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	enum drm_panel_orientation orientation;
 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_unprepare(struct drm_panel *panel)
 50{
 51	struct panel_lvds *lvds = to_panel_lvds(panel);
 52
 53	if (lvds->enable_gpio)
 54		gpiod_set_value_cansleep(lvds->enable_gpio, 0);
 55
 56	if (lvds->supply)
 57		regulator_disable(lvds->supply);
 58
 59	return 0;
 60}
 61
 62static int panel_lvds_prepare(struct drm_panel *panel)
 63{
 64	struct panel_lvds *lvds = to_panel_lvds(panel);
 65
 66	if (lvds->supply) {
 67		int err;
 68
 69		err = regulator_enable(lvds->supply);
 70		if (err < 0) {
 71			dev_err(lvds->dev, "failed to enable supply: %d\n",
 72				err);
 73			return err;
 74		}
 75	}
 76
 77	if (lvds->enable_gpio)
 78		gpiod_set_value_cansleep(lvds->enable_gpio, 1);
 79
 80	return 0;
 81}
 82
 83static int panel_lvds_get_modes(struct drm_panel *panel,
 84				struct drm_connector *connector)
 85{
 86	struct panel_lvds *lvds = to_panel_lvds(panel);
 87	struct drm_display_mode *mode;
 88
 89	mode = drm_mode_create(connector->dev);
 90	if (!mode)
 91		return 0;
 92
 93	drm_display_mode_from_videomode(&lvds->video_mode, mode);
 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->width;
 98	connector->display_info.height_mm = lvds->height;
 99	drm_display_info_set_bus_formats(&connector->display_info,
100					 &lvds->bus_format, 1);
101	connector->display_info.bus_flags = lvds->data_mirror
102					  ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
103					  : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
104	drm_connector_set_panel_orientation(connector, lvds->orientation);
105
106	return 1;
107}
108
109static const struct drm_panel_funcs panel_lvds_funcs = {
110	.unprepare = panel_lvds_unprepare,
111	.prepare = panel_lvds_prepare,
112	.get_modes = panel_lvds_get_modes,
113};
114
115static int panel_lvds_parse_dt(struct panel_lvds *lvds)
116{
117	struct device_node *np = lvds->dev->of_node;
118	struct display_timing timing;
119	const char *mapping;
120	int ret;
121
122	ret = of_drm_get_panel_orientation(np, &lvds->orientation);
123	if (ret < 0) {
124		dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
125		return ret;
126	}
127
128	ret = of_get_display_timing(np, "panel-timing", &timing);
129	if (ret < 0) {
130		dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
131			np, ret);
132		return ret;
133	}
134
135	videomode_from_timing(&timing, &lvds->video_mode);
136
137	ret = of_property_read_u32(np, "width-mm", &lvds->width);
138	if (ret < 0) {
139		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
140			np, "width-mm");
141		return -ENODEV;
142	}
143	ret = of_property_read_u32(np, "height-mm", &lvds->height);
144	if (ret < 0) {
145		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
146			np, "height-mm");
147		return -ENODEV;
148	}
149
150	of_property_read_string(np, "label", &lvds->label);
151
152	ret = of_property_read_string(np, "data-mapping", &mapping);
153	if (ret < 0) {
154		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
155			np, "data-mapping");
156		return -ENODEV;
157	}
158
159	if (!strcmp(mapping, "jeida-18")) {
160		lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
161	} else if (!strcmp(mapping, "jeida-24")) {
162		lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
163	} else if (!strcmp(mapping, "vesa-24")) {
164		lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
165	} else {
166		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
167			np, "data-mapping");
168		return -EINVAL;
169	}
170
171	lvds->data_mirror = of_property_read_bool(np, "data-mirror");
172
173	return 0;
174}
175
176static int panel_lvds_probe(struct platform_device *pdev)
177{
178	struct panel_lvds *lvds;
179	int ret;
180
181	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
182	if (!lvds)
183		return -ENOMEM;
184
185	lvds->dev = &pdev->dev;
186
187	ret = panel_lvds_parse_dt(lvds);
188	if (ret < 0)
189		return ret;
190
191	lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
192	if (IS_ERR(lvds->supply)) {
193		ret = PTR_ERR(lvds->supply);
194
195		if (ret != -ENODEV) {
196			if (ret != -EPROBE_DEFER)
197				dev_err(lvds->dev, "failed to request regulator: %d\n",
198					ret);
199			return ret;
200		}
201
202		lvds->supply = NULL;
203	}
204
205	/* Get GPIOs and backlight controller. */
206	lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
207						     GPIOD_OUT_LOW);
208	if (IS_ERR(lvds->enable_gpio)) {
209		ret = PTR_ERR(lvds->enable_gpio);
210		dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
211			"enable", ret);
212		return ret;
213	}
214
215	lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
216						     GPIOD_OUT_HIGH);
217	if (IS_ERR(lvds->reset_gpio)) {
218		ret = PTR_ERR(lvds->reset_gpio);
219		dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
220			"reset", ret);
221		return ret;
222	}
223
224	/*
225	 * TODO: Handle all power supplies specified in the DT node in a generic
226	 * way for panels that don't care about power supply ordering. LVDS
227	 * panels that require a specific power sequence will need a dedicated
228	 * driver.
229	 */
230
231	/* Register the panel. */
232	drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
233		       DRM_MODE_CONNECTOR_LVDS);
234
235	ret = drm_panel_of_backlight(&lvds->panel);
236	if (ret)
237		return ret;
238
239	drm_panel_add(&lvds->panel);
240
241	dev_set_drvdata(lvds->dev, lvds);
242	return 0;
243}
244
245static int panel_lvds_remove(struct platform_device *pdev)
246{
247	struct panel_lvds *lvds = platform_get_drvdata(pdev);
248
249	drm_panel_remove(&lvds->panel);
250
251	drm_panel_disable(&lvds->panel);
252
253	return 0;
254}
255
256static const struct of_device_id panel_lvds_of_table[] = {
257	{ .compatible = "panel-lvds", },
258	{ /* Sentinel */ },
259};
260
261MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
262
263static struct platform_driver panel_lvds_driver = {
264	.probe		= panel_lvds_probe,
265	.remove		= panel_lvds_remove,
266	.driver		= {
267		.name	= "panel-lvds",
268		.of_match_table = panel_lvds_of_table,
269	},
270};
271
272module_platform_driver(panel_lvds_driver);
273
274MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
275MODULE_DESCRIPTION("LVDS Panel Driver");
276MODULE_LICENSE("GPL");