1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Generic LVDS panel driver 4 * 5 * Copyright (C) 2016 Laurent Pinchart 6 * Copyright (C) 2016 Renesas Electronics Corporation 7 * 8 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com) 9 */ 10 11 #include <linux/gpio/consumer.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 #include <linux/regulator/consumer.h> 16 #include <linux/slab.h> 17 18 #include <video/display_timing.h> 19 #include <video/of_display_timing.h> 20 #include <video/videomode.h> 21 22 #include <drm/drm_crtc.h> 23 #include <drm/drm_of.h> 24 #include <drm/drm_panel.h> 25 26 struct panel_lvds { 27 struct drm_panel panel; 28 struct device *dev; 29 30 const char *label; 31 unsigned int width; 32 unsigned int height; 33 struct drm_display_mode dmode; 34 u32 bus_flags; 35 unsigned int bus_format; 36 37 struct regulator *supply; 38 39 struct gpio_desc *enable_gpio; 40 struct gpio_desc *reset_gpio; 41 42 enum drm_panel_orientation orientation; 43 }; 44 45 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel) 46 { 47 return container_of(panel, struct panel_lvds, panel); 48 } 49 50 static int panel_lvds_unprepare(struct drm_panel *panel) 51 { 52 struct panel_lvds *lvds = to_panel_lvds(panel); 53 54 if (lvds->enable_gpio) 55 gpiod_set_value_cansleep(lvds->enable_gpio, 0); 56 57 if (lvds->supply) 58 regulator_disable(lvds->supply); 59 60 return 0; 61 } 62 63 static int panel_lvds_prepare(struct drm_panel *panel) 64 { 65 struct panel_lvds *lvds = to_panel_lvds(panel); 66 67 if (lvds->supply) { 68 int err; 69 70 err = regulator_enable(lvds->supply); 71 if (err < 0) { 72 dev_err(lvds->dev, "failed to enable supply: %d\n", 73 err); 74 return err; 75 } 76 } 77 78 if (lvds->enable_gpio) 79 gpiod_set_value_cansleep(lvds->enable_gpio, 1); 80 81 return 0; 82 } 83 84 static int panel_lvds_get_modes(struct drm_panel *panel, 85 struct drm_connector *connector) 86 { 87 struct panel_lvds *lvds = to_panel_lvds(panel); 88 struct drm_display_mode *mode; 89 90 mode = drm_mode_duplicate(connector->dev, &lvds->dmode); 91 if (!mode) 92 return 0; 93 94 mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED; 95 drm_mode_probed_add(connector, mode); 96 97 connector->display_info.width_mm = lvds->dmode.width_mm; 98 connector->display_info.height_mm = lvds->dmode.height_mm; 99 drm_display_info_set_bus_formats(&connector->display_info, 100 &lvds->bus_format, 1); 101 connector->display_info.bus_flags = lvds->bus_flags; 102 103 /* 104 * TODO: Remove once all drm drivers call 105 * drm_connector_set_orientation_from_panel() 106 */ 107 drm_connector_set_panel_orientation(connector, lvds->orientation); 108 109 return 1; 110 } 111 112 static enum drm_panel_orientation panel_lvds_get_orientation(struct drm_panel *panel) 113 { 114 struct panel_lvds *lvds = to_panel_lvds(panel); 115 116 return lvds->orientation; 117 } 118 119 static const struct drm_panel_funcs panel_lvds_funcs = { 120 .unprepare = panel_lvds_unprepare, 121 .prepare = panel_lvds_prepare, 122 .get_modes = panel_lvds_get_modes, 123 .get_orientation = panel_lvds_get_orientation, 124 }; 125 126 static int panel_lvds_parse_dt(struct panel_lvds *lvds) 127 { 128 struct device_node *np = lvds->dev->of_node; 129 int ret; 130 131 ret = of_drm_get_panel_orientation(np, &lvds->orientation); 132 if (ret < 