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 int ret;
203
204 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
205 if (!lvds)
206 return -ENOMEM;
207
208 lvds->dev = &pdev->dev;
209
210 ret = panel_lvds_parse_dt(lvds);
211 if (ret < 0)
212 return ret;
213
214 lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
215 if (IS_ERR(lvds->supply)) {
216 ret = PTR_ERR(lvds->supply);
217
218 if (ret != -ENODEV) {
219 if (ret != -EPROBE_DEFER)
220 dev_err(lvds->dev, "failed to request regulator: %d\n",
221 ret);
222 return ret;
223 }
224
225 lvds->supply = NULL;
226 }
227
228 /* Get GPIOs and backlight controller. */
229 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
230 GPIOD_OUT_LOW);
231 if (IS_ERR(lvds->enable_gpio)) {
232 ret = PTR_ERR(lvds->enable_gpio);
233 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
234 "enable", ret);
235 return ret;
236 }
237
238 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
239 GPIOD_OUT_HIGH);
240 if (IS_ERR(lvds->reset_gpio)) {
241 ret = PTR_ERR(lvds->reset_gpio);
242 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
243 "reset", ret);
244 return ret;
245 }
246
247 lvds->backlight = devm_of_find_backlight(lvds->dev);
248 if (IS_ERR(lvds->backlight))
249 return PTR_ERR(lvds->backlight);
250
251 /*
252 * TODO: Handle all power supplies specified in the DT node in a generic
253 * way for panels that don't care about power supply ordering. LVDS
254 * panels that require a specific power sequence will need a dedicated
255 * driver.
256 */
257
258 /* Register the panel. */
259 drm_panel_init(&lvds->panel);
260 lvds->panel.dev = lvds->dev;
261 lvds->panel.funcs = &panel_lvds_funcs;
262
263 ret = drm_panel_add(&lvds->panel);
264 if (ret < 0)
265 return ret;
266
267 dev_set_drvdata(lvds->dev, lvds);
268 return 0;
269 }
270
panel_lvds_remove(struct platform_device * pdev)271 static int panel_lvds_remove(struct platform_device *pdev)
272 {
273 struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev);
274
275 drm_panel_remove(&lvds->panel);
276
277 panel_lvds_disable(&lvds->panel);
278
279 return 0;
280 }
281
282 static const struct of_device_id panel_lvds_of_table[] = {
283 { .compatible = "panel-lvds", },
284 { /* Sentinel */ },
285 };
286
287 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
288
289 static struct platform_driver panel_lvds_driver = {
290 .probe = panel_lvds_probe,
291 .remove = panel_lvds_remove,
292 .driver = {
293 .name = "panel-lvds",
294 .of_match_table = panel_lvds_of_table,
295 },
296 };
297
298 module_platform_driver(panel_lvds_driver);
299
300 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
301 MODULE_DESCRIPTION("LVDS Panel Driver");
302 MODULE_LICENSE("GPL");
303