1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * THC63LVD1024 LVDS to parallel data DRM bridge driver. 4 * 5 * Copyright (C) 2018 Jacopo Mondi <jacopo+renesas@jmondi.org> 6 */ 7 8 #include <linux/gpio/consumer.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/of_graph.h> 12 #include <linux/platform_device.h> 13 #include <linux/regulator/consumer.h> 14 #include <linux/slab.h> 15 16 #include <drm/drm_bridge.h> 17 #include <drm/drm_panel.h> 18 19 enum thc63_ports { 20 THC63_LVDS_IN0, 21 THC63_LVDS_IN1, 22 THC63_RGB_OUT0, 23 THC63_RGB_OUT1, 24 }; 25 26 struct thc63_dev { 27 struct device *dev; 28 29 struct regulator *vcc; 30 31 struct gpio_desc *pdwn; 32 struct gpio_desc *oe; 33 34 struct drm_bridge bridge; 35 struct drm_bridge *next; 36 37 struct drm_bridge_timings timings; 38 }; 39 40 static inline struct thc63_dev *to_thc63(struct drm_bridge *bridge) 41 { 42 return container_of(bridge, struct thc63_dev, bridge); 43 } 44 45 static int thc63_attach(struct drm_bridge *bridge) 46 { 47 struct thc63_dev *thc63 = to_thc63(bridge); 48 49 return drm_bridge_attach(bridge->encoder, thc63->next, bridge); 50 } 51 52 static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge, 53 const struct drm_display_mode *mode) 54 { 55 struct thc63_dev *thc63 = to_thc63(bridge); 56 unsigned int min_freq; 57 unsigned int max_freq; 58 59 /* 60 * The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but 61 * dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out 62 * isn't supported by the driver yet, simply derive the limits from the 63 * input mode. 64 */ 65 if (thc63->timings.dual_link) { 66 min_freq = 40000; 67 max_freq = 150000; 68 } else { 69 min_freq = 8000; 70 max_freq = 135000; 71 } 72 73 if (mode->clock < min_freq) 74 return MODE_CLOCK_LOW; 75 76 if (mode->clock > max_freq) 77 return MODE_CLOCK_HIGH; 78 79 return MODE_OK; 80 } 81 82 static void thc63_enable(struct drm_bridge *bridge) 83 { 84 struct thc63_dev *thc63 = to_thc63(bridge); 85 int ret; 86 87 ret = regulator_enable(thc63->vcc); 88 if (ret) { 89 dev_err(thc63->dev, 90 "Failed to enable regulator \"vcc\": %d\n", ret); 91 return; 92 } 93 94 gpiod_set_value(thc63->pdwn, 0); 95 gpiod_set_value(thc63->oe, 1); 96 } 97 98 static void thc63_disable(struct drm_bridge *bridge) 99 { 100 struct thc63_dev *thc63 = to_thc63(bridge); 101 int ret; 102 103 gpiod_set_value(thc63->oe, 0); 104 gpiod_set_value(thc63->pdwn, 1); 105 106 ret = regulator_disable(thc63->vcc); 107 if (ret) 108 dev_err(thc63->dev, 109 "Failed to disable regulator \"vcc\": %d\n", ret); 110 } 111 112 static const struct drm_bridge_funcs thc63_bridge_func = { 113 .attach = thc63_attach, 114 .mode_valid = thc63_mode_valid, 115 .enable = thc63_enable, 116 .disable = thc63_disable, 117 }; 118 119 static int thc63_parse_dt(struct thc63_dev *thc63) 120 { 121 struct device_node *endpoint; 122 struct device_node *remote; 123 124 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node, 125 THC63_RGB_OUT0, -1); 126 if (!endpoint) { 127 dev_err(thc63->dev, "Missing endpoint in port@%u\n", 128 THC63_RGB_OUT0); 129 return -ENODEV; 130 } 131 132 remote = of_graph_get_remote_port_parent(endpoint); 133 of_node_put(endpoint); 134 if (!remote) { 135 dev_err(thc63->dev, "Endpoint in port@%u unconnected\n", 136 THC63_RGB_OUT0); 137 return -ENODEV; 138 } 139 140 if (!of_device_is_available(remote)) { 141 dev_err(thc63->dev, "port@%u remote endpoint is disabled\n", 142 THC63_RGB_OUT0); 143 of_node_put(remote); 144 return -ENODEV; 145 } 146 147 thc63->next = of_drm_find_bridge(remote); 148 of_node_put(remote); 149 if (!thc63->next) 150 return -EPROBE_DEFER; 151 152 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node, 153 THC63_LVDS_IN1, -1); 154 if (endpoint) { 155 remote = of_graph_get_remote_port_parent(endpoint); 156 of_node_put(endpoint); 157 158 if (remote) { 159 if (of_device_is_available(remote)) 160 thc63->timings.dual_link = true; 161 of_node_put(remote); 162 } 163 } 164 165 dev_dbg(thc63->dev, "operating in %s-link mode\n", 166 thc63->timings.dual_link ? "dual" : "single"); 167 168 return 0; 169 } 170 171 static int thc63_gpio_init(struct thc63_dev *thc63) 172 { 173 thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW); 174 if (IS_ERR(thc63->oe)) { 175 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n", 176 PTR_ERR(thc63->oe)); 177 return PTR_ERR(thc63->oe); 178 } 179 180 thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown", 181 GPIOD_OUT_HIGH); 182 if (IS_ERR(thc63->pdwn)) { 183 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n", 184 PTR_ERR(thc63->pdwn)); 185 return PTR_ERR(thc63->pdwn); 186 } 187 188 return 0; 189 } 190 191 static int thc63_probe(struct platform_device *pdev) 192 { 193 struct thc63_dev *thc63; 194 int ret; 195 196 thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL); 197 if (!thc63) 198 return -ENOMEM; 199 200 thc63->dev = &pdev->dev; 201 platform_set_drvdata(pdev, thc63); 202 203 thc63->vcc = devm_regulator_get_optional(thc63->dev, "vcc"); 204 if (IS_ERR(thc63->vcc)) { 205 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER) 206 return -EPROBE_DEFER; 207 208 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n", 209 PTR_ERR(thc63->vcc)); 210 return PTR_ERR(thc63->vcc); 211 } 212 213 ret = thc63_gpio_init(thc63); 214 if (ret) 215 return ret; 216 217 ret = thc63_parse_dt(thc63); 218 if (ret) 219 return ret; 220 221 thc63->bridge.driver_private = thc63; 222 thc63->bridge.of_node = pdev->dev.of_node; 223 thc63->bridge.funcs = &thc63_bridge_func; 224 thc63->bridge.timings = &thc63->timings; 225 226 drm_bridge_add(&thc63->bridge); 227 228 return 0; 229 } 230 231 static int thc63_remove(struct platform_device *pdev) 232 { 233 struct thc63_dev *thc63 = platform_get_drvdata(pdev); 234 235 drm_bridge_remove(&thc63->bridge); 236 237 return 0; 238 } 239 240 static const struct of_device_id thc63_match[] = { 241 { .compatible = "thine,thc63lvd1024", }, 242 { }, 243 }; 244 MODULE_DEVICE_TABLE(of, thc63_match); 245 246 static struct platform_driver thc63_driver = { 247 .probe = thc63_probe, 248 .remove = thc63_remove, 249 .driver = { 250 .name = "thc63lvd1024", 251 .of_match_table = thc63_match, 252 }, 253 }; 254 module_platform_driver(thc63_driver); 255 256 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); 257 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver"); 258 MODULE_LICENSE("GPL v2"); 259