1 files changed, 360 insertions, 0 deletions

diff --git a/drivers/gpu/drm/panel/panel-novatek-nt39016.c b/drivers/gpu/drm/panel/panel-novatek-nt39016.c
new file mode 100644
index 000000000..f58cfb10b
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-novatek-nt39016.c
@@ -0,0 +1,360 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Novatek NT39016 TFT LCD panel driver
+ *
+ * Copyright (C) 2017, Maarten ter Huurne <maarten@treewalker.org>
+ * Copyright (C) 2019, Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+enum nt39016_regs {
+	NT39016_REG_SYSTEM,
+	NT39016_REG_TIMING,
+	NT39016_REG_OP,
+	NT39016_REG_DATA_IN,
+	NT39016_REG_SRC_TIMING_DELAY,
+	NT39016_REG_GATE_TIMING_DELAY,
+	NT39016_REG_RESERVED,
+	NT39016_REG_INITIAL_FUNC,
+	NT39016_REG_CONTRAST,
+	NT39016_REG_BRIGHTNESS,
+	NT39016_REG_HUE_SATURATION,
+	NT39016_REG_RB_SUBCONTRAST,
+	NT39016_REG_R_SUBBRIGHTNESS,
+	NT39016_REG_B_SUBBRIGHTNESS,
+	NT39016_REG_VCOMDC,
+	NT39016_REG_VCOMAC,
+	NT39016_REG_VGAM2,
+	NT39016_REG_VGAM34,
+	NT39016_REG_VGAM56,
+	NT39016_REG_VCOMDC_TRIM = 0x1e,
+	NT39016_REG_DISPLAY_MODE = 0x20,
+};
+
+#define NT39016_SYSTEM_RESET_N	BIT(0)
+#define NT39016_SYSTEM_STANDBY	BIT(1)
+
+struct nt39016_panel_info {
+	const struct drm_display_mode *display_modes;
+	unsigned int num_modes;
+	u16 width_mm, height_mm;
+	u32 bus_format, bus_flags;
+};
+
+struct nt39016 {
+	struct drm_panel drm_panel;
+	struct regmap *map;
+	struct regulator *supply;
+	const struct nt39016_panel_info *panel_info;
+
+	struct gpio_desc *reset_gpio;
+};
+
+static inline struct nt39016 *to_nt39016(struct drm_panel *panel)
+{
+	return container_of(panel, struct nt39016, drm_panel);
+}
+
+#define RV(REG, VAL) { .reg = (REG), .def = (VAL), .delay_us = 2 }
+static const struct reg_sequence nt39016_panel_regs[] = {
+	RV(NT39016_REG_SYSTEM, 0x00),
+	RV(NT39016_REG_TIMING, 0x00),
+	RV(NT39016_REG_OP, 0x03),
+	RV(NT39016_REG_DATA_IN, 0xCC),
+	RV(NT39016_REG_SRC_TIMING_DELAY, 0x46),
+	RV(NT39016_REG_GATE_TIMING_DELAY, 0x05),
+	RV(NT39016_REG_RESERVED, 0x00),
+	RV(NT39016_REG_INITIAL_FUNC, 0x00),
+	RV(NT39016_REG_CONTRAST, 0x08),
+	RV(NT39016_REG_BRIGHTNESS, 0x40),
+	RV(NT39016_REG_HUE_SATURATION, 0x88),
+	RV(NT39016_REG_RB_SUBCONTRAST, 0x88),
+	RV(NT39016_REG_R_SUBBRIGHTNESS, 0x20),
+	RV(NT39016_REG_B_SUBBRIGHTNESS, 0x20),
+	RV(NT39016_REG_VCOMDC, 0x67),
+	RV(NT39016_REG_VCOMAC, 0xA4),
+	RV(NT39016_REG_VGAM2, 0x04),
+	RV(NT39016_REG_VGAM34, 0x24),
+	RV(NT39016_REG_VGAM56, 0x24),
+	RV(NT39016_REG_DISPLAY_MODE, 0x00),
+};
+
+#undef RV
+
+static const struct regmap_range nt39016_regmap_no_ranges[] = {
+	regmap_reg_range(0x13, 0x1D),
+	regmap_reg_range(0x1F, 0x1F),
+};
+
+static const struct regmap_access_table nt39016_regmap_access_table = {
+	.no_ranges = nt39016_regmap_no_ranges,
+	.n_no_ranges = ARRAY_SIZE(nt39016_regmap_no_ranges),
+};
+
+static const struct regmap_config nt39016_regmap_config = {
+	.reg_bits = 6,
+	.pad_bits = 2,
+	.val_bits = 8,
+
+	.max_register = NT39016_REG_DISPLAY_MODE,
+	.wr_table = &nt39016_regmap_access_table,
+	.write_flag_mask = 0x02,
+
+	.cache_type = REGCACHE_FLAT,
+};
+
+static int nt39016_prepare(struct drm_panel *drm_panel)
+{
+	struct nt39016 *panel = to_nt39016(drm_panel);
+	int err;
+
+	err = regulator_enable(panel->supply);
+	if (err) {
+		dev_err(drm_panel->dev, "Failed to enable power supply: %d\n", err);
+		return err;
+	}
+
+	/*
+	 * Reset the NT39016.
