1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Generic LVDS panel driver
4 *
5 * Copyright (C) 2016 Laurent Pinchart
6 * Copyright (C) 2016 Renesas Electronics Corporation
7 *
8 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
9 */
10
11 #include <linux/gpio/consumer.h>
12 #include <linux/module.h>
13 #include <linux/of_platform.h>
14 #include <linux/platform_device.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/slab.h>
17
18 #include <video/display_timing.h>
19 #include <video/of_display_timing.h>
20 #include <video/videomode.h>
21
22 #include <drm/drm_crtc.h>
23 #include <drm/drm_panel.h>
24
25 struct panel_lvds {
26 struct drm_panel panel;
27 struct device *dev;
28
29 const char *label;
30 unsigned int width;
31 unsigned int height;
32 struct videomode video_mode;
33 unsigned int bus_format;
34 bool data_mirror;
35
36 struct regulator *supply;
37
38 struct gpio_desc *enable_gpio;
39 struct gpio_desc *reset_gpio;
40
41 enum drm_panel_orientation orientation;
42 };
43
to_panel_lvds(struct drm_panel * panel)44 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
45 {
46 return container_of(panel, struct panel_lvds, panel);
47 }
48
panel_lvds_unprepare(struct drm_panel * panel)49 static int panel_lvds_unprepare(struct drm_panel *panel)
50 {
51 struct panel_lvds *lvds = to_panel_lvds(panel);
52
53 if (lvds->enable_gpio)
54 gpiod_set_value_cansleep(lvds->enable_gpio, 0);
55
56 if (lvds->supply)
57 regulator_disable(lvds->supply);
58
59 return 0;
60 }
61
panel_lvds_prepare(struct drm_panel * panel)62 static int panel_lvds_prepare(struct drm_panel *panel)
63 {
64 struct panel_lvds *lvds = to_panel_lvds(panel);
65
66 if (lvds->supply) {
67 int err;
68
69 err = regulator_enable(lvds->supply);
70 if (err < 0) {
71 dev_err(lvds->dev, "failed to enable supply: %d\n",
72 err);
73 return err;
74 }
75 }
76
77 if (lvds->enable_gpio)
78 gpiod_set_value_cansleep(lvds->enable_gpio, 1);
79
80 return 0;
81 }
82
panel_lvds_get_modes(struct drm_panel * panel,struct drm_connector * connector)83 static int panel_lvds_get_modes(struct drm_panel *panel,
84 struct drm_connector *connector)
85 {
86 struct panel_lvds *lvds = to_panel_lvds(panel);
87 struct drm_display_mode *mode;
88
89 mode = drm_mode_create(connector->dev);
90 if (!mode)
91 return 0;
92
93 drm_display_mode_from_videomode(&lvds->video_mode, mode);
94 mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
95 drm_mode_probed_add(connector, mode);
96
97 connector->display_info.width_mm = lvds->width;
98 connector->display_info.height_mm = lvds->height;
99 drm_display_info_set_bus_formats(&connector->display_info,
100 &lvds->bus_format, 1);
101 connector->display_info.bus_flags = lvds->data_mirror
102 ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
103 : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
104 drm_connector_set_panel_orientation(connector, lvds->orientation);
105
106 return 1;
107 }
108
109 static const struct drm_panel_funcs panel_lvds_funcs = {
110 .unprepare = panel_lvds_unprepare,
111 .prepare = panel_lvds_prepare,
112 .get_modes = panel_lvds_get_modes,
113 };
114
panel_lvds_parse_dt(struct panel_lvds * lvds)115 static int panel_lvds_parse_dt(struct panel_lvds *lvds)
116 {
117 struct device_node *np = lvds->dev->of_node;
118 struct display_timing timing;
119 const char *mapping;
120 int ret;
121
122 ret = of_drm_get_panel_orientation(np, &lvds->orientation);
123 if (ret < 0) {
124 dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
125 return ret;
126 }
127
128 ret = of_get_display_timing(np, "panel-timing", &timing);
129 if (ret < 0) {
130 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
131 np, ret);
132 return ret;
133 }
134
135 videomode_from_timing(&timing, &lvds->video_mode);
136
137 ret = of_property_read_u32(np, "width-mm", &lvds->width);
