drm/panel: add panel driver for Elida KD35T133 panels

Panel driver for the KD35T133 display from Elida, used for example
in the rk3326-based Odroid Go Advance handheld.

changes in v3:
- add missing return value assignment (Francesco)
- re-sort header includes (Sam)
changes in v2:
- rename dsi_generic_write_seq macro to dsi_dcs_write_seq to honor
  the underlying mipi_dsi_dcs_write (Robin)
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200229151506.750242-3-heiko@sntech.de

drivers/gpu/drm/panel/Kconfig

@@ -59,6 +59,16 @@ config DRM_PANEL_SIMPLE
 	  that it can be automatically turned off when the panel goes into a
 	  low power state.
 
+config DRM_PANEL_ELIDA_KD35T133
+	tristate "Elida KD35T133 panel driver"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for the Elida
+	  KD35T133 controller for 320x480 LCD panels with MIPI-DSI
+	  system interfaces.
+
 config DRM_PANEL_FEIXIN_K101_IM2BA02
 	tristate "Feixin K101 IM2BA02 panel"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_PANEL_BOE_HIMAX8279D) += panel-boe-himax8279d.o
 obj-$(CONFIG_DRM_PANEL_BOE_TV101WUM_NL6) += panel-boe-tv101wum-nl6.o
 obj-$(CONFIG_DRM_PANEL_LVDS) += panel-lvds.o
 obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
+obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) += panel-elida-kd35t133.o
 obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) += panel-feixin-k101-im2ba02.o
 obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o