+	 * The documentation says the reset pulse should be at least 40 us to
+	 * pass the glitch filter, but when testing I see some resets fail and
+	 * some succeed when using a 70 us delay, so we use 100 us instead.
+	 */
+	gpiod_set_value_cansleep(panel->reset_gpio, 1);
+	usleep_range(100, 1000);
+	gpiod_set_value_cansleep(panel->reset_gpio, 0);
+	udelay(2);
+
+	/* Init all registers. */
+	err = regmap_multi_reg_write(panel->map, nt39016_panel_regs,
+				     ARRAY_SIZE(nt39016_panel_regs));
+	if (err) {
+		dev_err(drm_panel->dev, "Failed to init registers: %d\n", err);
+		goto err_disable_regulator;
+	}
+
+	return 0;
+
+err_disable_regulator:
+	regulator_disable(panel->supply);
+	return err;
+}
+
+static int nt39016_unprepare(struct drm_panel *drm_panel)
+{
+	struct nt39016 *panel = to_nt39016(drm_panel);
+
+	gpiod_set_value_cansleep(panel->reset_gpio, 1);
+
+	regulator_disable(panel->supply);
+
+	return 0;
+}
+
+static int nt39016_enable(struct drm_panel *drm_panel)
+{
+	struct nt39016 *panel = to_nt39016(drm_panel);
+	int ret;
+
+	ret = regmap_write(panel->map, NT39016_REG_SYSTEM,
+			   NT39016_SYSTEM_RESET_N | NT39016_SYSTEM_STANDBY);
+	if (ret) {
+		dev_err(drm_panel->dev, "Unable to enable panel: %d\n", ret);
+		return ret;
+	}
+
+	if (drm_panel->backlight) {
+		/* Wait for the picture to be ready before enabling backlight */
+		msleep(150);
+	}
+
+	return 0;
+}
+
+static int nt39016_disable(struct drm_panel *drm_panel)
+{
+	struct nt39016 *panel = to_nt39016(drm_panel);
+	int err;
+
+	err = regmap_write(panel->map, NT39016_REG_SYSTEM,
+			   NT39016_SYSTEM_RESET_N);
+	if (err) {
+		dev_err(drm_panel->dev, "Unable to disable panel: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int nt39016_get_modes(struct drm_panel *drm_panel,
+			     struct drm_connector *connector)
+{
+	struct nt39016 *panel = to_nt39016(drm_panel);
+	const struct nt39016_panel_info *panel_info = panel->panel_info;
+	struct drm_display_mode *mode;
+	unsigned int i;
+
+	for (i = 0; i < panel_info->num_modes; i++) {
+		mode = drm_mode_duplicate(connector->dev,
+					  &panel_info->display_modes[i]);
+		if (!mode)
+			return -ENOMEM;
+
+		drm_mode_set_name(mode);
+
+		mode->type = DRM_MODE_TYPE_DRIVER;
+		if (panel_info->num_modes == 1)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+		drm_mode_probed_add(connector, mode);
+	}
+
+	connector->display_info.bpc = 8;
+	connector->display_info.width_mm = panel_info->width_mm;
+	connector->display_info.height_mm = panel_info->height_mm;
+
+	drm_display_info_set_bus_formats(&connector->display_info,
+					 &panel_info->bus_format, 1);
+	connector->display_info.bus_flags = panel_info->bus_flags;
+
+	return panel_info->num_modes;
+}
+
+static const struct drm_panel_funcs nt39016_funcs = {
+	.prepare	= nt39016_prepare,
+	.unprepare	= nt39016_unprepare,
+	.enable		= nt39016_enable,
+	.disable	= nt39016_disable,
+	.get_modes	= nt39016_get_modes,
+};
+
+static int nt39016_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct nt39016 *panel;
