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.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_of.h>
24 #include <drm/drm_panel.h>
25
26 struct panel_lvds {
27 struct drm_panel panel;
28 struct device *dev;
29
30 const char *label;
31 struct drm_display_mode dmode;
32 u32 bus_flags;
33 unsigned int bus_format;
34
35 struct regulator *supply;
36
37 struct gpio_desc *enable_gpio;
38 struct gpio_desc *reset_gpio;
39
40 enum drm_panel_orientation orientation;
41 };
42
to_panel_lvds(struct drm_panel * panel)43 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
44 {
45 return container_of(panel, struct panel_lvds, panel);
46 }
47
panel_lvds_unprepare(struct drm_panel * panel)48 static int panel_lvds_unprepare(struct drm_panel *panel)
49 {
50 struct panel_lvds *lvds = to_panel_lvds(panel);
51
52 if (lvds->enable_gpio)
53 gpiod_set_value_cansleep(lvds->enable_gpio, 0);
54
55 if (lvds->supply)
56 regulator_disable(lvds->supply);
57
58 return 0;
59 }
60
panel_lvds_prepare(struct drm_panel * panel)61 static int panel_lvds_prepare(struct drm_panel *panel)
62 {
63 struct panel_lvds *lvds = to_panel_lvds(panel);
64
65 if (lvds->supply) {
66 int err;
67
68 err = regulator_enable(lvds->supply);
69 if (err < 0) {
70 dev_err(lvds->dev, "failed to enable supply: %d\n",
71 err);
72 return err;
73 }
74 }
75
76 if (lvds->enable_gpio)
77 gpiod_set_value_cansleep(lvds->enable_gpio, 1);
78
79 return 0;
80 }
81
panel_lvds_get_modes(struct drm_panel * panel,struct drm_connector * connector)82 static int panel_lvds_get_modes(struct drm_panel *panel,
83 struct drm_connector *connector)
84 {
85 struct panel_lvds *lvds = to_panel_lvds(panel);
86 struct drm_display_mode *mode;
87
88 mode = drm_mode_duplicate(connector->dev, &lvds->dmode);
89 if (!mode)
90 return 0;
91
92 mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
93 drm_mode_probed_add(connector, mode);
94
95 connector->display_info.width_mm = lvds->dmode.width_mm;
96 connector->display_info.height_mm = lvds->dmode.height_mm;
97 drm_display_info_set_bus_formats(&connector->display_info,
98 &lvds->bus_format, 1);
99 connector->display_info.bus_flags = lvds->bus_flags;
100
101 /*
102 * TODO: Remove once all drm drivers call
103 * drm_connector_set_orientation_from_panel()
104 */
105 drm_connector_set_panel_orientation(connector, lvds->orientation);
106
107 return 1;
108 }
109
panel_lvds_get_orientation(struct drm_panel * panel)110 static enum drm_panel_orientation panel_lvds_get_orientation(struct drm_panel *panel)
111 {
112 struct panel_lvds *lvds = to_panel_lvds(panel);
113
114 return lvds->orientation;
115 }
116
117 static const struct drm_panel_funcs panel_lvds_funcs = {
118 .unprepare = panel_lvds_unprepare,
119 .prepare = panel_lvds_prepare,
120 .get_modes = panel_lvds_get_modes,
121 .get_orientation = panel_lvds_get_orientation,
122 };
123
panel_lvds_parse_dt(struct panel_lvds * lvds)124 static int panel_lvds_parse_dt(struct panel_lvds *lvds)
125 {
126 struct device_node *np = lvds->dev->of_node;
127 int ret;
128
129 ret = of_drm_get_panel_orientation(np, &lvds->orientation);
130 if (ret < 0) {
131 dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
132 return ret;
133 }
134
135 ret = of_get_drm_panel_display_mode(np, &lvds->dmode, &lvds->bus_flags);
136 if (ret < 0) {
137 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
138 np, ret);
139 return ret;
140 }
141
142 of_property_read_string(np, "label", &lvds->label);
143
144 ret = drm_of_lvds_get_data_mapping(np);
145 if (ret < 0) {
146 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
147 np, "data-mapping");
148 return ret;
149 }
150
151 lvds->bus_format = ret;
152
153 lvds->bus_flags |= of_property_read_bool(np, "data-mirror") ?
154 DRM_BUS_FLAG_DATA_LSB_TO_MSB :
155 DRM_BUS_FLAG_DATA_MSB_TO_LSB;
156
157 return 0;
158 }
159
panel_lvds_probe(struct platform_device * pdev)160 static int panel_lvds_probe(struct platform_device *pdev)
161 {
162 struct panel_lvds *lvds;
163 int ret;
164
165 lvds = devm_drm_panel_alloc(&pdev->dev, struct panel_lvds, panel,
166 &panel_lvds_funcs,
167 DRM_MODE_CONNECTOR_LVDS);
168 if (IS_ERR(lvds))
169 return PTR_ERR(lvds);
170
171 lvds->dev = &pdev->dev;
172
173 ret = panel_lvds_parse_dt(lvds);
174 if (ret < 0)
175 return ret;
176
177 lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
178 if (IS_ERR(lvds->supply)) {
179 ret = PTR_ERR(lvds->supply);
180
181 if (ret != -ENODEV) {
182 if (ret != -EPROBE_DEFER)
183 dev_err(lvds->dev, "failed to request regulator: %d\n",
184 ret);
185 return ret;
186 }
187
188 lvds->supply = NULL;
189 }
190
191 /* Get GPIOs and backlight controller. */
192 lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
193 GPIOD_OUT_LOW);
194 if (IS_ERR(lvds->enable_gpio)) {
195 ret = PTR_ERR(lvds->enable_gpio);
196 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
197 "enable", ret);
198 return ret;
199 }
200
201 lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
202 GPIOD_OUT_HIGH);
203 if (IS_ERR(lvds->reset_gpio)) {
204 ret = PTR_ERR(lvds->reset_gpio);
205 dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
206 "reset", ret);
207 return ret;
208 }
209
210 /*
211 * TODO: Handle all power supplies specified in the DT node in a generic
212 * way for panels that don't care about power supply ordering. LVDS
213 * panels that require a specific power sequence will need a dedicated
214 * driver.
215 */
216
217 ret = drm_panel_of_backlight(&lvds->panel);
218 if (ret)
219 return ret;
220
221 drm_panel_add(&lvds->panel);
222
223 dev_set_drvdata(lvds->dev, lvds);
224 return 0;
225 }
226
panel_lvds_remove(struct platform_device * pdev)227 static void panel_lvds_remove(struct platform_device *pdev)
228 {
229 struct panel_lvds *lvds = platform_get_drvdata(pdev);
230
231 drm_panel_remove(&lvds->panel);
232
233 drm_panel_disable(&lvds->panel);
234 }
235
236 static const struct of_device_id panel_lvds_of_table[] = {
237 { .compatible = "panel-lvds", },
238 { /* Sentinel */ },
239 };
240
241 MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
242
243 static struct platform_driver panel_lvds_driver = {
244 .probe = panel_lvds_probe,
245 .remove = panel_lvds_remove,
246 .driver = {
247 .name = "panel-lvds",
248 .of_match_table = panel_lvds_of_table,
249 },
250 };
251
252 module_platform_driver(panel_lvds_driver);
253
254 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
255 MODULE_DESCRIPTION("LVDS Panel Driver");
256 MODULE_LICENSE("GPL");
257