1 /*
2 * Generic LVDS panel driver
3 *
4 * Copyright (C) 2016 Laurent Pinchart
5 * Copyright (C) 2016 Renesas Electronics Corporation
6 *
7 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 */
14
15 #include <linux/backlight.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/module.h>
18 #include <linux/of_platform.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/consumer.h>
21 #include <linux/slab.h>
22
23 #include <drm/drmP.h>
24 #include <drm/drm_crtc.h>
25 #include <drm/drm_panel.h>
26
27 #include <video/display_timing.h>
28 #include <video/of_display_timing.h>
29 #include <video/videomode.h>
30
31 struct panel_lvds {
32 struct drm_panel panel;
33 struct device *dev;
34
35 const char *label;
36 unsigned int width;
37 unsigned int height;
38 struct videomode video_mode;
39 unsigned int bus_format;
40 bool data_mirror;
41
42 struct backlight_device *backlight;
43 struct regulator *supply;
44
45 struct gpio_desc *enable_gpio;
46 struct gpio_desc *reset_gpio;
47 };
48
to_panel_lvds(struct drm_panel * panel)49 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
50 {
51 return container_of(panel, struct panel_lvds, panel);
52 }
53
panel_lvds_disable(struct drm_panel * panel)54 static int panel_lvds_disable(struct drm_panel *panel)
55 {
56 struct panel_lvds *lvds = to_panel_lvds(panel);
57
58 if (lvds->backlight) {
59 lvds->backlight->props.power = FB_BLANK_POWERDOWN;
60 lvds->backlight->props.state |= BL_CORE_FBBLANK;
61 backlight_update_status(lvds->backlight);
62 }
63
64 return 0;
65 }
66
panel_lvds_unprepare(struct drm_panel * panel)67 static int panel_lvds_unprepare(struct drm_panel *panel)
68 {
69 struct panel_lvds *lvds = to_panel_lvds(panel);
70
71 if (lvds->enable_gpio)
72 gpiod_set_value_cansleep(lvds->enable_gpio, 0);
73
74 if (lvds->supply)
75 regulator_disable(lvds->supply);
76
77 return 0;
78 }
79
panel_lvds_prepare(struct drm_panel * panel)80 static int panel_lvds_prepare(struct drm_panel *panel)
81 {
82 struct panel_lvds *lvds = to_panel_lvds(panel);
83
84 if (lvds->supply) {
85 int err;
86
87 err = regulator_enable(lvds->supply);
88 if (err < 0) {
89 dev_err(lvds->dev, "failed to enable supply: %d\n",
90 err);
91 return err;
92 }
93 }
94
95 if (lvds->enable_gpio)
96 gpiod_set_value_cansleep(lvds->enable_gpio, 1);
97
98 return 0;
99 }
100
panel_lvds_enable(struct drm_panel * panel)101 static int panel_lvds_enable(struct drm_panel *panel)
102 {
103 struct panel_lvds *lvds = to_panel_lvds(panel);
104
105 if (lvds->backlight) {
106 lvds->backlight->props.state &= ~BL_CORE_FBBLANK;
107 lvds->backlight->props.power = FB_BLANK_UNBLANK;
108 backlight_update_status(lvds->backlight);
109 }
110
111 return 0;
112 }
113
panel_lvds_get_modes(struct drm_panel * panel)114 static int panel_lvds_get_modes(struct drm_panel *panel)
115 {
116 struct panel_lvds *lvds = to_panel_lvds(panel);
117 struct drm_connector *connector = lvds->panel.connector;
118 struct drm_display_mode *mode;
119
120 mode = drm_mode_create(lvds->panel.drm);
121 if (!mode)
122 return 0;
123
124 drm_display_mode_from_videomode(&lvds->video_mode, mode);
125 mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
126 drm_mode_probed_add(connector, mode);
127
128 connector->display_info.width_mm = lvds->width;
129 connector->display_info.height_mm = lvds->height;
130 drm_display_info_set_bus_formats(&connector->display_info,
131 &lvds->bus_format, 1);
132 connector->display_info.bus_flags = lvds->data_mirror
133 ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
134 : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
135
136 return 1;
137 }
138
139 static const struct drm_panel_funcs panel_lvds_funcs = {
140 .disable = panel_lvds_disable,
141 .unprepare = panel_lvds_unprepare,
142 .prepare = panel_lvds_prepare,
143 .enable = panel_lvds_enable,
144 .get_modes = panel_lvds_get_modes,
145 };
146
panel_lvds_parse_dt(struct panel_lvds * lvds)147 static int panel_lvds_parse_dt(struct panel_lvds *lvds)
148 {
149 struct device_node *np = lvds->dev->of_node;
150 struct display_timing timing;
151 const char *mapping;
152 int ret;
153
154 ret = of_get_display_timing(np, "panel-timing", &timing);
155 if (ret < 0)
156 return ret;
157
158 videomode_from_timing(&timing, &lvds->video_mode);
