -static int ili9806e_power_on(struct ili9806e_panel *ctx)
> -{
> -	struct mipi_dsi_device *dsi = ctx->dsi;
> -	int ret;
> -
> -	gpiod_set_value(ctx->reset_gpio, 1);
> -
> -	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> -	if (ret < 0) {
> -		dev_err(&dsi->dev, "regulator bulk enable failed: %d\n", ret);
> -		return ret;
> -	}
> -
> -	usleep_range(10000, 20000);
> -	gpiod_set_value(ctx->reset_gpio, 0);
> -	usleep_range(10000, 20000);
> -
> -	return 0;
> -}
> -
> -static int ili9806e_power_off(struct ili9806e_panel *ctx)
> -{
> -	struct mipi_dsi_device *dsi = ctx->dsi;
> -	int ret;
> -
> -	gpiod_set_value(ctx->reset_gpio, 1);
> -
> -	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> -	if (ret)
> -		dev_err(&dsi->dev, "regulator bulk disable failed: %d\n", ret);
> -
> -	return ret;
> -}
> -
> -static int ili9806e_on(struct ili9806e_panel *ili9806e)
> +static int ili9806e_dsi_on(struct ili9806e_dsi_panel *ili9806e)
>   {
>   	struct mipi_dsi_multi_context ctx = { .dsi = ili9806e->dsi };
>   
> @@ -93,7 +45,7 @@ static int ili9806e_on(struct ili9806e_panel *ili9806e)
>   	return ctx.accum_err;
>   }
>   
> -static int ili9806e_off(struct ili9806e_panel *panel)
> +static int ili9806e_dsi_off(struct ili9806e_dsi_panel *panel)
>   {
>   	struct mipi_dsi_multi_context ctx = { .dsi = panel->dsi };
>   
> @@ -104,88 +56,75 @@ static int ili9806e_off(struct ili9806e_panel *panel)
>   	return ctx.accum_err;
>   }
>   
> -static int ili9806e_prepare(struct drm_panel *panel)
> +static int ili9806e_dsi_prepare(struct drm_panel *panel)
>   {
> -	struct ili9806e_panel *ctx = to_ili9806e_panel(panel);
> +	struct ili9806e_dsi_panel *ctx = ili9806e_get_transport(panel);
> +	struct device *dev = &ctx->dsi->dev;
>   	int ret;
>   
> -	ret = ili9806e_power_on(ctx);
> +	ret = ili9806e_power_on(dev);
>   	if (ret < 0)
>   		return ret;
>   
> -	ret = ili9806e_on(ctx);
> +	ret = ili9806e_dsi_on(ctx);
>   	if (ret < 0) {
> -		ili9806e_power_off(ctx);
> +		ili9806e_power_off(dev);
>   		return ret;
>   	}
>   
>   	return 0;
>   }
>   
> -static int ili9806e_unprepare(struct drm_panel *panel)
> +static int ili9806e_dsi_unprepare(struct drm_panel *panel)
>   {
> -	struct ili9806e_panel *ctx = to_ili9806e_panel(panel);
> -	struct mipi_dsi_device *dsi = ctx->dsi;
> +	struct ili9806e_dsi_panel *ctx = ili9806e_get_transport(panel);
> +	struct device *dev = &ctx->dsi->dev;
>   	int ret;
>   
> -	ili9806e_off(ctx);
> +	ili9806e_dsi_off(ctx);
>   
> -	ret = ili9806e_power_off(ctx);
> +	ret = ili9806e_power_off(dev);
>   	if (ret < 0)
> -		dev_err(&dsi->dev, "power off failed: %d\n", ret);
> +		dev_err(dev, "power off failed: %d\n", ret);
>   
>   	return ret;
>   }
>   
> -static int ili9806e_get_modes(struct drm_panel *panel,
> +static int ili9806e_dsi_get_modes(struct drm_panel *panel,
>   			      struct drm_connector *connector)
>   {
> -	struct ili9806e_panel *ctx = to_ili9806e_panel(panel);
> +	struct ili9806e_dsi_panel *ctx = ili9806e_get_transport(panel);
>   	const struct drm_display_mode *mode = ctx->desc->display_mode;
>   
>   	return drm_connector_helper_get_modes_fixed(connector, mode);
>   }
>   
> -static enum drm_panel_orientation ili9806e_get_orientation(struct drm_panel *panel)
> +static enum drm_panel_orientation ili9806e_dsi_get_orientation(struct drm_panel *panel)
>   {
> -	struct ili9806e_panel *ctx = to_ili9806e_panel(panel);
> +	struct ili9806e_dsi_panel *ctx = ili9806e_get_transport(panel);
>   
>   	return ctx->orientation;
>   }
>   
> -static const struct drm_panel_funcs ili9806e_funcs = {
> -	.prepare = ili9806e_prepare,
> -	.unprepare = ili9806e_unprepare,
> -	.get_modes = ili9806e_get_modes,
> -	.get_orientation = ili9806e_get_orientation,
> +static const struct drm_panel_funcs ili9806e_dsi_funcs = {
> +	.prepare = ili9806e_dsi_prepare,
> +	.unprepare = ili9806e_dsi_unprepare,
> +	.get_modes = ili9806e_dsi_get_modes,
