Commit f40f5b87 authored by Linus Walleij's avatar Linus Walleij
Browse files

drm/panel: Add support for ARM Versatile panels 



The ARM reference designs "Versatile AB" and "Versatile PB"
contain panel connectors with autodetection of the connected
panel type. This adds a small driver utilizing the MFD syscon
look-up to read the autodetection register and set up the
corresponding panel appropriately.

In the source file there is a bit of elaboration of the
panel types and interfaces on these boards.

This was tested with the PL111 DRM driver on the ARM Versatile
AB with the IB2 daughterboard.

Reviewed-by: default avatarEric Anholt <eric@anholt.net>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205192013.5349-2-linus.walleij@linaro.org
parent 98ae3b26

MAINTAINERS

+7 −0
Original line number Diff line number Diff line
@@ -4442,6 +4442,13 @@ T: git git://anongit.freedesktop.org/drm/drm-misc 
S:	Supported

F:	drivers/gpu/drm/pl111/



DRM DRIVER FOR ARM VERSATILE TFT PANELS

M:	Linus Walleij <linus.walleij@linaro.org>

T:	git git://anongit.freedesktop.org/drm/drm-misc

S:	Maintained

F:	drivers/gpu/drm/panel/panel-arm-versatile.c

F:	Documentation/devicetree/bindings/display/panel/arm,versatile-tft-panel.txt



DRM DRIVER FOR AST SERVER GRAPHICS CHIPS

M:	Dave Airlie <airlied@redhat.com>

S:	Odd Fixes

drivers/gpu/drm/panel/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -7,6 +7,16 @@ config DRM_PANEL 
menu "Display Panels"

	depends on DRM && DRM_PANEL



config DRM_PANEL_ARM_VERSATILE

	tristate "ARM Versatile panel driver"

	depends on OF

	depends on MFD_SYSCON

	select VIDEOMODE_HELPERS

	help

	  This driver supports the ARM Versatile panels connected to ARM

	  reference designs. The panel is detected using special registers

	  in the Versatile family syscon registers.



config DRM_PANEL_LVDS

	tristate "Generic LVDS panel driver"

	depends on OF

drivers/gpu/drm/panel/Makefile

+1 −0
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# SPDX-License-Identifier: GPL-2.0

obj-$(CONFIG_DRM_PANEL_ARM_VERSATILE) += panel-arm-versatile.o

obj-$(CONFIG_DRM_PANEL_LVDS) += panel-lvds.o

obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o

obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o

drivers/gpu/drm/panel/panel-arm-versatile.c

0 → 100644
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// SPDX-License-Identifier: GPL-2.0

/*

 * Panel driver for the ARM Versatile family reference designs from

 * ARM Limited.

 *

 * Author:

 * Linus Walleij <linus.wallei@linaro.org>

 *

 * On the Versatile AB, these panels come mounted on daughterboards

 * named "IB1" or "IB2" (Interface Board 1 & 2 respectively.) They

 * are documented in ARM DUI 0225D Appendix C and D. These daughter

 * boards support TFT display panels.

 *

 * - The IB1 is a passive board where the display connector defines a

 *   few wires for encoding the display type for autodetection,

 *   suitable display settings can then be looked up from this setting.

 *   The magic bits can be read out from the system controller.

 *

 * - The IB2 is a more complex board intended for GSM phone development

 *   with some logic and a control register, which needs to be accessed

 *   and the board display needs to be turned on explicitly.

 *

 * On the Versatile PB, a special CLCD adaptor board is available

 * supporting the same displays as the Versatile AB, plus one more

 * Epson QCIF display.

 *

 */

#include <drm/drmP.h>

#include <drm/drm_panel.h>



#include <linux/bitops.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/mfd/syscon.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>



#include <video/of_videomode.h>

#include <video/videomode.h>



/*

 * This configuration register in the Versatile and RealView

 * family is uniformly present but appears more and more

 * unutilized starting with the RealView series.

 */

#define SYS_CLCD			0x50



/* The Versatile can detect the connected panel type */

#define SYS_CLCD_CLCDID_MASK		(BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))

#define SYS_CLCD_ID_SANYO_3_8		(0x00 << 8)

#define SYS_CLCD_ID_SHARP_8_4		(0x01 << 8)

#define SYS_CLCD_ID_EPSON_2_2		(0x02 << 8)

#define SYS_CLCD_ID_SANYO_2_5		(0x07 << 8)

#define SYS_CLCD_ID_VGA			(0x1f << 8)



/* IB2 control register for the Versatile daughterboard */

#define IB2_CTRL			0x00

#define IB2_CTRL_LCD_SD			BIT(1) /* 1 = shut down LCD */

#define IB2_CTRL_LCD_BL_ON		BIT(0)

