1/*
  2 * Generic LVDS panel driver
  3 *
  4 * Copyright (C) 2016 Laurent Pinchart
  5 * Copyright (C) 2016 Renesas Electronics Corporation
  6 *
  7 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 */
 14
 15#include <linux/backlight.h>
 16#include <linux/gpio/consumer.h>
 17#include <linux/module.h>
 18#include <linux/of_platform.h>
 19#include <linux/platform_device.h>
 20#include <linux/regulator/consumer.h>
 21#include <linux/slab.h>
 22
 23#include <drm/drmP.h>
 24#include <drm/drm_crtc.h>
 25#include <drm/drm_panel.h>
 26
 27#include <video/display_timing.h>
 28#include <video/of_display_timing.h>
 29#include <video/videomode.h>
 30
 31struct panel_lvds {
 32	struct drm_panel panel;
 33	struct device *dev;
 34
 35	const char *label;
 36	unsigned int width;
 37	unsigned int height;
 38	struct videomode video_mode;
 39	unsigned int bus_format;
 40	bool data_mirror;
 41
 42	struct backlight_device *backlight;
 43	struct regulator *supply;
 44
 45	struct gpio_desc *enable_gpio;
 46	struct gpio_desc *reset_gpio;
 47};
 48
 49static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
 50{
 51	return container_of(panel, struct panel_lvds, panel);
 52}
 53
 54static int panel_lvds_disable(struct drm_panel *panel)
 55{
 56	struct panel_lvds *lvds = to_panel_lvds(panel);
 57
 58	if (lvds->backlight) {
 59		lvds->backlight->props.power = FB_BLANK_POWERDOWN;
 60		lvds->backlight->props.state |= BL_CORE_FBBLANK;
 61		backlight_update_status(lvds->backlight);
 62	}
 63
 64	return 0;
 65}
 66
 67static int panel_lvds_unprepare(struct drm_panel *panel)
 68{
 69	struct panel_lvds *lvds = to_panel_lvds(panel);
 70
 71	if (lvds->enable_gpio)
 72		gpiod_set_value_cansleep(lvds->enable_gpio, 0);
 73
 74	if (lvds->supply)
 75		regulator_disable(lvds->supply);
 76
 77	return 0;
 78}
 79
 80static int panel_lvds_prepare(struct drm_panel *panel)
 81{
 82	struct panel_lvds *lvds = to_panel_lvds(panel);
 83
 84	if (lvds->supply) {
 85		int err;
 86
 87		err = regulator_enable(lvds->supply);
 88		if (err < 0) {
 89			dev_err(lvds->dev, "failed to enable supply: %d\n",
 90				err);
 91			return err;
 92		}
 93	}
 94
 95	if (lvds->enable_gpio)
 96		gpiod_set_value_cansleep(lvds->enable_gpio, 1);
 97
 98	return 0;
 99}
100
101static int panel_lvds_enable(struct drm_panel *panel)
102{
103	struct panel_lvds *lvds = to_panel_lvds(panel);
104
105	if (lvds->backlight) {
106		lvds->backlight->props.state &= ~BL_CORE_FBBLANK;
107		lvds->backlight->props.power = FB_BLANK_UNBLANK;
108		backlight_update_status(lvds->backlight);
109	}
110
111	return 0;
112}
113
114static int panel_lvds_get_modes(struct drm_panel *panel)
115{
116	struct panel_lvds *lvds = to_panel_lvds(panel);
117	struct drm_connector *connector = lvds->panel.connector;
118	struct drm_display_mode *mode;
119
120	mode = drm_mode_create(lvds->panel.drm);
121	if (!mode)
122		return 0;
123
124	drm_display_mode_from_videomode(&lvds->video_mode, mode);
125	mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
126	drm_mode_probed_add(connector, mode);
127
128	connector->display_info.width_mm = lvds->width;
129	connector->display_info.height_mm = lvds->height;
130	drm_display_info_set_bus_formats(&connector->display_info,
131					 &lvds->bus_format, 1);
132	connector->display_info.bus_flags = lvds->data_mirror
133					  ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
134					  : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
135
136	return 1;
137}
138
139static const struct drm_panel_funcs panel_lvds_funcs = {
140	.disable = panel_lvds_disable,
141	.unprepare = panel_lvds_unprepare,
142	.prepare = panel_lvds_prepare,
143	.enable = panel_lvds_enable,
144	.get_modes = panel_lvds_get_modes,
145};
146
147static int panel_lvds_parse_dt(struct panel_lvds *lvds)
148{
149	struct device_node *np = lvds->dev->of_node;
150	struct display_timing timing;
151	const char *mapping;
152	int ret;
153
154	ret = of_get_display_timing(np, "panel-timing", &timing);
155	if (ret < 0)
156		return ret;
157
158	videomode_from_timing(&timing, &lvds->video_mode);
159
160	ret = of_property_read_u32(np, "width-mm", &lvds->width);
161	if (ret < 0) {