138 if (ret < 0) {
139 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
140 np, "width-mm");
141 return -ENODEV;
142 }
143 ret = of_property_read_u32(np, "height-mm", &lvds->height);
144 if (ret < 0) {
145 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
146 np, "height-mm");
147 return -ENODEV;
148 }
149
150 of_property_read_string(np, "label", &lvds->label);
151
152 ret = of_property_read_string(np, "data-mapping", &mapping);
153 if (ret < 0) {
154 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
155 np, "data-mapping");
156 return -ENODEV;
157 }
158
159 if (!strcmp(mapping, "jeida-18")) {
160 lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
161 } else if (!strcmp(mapping, "jeida-24")) {
162 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
163 } else if (!strcmp(mapping, "vesa-24")) {
164 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
165 } else {
166 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
167 np, "data-mapping");
168 return -EINVAL;
169 }
170
171 lvds->data_mirror = of_property_read_bool(np, "data-mirror");
172
173 return 0;
174 }
175
panel_lvds_probe(struct platform_device * pdev)176 static int panel_lvds_probe(struct platform_device *pdev)
177 {
178 struct panel_lvds *lvds;
179 int ret;
180
181 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
182 if (!lvds)
183 return -ENOMEM;
184
185 lvds->dev = &pdev->dev;
186
187 ret = panel_lvds_parse_dt(lvds);
188 if (ret < 0)
189 return ret;
190
191 lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
192 if (IS_ERR(lvds->supply)) {
193 ret = PTR_ERR(lvds->supply);
194
195 if (ret != -ENODEV) {
196 if (ret != -EPROBE_DEFER)
197 dev_err(lvds->dev, "failed to request regulator: %d\n",
198 ret);
199 return ret;
200 }
201
202 lvds->supply = NULL;
203 }
204
205 /* Get GPIOs and backlight controller. */
206 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
207 GPIOD_OUT_LOW);
208 if (IS_ERR(lvds->enable_gpio)) {
209 ret = PTR_ERR(lvds->enable_gpio);
210 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
211 "enable", ret);
212 return ret;
213 }
214
215 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
216 GPIOD_OUT_HIGH);
217 if (IS_ERR(lvds->reset_gpio)) {
218 ret = PTR_ERR(lvds->reset_gpio);
219 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
220 "reset", ret);
221 return ret;
222 }
223
224 /*
225 * TODO: Handle all power supplies specified in the DT node in a generic
226 * way for panels that don't care about power supply ordering. LVDS
227 * panels that require a specific power sequence will need a dedicated
228 * driver.
229 */
230
231 /* Register the panel. */
232 drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
233 DRM_MODE_CONNECTOR_LVDS);
234
235 ret = drm_panel_of_backlight(&lvds->panel);
236 if (ret)
237 return ret;
238
239 drm_panel_add(&lvds->panel);
240
241 dev_set_drvdata(lvds->dev, lvds);
242 return 0;
243 }
244
panel_lvds_remove(struct platform_device * pdev)245 static int panel_lvds_remove(struct platform_device *pdev)
246 {
247 struct panel_lvds *lvds = platform_get_drvdata(pdev);
248
249 drm_panel_remove(&lvds->panel);
250
251 drm_panel_disable(&lvds->panel);
252
253 return 0;
254 }
255
256 static const struct of_device_id panel_lvds_of_table[] = {
257 { .compatible = "panel-lvds", },
258 { /* Sentinel */ },
259 };
260
261 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
262
263 static struct platform_driver panel_lvds_driver = {
264 .probe = panel_lvds_probe,
265 .remove = panel_lvds_remove,
266 .driver = {
267 .name = "panel-lvds",
268 .of_match_table = panel_lvds_of_table,
269 },
270 };
271
272 module_platform_driver(panel_lvds_driver);
273
274 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
275 MODULE_DESCRIPTION("LVDS Panel Driver");
276 MODULE_LICENSE("GPL");
277