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: Eric Anholt <eric@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v1->v2:
- Use inline documentation style for the structs.
- Explicit positive hsync and vsync on the panels requiring it
- Convert two dev_info() to dev_dbg()
- Collect Eric's Review tag.
---
MAINTAINERS | 7 +
drivers/gpu/drm/panel/Kconfig | 10 +
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-arm-versatile.c | 377 ++++++++++++++++++++++++++++
4 files changed, 395 insertions(+)
create mode 100644 drivers/gpu/drm/panel/panel-arm-versatile.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 18994806e441..e4fc490fa320 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -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@xxxxxxxxxx>
+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@xxxxxxxxxx>
S: Odd Fixes
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 726f3fb3312d..04732adbb48f 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -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
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 2c4e1a93e05f..091fa6647769 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -1,4 +1,5 @@
# 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_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
diff --git a/drivers/gpu/drm/panel/panel-arm-versatile.c b/drivers/gpu/drm/panel/panel-arm-versatile.c
new file mode 100644
index 000000000000..3930b4925b15
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-arm-versatile.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Panel driver for the ARM Versatile family reference designs from
+ * ARM Limited.
+ *
+ * Author:
+ * Linus Walleij <linus.wallei@xxxxxxxxxx>
+ *
+ * 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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("ARM Versatile panel driver");
+MODULE_LICENSE("GPL v2");
--
2.14.3
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