drivers/gpu/drm/panel/panel-elida-kd35t133.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Elida kd35t133 5.5" MIPI-DSI panel driver
+ * Copyright (C) 2020 Theobroma Systems Design und Consulting GmbH
+ *
+ * based on
+ *
+ * Rockteck jh057n00900 5.5" MIPI-DSI panel driver
+ * Copyright (C) Purism SPC 2019
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/display_timing.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+/* Manufacturer specific Commands send via DSI */
+#define KD35T133_CMD_INTERFACEMODECTRL		0xb0
+#define KD35T133_CMD_FRAMERATECTRL		0xb1
+#define KD35T133_CMD_DISPLAYINVERSIONCTRL	0xb4
+#define KD35T133_CMD_DISPLAYFUNCTIONCTRL	0xb6
+#define KD35T133_CMD_POWERCONTROL1		0xc0
+#define KD35T133_CMD_POWERCONTROL2		0xc1
+#define KD35T133_CMD_VCOMCONTROL		0xc5
+#define KD35T133_CMD_POSITIVEGAMMA		0xe0
+#define KD35T133_CMD_NEGATIVEGAMMA		0xe1
+#define KD35T133_CMD_SETIMAGEFUNCTION		0xe9
+#define KD35T133_CMD_ADJUSTCONTROL3		0xf7
+
+struct kd35t133 {
+	struct device *dev;
+	struct drm_panel panel;
+	struct gpio_desc *reset_gpio;
+	struct regulator *vdd;
+	struct regulator *iovcc;
+	bool prepared;
+};
+
+static inline struct kd35t133 *panel_to_kd35t133(struct drm_panel *panel)
+{
+	return container_of(panel, struct kd35t133, panel);
+}
+
+#define dsi_dcs_write_seq(dsi, cmd, seq...) do {			\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static int kd35t133_init_sequence(struct kd35t133 *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	struct device *dev = ctx->dev;
+
+	/*
+	 * Init sequence was supplied by the panel vendor with minimal
+	 * documentation.
+	 */
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_POSITIVEGAMMA,
+			  0x00, 0x13, 0x18, 0x04, 0x0f, 0x06, 0x3a, 0x56,
+			  0x4d, 0x03, 0x0a, 0x06, 0x30, 0x3e, 0x0f);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_NEGATIVEGAMMA,
+			  0x00, 0x13, 0x18, 0x01, 0x11, 0x06, 0x38, 0x34,
+			  0x4d, 0x06, 0x0d, 0x0b, 0x31, 0x37, 0x0f);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_POWERCONTROL1, 0x18, 0x17);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_POWERCONTROL2, 0x41);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_VCOMCONTROL, 0x00, 0x1a, 0x80);
+	dsi_dcs_write_seq(dsi, MIPI_DCS_SET_ADDRESS_MODE, 0x48);
+	dsi_dcs_write_seq(dsi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_INTERFACEMODECTRL, 0x00);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_FRAMERATECTRL, 0xa0);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_DISPLAYINVERSIONCTRL, 0x02);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_DISPLAYFUNCTIONCTRL,
+			  0x20, 0x02);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_SETIMAGEFUNCTION, 0x00);
+	dsi_dcs_write_seq(dsi, KD35T133_CMD_ADJUSTCONTROL3,
+			  0xa9, 0x51, 0x2c, 0x82);
+	mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_INVERT_MODE, NULL, 0);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");
+	return 0;
+}
+
+static int kd35t133_unprepare(struct drm_panel *panel)
+{
+	struct kd35t133 *ctx = panel_to_kd35t133(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (!ctx->prepared)
+		return 0;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0)
+		DRM_DEV_ERROR(ctx->dev, "failed to set display off: %d\n",
+			      ret);
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to enter sleep mode: %d\n",
+			      ret);
+		return ret;
+	}
+
+	regulator_disable(ctx->iovcc);
+	regulator_disable(ctx->vdd);
+
+	ctx->prepared = false;
+
+	return 0;
+}
+
+static int kd35t133_prepare(struct drm_panel *panel)
+{
+	struct kd35t133 *ctx = panel_to_kd35t133(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (ctx->prepared)
+		return 0;
+
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
+	ret = regulator_enable(ctx->vdd);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev,
+			      "Failed to enable vdd supply: %d\n", ret);
+		return ret;
+	}
+
+	ret = regulator_enable(ctx->iovcc);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev,
+			      "Failed to enable iovcc supply: %d\n", ret);
+		goto disable_vdd;
+	}
+
+	msleep(20);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(10, 20);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+
+	msleep(20);
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
+		goto disable_iovcc;
+	}
+
+	msleep(250);
+
+	ret = kd35t133_init_sequence(ctx);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",
+			      ret);
+		goto disable_iovcc;
+	}
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to set display on: %d\n", ret);
+		goto disable_iovcc;
+	}
+
+	msleep(50);
+
+	ctx->prepared = true;
+
+	return 0;
+
+disable_iovcc:
+	regulator_disable(ctx->iovcc);
+disable_vdd:
+	regulator_disable(ctx->vdd);
+	return ret;
+}
+
+static const struct drm_display_mode default_mode = {
+	.hdisplay	= 320,
+	.hsync_start	= 320 + 130,
+	.hsync_end	= 320 + 130 + 4,
+	.htotal		= 320 + 130 + 4 + 130,
+	.vdisplay	= 480,
+	.vsync_start	= 480 + 2,
+	.vsync_end	= 480 + 2 + 1,
+	.vtotal		= 480 + 2 + 1 + 2,
+	.vrefresh	= 60,
+	.clock		= 17000,
+	.width_mm	= 42,
+	.height_mm	= 82,
+};
+
+static int kd35t133_get_modes(struct drm_panel *panel,
+				struct drm_connector *connector)
+{
+	struct kd35t133 *ctx = panel_to_kd35t133(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, &default_mode);
+	if (!mode) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u\n",
+			      default_mode.hdisplay, default_mode.vdisplay,
+			      default_mode.vrefresh);
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs kd35t133_funcs = {
+	.unprepare	= kd35t133_unprepare,
+	.prepare	= kd35t133_prepare,
+	.get_modes	= kd35t133_get_modes,
+};
+
+static int kd35t133_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct kd35t133 *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio\n");
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	ctx->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(ctx->vdd)) {
+		ret = PTR_ERR(ctx->vdd);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev,
+				      "Failed to request vdd regulator: %d\n",
+				      ret);
+		return ret;
+	}
+
+	ctx->iovcc = devm_regulator_get(dev, "iovcc");
+	if (IS_ERR(ctx->iovcc)) {
+		ret = PTR_ERR(ctx->iovcc);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev,
+				      "Failed to request iovcc regulator: %d\n",
+				      ret);
+		return ret;
+	}
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+
+	dsi->lanes = 1;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET;
+
+	drm_panel_init(&ctx->panel, &dsi->dev, &kd35t133_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed: %d\n", ret);
+		drm_panel_remove(&ctx->panel);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void kd35t133_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct kd35t133 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = drm_panel_unprepare(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",
+			      ret);
+
+	ret = drm_panel_disable(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",
+			      ret);
+}
+
+static int kd35t133_remove(struct mipi_dsi_device *dsi)
+{
+	struct kd35t133 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	kd35t133_shutdown(dsi);
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to detach from DSI host: %d\n",
+			      ret);
+
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct of_device_id kd35t133_of_match[] = {
+	{ .compatible = "elida,kd35t133" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, kd35t133_of_match);
+
+static struct mipi_dsi_driver kd35t133_driver = {
+	.driver = {
+		.name = "panel-elida-kd35t133",
+		.of_match_table = kd35t133_of_match,
+	},
+	.probe	= kd35t133_probe,
+	.remove = kd35t133_remove,
+	.shutdown = kd35t133_shutdown,
+};
+module_mipi_dsi_driver(kd35t133_driver);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@theobroma-systems.com>");
+MODULE_DESCRIPTION("DRM driver for Elida kd35t133 MIPI DSI panel");
+MODULE_LICENSE("GPL v2");