panel-lvds.c

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