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 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->next, 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 { 87 struct thc63_dev *thc63 = to_thc63(bridge); 88 int ret; 89 90 ret = regulator_enable(thc63->vcc); 91 if (ret) { 92 dev_err(thc63->dev, 93 "Failed to enable regulator \"vcc\": %d\n", ret); 94 return; 95 } 96 97 gpiod_set_value(thc63->pdwn, 0); 98 gpiod_set_value(thc63->oe, 1); 99 } 100 101 static void thc63_disable(struct drm_bridge *bridge) 102 { 103 struct thc63_dev *thc63 = to_thc63(bridge); 104 int ret; 105 106 gpiod_set_value(thc63->oe, 0); 107 gpiod_set_value(thc63->pdwn, 1); 108 109 ret = regulator_disable(thc63->vcc); 110 if (ret) 111 dev_err(thc63->dev, 112 "Failed to disable regulator \"vcc\": %d\n", ret); 113 } 114 115 static const struct drm_bridge_funcs thc63_bridge_func = { 116 .attach = thc63_attach, 117 .mode_valid = thc63_mode_valid, 118 .enable = thc63_enable, 119 .disable = thc63_disable, 120 }; 121 122 static int thc63_parse_dt(struct thc63_dev *thc63) 123 { 124 struct device_node *endpoint; 125 struct device_node *remote; 126 127 remote = of_graph_get_remote_node(thc63->dev->of_node, 128 THC63_RGB_OUT0, -1); 129 if (!remote) { 130 dev_err(thc63->dev, "No remote endpoint for port@%u\n", 131 THC63_RGB_OUT0); 132 return -ENODEV; 133 } 134 135 thc63->next = of_drm_find_bridge(remote); 136 of_node_put(remote); 137 if (!thc63->next) 138 return -EPROBE_DEFER; 139 140 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node, 141 THC63_LVDS_IN1, -1); 142 if (endpoint) { 143 remote = of_graph_get_remote_port_parent(endpoint); 144 of_node_put(endpoint); 145 146 if (remote) { 147 if (of_device_is_available(remote)) 148 thc63->timings.dual_link = true; 149 of_node_put(remote); 150 } 151 } 152 153 dev_dbg(thc63->dev, "operating in %s-link mode\n", 154 thc63->timings.dual_link ? "dual" : "single"); 155 156 return 0; 157 } 158 159 static int thc63_gpio_init(struct thc63_dev *thc63) 160 { 161 thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW); 162 if (IS_ERR(thc63->oe)) { 163 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n", 164 PTR_ERR(thc63->oe)); 165 return PTR_ERR(thc63->oe); 166 } 167 168 thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown", 169 GPIOD_OUT_HIGH); 170 if (IS_ERR(thc63->pdwn)) { 171 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n", 172 PTR_ERR(thc63->pdwn)); 173 return PTR_ERR(thc63->pdwn); 174 } 175 176 return 0; 177 } 178 179 static int thc63_probe(struct platform_device *pdev) 180 { 181 struct thc63_dev *thc63; 182 int ret; 183 184 thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL); 185 if (!thc63) 186 return -ENOMEM; 187 188 thc63->dev = &pdev->dev; 189 platform_set_drvdata(pdev, thc63); 190 191 thc63->vcc = devm_regulator_get(thc63->dev, "vcc"); 192 if (IS_ERR(thc63->vcc)) { 193 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER) 194 return -EPROBE_DEFER; 195 196 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n", 197 PTR_ERR(thc63->vcc)); 198 return PTR_ERR(thc63->vcc); 199 } 200 201 ret = thc63_gpio_init(thc63); 202 if (ret) 203 return ret; 204 205 ret = thc63_parse_dt(thc63); 206 if (ret) 207 return ret; 208 209 thc63->bridge.driver_private = thc63; 210 thc63->bridge.of_node = pdev->dev.of_node; 211 thc63->bridge.funcs = &thc63_bridge_func; 212 thc63->bridge.timings = &thc63->timings; 213 214 drm_bridge_add(&thc63->bridge); 215 216 return 0; 217 } 218 219 static void thc63_remove(struct platform_device *pdev) 220 { 221 struct thc63_dev *thc63 = platform_get_drvdata(pdev); 222 223 drm_bridge_remove(&thc63->bridge); 224 } 225 226 static const struct of_device_id thc63_match[] = { 227 { .compatible = "thine,thc63lvd1024", }, 228 { }, 229 }; 230 MODULE_DEVICE_TABLE(of, thc63_match); 231 232 static struct platform_driver thc63_driver = { 233 .probe = thc63_probe, 234 .remove = thc63_remove, 235 .driver = { 236 .name = "thc63lvd1024", 237 .of_match_table = thc63_match, 238 }, 239 }; 240 module_platform_driver(thc63_driver); 241 242 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); 243 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver"); 244 MODULE_LICENSE("GPL v2"); 245