Message-Id: <20251016095043.1694736-3-yelangyan@huaqin.corp-partner.google.com>
Date: Thu, 16 Oct 2025 17:50:43 +0800
From: Langyan Ye <yelangyan@...qin.corp-partner.google.com>
To: neil.armstrong@...aro.org,
	jessica.zhang@....qualcomm.com,
	airlied@...il.com,
	simona@...ll.ch,
	maarten.lankhorst@...ux.intel.com,
	mripard@...nel.org,
	tzimmermann@...e.de,
	robh@...nel.org,
	krzk+dt@...nel.org,
	conor+dt@...nel.org,
	dianders@...omium.org
Cc: dri-devel@...ts.freedesktop.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Langyan Ye <yelangyan@...qin.corp-partner.google.com>
Subject: [PATCH v3 2/2] drm/panel: Add driver for Ilitek IL79900A-based panels

Add a DRM panel driver for the Ilitek IL79900A MIPI-DSI LCD controller.

The controller is used in panels such as the Tianma TL121BVMS07-00.
It requires multiple power supplies (AVDD, AVEE, 1.8V logic), an enable
GPIO, and a backlight device.

Signed-off-by: Langyan Ye <yelangyan@...qin.corp-partner.google.com>
---
 drivers/gpu/drm/panel/panel-ilitek-il79900a.c | 358 ++++++++++++++++++
 1 file changed, 358 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-il79900a.c

