drm/panel/panel-lvds.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Generic LVDS panel driver
0004  *
0005  * Copyright (C) 2016 Laurent Pinchart
0006  * Copyright (C) 2016 Renesas Electronics Corporation
0007  *
0008  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
0009  */
0010
0011 #include <linux/gpio/consumer.h>
0012 #include <linux/module.h>
0013 #include <linux/of_platform.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/regulator/consumer.h>
0016 #include <linux/slab.h>
0017
0018 #include <video/display_timing.h>
0019 #include <video/of_display_timing.h>
0020 #include <video/videomode.h>
0021
0022 #include <drm/drm_crtc.h>
0023 #include <drm/drm_of.h>
0024 #include <drm/drm_panel.h>
0025
0026 struct panel_lvds {
0027     struct drm_panel panel;
0028     struct device *dev;
0029
0030     const char *label;
0031     unsigned int width;
0032     unsigned int height;
0033     struct drm_display_mode dmode;
0034     u32 bus_flags;
0035     unsigned int bus_format;
0036
0037     struct regulator *supply;
0038
0039     struct gpio_desc *enable_gpio;
0040     struct gpio_desc *reset_gpio;
0041
0042     enum drm_panel_orientation orientation;
0043 };
0044
0045 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
0046 {
0047     return container_of(panel, struct panel_lvds, panel);
0048 }
0049
0050 static int panel_lvds_unprepare(struct drm_panel *panel)
0051 {
0052     struct panel_lvds *lvds = to_panel_lvds(panel);
0053
0054     if (lvds->enable_gpio)
0055         gpiod_set_value_cansleep(lvds->enable_gpio, 0);
0056
0057     if (lvds->supply)
0058         regulator_disable(lvds->supply);
0059
0060     return 0;
0061 }
0062
0063 static int panel_lvds_prepare(struct drm_panel *panel)
0064 {
0065     struct panel_lvds *lvds = to_panel_lvds(panel);
0066
0067     if (lvds->supply) {
0068         int err;
0069
0070         err = regulator_enable(lvds->supply);
0071         if (err < 0) {
0072             dev_err(lvds->dev, "failed to enable supply: %d\n",
0073                 err);
0074             return err;
0075         }
0076     }
0077
0078     if (lvds->enable_gpio)
0079         gpiod_set_value_cansleep(lvds->enable_gpio, 1);
0080
0081     return 0;
0082 }
0083
0084 static int panel_lvds_get_modes(struct drm_panel *panel,
0085                 struct drm_connector *connector)
0086 {
0087     struct panel_lvds *lvds = to_panel_lvds(panel);
0088     struct drm_display_mode *mode;
0089
0090     mode = drm_mode_duplicate(connector->dev, &lvds->dmode);
0091     if (!mode)
0092         return 0;
0093
0094     mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
0095     drm_mode_probed_add(connector, mode);
0096
0097     connector->display_info.width_mm = lvds->dmode.width_mm;
0098     connector->display_info.height_mm = lvds->dmode.height_mm;
0099     drm_display_info_set_bus_formats(&connector->display_info,
0100                      &lvds->bus_format, 1);
0101     connector->display_info.bus_flags = lvds->bus_flags;
0102
0103     /*
0104      * TODO: Remove once all drm drivers call
0105      * drm_connector_set_orientation_from_panel()
0106      */
0107     drm_connector_set_panel_orientation(connector, lvds->orientation);
0108
0109     return 1;
0110 }
0111
0112 static enum drm_panel_orientation panel_lvds_get_orientation(struct drm_panel *panel)
0113 {
0114     struct panel_lvds *lvds = to_panel_lvds(panel);
0115
0116     return lvds->orientation;
0117 }
0118
0119 static const struct drm_panel_funcs panel_lvds_funcs = {
0120     .unprepare = panel_lvds_unprepare,
0121     .prepare = panel_lvds_prepare,
0122     .get_modes = panel_lvds_get_modes,
0123     .get_orientation = panel_lvds_get_orientation,
0124 };
0125
0126 static int panel_lvds_parse_dt(struct panel_lvds *lvds)
0127 {
0128     struct device_node *np = lvds->dev->of_node;
0129     int ret;
0130
0131     ret = of_drm_get_panel_orientation(np, &lvds->orientation);
0132     if (ret < 0) {
0133         dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
0134         return ret;
0135     }
0136
0137     ret = of_get_drm_panel_display_mode(np, &lvds->dmode, &lvds->bus_flags);
0138     if (ret < 0) {
0139         dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
0140             np, ret);
0141         return ret;
0142     }
0143
0144     of_property_read_string(np, "label", &lvds->label);
0145
0146     ret = drm_of_lvds_get_data_mapping(np);
0147     if (ret < 0) {
0148         dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
0149             np, "data-mapping");
0150         return ret;
0151     }
0152
0153     lvds->bus_format = ret;
0154
0155     lvds->bus_flags |= of_property_read_bool(np, "data-mirror") ?
