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(lvds->enable_gpio, 0);
 56
 57	if (lvds->supply)
 58		regulator_disable(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(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(lvds->enable_gpio, 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(connector->dev, &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(&connector->display_info,
100					 &lvds->bus_format, 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, 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, &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, &lvds->dmode, &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, "label", &lvds->label);
145
146	ret = drm_of_lvds_get_data_mapping(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, "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(&pdev->dev, 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(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	/* Register the panel. */
218	drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
219		       DRM_MODE_CONNECTOR_LVDS);
220
221	ret = drm_panel_of_backlight(&lvds->panel);
222	if (ret)
223		return ret;
224
225	drm_panel_add(&lvds->panel);
226
227	dev_set_drvdata(lvds->dev, 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(&lvds->panel);
236
237	drm_panel_disable(&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");