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
to_thc63(struct drm_bridge * bridge)40 static inline struct thc63_dev *to_thc63(struct drm_bridge *bridge)
41 {
42 return container_of(bridge, struct thc63_dev, bridge);
43 }
44
thc63_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)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
thc63_mode_valid(struct drm_bridge * bridge,const struct drm_display_info * info,const struct drm_display_mode * mode)53 static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge,
54 const struct drm_display_info *info,
55 const struct drm_display_mode *mode)
56 {
57 struct thc63_dev *thc63 = to_thc63(bridge);
58 unsigned int min_freq;
59 unsigned int max_freq;
60
61 /*
62 * The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but
63 * dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out
64 * isn't supported by the driver yet, simply derive the limits from the
65 * input mode.
66 */
67 if (thc63->timings.dual_link) {
68 min_freq = 40000;
69 max_freq = 150000;
70 } else {
71 min_freq = 8000;
72 max_freq = 135000;
73 }
74
75 if (mode->clock < min_freq)
76 return MODE_CLOCK_LOW;
77
78 if (mode->clock > max_freq)
79 return MODE_CLOCK_HIGH;
80
81 return MODE_OK;
82 }
83
thc63_enable(struct drm_bridge * bridge)84 static void thc63_enable(struct drm_bridge *bridge)
85 {
86 struct thc63_dev *thc63 = to_thc63(bridge);
87 int ret;
88
89 ret = regulator_enable(thc63->vcc);
90 if (ret) {
91 dev_err(thc63->dev,
92 "Failed to enable regulator \"vcc\": %d\n", ret);
93 return;
94 }
95
96 gpiod_set_value(thc63->pdwn, 0);
97 gpiod_set_value(thc63->oe, 1);
98 }
99
thc63_disable(struct drm_bridge * bridge)100 static void thc63_disable(struct drm_bridge *bridge)
101 {
102 struct thc63_dev *thc63 = to_thc63(bridge);
103 int ret;
104
105 gpiod_set_value(thc63->oe, 0);
106 gpiod_set_value(thc63->pdwn, 1);
107
108 ret = regulator_disable(thc63->vcc);
109 if (ret)
110 dev_err(thc63->dev,
111 "Failed to disable regulator \"vcc\": %d\n", ret);
112 }
113
114 static const struct drm_bridge_funcs thc63_bridge_func = {
115 .attach = thc63_attach,
116 .mode_valid = thc63_mode_valid,
117 .enable = thc63_enable,
118 .disable = thc63_disable,
119 };
120
thc63_parse_dt(struct thc63_dev * thc63)121 static int thc63_parse_dt(struct thc63_dev *thc63)
122 {
123 struct device_node *endpoint;
124 struct device_node *remote;
125
126 remote = of_graph_get_remote_node(thc63->dev->of_node,
127 THC63_RGB_OUT0, -1);
128 if (!remote) {
129 dev_err(thc63->dev, "No remote endpoint for port@%u\n",
130 THC63_RGB_OUT0);
131 return -ENODEV;
132 }
133
134 thc63->next = of_drm_find_bridge(remote);
135 of_node_put(remote);
136 if (!thc63->next)
137 return -EPROBE_DEFER;
138
139 endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
140 THC63_LVDS_IN1, -1);
141 if (endpoint) {
142 remote = of_graph_get_remote_port_parent(endpoint);
143 of_node_put(endpoint);
144
145 if (remote) {
146 if (of_device_is_available(remote))
147 thc63->timings.dual_link = true;
148 of_node_put(remote);
149 }
150 }
151
152 dev_dbg(thc63->dev, "operating in %s-link mode\n",
153 thc63->timings.dual_link ? "dual" : "single");
154
155 return 0;
156 }
157
thc63_gpio_init(struct thc63_dev * thc63)158 static int thc63_gpio_init(struct thc63_dev *thc63)
159 {
160 thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW);
161 if (IS_ERR(thc63->oe)) {
162 dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n",
163 PTR_ERR(thc63->oe));
164 return PTR_ERR(thc63->oe);
165 }
166
167 thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown",
168 GPIOD_OUT_HIGH);
169 if (IS_ERR(thc63->pdwn)) {
170 dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n",
171 PTR_ERR(thc63->pdwn));
172 return PTR_ERR(thc63->pdwn);
173 }
174
175 return 0;
176 }
177
thc63_probe(struct platform_device * pdev)178 static int thc63_probe(struct platform_device *pdev)
179 {
180 struct thc63_dev *thc63;
181 int ret;
182
183 thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL);
184 if (!thc63)
185 return -ENOMEM;
186
187 thc63->dev = &pdev->dev;
188 platform_set_drvdata(pdev, thc63);
189
190 thc63->vcc = devm_regulator_get(thc63->dev, "vcc");
191 if (IS_ERR(thc63->vcc)) {
192 if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER)
193 return -EPROBE_DEFER;
194
195 dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n",
196 PTR_ERR(thc63->vcc));
197 return PTR_ERR(thc63->vcc);
198 }
199
200 ret = thc63_gpio_init(thc63);
201 if (ret)
202 return ret;
203
204 ret = thc63_parse_dt(thc63);
205 if (ret)
206 return ret;
207
208 thc63->bridge.driver_private = thc63;
209 thc63->bridge.of_node = pdev->dev.of_node;
210 thc63->bridge.funcs = &thc63_bridge_func;
211 thc63->bridge.timings = &thc63->timings;
212
213 drm_bridge_add(&thc63->bridge);
214
215 return 0;
216 }
217
thc63_remove(struct platform_device * pdev)218 static void thc63_remove(struct platform_device *pdev)
219 {
220 struct thc63_dev *thc63 = platform_get_drvdata(pdev);
221
222 drm_bridge_remove(&thc63->bridge);
223 }
224
225 static const struct of_device_id thc63_match[] = {
226 { .compatible = "thine,thc63lvd1024", },
227 { },
228 };
229 MODULE_DEVICE_TABLE(of, thc63_match);
230
231 static struct platform_driver thc63_driver = {
232 .probe = thc63_probe,
233 .remove_new = thc63_remove,
234 .driver = {
235 .name = "thc63lvd1024",
236 .of_match_table = thc63_match,
237 },
238 };
239 module_platform_driver(thc63_driver);
240
241 MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
242 MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver");
243 MODULE_LICENSE("GPL v2");
244