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