1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2019 Renesas Electronics Corporation 4 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com> 5 */ 6 7 #include <linux/gpio/consumer.h> 8 #include <linux/module.h> 9 #include <linux/of.h> 10 #include <linux/of_device.h> 11 #include <linux/of_graph.h> 12 #include <linux/platform_device.h> 13 14 #include <drm/drm_bridge.h> 15 #include <drm/drm_panel.h> 16 17 struct lvds_codec { 18 struct drm_bridge bridge; 19 struct drm_bridge *panel_bridge; 20 struct gpio_desc *powerdown_gpio; 21 u32 connector_type; 22 }; 23 24 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge) 25 { 26 return container_of(bridge, struct lvds_codec, bridge); 27 } 28 29 static int lvds_codec_attach(struct drm_bridge *bridge, 30 enum drm_bridge_attach_flags flags) 31 { 32 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 33 34 return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge, 35 bridge, flags); 36 } 37 38 static void lvds_codec_enable(struct drm_bridge *bridge) 39 { 40 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 41 42 if (lvds_codec->powerdown_gpio) 43 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0); 44 } 45 46 static void lvds_codec_disable(struct drm_bridge *bridge) 47 { 48 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 49 50 if (lvds_codec->powerdown_gpio) 51 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1); 52 } 53 54 static const struct drm_bridge_funcs funcs = { 55 .attach = lvds_codec_attach, 56 .enable = lvds_codec_enable, 57 .disable = lvds_codec_disable, 58 }; 59 60 static int lvds_codec_probe(struct platform_device *pdev) 61 { 62 struct device *dev = &pdev->dev; 63 struct device_node *panel_node; 64 struct drm_panel *panel; 65 struct lvds_codec *lvds_codec; 66 67 lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL); 68 if (!lvds_codec) 69 return -ENOMEM; 70 71 lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev); 72 lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown", 73 GPIOD_OUT_HIGH); 74 if (IS_ERR(lvds_codec->powerdown_gpio)) { 75 int err = PTR_ERR(lvds_codec->powerdown_gpio); 76 77 if (err != -EPROBE_DEFER) 78 dev_err(dev, "powerdown GPIO failure: %d\n", err); 79 return err; 80 } 81 82 /* Locate the panel DT node. */ 83 panel_node = of_graph_get_remote_node(dev->of_node, 1, 0); 84 if (!panel_node) { 85 dev_dbg(dev, "panel DT node not found\n"); 86 return -ENXIO; 87 } 88 89 panel = of_drm_find_panel(panel_node); 90 of_node_put(panel_node); 91 if (IS_ERR(panel)) { 92 dev_dbg(dev, "panel not found, deferring probe\n"); 93 return PTR_ERR(panel); 94 } 95 96 lvds_codec->panel_bridge = 97 devm_drm_panel_bridge_add_typed(dev, panel, 98 lvds_codec->connector_type); 99 if (IS_ERR(lvds_codec->panel_bridge)) 100 return PTR_ERR(lvds_codec->panel_bridge); 101 102 /* 103 * The panel_bridge bridge is attached to the panel's of_node, 104 * but we need a bridge attached to our of_node for our user 105 * to look up. 106 */ 107 lvds_codec->bridge.of_node = dev->of_node; 108 lvds_codec->bridge.funcs = &funcs; 109 drm_bridge_add(&lvds_codec->bridge); 110 111 platform_set_drvdata(pdev, lvds_codec); 112 113 return 0; 114 } 115 116 static int lvds_codec_remove(struct platform_device *pdev) 117 { 118 struct lvds_codec *lvds_codec = platform_get_drvdata(pdev); 119 120 drm_bridge_remove(&lvds_codec->bridge); 121 122 return 0; 123 } 124 125 static const struct of_device_id lvds_codec_match[] = { 126 { 127 .compatible = "lvds-decoder", 128 .data = (void *)DRM_MODE_CONNECTOR_DPI, 129 }, 130 { 131 .compatible = "lvds-encoder", 132 .data = (void *)DRM_MODE_CONNECTOR_LVDS, 133 }, 134 { 135 .compatible = "thine,thc63lvdm83d", 136 .data = (void *)DRM_MODE_CONNECTOR_LVDS, 137 }, 138 {}, 139 }; 140 MODULE_DEVICE_TABLE(of, lvds_codec_match); 141 142 static struct platform_driver lvds_codec_driver = { 143 .probe = lvds_codec_probe, 144 .remove = lvds_codec_remove, 145 .driver = { 146 .name = "lvds-codec", 147 .of_match_table = lvds_codec_match, 148 }, 149 }; 150 module_platform_driver(lvds_codec_driver); 151 152 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 153 MODULE_DESCRIPTION("LVDS encoders and decoders"); 154 MODULE_LICENSE("GPL"); 155