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_platform.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 drm_connector_set_panel_orientation(connector, lvds->orientation); 103 104 return 1; 105 } 106 107 static const struct drm_panel_funcs panel_lvds_funcs = { 108 .unprepare = panel_lvds_unprepare, 109 .prepare = panel_lvds_prepare, 110 .get_modes = panel_lvds_get_modes, 111 }; 112 113 static int panel_lvds_parse_dt(struct panel_lvds *lvds) 114 { 115 struct device_node *np = lvds->dev->of_node; 116 int ret; 117 118 ret = of_drm_get_panel_orientation(np, &lvds->orientation); 119 if (ret < 0) { 120 dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret); 121 return ret; 122 } 123 124 ret = of_get_drm_panel_display_mode(np, &lvds->dmode, &lvds->bus_flags); 125 if (ret < 0) { 126 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n", 127 np, ret); 128 return ret; 129 } 130 131 of_property_read_string(np, "label", &lvds->label); 132 133 ret = drm_of_lvds_get_data_mapping(np); 134 if (ret < 0) { 135 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n", 136 np, "data-mapping"); 137 return ret; 138 } 139 140 lvds->bus_format = ret; 141 142 lvds->bus_flags |= of_property_read_bool(np, "data-mirror") ? 143 DRM_BUS_FLAG_DATA_LSB_TO_MSB : 144 DRM_BUS_FLAG_DATA_MSB_TO_LSB; 145 146 return 0; 147 } 148 149 static int panel_lvds_probe(struct platform_device *pdev) 150 { 151 struct panel_lvds *lvds; 152 int ret; 153 154 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); 155 if (!lvds) 156 return -ENOMEM; 157 158 lvds->dev = &pdev->dev; 159 160 ret = panel_lvds_parse_dt(lvds); 161 if (ret < 0) 162 return ret; 163 164 lvds->supply = devm_regulator_get_optional(lvds->dev, "power"); 165 if (IS_ERR(lvds->supply)) { 166 ret = PTR_ERR(lvds->supply); 167 168 if (ret != -ENODEV) { 169 if (ret != -EPROBE_DEFER) 170 dev_err(lvds->dev, "failed to request regulator: %d\n", 171 ret); 172 return ret; 173 } 174 175 lvds->supply = NULL; 176 } 177 178 /* Get GPIOs and backlight controller. */ 179 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable", 180 GPIOD_OUT_LOW); 181 if (IS_ERR(lvds->enable_gpio)) { 182 ret = PTR_ERR(lvds->enable_gpio); 183 dev_err(lvds->dev, "failed to request %s GPIO: %d\n", 184 "enable", ret); 185 return ret; 186 } 187 188 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset", 189 GPIOD_OUT_HIGH); 190 if (IS_ERR(lvds->reset_gpio)) { 191 ret = PTR_ERR(lvds->reset_gpio); 192 dev_err(lvds->dev, "failed to request %s GPIO: %d\n", 193 "reset", ret); 194 return ret; 195 } 196 197 /* 198 * TODO: Handle all power supplies specified in the DT node in a generic 199 * way for panels that don't care about power supply ordering. LVDS 200 * panels that require a specific power sequence will need a dedicated 201 * driver. 202 */ 203 204 /* Register the panel. */ 205 drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs, 206 DRM_MODE_CONNECTOR_LVDS); 207 208 ret = drm_panel_of_backlight(&lvds->panel); 209 if (ret) 210 return ret; 211 212 drm_panel_add(&lvds->panel); 213 214 dev_set_drvdata(lvds->dev, lvds); 215 return 0; 216 } 217 218 static int panel_lvds_remove(struct platform_device *pdev) 219 { 220 struct panel_lvds *lvds = platform_get_drvdata(pdev); 221 222 drm_panel_remove(&lvds->panel); 223 224 drm_panel_disable(&lvds->panel); 225 226 return 0; 227 } 228 229 static const struct of_device_id panel_lvds_of_table[] = { 230 { .compatible = "panel-lvds", }, 231 { /* Sentinel */ }, 232 }; 233 234 MODULE_DEVICE_TABLE(of, panel_lvds_of_table); 235 236 static struct platform_driver panel_lvds_driver = { 237 .probe = panel_lvds_probe, 238 .remove = panel_lvds_remove, 239 .driver = { 240 .name = "panel-lvds", 241 .of_match_table = panel_lvds_of_table, 242 }, 243 }; 244 245 module_platform_driver(panel_lvds_driver); 246 247 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 248 MODULE_DESCRIPTION("LVDS Panel Driver"); 249 MODULE_LICENSE("GPL"); 250