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 #include <linux/regulator/consumer.h> 14 15 #include <drm/drm_atomic_helper.h> 16 #include <drm/drm_bridge.h> 17 #include <drm/drm_of.h> 18 #include <drm/drm_panel.h> 19 20 struct lvds_codec { 21 struct device *dev; 22 struct drm_bridge bridge; 23 struct drm_bridge *panel_bridge; 24 struct drm_bridge_timings timings; 25 struct regulator *vcc; 26 struct gpio_desc *powerdown_gpio; 27 u32 connector_type; 28 unsigned int bus_format; 29 }; 30 31 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge) 32 { 33 return container_of(bridge, struct lvds_codec, bridge); 34 } 35 36 static int lvds_codec_attach(struct drm_bridge *bridge, 37 enum drm_bridge_attach_flags flags) 38 { 39 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 40 41 return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge, 42 bridge, flags); 43 } 44 45 static void lvds_codec_enable(struct drm_bridge *bridge) 46 { 47 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 48 int ret; 49 50 ret = regulator_enable(lvds_codec->vcc); 51 if (ret) { 52 dev_err(lvds_codec->dev, 53 "Failed to enable regulator \"vcc\": %d\n", ret); 54 return; 55 } 56 57 if (lvds_codec->powerdown_gpio) 58 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0); 59 } 60 61 static void lvds_codec_disable(struct drm_bridge *bridge) 62 { 63 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 64 int ret; 65 66 if (lvds_codec->powerdown_gpio) 67 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1); 68 69 ret = regulator_disable(lvds_codec->vcc); 70 if (ret) 71 dev_err(lvds_codec->dev, 72 "Failed to disable regulator \"vcc\": %d\n", ret); 73 } 74 75 static const struct drm_bridge_funcs funcs = { 76 .attach = lvds_codec_attach, 77 .enable = lvds_codec_enable, 78 .disable = lvds_codec_disable, 79 }; 80 81 #define MAX_INPUT_SEL_FORMATS 1 82 static u32 * 83 lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge, 84 struct drm_bridge_state *bridge_state, 85 struct drm_crtc_state *crtc_state, 86 struct drm_connector_state *conn_state, 87 u32 output_fmt, 88 unsigned int *num_input_fmts) 89 { 90 struct lvds_codec *lvds_codec = to_lvds_codec(bridge); 91 u32 *input_fmts; 92 93 *num_input_fmts = 0; 94 95 input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts), 96 GFP_KERNEL); 97 if (!input_fmts) 98 return NULL; 99 100 input_fmts[0] = lvds_codec->bus_format; 101 *num_input_fmts = MAX_INPUT_SEL_FORMATS; 102 103 return input_fmts; 104 } 105 106 static const struct drm_bridge_funcs funcs_decoder = { 107 .attach = lvds_codec_attach, 108 .enable = lvds_codec_enable, 109 .disable = lvds_codec_disable, 110 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, 111 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, 112 .atomic_reset = drm_atomic_helper_bridge_reset, 113 .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts, 114 }; 115 116 static int lvds_codec_probe(struct platform_device *pdev) 117 { 118 struct device *dev = &pdev->dev; 119 struct device_node *panel_node; 120 struct device_node *bus_node; 121 struct drm_panel *panel; 122 struct lvds_codec *lvds_codec; 123 u32 val; 124 int ret; 125 126 lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL); 127 if (!lvds_codec) 128 return -ENOMEM; 129 130 lvds_codec->dev = &pdev->dev; 131 lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev); 132 133 lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power"); 134 if (IS_ERR(lvds_codec->vcc)) 135 return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc), 136 "Unable to get \"vcc\" supply\n"); 137 138 lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown", 