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