> +	.get_orientation = ili9806e_dsi_get_orientation,
>   };
>   
>   static int ili9806e_dsi_probe(struct mipi_dsi_device *dsi)
>   {
>   	struct device *dev = &dsi->dev;
> -	struct ili9806e_panel *ctx;
> -	int i, ret;
> +	struct ili9806e_dsi_panel *ctx;
> +	int ret;
>   
> -	ctx = devm_drm_panel_alloc(dev, struct ili9806e_panel, panel, &ili9806e_funcs,
> -				   DRM_MODE_CONNECTOR_DSI);
> -	if (IS_ERR(ctx))
> -		return PTR_ERR(ctx);
> +	ctx = devm_kzalloc(dev, sizeof(struct ili9806e_dsi_panel), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
>   
>   	ctx->desc = device_get_match_data(dev);
>   
> -	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
> -		ctx->supplies[i].supply = regulator_names[i];
> -
> -	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
> -				      ctx->supplies);
> -	if (ret < 0)
> -		return ret;
> -
> -	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> -	if (IS_ERR(ctx->reset_gpio))
> -		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
> -				     "Failed to get reset-gpios\n");
> -
>   	mipi_dsi_set_drvdata(dsi, ctx);
>   	ctx->dsi = dsi;
>   
> @@ -197,17 +136,15 @@ static int ili9806e_dsi_probe(struct mipi_dsi_device *dsi)
>   	if (ret)
>   		return dev_err_probe(dev, ret, "Failed to get orientation\n");
>   
> -	ret = drm_panel_of_backlight(&ctx->panel);
> +	ret = ili9806e_probe(dev, ctx, &ili9806e_dsi_funcs,
> +			     DRM_MODE_CONNECTOR_DSI);
>   	if (ret)
> -		return dev_err_probe(dev, ret, "Failed to get backlight\n");
> -
> -	ctx->panel.prepare_prev_first = true;
> -	drm_panel_add(&ctx->panel);
> +		return ret;
>   
>   	ret = mipi_dsi_attach(dsi);
>   	if (ret < 0) {
>   		dev_err_probe(dev, ret, "Failed to attach to DSI host\n");
> -		drm_panel_remove(&ctx->panel);
> +		ili9806e_remove(dev);
>   		return ret;
>   	}
>   
> @@ -216,10 +153,8 @@ static int ili9806e_dsi_probe(struct mipi_dsi_device *dsi)
>   
>   static void ili9806e_dsi_remove(struct mipi_dsi_device *dsi)
>   {
> -	struct ili9806e_panel *ctx = mipi_dsi_get_drvdata(dsi);
> -
>   	mipi_dsi_detach(dsi);
> -	drm_panel_remove(&ctx->panel);
> +	ili9806e_remove(&dsi->dev);
>   }
>   
>   static void com35h3p70ulc_init(struct mipi_dsi_multi_context *ctx)
> @@ -369,7 +304,7 @@ static const struct drm_display_mode com35h3p70ulc_default_mode = {
>   	.height_mm = 71,
>   };
>   
> -static const struct panel_desc com35h3p70ulc_desc = {
> +static const struct ili9806e_dsi_panel_desc com35h3p70ulc_desc = {
>   	.init_sequence = com35h3p70ulc_init,
>   	.display_mode = &com35h3p70ulc_default_mode,
>   	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
> @@ -533,7 +468,7 @@ static const struct drm_display_mode dmt028vghmcmi_1d_default_mode = {
>   	.type		= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
>   };
>   
> -static const struct panel_desc dmt028vghmcmi_1d_desc = {
> +static const struct ili9806e_dsi_panel_desc dmt028vghmcmi_1d_desc = {
>   	.init_sequence = dmt028vghmcmi_1d_init,
>   	.display_mode = &dmt028vghmcmi_1d_default_mode,
>   	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
> @@ -542,17 +477,17 @@ static const struct panel_desc dmt028vghmcmi_1d_desc = {
>   	.lanes = 2,
>   };
>   
> -static const struct of_device_id ili9806e_of_match[] = {
> +static const struct of_device_id ili9806e_dsi_of_match[] = {
>   	{ .compatible = "densitron,dmt028vghmcmi-1d", .data = &dmt028vghmcmi_1d_desc },
>   	{ .compatible = "ortustech,com35h3p70ulc", .data = &com35h3p70ulc_desc },
>   	{ }
>   };
> -MODULE_DEVICE_TABLE(of, ili9806e_of_match);
> +MODULE_DEVICE_TABLE(of, ili9806e_dsi_of_match);
>   
>   static struct mipi_dsi_driver ili9806e_dsi_driver = {
>   	.driver = {
>   		.name = "ili9806e-dsi",
> -		.of_match_table = ili9806e_of_match,
> +		.of_match_table = ili9806e_dsi_of_match,
>   	},
>   	.probe = ili9806e_dsi_probe,
>   	.remove = ili9806e_dsi_remove,

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Thanks,
Neil