1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2019 Renesas Electronics Corporation
  4 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  5 */
  6
  7#include <linux/gpio/consumer.h>
  8#include <linux/module.h>
  9#include <linux/of.h>
 10#include <linux/of_device.h>
 11#include <linux/of_graph.h>
 12#include <linux/platform_device.h>
 13#include <linux/regulator/consumer.h>
 14
 15#include <drm/drm_atomic_helper.h>
 16#include <drm/drm_bridge.h>
 17#include <drm/drm_of.h>
 18#include <drm/drm_panel.h>
 19
 20struct lvds_codec {
 21	struct device *dev;
 22	struct drm_bridge bridge;
 23	struct drm_bridge *panel_bridge;
 24	struct drm_bridge_timings timings;
 25	struct regulator *vcc;
 26	struct gpio_desc *powerdown_gpio;
 27	u32 connector_type;
 28	unsigned int bus_format;
 29};
 30
 31static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
 32{
 33	return container_of(bridge, struct lvds_codec, bridge);
 34}
 35
 36static int lvds_codec_attach(struct drm_bridge *bridge,
 37			     enum drm_bridge_attach_flags flags)
 38{
 39	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
 40
 41	return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
 42				 bridge, flags);
 43}
 44
 45static void lvds_codec_enable(struct drm_bridge *bridge)
 46{
 47	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
 48	int ret;
 49
 50	ret = regulator_enable(lvds_codec->vcc);
 51	if (ret) {
 52		dev_err(lvds_codec->dev,
 53			"Failed to enable regulator \"vcc\": %d\n", ret);
 54		return;
 55	}
 56
 57	if (lvds_codec->powerdown_gpio)
 58		gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
 59}
 60
 61static void lvds_codec_disable(struct drm_bridge *bridge)
 62{
 63	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
 64	int ret;
 65
 66	if (lvds_codec->powerdown_gpio)
 67		gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
 68
 69	ret = regulator_disable(lvds_codec->vcc);
 70	if (ret)
 71		dev_err(lvds_codec->dev,
 72			"Failed to disable regulator \"vcc\": %d\n", ret);
 73}
 74
 75static const struct drm_bridge_funcs funcs = {
 76	.attach = lvds_codec_attach,
 77	.enable = lvds_codec_enable,
 78	.disable = lvds_codec_disable,
 79};
 80
 81#define MAX_INPUT_SEL_FORMATS 1
 82static u32 *
 83lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
 84				     struct drm_bridge_state *bridge_state,
 85				     struct drm_crtc_state *crtc_state,
 86				     struct drm_connector_state *conn_state,
 87				     u32 output_fmt,
 88				     unsigned int *num_input_fmts)
 89{
 90	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
 91	u32 *input_fmts;
 92
 93	*num_input_fmts = 0;
 94
 95	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
 96			     GFP_KERNEL);
 97	if (!input_fmts)
 98		return NULL;
 99
100	input_fmts[0] = lvds_codec->bus_format;
101	*num_input_fmts = MAX_INPUT_SEL_FORMATS;
102
103	return input_fmts;
104}
105
106static const struct drm_bridge_funcs funcs_decoder = {
107	.attach = lvds_codec_attach,
108	.enable = lvds_codec_enable,
109	.disable = lvds_codec_disable,
110	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
111	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
112	.atomic_reset = drm_atomic_helper_bridge_reset,
113	.atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
114};
115
116static int lvds_codec_probe(struct platform_device *pdev)
117{
118	struct device *dev = &pdev->dev;
119	struct device_node *panel_node;
120	struct device_node *bus_node;
121	struct drm_panel *panel;
122	struct lvds_codec *lvds_codec;
123	u32 val;
124	int ret;
125
126	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
127	if (!lvds_codec)
128		return -ENOMEM;
129
130	lvds_codec->dev = &pdev->dev;
131	lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
132
133	lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
134	if (IS_ERR(lvds_codec->vcc))