162		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
163			np, "width-mm");
164		return -ENODEV;
165	}
166	ret = of_property_read_u32(np, "height-mm", &lvds->height);
167	if (ret < 0) {
168		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
169			np, "height-mm");
170		return -ENODEV;
171	}
172
173	of_property_read_string(np, "label", &lvds->label);
174
175	ret = of_property_read_string(np, "data-mapping", &mapping);
176	if (ret < 0) {
177		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
178			np, "data-mapping");
179		return -ENODEV;
180	}
181
182	if (!strcmp(mapping, "jeida-18")) {
183		lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
184	} else if (!strcmp(mapping, "jeida-24")) {
185		lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
186	} else if (!strcmp(mapping, "vesa-24")) {
187		lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
188	} else {
189		dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
190			np, "data-mapping");
191		return -EINVAL;
192	}
193
194	lvds->data_mirror = of_property_read_bool(np, "data-mirror");
195
196	return 0;
197}
198
199static int panel_lvds_probe(struct platform_device *pdev)
200{
201	struct panel_lvds *lvds;
202	struct device_node *np;
203	int ret;
204
205	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
206	if (!lvds)
207		return -ENOMEM;
208
209	lvds->dev = &pdev->dev;
210
211	ret = panel_lvds_parse_dt(lvds);
212	if (ret < 0)
213		return ret;
214
215	lvds->supply = devm_regulator_get_optional(lvds->dev, "power");
216	if (IS_ERR(lvds->supply)) {
217		ret = PTR_ERR(lvds->supply);
218
219		if (ret != -ENODEV) {
220			if (ret != -EPROBE_DEFER)
221				dev_err(lvds->dev, "failed to request regulator: %d\n",
222					ret);
223			return ret;
224		}
225
226		lvds->supply = NULL;
227	}
228
229	/* Get GPIOs and backlight controller. */
230	lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
231						     GPIOD_OUT_LOW);
232	if (IS_ERR(lvds->enable_gpio)) {
233		ret = PTR_ERR(lvds->enable_gpio);
234		dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
235			"enable", ret);
236		return ret;
237	}
238
239	lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
240						     GPIOD_OUT_HIGH);
241	if (IS_ERR(lvds->reset_gpio)) {
242		ret = PTR_ERR(lvds->reset_gpio);
243		dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
244			"reset", ret);
245		return ret;
246	}
247
248	np = of_parse_phandle(lvds->dev->of_node, "backlight", 0);
249	if (np) {
250		lvds->backlight = of_find_backlight_by_node(np);
251		of_node_put(np);
252
253		if (!lvds->backlight)
254			return -EPROBE_DEFER;
255	}
256
257	/*
258	 * TODO: Handle all power supplies specified in the DT node in a generic
259	 * way for panels that don't care about power supply ordering. LVDS
260	 * panels that require a specific power sequence will need a dedicated
261	 * driver.
262	 */
263
264	/* Register the panel. */
265	drm_panel_init(&lvds->panel);
266	lvds->panel.dev = lvds->dev;
267	lvds->panel.funcs = &panel_lvds_funcs;
268
269	ret = drm_panel_add(&lvds->panel);
270	if (ret < 0)
271		goto error;
272
273	dev_set_drvdata(lvds->dev, lvds);
274	return 0;
275
276error:
277	put_device(&lvds->backlight->dev);
278	return ret;
279}
280
281static int panel_lvds_remove(struct platform_device *pdev)
282{
283	struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev);
284
285	drm_panel_detach(&lvds->panel);
286	drm_panel_remove(&lvds->panel);
287
288	panel_lvds_disable(&lvds->panel);
289
290	if (lvds->backlight)
291		put_device(&lvds->backlight->dev);
292
293	return 0;
294}
295
296static const struct of_device_id panel_lvds_of_table[] = {
297	{ .compatible = "panel-lvds", },
298	{ /* Sentinel */ },
299};
300
301MODULE_DEVICE_TABLE(of, panel_lvds_of_table);
302
303static struct platform_driver panel_lvds_driver = {
304	.probe		= panel_lvds_probe,
305	.remove		= panel_lvds_remove,
306	.driver		= {
307		.name	= "panel-lvds",
308		.of_match_table = panel_lvds_of_table,
309	},
310};
311
312module_platform_driver(panel_lvds_driver);
313
314MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
315MODULE_DESCRIPTION("LVDS Panel Driver");
316MODULE_LICENSE("GPL");