+	int err;
+
+	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
+	if (!panel)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, panel);
+
+	panel->panel_info = of_device_get_match_data(dev);
+	if (!panel->panel_info)
+		return -EINVAL;
+
+	panel->supply = devm_regulator_get(dev, "power");
+	if (IS_ERR(panel->supply))
+		return dev_err_probe(dev, PTR_ERR(panel->supply),
+				     "Failed to get power supply\n");
+
+	panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(panel->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(panel->reset_gpio), "Failed to get reset GPIO\n");
+
+	spi->bits_per_word = 8;
+	spi->mode = SPI_MODE_3 | SPI_3WIRE;
+	err = spi_setup(spi);
+	if (err) {
+		dev_err(dev, "Failed to setup SPI\n");
+		return err;
+	}
+
+	panel->map = devm_regmap_init_spi(spi, &nt39016_regmap_config);
+	if (IS_ERR(panel->map)) {
+		dev_err(dev, "Failed to init regmap\n");
+		return PTR_ERR(panel->map);
+	}
+
+	drm_panel_init(&panel->drm_panel, dev, &nt39016_funcs,
+		       DRM_MODE_CONNECTOR_DPI);
+
+	err = drm_panel_of_backlight(&panel->drm_panel);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to get backlight handle\n");
+
+	drm_panel_add(&panel->drm_panel);
+
+	return 0;
+}
+
+static void nt39016_remove(struct spi_device *spi)
+{
+	struct nt39016 *panel = spi_get_drvdata(spi);
+
+	drm_panel_remove(&panel->drm_panel);
+
+	nt39016_disable(&panel->drm_panel);
+	nt39016_unprepare(&panel->drm_panel);
+}
+
+static const struct drm_display_mode kd035g6_display_modes[] = {
+	{	/* 60 Hz */
+		.clock = 6000,
+		.hdisplay = 320,
+		.hsync_start = 320 + 10,
+		.hsync_end = 320 + 10 + 50,
+		.htotal = 320 + 10 + 50 + 20,
+		.vdisplay = 240,
+		.vsync_start = 240 + 5,
+		.vsync_end = 240 + 5 + 1,
+		.vtotal = 240 + 5 + 1 + 4,
+		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	},
+	{	/* 50 Hz */
+		.clock = 5400,
+		.hdisplay = 320,
+		.hsync_start = 320 + 42,
+		.hsync_end = 320 + 42 + 50,
+		.htotal = 320 + 42 + 50 + 20,
+		.vdisplay = 240,
+		.vsync_start = 240 + 5,
+		.vsync_end = 240 + 5 + 1,
+		.vtotal = 240 + 5 + 1 + 4,
+		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	},
+};
+
+static const struct nt39016_panel_info kd035g6_info = {
+	.display_modes = kd035g6_display_modes,
+	.num_modes = ARRAY_SIZE(kd035g6_display_modes),
+	.width_mm = 71,
+	.height_mm = 53,
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
+};
+
+static const struct of_device_id nt39016_of_match[] = {
+	{ .compatible = "kingdisplay,kd035g6-54nt", .data = &kd035g6_info },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, nt39016_of_match);
+
+static struct spi_driver nt39016_driver = {
+	.driver = {
+		.name = "nt39016",
+		.of_match_table = nt39016_of_match,
+	},
+	.probe = nt39016_probe,
+	.remove = nt39016_remove,
+};
+
+module_spi_driver(nt39016_driver);
+
+MODULE_AUTHOR("Maarten ter Huurne <maarten@treewalker.org>");
+MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
+MODULE_LICENSE("GPL v2");