From aecb583cb997935fb4f4a667a8013469528a8d53 Mon Sep 17 00:00:00 2001 From: Konrad Dybcio Date: Mon, 17 Apr 2023 16:39:04 +0200 Subject: [PATCH] drm/panel: nt36523: Add DCS backlight support This chip supports controlling the backlight via DCS commands, on at least some panels. Add support for doing so. Note this may only concern the NT36523*W* variant. Nobody knows, really, there's no docs. Reviewed-by: Linus Walleij Reviewed-by: Jianhua Lu Signed-off-by: Konrad Dybcio Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20230412-topic-lenovopanel-v3-2-bcf9ba4de46f@linaro.org --- drivers/gpu/drm/panel/panel-novatek-nt36523.c | 68 +++++++++++++++++++++++++-- 1 file changed, 65 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-novatek-nt36523.c b/drivers/gpu/drm/panel/panel-novatek-nt36523.c index d30dbbf..b0466ab 100644 --- a/drivers/gpu/drm/panel/panel-novatek-nt36523.c +++ b/drivers/gpu/drm/panel/panel-novatek-nt36523.c @@ -5,6 +5,7 @@ * Copyright (c) 2022, 2023 Jianhua Lu */ +#include #include #include #include @@ -53,6 +54,7 @@ struct panel_desc { int (*init_sequence)(struct panel_info *pinfo); bool is_dual_dsi; + bool has_dcs_backlight; }; static inline struct panel_info *to_panel_info(struct drm_panel *panel) @@ -679,6 +681,59 @@ static const struct drm_panel_funcs nt36523_panel_funcs = { .get_modes = nt36523_get_modes, }; +static int nt36523_bl_update_status(struct backlight_device *bl) +{ + struct mipi_dsi_device *dsi = bl_get_data(bl); + u16 brightness = backlight_get_brightness(bl); + int ret; + + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM; + + ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness); + if (ret < 0) + return ret; + + dsi->mode_flags |= MIPI_DSI_MODE_LPM; + + return 0; +} + +static int nt36523_bl_get_brightness(struct backlight_device *bl) +{ + struct mipi_dsi_device *dsi = bl_get_data(bl); + u16 brightness; + int ret; + + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM; + + ret = mipi_dsi_dcs_get_display_brightness_large(dsi, &brightness); + if (ret < 0) + return ret; + + dsi->mode_flags |= MIPI_DSI_MODE_LPM; + + return brightness; +} + +static const struct backlight_ops nt36523_bl_ops = { + .update_status = nt36523_bl_update_status, + .get_brightness = nt36523_bl_get_brightness, +}; + +static struct backlight_device *nt36523_create_backlight(struct mipi_dsi_device *dsi) +{ + struct device *dev = &dsi->dev; + const struct backlight_properties props = { + .type = BACKLIGHT_RAW, + .brightness = 512, + .max_brightness = 4095, + .scale = BACKLIGHT_SCALE_NON_LINEAR, + }; + + return devm_backlight_device_register(dev, dev_name(dev), dev, dsi, + &nt36523_bl_ops, &props); +} + static int nt36523_probe(struct mipi_dsi_device *dsi) { struct device *dev = &dsi->dev; @@ -730,9 +785,16 @@ static int nt36523_probe(struct mipi_dsi_device *dsi) mipi_dsi_set_drvdata(dsi, pinfo); drm_panel_init(&pinfo->panel, dev, &nt36523_panel_funcs, DRM_MODE_CONNECTOR_DSI); - ret = drm_panel_of_backlight(&pinfo->panel); - if (ret) - return dev_err_probe(dev, ret, "failed to get backlight\n"); + if (pinfo->desc->has_dcs_backlight) { + pinfo->panel.backlight = nt36523_create_backlight(dsi); + if (IS_ERR(pinfo->panel.backlight)) + return dev_err_probe(dev, PTR_ERR(pinfo->panel.backlight), + "Failed to create backlight\n"); + } else { + ret = drm_panel_of_backlight(&pinfo->panel); + if (ret) + return dev_err_probe(dev, ret, "Failed to get backlight\n"); + } drm_panel_add(&pinfo->panel); -- 2.7.4