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 <drm/drmP.h>
9 #include <drm/drm_bridge.h>
10 #include <drm/drm_panel.h>
11
12 #include <linux/gpio/consumer.h>
13 #include <linux/of_graph.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/slab.h>
16
17 enum thc63_ports {
18 THC63_LVDS_IN0,
19 THC63_LVDS_IN1,
20 THC63_RGB_OUT0,
21 THC63_RGB_OUT1,
22 };
23
24 struct thc63_dev {
25 struct device *dev;
26
27 struct regulator *vcc;
28
29 struct gpio_desc *pdwn;
30 struct gpio_desc *oe;
31
32 struct drm_bridge bridge;
33 struct drm_bridge *next;
34 };
35
to_thc63(struct drm_bridge * bridge)36 static inline struct thc63_dev *to_thc63(struct drm_bridge *bridge)
37 {
38 return container_of(bridge, struct thc63_dev, bridge);
39 }
40
thc63_attach(struct drm_bridge * bridge)41 static int thc63_attach(struct drm_bridge *bridge)
42 {
43 struct thc63_dev *thc63 = to_thc63(bridge);
44
45 return drm_bridge_attach(bridge->encoder, thc63->next, bridge);
46 }
47
thc63_enable(struct drm_bridge * bridge)48 static void thc63_enable(struct drm_bridge *bridge)
49 {
50 struct thc63_dev *thc63 = to_thc63(bridge);
51 int ret;
52
53 ret = regulator_enable(thc63->vcc);
54 if (ret) {
55 dev_err(thc63->dev,
56 "Failed to enable regulator \"vcc\": %d\n", ret);
57 return;
58 }
59
60 gpiod_set_value(thc63->pdwn, 0);
61 gpiod_set_value(thc63->oe, 1);
62 }
63
thc63_disable(struct drm_bridge * bridge)64 static void thc63_disable(struct drm_bridge *bridge)
65 {
66 struct thc63_dev *thc63 = to_thc63(bridge);
67 int ret;
68
69 gpiod_set_value(thc63->oe, 0);
70 gpiod_set_value(thc63->pdwn, 1);
71
72 ret = regulator_disable(thc63->vcc);
73 if (ret)
74 dev_err(thc63->dev,
75 "Failed to disable regulator \"vcc\": %d\n", ret);
76 }
77
78 static const struct drm_bridge_funcs thc63_bridge_func = {
79 .attach = thc63_attach,
80 .enable = thc63_enable,
81 .disable = thc63_disable,
82 };
83
thc63_parse_dt(struct thc63_dev * thc63)84 static int thc63_parse_dt(struct thc63_dev *thc63)
85 {
86 struct device_node *thc63_out;
87 struct device_node *remote;
88
89 thc63_out = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
90 THC63_RGB_OUT0, -1);
91 if (!thc63_out) {
92 dev_err(thc63->dev, "Missing endpoint in port@%u\n",
93 THC63_RGB_OUT0);
94 return -ENODEV;
95 }
96
97 remote = of_graph_get_remote_port_parent(thc63_out);
98 of_node_put(thc63_out);
99 if (!remote) {
100 dev_err(thc63->dev, "Endpoint in port@%u unconnected\n",
101 THC63_RGB_OUT0);
102 return -ENODEV;
103 }
104
105 if (!of_device_is_available(remote)) {
106 dev_err(thc63->dev, "port@%u remote endpoint is disabled\n",
107 THC63_RGB_OUT0);
108 of_node_put(remote);
109 return -ENODEV;
110 }
111
112 thc63->next = of_drm_find_bridge(remote);
113 of_node_put(remote);
114 if (!thc63->next)
115 return -EPROBE_DEFER;
116
117 return 0;
118 }
119
thc63_gpio_init(struct thc63_dev * thc63)120 static int thc63_gpio_init(struct thc63_dev *thc63)
121 {
122 thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW);
123 if (IS_ERR(thc63->oe)) {
124 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n",
125 PTR_ERR(thc63->oe));
126 return PTR_ERR(thc63->oe);
127 }
128
129 thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown",
130 GPIOD_OUT_HIGH);
131 if (IS_ERR(thc63->pdwn)) {
132 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n",
133 PTR_ERR(thc63->pdwn));
134 return PTR_ERR(thc63->pdwn);
135 }
136
137 return 0;
138 }
139
thc63_probe(struct platform_device * pdev)140 static int thc63_probe(struct platform_device *pdev)
141 {
142 struct thc63_dev *thc63;
143 int ret;
144
145 thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL);
146 if (!thc63)
147 return -ENOMEM;
148
149 thc63->dev = &pdev->dev;
150 platform_set_drvdata(pdev, thc63);
151
152 thc63->vcc = devm_regulator_get_optional(thc63->dev, "vcc");
153 if (IS_ERR(thc63->vcc)) {
154 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER)
155 return -EPROBE_DEFER;
156
157 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n",
158 PTR_ERR(thc63->vcc));
159 return PTR_ERR(thc63->vcc);
160 }
161
162 ret = thc63_gpio_init(thc63);
163 if (ret)
164 return ret;
165
166 ret = thc63_parse_dt(thc63);
167 if (ret)
168 return ret;
169
170 thc63->bridge.driver_private = thc63;
171 thc63->bridge.of_node = pdev->dev.of_node;
172 thc63->bridge.funcs = &thc63_bridge_func;
173
174 drm_bridge_add(&thc63->bridge);
175
176 return 0;
177 }
178
thc63_remove(struct platform_device * pdev)179 static int thc63_remove(struct platform_device *pdev)
180 {
181 struct thc63_dev *thc63 = platform_get_drvdata(pdev);
182
183 drm_bridge_remove(&thc63->bridge);
184
185 return 0;
186 }
187
188 static const struct of_device_id thc63_match[] = {
189 { .compatible = "thine,thc63lvd1024", },
190 { },
191 };
192 MODULE_DEVICE_TABLE(of, thc63_match);
193
194 static struct platform_driver thc63_driver = {
195 .probe = thc63_probe,
196 .remove = thc63_remove,
197 .driver = {
198 .name = "thc63lvd1024",
199 .of_match_table = thc63_match,
200 },
201 };
202 module_platform_driver(thc63_driver);
203
204 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
205 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver");
206 MODULE_LICENSE("GPL v2");
207
