| // 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/backlight.h> |
| #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 { |
| struct drm_display_mode display_mode; |
| u16 width_mm, height_mm; |
| u32 bus_format, bus_flags; |
| }; |
| |
| struct nt39016 { |
| struct drm_panel drm_panel; |
| struct device *dev; |
| struct regmap *map; |
| struct regulator *supply; |
| const struct nt39016_panel_info *panel_info; |
| |
| struct gpio_desc *reset_gpio; |
| |
| struct backlight_device *backlight; |
| }; |
| |
| 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(panel->dev, "Failed to enable power supply: %d", 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(panel->dev, "Failed to init registers: %d", 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(panel->dev, "Unable to enable panel: %d", ret); |
| return ret; |
| } |
| |
| if (panel->backlight) { |
| /* Wait for the picture to be ready before enabling backlight */ |
| msleep(150); |
| |
| ret = backlight_enable(panel->backlight); |
| } |
| |
| return ret; |
| } |
| |
| static int nt39016_disable(struct drm_panel *drm_panel) |
| { |
| struct nt39016 *panel = to_nt39016(drm_panel); |
| int err; |
| |
| backlight_disable(panel->backlight); |
| |
| err = regmap_write(panel->map, NT39016_REG_SYSTEM, |
| NT39016_SYSTEM_RESET_N); |
| if (err) { |
| dev_err(panel->dev, "Unable to disable panel: %d", err); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static int nt39016_get_modes(struct drm_panel *drm_panel) |
| { |
| struct nt39016 *panel = to_nt39016(drm_panel); |
| const struct nt39016_panel_info *panel_info = panel->panel_info; |
| struct drm_connector *connector = drm_panel->connector; |
| struct drm_display_mode *mode; |
| |
| mode = drm_mode_duplicate(drm_panel->drm, &panel_info->display_mode); |
| if (!mode) |
| return -ENOMEM; |
| |
| drm_mode_set_name(mode); |
| |
| mode->type = DRM_MODE_TYPE_DRIVER | 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 1; |
| } |
| |
| 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; |
| |
| panel->dev = dev; |
| 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)) { |
| dev_err(dev, "Failed to get power supply"); |
| return PTR_ERR(panel->supply); |
| } |
| |
| panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); |
| if (IS_ERR(panel->reset_gpio)) { |
| dev_err(dev, "Failed to get reset GPIO"); |
| return PTR_ERR(panel->reset_gpio); |
| } |
| |
| 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"); |
| return err; |
| } |
| |
| panel->map = devm_regmap_init_spi(spi, &nt39016_regmap_config); |
| if (IS_ERR(panel->map)) { |
| dev_err(dev, "Failed to init regmap"); |
| return PTR_ERR(panel->map); |
| } |
| |
| panel->backlight = devm_of_find_backlight(dev); |
| if (IS_ERR(panel->backlight)) { |
| err = PTR_ERR(panel->backlight); |
| if (err != -EPROBE_DEFER) |
| dev_err(dev, "Failed to get backlight handle"); |
| return err; |
| } |
| |
| drm_panel_init(&panel->drm_panel); |
| panel->drm_panel.dev = dev; |
| panel->drm_panel.funcs = &nt39016_funcs; |
| |
| err = drm_panel_add(&panel->drm_panel); |
| if (err < 0) { |
| dev_err(dev, "Failed to register panel"); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static int 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); |
| |
| return 0; |
| } |
| |
| static const struct nt39016_panel_info kd035g6_info = { |
| .display_mode = { |
| .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, |
| .vrefresh = 60, |
| .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, |
| }, |
| .width_mm = 71, |
| .height_mm = 53, |
| .bus_format = MEDIA_BUS_FMT_RGB888_1X24, |
| .bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE, |
| }; |
| |
| 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"); |