1/*
2 * V4L2 OF binding parsing library
3 *
4 * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
5 * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
6 *
7 * Copyright (C) 2012 Renesas Electronics Corp.
8 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License as
12 * published by the Free Software Foundation.
13 */
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/string.h>
18#include <linux/types.h>
19
20#include <media/v4l2-of.h>
21
22static int v4l2_of_parse_csi_bus(const struct device_node *node,
23				 struct v4l2_of_endpoint *endpoint)
24{
25	struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
26	struct property *prop;
27	bool have_clk_lane = false;
28	unsigned int flags = 0;
29	u32 v;
30
31	prop = of_find_property(node, "data-lanes", NULL);
32	if (prop) {
33		const __be32 *lane = NULL;
34		unsigned int i;
35
36		for (i = 0; i < ARRAY_SIZE(bus->data_lanes); i++) {
37			lane = of_prop_next_u32(prop, lane, &v);
38			if (!lane)
39				break;
40			bus->data_lanes[i] = v;
41		}
42		bus->num_data_lanes = i;
43	}
44
45	prop = of_find_property(node, "lane-polarities", NULL);
46	if (prop) {
47		const __be32 *polarity = NULL;
48		unsigned int i;
49
50		for (i = 0; i < ARRAY_SIZE(bus->lane_polarities); i++) {
51			polarity = of_prop_next_u32(prop, polarity, &v);
52			if (!polarity)
53				break;
54			bus->lane_polarities[i] = v;
55		}
56
57		if (i < 1 + bus->num_data_lanes /* clock + data */) {
58			pr_warn("%s: too few lane-polarities entries (need %u, got %u)\n",
59				node->full_name, 1 + bus->num_data_lanes, i);
60			return -EINVAL;
61		}
62	}
63
64	if (!of_property_read_u32(node, "clock-lanes", &v)) {
65		bus->clock_lane = v;
66		have_clk_lane = true;
67	}
68
69	if (of_get_property(node, "clock-noncontinuous", &v))
70		flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
71	else if (have_clk_lane || bus->num_data_lanes > 0)
72		flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
73
74	bus->flags = flags;
75	endpoint->bus_type = V4L2_MBUS_CSI2;
76
77	return 0;
78}
79
80static void v4l2_of_parse_parallel_bus(const struct device_node *node,
81				       struct v4l2_of_endpoint *endpoint)
82{
83	struct v4l2_of_bus_parallel *bus = &endpoint->bus.parallel;
84	unsigned int flags = 0;
85	u32 v;
86
87	if (!of_property_read_u32(node, "hsync-active", &v))
88		flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
89			V4L2_MBUS_HSYNC_ACTIVE_LOW;
90
91	if (!of_property_read_u32(node, "vsync-active", &v))
92		flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
93			V4L2_MBUS_VSYNC_ACTIVE_LOW;
94
95	if (!of_property_read_u32(node, "pclk-sample", &v))
96		flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
97			V4L2_MBUS_PCLK_SAMPLE_FALLING;
98
99	if (!of_property_read_u32(node, "field-even-active", &v))
100		flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
101			V4L2_MBUS_FIELD_EVEN_LOW;
102	if (flags)
103		endpoint->bus_type = V4L2_MBUS_PARALLEL;
104	else
105		endpoint->bus_type = V4L2_MBUS_BT656;
106
107	if (!of_property_read_u32(node, "data-active", &v))
108		flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
109			V4L2_MBUS_DATA_ACTIVE_LOW;
110
111	if (of_get_property(node, "slave-mode", &v))
112		flags |= V4L2_MBUS_SLAVE;
113	else
114		flags |= V4L2_MBUS_MASTER;
115
116	if (!of_property_read_u32(node, "bus-width", &v))
117		bus->bus_width = v;
118
119	if (!of_property_read_u32(node, "data-shift", &v))
120		bus->data_shift = v;
121
122	if (!of_property_read_u32(node, "sync-on-green-active", &v))
123		flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
124			V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
125
126	bus->flags = flags;
127
128}
129
130/**
131 * v4l2_of_parse_endpoint() - parse all endpoint node properties
132 * @node: pointer to endpoint device_node
133 * @endpoint: pointer to the V4L2 OF endpoint data structure
134 *
135 * All properties are optional. If none are found, we don't set any flags.
136 * This means the port has a static configuration and no properties have
137 * to be specified explicitly.
138 * If any properties that identify the bus as parallel are found and
139 * slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
140 * the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
141 * V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
142 * The caller should hold a reference to @node.
143 *
144 * Return: 0.
145 */
146int v4l2_of_parse_endpoint(const struct device_node *node,
147			   struct v4l2_of_endpoint *endpoint)
148{
149	int rval;
150
151	of_graph_parse_endpoint(node, &endpoint->base);
152	endpoint->bus_type = 0;
153	memset(&endpoint->bus, 0, sizeof(endpoint->bus));
154
155	rval = v4l2_of_parse_csi_bus(node, endpoint);
156	if (rval)
157		return rval;
158	/*
159	 * Parse the parallel video bus properties only if none
160	 * of the MIPI CSI-2 specific properties were found.
161	 */
162	if (endpoint->bus.mipi_csi2.flags == 0)
163		v4l2_of_parse_parallel_bus(node, endpoint);
164
165	return 0;
166}
167EXPORT_SYMBOL(v4l2_of_parse_endpoint);
168
169/**
170 * v4l2_of_parse_link() - parse a link between two endpoints
171 * @node: pointer to the endpoint at the local end of the link
172 * @link: pointer to the V4L2 OF link data structure
173 *
174 * Fill the link structure with the local and remote nodes and port numbers.
175 * The local_node and remote_node fields are set to point to the local and
176 * remote port's parent nodes respectively (the port parent node being the
177 * parent node of the port node if that node isn't a 'ports' node, or the
178 * grand-parent node of the port node otherwise).
179 *
180 * A reference is taken to both the local and remote nodes, the caller must use
181 * v4l2_of_put_link() to drop the references when done with the link.
182 *
183 * Return: 0 on success, or -ENOLINK if the remote endpoint can't be found.
184 */
185int v4l2_of_parse_link(const struct device_node *node,
186		       struct v4l2_of_link *link)
187{
188	struct device_node *np;
189
190	memset(link, 0, sizeof(*link));
191
192	np = of_get_parent(node);
193	of_property_read_u32(np, "reg", &link->local_port);
194	np = of_get_next_parent(np);
195	if (of_node_cmp(np->name, "ports") == 0)
196		np = of_get_next_parent(np);
197	link->local_node = np;
198
199	np = of_parse_phandle(node, "remote-endpoint", 0);
200	if (!np) {
201		of_node_put(link->local_node);
202		return -ENOLINK;
203	}
204
205	np = of_get_parent(np);
206	of_property_read_u32(np, "reg", &link->remote_port);
207	np = of_get_next_parent(np);
208	if (of_node_cmp(np->name, "ports") == 0)
209		np = of_get_next_parent(np);
210	link->remote_node = np;
211
212	return 0;
213}
214EXPORT_SYMBOL(v4l2_of_parse_link);
215
216/**
217 * v4l2_of_put_link() - drop references to nodes in a link
218 * @link: pointer to the V4L2 OF link data structure
219 *
220 * Drop references to the local and remote nodes in the link. This function must
221 * be called on every link parsed with v4l2_of_parse_link().
222 */
223void v4l2_of_put_link(struct v4l2_of_link *link)
224{
225	of_node_put(link->local_node);
226	of_node_put(link->remote_node);
227}
228EXPORT_SYMBOL(v4l2_of_put_link);
229