159
160 ret = of_property_read_u32(np, "width-mm", &lvds->width);
161 if (ret < 0) {
162 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
163 np, "width-mm");
164 return -ENODEV;
165 }
166 ret = of_property_read_u32(np, "height-mm", &lvds->height);
167 if (ret < 0) {
168 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
169 np, "height-mm");
170 return -ENODEV;
171 }
172
173 of_property_read_string(np, "label", &lvds->label);
174
175 ret = of_property_read_string(np, "data-mapping", &mapping);
176 if (ret < 0) {
177 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
178 np, "data-mapping");
179 return -ENODEV;
180 }
181
182 if (!strcmp(mapping, "jeida-18")) {
183 lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
184 } else if (!strcmp(mapping, "jeida-24")) {
185 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
186 } else if (!strcmp(mapping, "vesa-24")) {
187 lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
188 } else {
189 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
190 np, "data-mapping");
191 return -EINVAL;
192 }
193
194 lvds->data_mirror = of_property_read_bool(np, "data-mirror");
195
196 return 0;
197 }
198
panel_lvds_probe(struct platform_device * pdev)199 static int panel_lvds_probe(struct platform_device *pdev)
200 {
201 struct panel_lvds *lvds;
202 struct device_node *np;
203 int ret;
204
205 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
206 if (!lvds)
207 return -ENOMEM;
208
209 lvds->dev = &pdev->dev;
210
211 ret = panel_lvds_parse_dt(lvds);
212 if (ret < 0)
213 return ret;
214
215 lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
216 if (IS_ERR(lvds->supply)) {
217 ret = PTR_ERR(lvds->supply);
218
219 if (ret != -ENODEV) {
220 if (ret != -EPROBE_DEFER)
221 dev_err(lvds->dev, "failed to request regulator: %d\n",
222 ret);
223 return ret;
224 }
225
226 lvds->supply = NULL;
227 }
228
229 /* Get GPIOs and backlight controller. */
230 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
231 GPIOD_OUT_LOW);
232 if (IS_ERR(lvds->enable_gpio)) {
233 ret = PTR_ERR(lvds->enable_gpio);
234 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
235 "enable", ret);
236 return ret;
237 }
238
239 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
240 GPIOD_OUT_HIGH);
241 if (IS_ERR(lvds->reset_gpio)) {
242 ret = PTR_ERR(lvds->reset_gpio);
243 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
244 "reset", ret);
245 return ret;
246 }
247
248 np = of_parse_phandle(lvds->dev->of_node, "backlight", 0);
249 if (np) {
250 lvds->backlight = of_find_backlight_by_node(np);
251 of_node_put(np);
252
253 if (!lvds->backlight)
254 return -EPROBE_DEFER;
255 }
256
257 /*
258 * TODO: Handle all power supplies specified in the DT node in a generic
259 * way for panels that don't care about power supply ordering. LVDS
260 * panels that require a specific power sequence will need a dedicated
261 * driver.
262 */
263
264 /* Register the panel. */
265 drm_panel_init(&lvds->panel);
266 lvds->panel.dev = lvds->dev;
267 lvds->panel.funcs = &panel_lvds_funcs;
268
269 ret = drm_panel_add(&lvds->panel);
270 if (ret < 0)
271 goto error;
272
273 dev_set_drvdata(lvds->dev, lvds);
274 return 0;
275
276 error:
277 put_device(&lvds->backlight->dev);
278 return ret;
279 }
280
panel_lvds_remove(struct platform_device * pdev)281 static int panel_lvds_remove(struct platform_device *pdev)
282 {
283 struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev);
284
285 drm_panel_remove(&lvds->panel);
286
287 panel_lvds_disable(&lvds->panel);
288
289 if (lvds->backlight)
290 put_device(&lvds->backlight->dev);
291
292 return 0;
293 }
294
295 static const struct of_device_id panel_lvds_of_table[] = {
296 { .compatible = "panel-lvds", },
297 { /* Sentinel */ },
298 };
299
300 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
301
302 static struct platform_driver panel_lvds_driver = {
303 .probe = panel_lvds_probe,
304 .remove = panel_lvds_remove,
305 .driver = {
306 .name = "panel-lvds",
307 .of_match_table = panel_lvds_of_table,
308 },
309 };
310
311 module_platform_driver(panel_lvds_driver);
312
313 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
314 MODULE_DESCRIPTION("LVDS Panel Driver");
315 MODULE_LICENSE("GPL");
316
