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_atomic_helper.h> 17 #include <drm/drm_bridge.h> 18 #include <drm/drm_panel.h> 19 20 enum thc63_ports { 21 THC63_LVDS_IN0, 22 THC63_LVDS_IN1, 23 THC63_RGB_OUT0, 24 THC63_RGB_OUT1, 25 }; 26 27 struct thc63_dev { 28 struct device *dev; 29 30 struct regulator *vcc; 31 32 struct gpio_desc *pdwn; 33 struct gpio_desc *oe; 34 35 struct drm_bridge bridge; 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 struct drm_encoder *encoder, 47 enum drm_bridge_attach_flags flags) 48 { 49 struct thc63_dev *thc63 = to_thc63(bridge); 50 51 return drm_bridge_attach(encoder, thc63->bridge.next_bridge, bridge, flags); 52 } 53 54 static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge, 55 const struct drm_display_info *info, 56 const struct drm_display_mode *mode) 57 { 58 struct thc63_dev *thc63 = to_thc63(bridge); 59 unsigned int min_freq; 60 unsigned int max_freq; 61 62 /* 63 * The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but 64 * dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out 65 * isn't supported by the driver yet, simply derive the limits from the 66 * input mode. 67 */ 68 if (thc63->timings.dual_link) { 69 min_freq = 40000; 70 max_freq = 150000; 71 } else { 72 min_freq = 8000; 73 max_freq = 135000; 74 } 75 76 if (mode->clock < min_freq) 77 return MODE_CLOCK_LOW; 78 79 if (mode->clock > max_freq) 80 return MODE_CLOCK_HIGH; 81 82 return MODE_OK; 83 } 84 85 static void thc63_enable(struct drm_bridge *bridge, 86 struct drm_atomic_commit *commit) 87 { 88 struct thc63_dev *thc63 = to_thc63(bridge); 89 int ret; 90 91 ret = regulator_enable(thc63->vcc); 92 if (ret) { 93 dev_err(thc63->dev, 94 "Failed to enable regulator \"vcc\": %d\n", ret); 95 return; 96 } 97 98 gpiod_set_value(thc63->pdwn, 0); 99 gpiod_set_value(thc63->oe, 1); 100 } 101 102 static void thc63_disable(struct drm_bridge *bridge, 103 struct drm_atomic_commit *commit) 104 { 105 struct thc63_dev *thc63 = to_thc63(bridge); 106 int ret; 107 108 gpiod_set_value(thc63->oe, 0); 109 gpiod_set_value(thc63->pdwn, 1); 110 111 ret = regulator_disable(thc63->vcc); 112 if (ret) 113 dev_err(thc63->dev, 114 "Failed to disable regulator \"vcc\": %d\n", ret); 115 } 116 117 static const struct drm_bridge_funcs thc63_bridge_func = { 118 .atomic_create_state = drm_atomic_helper_bridge_create_state, 119 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, 120 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, 121 .attach = thc63_attach, 122 .mode_valid = thc63_mode_valid, 123 .atomic_enable = thc63_enable, 124 .atomic_disable = thc63_disable, 125 }; 126 127 static int thc63_parse_dt(struct thc63_dev *thc63) 128 { 129 struct device_node *endpoint; 130 struct device_node *remote; 131 132 remote = of_graph_get_remote_node(thc63->dev->of_node, 133 THC63_RGB_OUT0, -1); 134 if (!remote) { 135 dev_err(thc63->dev, "No remote endpoint for port@%u\n", 136 THC63_RGB_OUT0); 137 return -ENODEV; 138 } 139 140 thc63->bridge.next_bridge = of_drm_find_and_get_bridge(remote); 141 of_node_put(remote); 142 if (!thc63->bridge.next_bridge) 143 return -EPROBE_DEFER; 144 145 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node, 146 THC63_LVDS_IN1, -1); 147 if (endpoint) { 148 remote = of_graph_get_remote_port_parent(endpoint); 149 of_node_put(endpoint); 150 151 if (remote) { 152 if (of_device_is_available(remote)) 153 thc63->timings.dual_link = true; 154 of_node_put(remote); 155 } 156 } 157 158 dev_dbg(thc63->dev, "operating in %s-link mode\n", 159 thc63->timings.dual_link ? "dual" : "single"); 160 161 return 0; 162 } 163 164 static int thc63_gpio_init(struct thc63_dev *thc63) 165 { 166 thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW); 167 if (IS_ERR(thc63->oe)) { 168 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n", 169 PTR_ERR(thc63->oe)); 170 return PTR_ERR(thc63->oe); 171 } 172 173 thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown", 174 GPIOD_OUT_HIGH); 175 if (IS_ERR(thc63->pdwn)) { 176 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n", 177 PTR_ERR(thc63->pdwn)); 178 return PTR_ERR(thc63->pdwn); 179 } 180 181 return 0; 182 } 183 184 static int thc63_probe(struct platform_device *pdev) 185 { 186 struct thc63_dev *thc63; 187 int ret; 188 189 thc63 = devm_drm_bridge_alloc(&pdev->dev, struct thc63_dev, bridge, 190 &thc63_bridge_func); 191 if (IS_ERR(thc63)) 192 return PTR_ERR(thc63); 193 194 thc63->dev = &pdev->dev; 195 platform_set_drvdata(pdev, thc63); 196 197 thc63->vcc = devm_regulator_get(thc63->dev, "vcc"); 198 if (IS_ERR(thc63->vcc)) { 199 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER) 200 return -EPROBE_DEFER; 201 202 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n", 203 PTR_ERR(thc63->vcc)); 204 return PTR_ERR(thc63->vcc); 205 } 206 207 ret = thc63_gpio_init(thc63); 208 if (ret) 209 return ret; 210 211 ret = thc63_parse_dt(thc63); 212 if (ret) 213 return ret; 214 215 thc63->bridge.driver_private = thc63; 216 thc63->bridge.of_node = pdev->dev.of_node; 217 thc63->bridge.timings = &thc63->timings; 218 219 drm_bridge_add(&thc63->bridge); 220 221 return 0; 222 } 223 224 static void thc63_remove(struct platform_device *pdev) 225 { 226 struct thc63_dev *thc63 = platform_get_drvdata(pdev); 227 228 drm_bridge_remove(&thc63->bridge); 229 } 230 231 static const struct of_device_id thc63_match[] = { 232 { .compatible = "thine,thc63lvd1024", }, 233 { }, 234 }; 235 MODULE_DEVICE_TABLE(of, thc63_match); 236 237 static struct platform_driver thc63_driver = { 238 .probe = thc63_probe, 239 .remove = thc63_remove, 240 .driver = { 241 .name = "thc63lvd1024", 242 .of_match_table = thc63_match, 243 }, 244 }; 245 module_platform_driver(thc63_driver); 246 247 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); 248 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver"); 249 MODULE_LICENSE("GPL v2"); 250