#define IB2_CTRL_LCD_MASK		(BIT(0)|BIT(1))



/**

 * struct versatile_panel_type - lookup struct for the supported panels

 */

struct versatile_panel_type {

	/**

	 * @name: the name of this panel

	 */

	const char *name;

	/**

	 * @magic: the magic value from the detection register

	 */

	u32 magic;

	/**

	 * @mode: the DRM display mode for this panel

	 */

	struct drm_display_mode mode;

	/**

	 * @bus_flags: the DRM bus flags for this panel e.g. inverted clock

	 */

	u32 bus_flags;

	/**

	 * @width_mm: the panel width in mm

	 */

	u32 width_mm;

	/**

	 * @height_mm: the panel height in mm

	 */

	u32 height_mm;

	/**

	 * @ib2: the panel may be connected on an IB2 daughterboard

	 */

	bool ib2;

};



/**

 * struct versatile_panel - state container for the Versatile panels

 */

struct versatile_panel {

	/**

	 * @dev: the container device

	 */

	struct device *dev;

	/**

	 * @panel: the DRM panel instance for this device

	 */

	struct drm_panel panel;

	/**

	 * @panel_type: the Versatile panel type as detected

	 */

	const struct versatile_panel_type *panel_type;

	/**

	 * @map: map to the parent syscon where the main register reside

	 */

	struct regmap *map;

	/**

	 * @ib2_map: map to the IB2 syscon, if applicable

	 */

	struct regmap *ib2_map;

};



static const struct versatile_panel_type versatile_panels[] = {

	/*

	 * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT

	 * found on the Versatile AB IB1 connector or the Versatile

	 * PB adaptor board connector.

	 */

	{

		.name = "Sanyo TM38QV67A02A",

		.magic = SYS_CLCD_ID_SANYO_3_8,

		.width_mm = 79,

		.height_mm = 54,

		.mode = {

			.clock = 10000000,

			.hdisplay = 320,

			.hsync_start = 320 + 6,

			.hsync_end = 320 + 6 + 6,

			.htotal = 320 + 6 + 6 + 6,

			.vdisplay = 240,

			.vsync_start = 240 + 5,

			.vsync_end = 240 + 5 + 6,

			.vtotal = 240 + 5 + 6 + 5,

			.vrefresh = 116,

			.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,

		},

	},

	/*

	 * Sharp LQ084V1DG21 640x480 VGA Color TFT module

	 * found on the Versatile AB IB1 connector or the Versatile

	 * PB adaptor board connector.

	 */

	{

		.name = "Sharp LQ084V1DG21",

		.magic = SYS_CLCD_ID_SHARP_8_4,

		.width_mm = 171,

		.height_mm = 130,

		.mode = {

			.clock = 25000000,

			.hdisplay = 640,

			.hsync_start = 640 + 24,

			.hsync_end = 640 + 24 + 96,

			.htotal = 640 + 24 + 96 + 24,

			.vdisplay = 480,

			.vsync_start = 480 + 11,

			.vsync_end = 480 + 11 + 2,

			.vtotal = 480 + 11 + 2 + 32,

			.vrefresh = 60,

			.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,

		},

	},

	/*

	 * Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT

	 * found on the Versatile PB adaptor board connector.

	 */

	{

		.name = "Epson L2F50113T00",

		.magic = SYS_CLCD_ID_EPSON_2_2,

		.width_mm = 34,

		.height_mm = 45,

		.mode = {

			.clock = 625000000,

			.hdisplay = 176,

			.hsync_start = 176 + 2,

			.hsync_end = 176 + 2 + 3,

			.htotal = 176 + 2 + 3 + 3,

			.vdisplay = 220,

			.vsync_start = 220 + 0,

			.vsync_end = 220 + 0 + 2,

			.vtotal = 220 + 0 + 2 + 1,

			.vrefresh = 390,

			.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,

		},

		.bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE,

	},

	/*

	 * Sanyo ALR252RGT 240x320 portrait display found on the

	 * Versatile AB IB2 daughterboard for GSM prototyping.

	 */

	{

		.name = "Sanyo ALR252RGT",

		.magic = SYS_CLCD_ID_SANYO_2_5,

		.width_mm = 37,

		.height_mm = 50,

		.mode = {

			.clock = 5400000,

			.hdisplay = 240,

			.hsync_start = 240 + 10,

			.hsync_end = 240 + 10 + 10,

			.htotal = 240 + 10 + 10 + 20,

			.vdisplay = 320,

			.vsync_start = 320 + 2,

			.vsync_end = 320 + 2 + 2,

			.vtotal = 320 + 2 + 2 + 2,

			.vrefresh = 116,

			.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,

		},

		.bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE,

		.ib2 = true,

	},

};



static inline struct versatile_panel *

to_versatile_panel(struct drm_panel *panel)

