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
26struct panel_lvds {
27 struct drm_panel panel;
28 struct device *dev;
29
30 const char *label;
31 unsigned int width;
32 unsigned int height;
33 struct drm_display_mode dmode;
34 u32 bus_flags;
35 unsigned int bus_format;
36
37 struct regulator *supply;
38
39 struct gpio_desc *enable_gpio;
40 struct gpio_desc *reset_gpio;
41
42 enum drm_panel_orientation orientation;
43};
44
45static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
46{
47 return container_of(panel, struct panel_lvds, panel);
48}
49
50static int panel_lvds_unprepare(struct drm_panel *panel)
51{
52 struct panel_lvds *lvds = to_panel_lvds(panel);
53
54 if (lvds->enable_gpio)
55 gpiod_set_value_cansleep(desc: lvds->enable_gpio, value: 0);
56
57 if (lvds->supply)
58 regulator_disable(regulator: lvds->supply);
59
60 return 0;
61}
62
63static int panel_lvds_prepare(struct drm_panel *panel)
64{
65 struct panel_lvds *lvds = to_panel_lvds(panel);
66
67 if (lvds->supply) {
68 int err;
69
70 err = regulator_enable(regulator: lvds->supply);
71 if (err < 0) {
72 dev_err(lvds->dev, "failed to enable supply: %d\n",
73 err);
74 return err;
75 }
76 }
77
78 if (lvds->enable_gpio)
79 gpiod_set_value_cansleep(desc: lvds->enable_gpio, value: 1);
80
81 return 0;
82}
83
84static int panel_lvds_get_modes(struct drm_panel *panel,
85 struct drm_connector *connector)
86{
87 struct panel_lvds *lvds = to_panel_lvds(panel);
88 struct drm_display_mode *mode;
89
90 mode = drm_mode_duplicate(dev: connector->dev, mode: &lvds->dmode);
91 if (!mode)
92 return 0;
93
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->dmode.width_mm;
98 connector->display_info.height_mm = lvds->dmode.height_mm;
99 drm_display_info_set_bus_formats(info: &connector->display_info,
100 formats: &lvds->bus_format, num_formats: 1);
101 connector->display_info.bus_flags = lvds->bus_flags;
102
103 /*
104 * TODO: Remove once all drm drivers call
105 * drm_connector_set_orientation_from_panel()
106 */
107 drm_connector_set_panel_orientation(connector, panel_orientation: lvds->orientation);
108
109 return 1;
110}
111
112static enum drm_panel_orientation panel_lvds_get_orientation(struct drm_panel *panel)
113{
114 struct panel_lvds *lvds = to_panel_lvds(panel);
115
116 return lvds->orientation;
117}
118
119static const struct drm_panel_funcs panel_lvds_funcs = {
120 .unprepare = panel_lvds_unprepare,
121 .prepare = panel_lvds_prepare,
122 .get_modes = panel_lvds_get_modes,
123 .get_orientation = panel_lvds_get_orientation,
124};
125
126static int panel_lvds_parse_dt(struct panel_lvds *lvds)
127{
128 struct device_node *np = lvds->dev->of_node;
129 int ret;
130
131 ret = of_drm_get_panel_orientation(np, orientation: &lvds->orientation);
132 if (ret < 0) {
133 dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
134 return ret;
135 }
136
137 ret = of_get_drm_panel_display_mode(np, dmode: &lvds->dmode, bus_flags: &lvds->bus_flags);
138 if (ret < 0) {
139 dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
140 np, ret);
141 return ret;
142 }
143
144 of_property_read_string(np, propname: "label", out_string: &lvds->label);
145
146 ret = drm_of_lvds_get_data_mapping(port: np);
147 if (ret < 0) {
148 dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
149 np, "data-mapping");
150 return ret;
151 }
152
153 lvds->bus_format = ret;
154
155 lvds->bus_flags |= of_property_read_bool(np, propname: "data-mirror") ?
156 DRM_BUS_FLAG_DATA_LSB_TO_MSB :
157 DRM_BUS_FLAG_DATA_MSB_TO_LSB;
158
159 return 0;
160}
161
162static int panel_lvds_probe(struct platform_device *pdev)
163{
164 struct panel_lvds *lvds;
165 int ret;
166
167 lvds = devm_kzalloc(dev: &pdev->dev, size: sizeof(*lvds), GFP_KERNEL);
168 if (!lvds)
169 return -ENOMEM;
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(dev: lvds->dev, id: "power");
178 if (IS_ERR(ptr: lvds->supply)) {
179 ret = PTR_ERR(ptr: 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(dev: lvds->dev, con_id: "enable",
193 flags: GPIOD_OUT_LOW);
194 if (IS_ERR(ptr: lvds->enable_gpio)) {
195 ret = PTR_ERR(ptr: 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(dev: lvds->dev, con_id: "reset",
202 flags: GPIOD_OUT_HIGH);
203 if (IS_ERR(ptr: lvds->reset_gpio)) {
204 ret = PTR_ERR(ptr: 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 /* Register the panel. */
218 drm_panel_init(panel: &lvds->panel, dev: lvds->dev, funcs: &panel_lvds_funcs,
219 DRM_MODE_CONNECTOR_LVDS);
220
221 ret = drm_panel_of_backlight(panel: &lvds->panel);
222 if (ret)
223 return ret;
224
225 drm_panel_add(panel: &lvds->panel);
226
227 dev_set_drvdata(dev: lvds->dev, data: lvds);
228 return 0;
229}
230
231static void panel_lvds_remove(struct platform_device *pdev)
232{
233 struct panel_lvds *lvds = platform_get_drvdata(pdev);
234
235 drm_panel_remove(panel: &lvds->panel);
236
237 drm_panel_disable(panel: &lvds->panel);
238}
239
240static const struct of_device_id panel_lvds_of_table[] = {
241 { .compatible = "panel-lvds", },
242 { /* Sentinel */ },
243};
244
245MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
246
247static struct platform_driver panel_lvds_driver = {
248 .probe = panel_lvds_probe,
249 .remove = panel_lvds_remove,
250 .driver = {
251 .name = "panel-lvds",
252 .of_match_table = panel_lvds_of_table,
253 },
254};
255
256module_platform_driver(panel_lvds_driver);
257
258MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
259MODULE_DESCRIPTION("LVDS Panel Driver");
260MODULE_LICENSE("GPL");
261

source code of linux/drivers/gpu/drm/panel/panel-lvds.c