diff --git a/drivers/gpu/drm/panel/panel-ilitek-il79900a.c b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
new file mode 100644
index 000000000000..22338bef5609
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Panels based on the Ilitek IL79900A display controller.
+ *
+ * Based on drivers/gpu/drm/panel/panel-ilitek-ili9882t.c
+ */
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+struct il79900a;
+
+/*
+ * Use this descriptor struct to describe different panels using the
+ * Ilitek IL79900A display controller.
+ */
+struct panel_desc {
+	const struct drm_display_mode *modes;
+	unsigned int bpc;
+	unsigned long mode_flags;
+	enum mipi_dsi_pixel_format format;
+	int (*init)(struct il79900a *boe);
+	unsigned int lanes;
+};
+
+struct il79900a {
+	struct drm_panel base;
+	struct mipi_dsi_device *dsi;
+
+	const struct panel_desc *desc;
+
+	enum drm_panel_orientation orientation;
+	struct regulator *pp1800;
+	struct regulator *avee;
+	struct regulator *avdd;
+	struct gpio_desc *enable_gpio;
+};
+
+/* IL79900A-specific commands, add new commands as you decode them */
+#define IL79900A_DCS_SWITCH_PAGE	0xFF
+
+#define il79900a_switch_page(ctx, page) \
+	mipi_dsi_dcs_write_seq_multi(ctx, IL79900A_DCS_SWITCH_PAGE, \
+				     0x5a, 0xa5, (page))
+
+static int tianma_il79900a_init(struct il79900a *ili)
+{
+	struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
+
+	mipi_dsi_usleep_range(&ctx, 5000, 5100);
+
+	il79900a_switch_page(&ctx, 0x06);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x3e, 0x62);
+
+	il79900a_switch_page(&ctx, 0x02);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x1b, 0x20);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x5d, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x5e, 0x40);
+
+	il79900a_switch_page(&ctx, 0x07);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0X29, 0x00);
+
+	il79900a_switch_page(&ctx, 0x06);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x92, 0x22);
+
+	il79900a_switch_page(&ctx, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_EXIT_SLEEP_MODE);
+
+	mipi_dsi_msleep(&ctx, 120);
+
+	mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_SET_DISPLAY_ON);
+
+	mipi_dsi_msleep(&ctx, 80);
+
+	return 0;
+};
+
+static inline struct il79900a *to_il79900a(struct drm_panel *panel)
+{
+	return container_of(panel, struct il79900a, base);
+}
+
+static int il79900a_enter_sleep_mode(struct mipi_dsi_multi_context *ctx)
+{
+	mipi_dsi_dcs_set_display_off_multi(ctx);
+	mipi_dsi_dcs_enter_sleep_mode_multi(ctx);
+	return ctx->accum_err;
+}
+
+static int il79900a_disable(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+	struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
+	int ret;
+
+	il79900a_switch_page(&ctx, 0x00);
+	if (ctx.accum_err)
+		return ctx.accum_err;
+
+	ret = il79900a_enter_sleep_mode(&ctx);
+	if (ret < 0) {
+		dev_err(panel->dev, "failed to set panel off: %d\n", ret);
+		return ret;
+	}
+
+	mipi_dsi_msleep(&ctx, 150);
+
+	return 0;
+}
+
+static int il79900a_unprepare(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+
+	gpiod_set_value(ili->enable_gpio, 0);
+	usleep_range(1000, 2000);
+	regulator_disable(ili->avee);
+	regulator_disable(ili->avdd);
+	usleep_range(5000, 7000);
+	regulator_disable(ili->pp1800);
+
+	return 0;
+}
+
+static int il79900a_prepare(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+	int ret;
+
+	gpiod_set_value(ili->enable_gpio, 0);
+	usleep_range(1000, 1500);
+
+	ret = regulator_enable(ili->pp1800);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(3000, 5000);
+
+	ret = regulator_enable(ili->avdd);
+	if (ret < 0)
+		goto poweroff1v8;
+	ret = regulator_enable(ili->avee);
+	if (ret < 0)
+		goto poweroffavdd;
+
+	usleep_range(10000, 11000);
+
+	// MIPI needs to keep the LP11 state before the lcm_reset pin is pulled high
+	ret = mipi_dsi_dcs_nop(ili->dsi);
+	if (ret < 0) {
+		dev_err(&ili->dsi->dev, "Failed to send NOP: %d\n", ret);
+		goto poweroff;
+	}
+	usleep_range(1000, 2000);
+
+	gpiod_set_value(ili->enable_gpio, 1);
+	usleep_range(1000, 2000);
+	gpiod_set_value(ili->enable_gpio, 0);
+	usleep_range(10000, 11000);
+	gpiod_set_value(ili->enable_gpio, 1);
+	usleep_range(20000, 21000);
+
+	ret = ili->desc->init(ili);
+	if (ret < 0)
+		goto poweroff;
+
+	return 0;
+
+poweroff:
+	gpiod_set_value(ili->enable_gpio, 0);