0) { 133 dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret); 134 return ret; 135 } 136 137 ret = of_get_drm_panel_display_mode(np, &lvds->dmode, &lvds->bus_flags); 138 if (ret < 0) { 139 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n", 140 np, ret); 141 return ret; 142 } 143 144 of_property_read_string(np, "label", &lvds->label); 145 146 ret = drm_of_lvds_get_data_mapping(np); 147 if (ret < 0) { 148 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n", 149 np, "data-mapping"); 150 return ret; 151 } 152 153 lvds->bus_format = ret; 154 155 lvds->bus_flags |= of_property_read_bool(np, "data-mirror") ? 156 DRM_BUS_FLAG_DATA_LSB_TO_MSB : 157 DRM_BUS_FLAG_DATA_MSB_TO_LSB; 158 159 return 0; 160 } 161 162 static int panel_lvds_probe(struct platform_device *pdev) 163 { 164 struct panel_lvds *lvds; 165 int ret; 166 167 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); 168 if (!lvds) 169 return -ENOMEM; 170 171 lvds->dev = &pdev->dev; 172 173 ret = panel_lvds_parse_dt(lvds); 174 if (ret < 0) 175 return ret; 176 177 lvds->supply = devm_regulator_get_optional(lvds->dev, "power"); 178 if (IS_ERR(lvds->supply)) { 179 ret = PTR_ERR(lvds->supply); 180 181 if (ret != -ENODEV) { 182 if (ret != -EPROBE_DEFER) 183 dev_err(lvds->dev, "failed to request regulator: %d\n", 184 ret); 185 return ret; 186 } 187 188 lvds->supply = NULL; 189 } 190 191 /* Get GPIOs and backlight controller. */ 192 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable", 193 GPIOD_OUT_LOW); 194 if (IS_ERR(lvds->enable_gpio)) { 195 ret = PTR_ERR(lvds->enable_gpio); 196 dev_err(lvds->dev, "failed to request %s GPIO: %d\n", 197 "enable", ret); 198 return ret; 199 } 200 201 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset", 202 GPIOD_OUT_HIGH); 203 if (IS_ERR(lvds->reset_gpio)) { 204 ret = PTR_ERR(lvds->reset_gpio); 205 dev_err(lvds->dev, "failed to request %s GPIO: %d\n", 206 "reset", ret); 207 return ret; 208 } 209 210 /* 211 * TODO: Handle all power supplies specified in the DT node in a generic 212 * way for panels that don't care about power supply ordering. LVDS 213 * panels that require a specific power sequence will need a dedicated 214 * driver. 215 */ 216 217 /* Register the panel. */ 218 drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs, 219 DRM_MODE_CONNECTOR_LVDS); 220 221 ret = drm_panel_of_backlight(&lvds->panel); 222 if (ret) 223 return ret; 224 225 drm_panel_add(&lvds->panel); 226 227 dev_set_drvdata(lvds->dev, lvds); 228 return 0; 229 } 230 231 static void panel_lvds_remove(struct platform_device *pdev) 232 { 233 struct panel_lvds *lvds = platform_get_drvdata(pdev); 234 235 drm_panel_remove(&lvds->panel); 236 237 drm_panel_disable(&lvds->panel); 238 } 239 240 static const struct of_device_id panel_lvds_of_table[] = { 241 { .compatible = "panel-lvds", }, 242 { /* Sentinel */ }, 243 }; 244 245 MODULE_DEVICE_TABLE(of, panel_lvds_of_table); 246 247 static struct platform_driver panel_lvds_driver = { 248 .probe = panel_lvds_probe, 249 .remove_new = panel_lvds_remove, 250 .driver = { 251 .name = "panel-lvds", 252 .of_match_table = panel_lvds_of_table, 253 }, 254 }; 255 256 module_platform_driver(panel_lvds_driver); 257 258 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 259 MODULE_DESCRIPTION("LVDS Panel Driver"); 260 MODULE_LICENSE("GPL"); 261