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 enum drm_bridge_attach_flags flags) 47 { 48 struct thc63_dev *thc63 = to_thc63(bridge); 49 50 return drm_bridge_attach(bridge->encoder, thc63->next, bridge, flags); 51 } 52 53 static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge, 54 const struct drm_display_mode *mode) 55 { 56 struct thc63_dev *thc63 = to_thc63(bridge); 57 unsigned int min_freq; 58 unsigned int max_freq; 59 60 /* 61 * The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but 62 * dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out 63 * isn't supported by the driver yet, simply derive the limits from the 64 * input mode. 65 */ 66 if (thc63->timings.dual_link) { 67 min_freq = 40000; 68 max_freq = 150000; 69 } else { 70 min_freq = 8000; 71 max_freq = 135000; 72 } 73 74 if (mode->clock < min_freq) 75 return MODE_CLOCK_LOW; 76 77 if (mode->clock > max_freq) 78 return MODE_CLOCK_HIGH; 79 80 return MODE_OK; 81 } 82 83 static void thc63_enable(struct drm_bridge *bridge) 84 { 85 struct thc63_dev *thc63 = to_thc63(bridge); 86 int ret; 87 88 ret = regulator_enable(thc63->vcc); 89 if (ret) { 90 dev_err(thc63->dev, 91 "Failed to enable regulator \"vcc\": %d\n", ret); 92 return; 93 } 94 95 gpiod_set_value(thc63->pdwn, 0); 96 gpiod_set_value(thc63->oe, 1); 97 } 98 99 static void thc63_disable(struct drm_bridge *bridge) 100 { 101 struct thc63_dev *thc63 = to_thc63(bridge); 102 int ret; 103 104 gpiod_set_value(thc63->oe, 0); 105 gpiod_set_value(thc63->pdwn, 1); 106 107 ret = regulator_disable(thc63->vcc); 108 if (ret) 109 dev_err(thc63->dev, 110 "Failed to disable regulator \"vcc\": %d\n", ret); 111 } 112 113 static const struct drm_bridge_funcs thc63_bridge_func = { 114 .attach = thc63_attach, 115 .mode_valid = thc63_mode_valid, 116 .enable = thc63_enable, 117 .disable = thc63_disable, 118 }; 119 120 static int thc63_parse_dt(struct thc63_dev *thc63) 121 { 122 struct device_node *endpoint; 123 struct device_node *remote; 124 125 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node, 126 THC63_RGB_OUT0, -1); 127 if (!endpoint) { 128 dev_err(thc63->dev, "Missing endpoint in port@%u\n", 129 THC63_RGB_OUT0); 130 return -ENODEV; 131 } 132 133 remote = of_graph_get_remote_port_parent(endpoint); 134 of_node_put(endpoint); 135 if (!remote) { 136 dev_err(thc63->dev, "Endpoint in port@%u unconnected\n", 137 THC63_RGB_OUT0); 138 return -ENODEV; 139 } 140 141 if (!of_device_is_available(remote)) { 142 dev_err(thc63->dev, "port@%u remote endpoint is disabled\n", 143 THC63_RGB_OUT0); 144 of_node_put(remote); 145 return -ENODEV; 146 } 147 148 thc63->next = of_drm_find_bridge(remote); 149 of_node_put(remote); 150 if (!thc63->next) 151 return -EPROBE_DEFER; 152 153 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node, 154 THC63_LVDS_IN1, -1); 155 if (endpoint) { 156 remote = of_graph_get_remote_port_parent(endpoint); 157 of_node_put(endpoint); 158 159 if (remote) { 160 if (of_device_is_available(remote)) 161 thc63->timings.dual_link = true; 162 of_node_put(remote); 163 } 164 } 165 166 dev_dbg(thc63->dev, "operating in %s-link mode\n", 167 thc63->timings.dual_link ? "dual" : "single"); 168 169 return 0; 170 } 171 172 static int thc63_gpio_init(struct thc63_dev *thc63) 173 { 174 thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW); 175 if (IS_ERR(thc63->oe)) { 176 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n", 177 PTR_ERR(thc63->oe)); 178 return PTR_ERR(thc63->oe); 179 } 180 181 thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown", 182 GPIOD_OUT_HIGH); 183 if (IS_ERR(thc63->pdwn)) { 184 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n", 185 PTR_ERR(thc63->pdwn)); 186 return PTR_ERR(thc63->pdwn); 187 } 188 189 return 0; 190 } 191 192 static int thc63_probe(struct platform_device *pdev) 193 { 194 struct thc63_dev *thc63; 195 int ret; 196 197 thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL); 198 if (!thc63) 199 return -ENOMEM; 200 201 thc63->dev = &pdev->dev; 202 platform_set_drvdata(pdev, thc63); 203 204 thc63->vcc = devm_regulator_get_optional(thc63->dev, "vcc"); 205 if (IS_ERR(thc63->vcc)) { 206 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER) 207 return -EPROBE_DEFER; 208 209 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n", 210 PTR_ERR(thc63->vcc)); 211 return PTR_ERR(thc63->vcc); 212 } 213 214 ret = thc63_gpio_init(thc63); 215 if (ret) 216 return ret; 217 218 ret = thc63_parse_dt(thc63); 219 if (ret) 220 return ret; 221 222 thc63->bridge.driver_private = thc63; 223 thc63->bridge.of_node = pdev->dev.of_node; 224 thc63->bridge.funcs = &thc63_bridge_func; 225 thc63->bridge.timings = &thc63->timings; 226 227 drm_bridge_add(&thc63->bridge); 228 229 return 0; 230 } 231 232 static int thc63_remove(struct platform_device *pdev) 233 { 234 struct thc63_dev *thc63 = platform_get_drvdata(pdev); 235 236 drm_bridge_remove(&thc63->bridge); 237 238 return 0; 239 } 240 241 static const struct of_device_id thc63_match[] = { 242 { .compatible = "thine,thc63lvd1024", }, 243 { }, 244 }; 245 MODULE_DEVICE_TABLE(of, thc63_match); 246 247 static struct platform_driver thc63_driver = { 248 .probe = thc63_probe, 249 .remove = thc63_remove, 250 .driver = { 251 .name = "thc63lvd1024", 252 .of_match_table = thc63_match, 253 }, 254 }; 255 module_platform_driver(thc63_driver); 256 257 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); 258 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver"); 259 MODULE_LICENSE("GPL v2"); 260