{

	return container_of(panel, struct versatile_panel, panel);

}



static int versatile_panel_disable(struct drm_panel *panel)

{

	struct versatile_panel *vpanel = to_versatile_panel(panel);



	/* If we're on an IB2 daughterboard, turn off display */

	if (vpanel->ib2_map) {

		dev_dbg(vpanel->dev, "disable IB2 display\n");

		regmap_update_bits(vpanel->ib2_map,

				   IB2_CTRL,

				   IB2_CTRL_LCD_MASK,

				   IB2_CTRL_LCD_SD);

	}



	return 0;

}



static int versatile_panel_enable(struct drm_panel *panel)

{

	struct versatile_panel *vpanel = to_versatile_panel(panel);



	/* If we're on an IB2 daughterboard, turn on display */

	if (vpanel->ib2_map) {

		dev_dbg(vpanel->dev, "enable IB2 display\n");

		regmap_update_bits(vpanel->ib2_map,

				   IB2_CTRL,

				   IB2_CTRL_LCD_MASK,

				   IB2_CTRL_LCD_BL_ON);

	}



	return 0;

}



static int versatile_panel_get_modes(struct drm_panel *panel)

{

	struct drm_connector *connector = panel->connector;

	struct versatile_panel *vpanel = to_versatile_panel(panel);

	struct drm_display_mode *mode;



	strncpy(connector->display_info.name, vpanel->panel_type->name,

		DRM_DISPLAY_INFO_LEN);

	connector->display_info.width_mm = vpanel->panel_type->width_mm;

	connector->display_info.height_mm = vpanel->panel_type->height_mm;

	connector->display_info.bus_flags = vpanel->panel_type->bus_flags;



	mode = drm_mode_duplicate(panel->drm, &vpanel->panel_type->mode);

	drm_mode_set_name(mode);

	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;



	mode->width_mm = vpanel->panel_type->width_mm;

	mode->height_mm = vpanel->panel_type->height_mm;

	drm_mode_probed_add(connector, mode);



	return 1;

}



static const struct drm_panel_funcs versatile_panel_drm_funcs = {

	.disable = versatile_panel_disable,

	.enable = versatile_panel_enable,

	.get_modes = versatile_panel_get_modes,

};



static int versatile_panel_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct versatile_panel *vpanel;

	struct device *parent;

	struct regmap *map;

	int ret;

	u32 val;

	int i;



	parent = dev->parent;

	if (!parent) {

		dev_err(dev, "no parent for versatile panel\n");

		return -ENODEV;

	}

	map = syscon_node_to_regmap(parent->of_node);

	if (IS_ERR(map)) {

		dev_err(dev, "no regmap for versatile panel parent\n");

		return PTR_ERR(map);

	}



	vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL);

	if (!vpanel)

		return -ENOMEM;



	ret = regmap_read(map, SYS_CLCD, &val);

	if (ret) {

		dev_err(dev, "cannot access syscon regs\n");

		return ret;

	}



	val &= SYS_CLCD_CLCDID_MASK;



	for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {

		const struct versatile_panel_type *pt;



		pt = &versatile_panels[i];

		if (pt->magic == val) {

			vpanel->panel_type = pt;

			break;

		}

	}



	/* No panel detected or VGA, let's leave this show */

	if (i == ARRAY_SIZE(versatile_panels)) {

		dev_info(dev, "no panel detected\n");

		return -ENODEV;

	}



	dev_info(dev, "detected: %s\n", vpanel->panel_type->name);

	vpanel->dev = dev;

	vpanel->map = map;



	/* Check if the panel is mounted on an IB2 daughterboard */

	if (vpanel->panel_type->ib2) {

		vpanel->ib2_map = syscon_regmap_lookup_by_compatible(

			"arm,versatile-ib2-syscon");

		if (IS_ERR(vpanel->ib2_map))

			vpanel->ib2_map = NULL;

		else

			dev_info(dev, "panel mounted on IB2 daughterboard\n");

	}



	drm_panel_init(&vpanel->panel);

	vpanel->panel.dev = dev;

	vpanel->panel.funcs = &versatile_panel_drm_funcs;



	return drm_panel_add(&vpanel->panel);

}



static const struct of_device_id versatile_panel_match[] = {

	{ .compatible = "arm,versatile-tft-panel", },

	{},

};

MODULE_DEVICE_TABLE(of, versatile_panel_match);



static struct platform_driver versatile_panel_driver = {

	.probe		= versatile_panel_probe,

	.driver		= {

		.name	= "versatile-tft-panel",

		.of_match_table = versatile_panel_match,

	},

};

module_platform_driver(versatile_panel_driver);



MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");

MODULE_DESCRIPTION("ARM Versatile panel driver");

MODULE_LICENSE("GPL v2");

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