135		return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
136				     "Unable to get \"vcc\" supply\n");
137
138	lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
139							     GPIOD_OUT_HIGH);
140	if (IS_ERR(lvds_codec->powerdown_gpio))
141		return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
142				     "powerdown GPIO failure\n");
143
144	/* Locate the panel DT node. */
145	panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
146	if (!panel_node) {
147		dev_dbg(dev, "panel DT node not found\n");
148		return -ENXIO;
149	}
150
151	panel = of_drm_find_panel(panel_node);
152	of_node_put(panel_node);
153	if (IS_ERR(panel)) {
154		dev_dbg(dev, "panel not found, deferring probe\n");
155		return PTR_ERR(panel);
156	}
157
158	lvds_codec->panel_bridge =
159		devm_drm_panel_bridge_add_typed(dev, panel,
160						lvds_codec->connector_type);
161	if (IS_ERR(lvds_codec->panel_bridge))
162		return PTR_ERR(lvds_codec->panel_bridge);
163
164	lvds_codec->bridge.funcs = &funcs;
165
166	/*
167	 * Decoder input LVDS format is a property of the decoder chip or even
168	 * its strapping. Handle data-mapping the same way lvds-panel does. In
169	 * case data-mapping is not present, do nothing, since there are still
170	 * legacy bindings which do not specify this property.
171	 */
172	if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
173		bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
174		if (!bus_node) {
175			dev_dbg(dev, "bus DT node not found\n");
176			return -ENXIO;
177		}
178
179		ret = drm_of_lvds_get_data_mapping(bus_node);
180		of_node_put(bus_node);
181		if (ret == -ENODEV) {
182			dev_warn(dev, "missing 'data-mapping' DT property\n");
183		} else if (ret < 0) {
184			dev_err(dev, "invalid 'data-mapping' DT property\n");
185			return ret;
186		} else {
187			lvds_codec->bus_format = ret;
188			lvds_codec->bridge.funcs = &funcs_decoder;
189		}
190	}
191
192	/*
193	 * Encoder might sample data on different clock edge than the display,
194	 * for example OnSemi FIN3385 has a dedicated strapping pin to select
195	 * the sampling edge.
196	 */
197	if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
198	    !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
199		lvds_codec->timings.input_bus_flags = val ?
200			DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
201			DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
202	}
203
204	/*
205	 * The panel_bridge bridge is attached to the panel's of_node,
206	 * but we need a bridge attached to our of_node for our user
207	 * to look up.
208	 */
209	lvds_codec->bridge.of_node = dev->of_node;
210	lvds_codec->bridge.timings = &lvds_codec->timings;
211	drm_bridge_add(&lvds_codec->bridge);
212
213	platform_set_drvdata(pdev, lvds_codec);
214
215	return 0;
216}
217
218static int lvds_codec_remove(struct platform_device *pdev)
219{
220	struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
221
222	drm_bridge_remove(&lvds_codec->bridge);
223
224	return 0;
225}
226
227static const struct of_device_id lvds_codec_match[] = {
228	{
229		.compatible = "lvds-decoder",
230		.data = (void *)DRM_MODE_CONNECTOR_DPI,
231	},
232	{
233		.compatible = "lvds-encoder",
234		.data = (void *)DRM_MODE_CONNECTOR_LVDS,
235	},
236	{
237		.compatible = "thine,thc63lvdm83d",
238		.data = (void *)DRM_MODE_CONNECTOR_LVDS,
239	},
240	{},
241};
242MODULE_DEVICE_TABLE(of, lvds_codec_match);
243
244static struct platform_driver lvds_codec_driver = {
245	.probe	= lvds_codec_probe,
246	.remove	= lvds_codec_remove,
247	.driver		= {
248		.name		= "lvds-codec",
249		.of_match_table	= lvds_codec_match,
250	},
251};
252module_platform_driver(lvds_codec_driver);
253
254MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
255MODULE_DESCRIPTION("LVDS encoders and decoders");
256MODULE_LICENSE("GPL");