139 GPIOD_OUT_HIGH); 140 if (IS_ERR(lvds_codec->powerdown_gpio)) 141 return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio), 142 "powerdown GPIO failure\n"); 143 144 /* Locate the panel DT node. */ 145 panel_node = of_graph_get_remote_node(dev->of_node, 1, 0); 146 if (!panel_node) { 147 dev_dbg(dev, "panel DT node not found\n"); 148 return -ENXIO; 149 } 150 151 panel = of_drm_find_panel(panel_node); 152 of_node_put(panel_node); 153 if (IS_ERR(panel)) { 154 dev_dbg(dev, "panel not found, deferring probe\n"); 155 return PTR_ERR(panel); 156 } 157 158 lvds_codec->panel_bridge = 159 devm_drm_panel_bridge_add_typed(dev, panel, 160 lvds_codec->connector_type); 161 if (IS_ERR(lvds_codec->panel_bridge)) 162 return PTR_ERR(lvds_codec->panel_bridge); 163 164 lvds_codec->bridge.funcs = &funcs; 165 166 /* 167 * Decoder input LVDS format is a property of the decoder chip or even 168 * its strapping. Handle data-mapping the same way lvds-panel does. In 169 * case data-mapping is not present, do nothing, since there are still 170 * legacy bindings which do not specify this property. 171 */ 172 if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) { 173 bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); 174 if (!bus_node) { 175 dev_dbg(dev, "bus DT node not found\n"); 176 return -ENXIO; 177 } 178 179 ret = drm_of_lvds_get_data_mapping(bus_node); 180 of_node_put(bus_node); 181 if (ret == -ENODEV) { 182 dev_warn(dev, "missing 'data-mapping' DT property\n"); 183 } else if (ret) { 184 dev_err(dev, "invalid 'data-mapping' DT property\n"); 185 return ret; 186 } else { 187 lvds_codec->bus_format = ret; 188 lvds_codec->bridge.funcs = &funcs_decoder; 189 } 190 } 191 192 /* 193 * Encoder might sample data on different clock edge than the display, 194 * for example OnSemi FIN3385 has a dedicated strapping pin to select 195 * the sampling edge. 196 */ 197 if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS && 198 !of_property_read_u32(dev->of_node, "pclk-sample", &val)) { 199 lvds_codec->timings.input_bus_flags = val ? 200 DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE : 201 DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE; 202 } 203 204 /* 205 * The panel_bridge bridge is attached to the panel's of_node, 206 * but we need a bridge attached to our of_node for our user 207 * to look up. 208 */ 209 lvds_codec->bridge.of_node = dev->of_node; 210 lvds_codec->bridge.timings = &lvds_codec->timings; 211 drm_bridge_add(&lvds_codec->bridge); 212 213 platform_set_drvdata(pdev, lvds_codec); 214 215 return 0; 216 } 217 218 static int lvds_codec_remove(struct platform_device *pdev) 219 { 220 struct lvds_codec *lvds_codec = platform_get_drvdata(pdev); 221 222 drm_bridge_remove(&lvds_codec->bridge); 223 224 return 0; 225 } 226 227 static const struct of_device_id lvds_codec_match[] = { 228 { 229 .compatible = "lvds-decoder", 230 .data = (void *)DRM_MODE_CONNECTOR_DPI, 231 }, 232 { 233 .compatible = "lvds-encoder", 234 .data = (void *)DRM_MODE_CONNECTOR_LVDS, 235 }, 236 { 237 .compatible = "thine,thc63lvdm83d", 238 .data = (void *)DRM_MODE_CONNECTOR_LVDS, 239 }, 240 {}, 241 }; 242 MODULE_DEVICE_TABLE(of, lvds_codec_match); 243 244 static struct platform_driver lvds_codec_driver = { 245 .probe = lvds_codec_probe, 246 .remove = lvds_codec_remove, 247 .driver = { 248 .name = "lvds-codec", 249 .of_match_table = lvds_codec_match, 250 }, 251 }; 252 module_platform_driver(lvds_codec_driver); 253 254 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 255 MODULE_DESCRIPTION("LVDS encoders and decoders"); 256 MODULE_LICENSE("GPL"); 257