0156                DRM_BUS_FLAG_DATA_LSB_TO_MSB :
0157                DRM_BUS_FLAG_DATA_MSB_TO_LSB;
0158
0159     return 0;
0160 }
0161
0162 static int panel_lvds_probe(struct platform_device *pdev)
0163 {
0164     struct panel_lvds *lvds;
0165     int ret;
0166
0167     lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
0168     if (!lvds)
0169         return -ENOMEM;
0170
0171     lvds->dev = &pdev->dev;
0172
0173     ret = panel_lvds_parse_dt(lvds);
0174     if (ret < 0)
0175         return ret;
0176
0177     lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
0178     if (IS_ERR(lvds->supply)) {
0179         ret = PTR_ERR(lvds->supply);
0180
0181         if (ret != -ENODEV) {
0182             if (ret != -EPROBE_DEFER)
0183                 dev_err(lvds->dev, "failed to request regulator: %d\n",
0184                     ret);
0185             return ret;
0186         }
0187
0188         lvds->supply = NULL;
0189     }
0190
0191     /* Get GPIOs and backlight controller. */
0192     lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
0193                              GPIOD_OUT_LOW);
0194     if (IS_ERR(lvds->enable_gpio)) {
0195         ret = PTR_ERR(lvds->enable_gpio);
0196         dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
0197             "enable", ret);
0198         return ret;
0199     }
0200
0201     lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
0202                              GPIOD_OUT_HIGH);
0203     if (IS_ERR(lvds->reset_gpio)) {
0204         ret = PTR_ERR(lvds->reset_gpio);
0205         dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
0206             "reset", ret);
0207         return ret;
0208     }
0209
0210     /*
0211      * TODO: Handle all power supplies specified in the DT node in a generic
0212      * way for panels that don't care about power supply ordering. LVDS
0213      * panels that require a specific power sequence will need a dedicated
0214      * driver.
0215      */
0216
0217     /* Register the panel. */
0218     drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
0219                DRM_MODE_CONNECTOR_LVDS);
0220
0221     ret = drm_panel_of_backlight(&lvds->panel);
0222     if (ret)
0223         return ret;
0224
0225     drm_panel_add(&lvds->panel);
0226
0227     dev_set_drvdata(lvds->dev, lvds);
0228     return 0;
0229 }
0230
0231 static int panel_lvds_remove(struct platform_device *pdev)
0232 {
0233     struct panel_lvds *lvds = platform_get_drvdata(pdev);
0234
0235     drm_panel_remove(&lvds->panel);
0236
0237     drm_panel_disable(&lvds->panel);
0238
0239     return 0;
0240 }
0241
0242 static const struct of_device_id panel_lvds_of_table[] = {
0243     { .compatible = "panel-lvds", },
0244     { /* Sentinel */ },
0245 };
0246
0247 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
0248
0249 static struct platform_driver panel_lvds_driver = {
0250     .probe      = panel_lvds_probe,
0251     .remove     = panel_lvds_remove,
0252     .driver     = {
0253         .name   = "panel-lvds",
0254         .of_match_table = panel_lvds_of_table,
0255     },
0256 };
0257
0258 module_platform_driver(panel_lvds_driver);
0259
0260 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
0261 MODULE_DESCRIPTION("LVDS Panel Driver");
0262 MODULE_LICENSE("GPL");