+	regulator_disable(ili->avee);
+poweroffavdd:
+	regulator_disable(ili->avdd);
+poweroff1v8:
+	usleep_range(5000, 7000);
+	regulator_disable(ili->pp1800);
+
+	return ret;
+}
+
+static int il79900a_enable(struct drm_panel *panel)
+{
+	return 0;
+}
+
+static const struct drm_display_mode tianma_il79900a_default_mode = {
+	.clock = 264355,
+	.hdisplay = 1600,
+	.hsync_start = 1600 + 20,
+	.hsync_end = 1600 + 20 + 4,
+	.htotal = 1600 + 20 + 4 + 20,
+	.vdisplay = 2560,
+	.vsync_start = 2560 + 82,
+	.vsync_end = 2560 + 82 + 2,
+	.vtotal = 2560 + 82 + 2 + 36,
+	.width_mm = 163,
+	.height_mm = 260,
+};
+
+static const struct panel_desc tianma_il79900a_desc = {
+	.modes = &tianma_il79900a_default_mode,
+	.bpc = 8,
+	.lanes = 3,
+	.format = MIPI_DSI_FMT_RGB888,
+	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+		      MIPI_DSI_MODE_LPM,
+	.init = tianma_il79900a_init,
+};
+
+static int il79900a_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct il79900a *ili = to_il79900a(panel);
+	const struct drm_display_mode *m = ili->desc->modes;
+	int num_modes;
+
+	num_modes = drm_connector_helper_get_modes_fixed(connector, m);
+	if (num_modes <= 0)
+		return 0;
+
+	connector->display_info.bpc = ili->desc->bpc;
+
+	return num_modes;
+}
+
+static enum drm_panel_orientation il79900a_get_orientation(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+
+	return ili->orientation;
+}
+
+static const struct drm_panel_funcs il79900a_funcs = {
+	.disable = il79900a_disable,
+	.unprepare = il79900a_unprepare,
+	.prepare = il79900a_prepare,
+	.enable = il79900a_enable,
+	.get_modes = il79900a_get_modes,
+	.get_orientation = il79900a_get_orientation,
+};
+
+static int il79900a_add(struct il79900a *ili)
+{
+	struct device *dev = &ili->dsi->dev;
+	int err;
+
+	ili->avdd = devm_regulator_get(dev, "avdd");
+	if (IS_ERR(ili->avdd))
+		return PTR_ERR(ili->avdd);
+
+	ili->avee = devm_regulator_get(dev, "avee");
+	if (IS_ERR(ili->avee))
+		return PTR_ERR(ili->avee);
+
+	ili->pp1800 = devm_regulator_get(dev, "pp1800");
+	if (IS_ERR(ili->pp1800))
+		return PTR_ERR(ili->pp1800);
+
+	ili->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(ili->enable_gpio)) {
+		dev_err(dev, "cannot get reset-gpios %ld\n",
+			PTR_ERR(ili->enable_gpio));
+		return PTR_ERR(ili->enable_gpio);
+	}
+
+	gpiod_set_value(ili->enable_gpio, 0);
+
+	drm_panel_init(&ili->base, dev, &il79900a_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+	err = of_drm_get_panel_orientation(dev->of_node, &ili->orientation);
+	if (err < 0) {
+		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err);
+		return err;
+	}
+
+	err = drm_panel_of_backlight(&ili->base);
+	if (err)
+		return err;
+
+	ili->base.funcs = &il79900a_funcs;
+	ili->base.dev = &ili->dsi->dev;
+
+	drm_panel_add(&ili->base);
+
+	return 0;
+}
+
+static int il79900a_probe(struct mipi_dsi_device *dsi)
+{
+	struct il79900a *ili;
+	int ret;
+	const struct panel_desc *desc;
+
+	ili = devm_kzalloc(&dsi->dev, sizeof(*ili), GFP_KERNEL);
+	if (!ili)
+		return -ENOMEM;
+
+	desc = of_device_get_match_data(&dsi->dev);
+	dsi->lanes = desc->lanes;
+	dsi->format = desc->format;
+	dsi->mode_flags = desc->mode_flags;
+	ili->desc = desc;
+	ili->dsi = dsi;
+	ret = il79900a_add(ili);
+	if (ret < 0)
+		return ret;
+
+	mipi_dsi_set_drvdata(dsi, ili);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret)
+		drm_panel_remove(&ili->base);
+
+	return ret;
+}
+
+static void il79900a_remove(struct mipi_dsi_device *dsi)
+{
+	struct il79900a *ili = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
+
+	if (ili->base.dev)
+		drm_panel_remove(&ili->base);
+}
+
+static const struct of_device_id il79900a_of_match[] = {
+	{ .compatible = "tianma,il79900a", .data = &tianma_il79900a_desc },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, il79900a_of_match);
+
+static struct mipi_dsi_driver il79900a_driver = {
+	.driver = {
+		.name = "panel-il79900a",
+		.of_match_table = il79900a_of_match,
+	},
+	.probe = il79900a_probe,
+	.remove = il79900a_remove,
+};
+module_mipi_dsi_driver(il79900a_driver);
+
+MODULE_AUTHOR("Langyan Ye <yelangyan@...qin.corp-partner.google.com>");
+MODULE_DESCRIPTION("Ilitek IL79900A-based panels driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1

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