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