OMAPDSS: move 'compatible' converter to omapdss driver

Move the panel/encoder driver compatible-string converter from
arch/arm/mach-omap2/display.c to omapdss driver. That is a more logical
place for it, as it's really an omapdss internal hack.

The code is rewritten to follow the video node graph, starting from
omapdss. This removes the need to have the device compatible-string
database.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

4 files changed, 235 insertions, 1 deletions

diff --git a/drivers/video/fbdev/omap2/Makefile b/drivers/video/fbdev/omap2/Makefile
index bf8127df8c7..f8745ec369c 100644
--- a/drivers/video/fbdev/omap2/Makefile
+++ b/drivers/video/fbdev/omap2/Makefile
@@ -1,5 +1,5 @@
 obj-$(CONFIG_OMAP2_VRFB) += vrfb.o
 
-obj-$(CONFIG_OMAP2_DSS) += dss/
+obj-y += dss/
 obj-y += displays-new/
 obj-$(CONFIG_FB_OMAP2) += omapfb/
diff --git a/drivers/video/fbdev/omap2/dss/Kconfig b/drivers/video/fbdev/omap2/dss/Kconfig
index 8921a7a76a1..285bcd103dc 100644
--- a/drivers/video/fbdev/omap2/dss/Kconfig
+++ b/drivers/video/fbdev/omap2/dss/Kconfig
@@ -1,6 +1,10 @@
+config OMAP2_DSS_INIT
+	bool
+
 menuconfig OMAP2_DSS
         tristate "OMAP2+ Display Subsystem support"
 	select VIDEOMODE_HELPERS
+	select OMAP2_DSS_INIT
         help
 	  OMAP2+ Display Subsystem support.
 
diff --git a/drivers/video/fbdev/omap2/dss/Makefile b/drivers/video/fbdev/omap2/dss/Makefile
index 390ab746bdc..245f933060e 100644
--- a/drivers/video/fbdev/omap2/dss/Makefile
+++ b/drivers/video/fbdev/omap2/dss/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_OMAP2_DSS_INIT) += omapdss-boot-init.o
 obj-$(CONFIG_OMAP2_DSS) += omapdss.o
 # Core DSS files
 omapdss-y := core.o dss.o dss_features.o dispc.o dispc_coefs.o display.o \
diff --git a/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c b/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c
new file mode 100644
index 00000000000..99af9e88b2d
--- /dev/null
+++ b/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c
@@ -0,0 +1,229 @@
+/*
+ * Copyright (C) 2014 Texas Instruments
+ * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * As omapdss panel drivers are omapdss specific, but we want to define the
+ * DT-data in generic manner, we convert the compatible strings of the panel and
+ * encoder nodes from "panel-foo" to "omapdss,panel-foo". This way we can have
+ * both correct DT data and omapdss specific drivers.
+ *
+ * When we get generic panel drivers to the kernel, this file will be removed.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+static struct list_head dss_conv_list __initdata;
+
+static const char prefix[] __initconst = "omapdss,";
+
+struct dss_conv_node {
+	struct list_head list;
+	struct device_node *node;
+	bool root;
+};
+
+static int __init omapdss_count_strings(const struct property *prop)
+{
+	const char *p = prop->value;
+	int l = 0, total = 0;
+	int i;
+
+	for (i = 0; total < prop->length; total += l, p += l, i++)
+		l = strlen(p) + 1;
+
+	return i;
+}
+
+static void __init omapdss_update_prop(struct device_node *node, char *compat,
+	int len)
+{
+	struct property *prop;
+
+	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+	if (!prop)
+		return;
+
+	prop->name = "compatible";
+	prop->value = compat;
+	prop->length = len;
+
+	of_update_property(node, prop);
+}
+
+static void __init omapdss_prefix_strcpy(char *dst, int dst_len,
+	const char *src, int src_len)
+{
+	size_t total = 0;
+
+	while (total < src_len) {
+		size_t l = strlen(src) + 1;
+
+		strcpy(dst, prefix);
+		dst += strlen(prefix);
+
+		strcpy(dst, src);
+		dst += l;
+
+		src += l;
+		total += l;
+	}
+}
+
+/* prepend compatible property strings with "omapdss," */
+static void __init omapdss_omapify_node(struct device_node *node)
+{
+	struct property *prop;
+	char *new_compat;
+	int num_strs;
+	int new_len;
+
+	prop = of_find_property(node, "compatible", NULL);
+
+	if (!prop || !prop->value)
+		return;
+
+	if (strnlen(prop->value, prop->length) >= prop->length)
+		return;
+
+	/* is it already prefixed? */
+	if (strncmp(prefix, prop->value, strlen(prefix)) == 0)
+		return;
+
+	num_strs = omapdss_count_strings(prop);
+
+	new_len = prop->length + strlen(prefix) * num_strs;
+	new_compat = kmalloc(new_len, GFP_KERNEL);
+
+	omapdss_prefix_strcpy(new_compat, new_len, prop->value, prop->length);
+
+	omapdss_update_prop(node, new_compat, new_len);
+}
+
+static void __init omapdss_add_to_list(struct device_node *node, bool root)
+{
+	struct dss_conv_node *n = kmalloc(sizeof(struct dss_conv_node),
+		GFP_KERNEL);
+	n->node = node;
+	n->root = root;
+	list_add(&n->list, &dss_conv_list);
+}
+
+static bool __init omapdss_list_contains(const struct device_node *node)
+{
+	struct dss_conv_node *n;
+
+	list_for_each_entry(n, &dss_conv_list, list) {
+		if (n->node == node)
+			return true;
+	}
+
+	return false;
+}
+
+static void __init omapdss_walk_device(struct device_node *node, bool root)
+{
+	struct device_node *n;
+
+	omapdss_add_to_list(node, root);
+
+	/*
+	 * of_graph_get_remote_port_parent() prints an error if there is no
+	 * port/ports node. To avoid that, check first that there's the node.
+	 */
+	n = of_get_child_by_name(node, "ports");
+	if (!n)
+		n = of_get_child_by_name(node, "port");
+	if (!n)
+		return;
+
+	of_node_put(n);
+
+	n = NULL;
+	while ((n = of_graph_get_next_endpoint(node, n)) != NULL) {
+		struct device_node *pn;
+
+		pn = of_graph_get_remote_port_parent(n);
+
+		if (!pn) {
+			of_node_put(n);
+			continue;
+		}
+
+		if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
+			of_node_put(pn);
+			of_node_put(n);
+			continue;
+		}
+
+		omapdss_walk_device(pn, false);
+
+		of_node_put(n);
+	}
+}
+
+static const struct of_device_id omapdss_of_match[] __initconst = {
+	{ .compatible = "ti,omap2-dss", },
+	{ .compatible = "ti,omap3-dss", },
+	{ .compatible = "ti,omap4-dss", },
+	{ .compatible = "ti,omap5-dss", },
+	{},
+};
+
+static int __init omapdss_boot_init(void)
+{
+	struct device_node *dss, *child;
+
+	INIT_LIST_HEAD(&dss_conv_list);
+
+	dss = of_find_matching_node(NULL, omapdss_of_match);
+
+	if (dss == NULL || !of_device_is_available(dss))
+		return 0;
+
+	omapdss_walk_device(dss, true);
+
+	for_each_available_child_of_node(dss, child) {
+		if (!of_find_property(child, "compatible", NULL)) {
+			of_node_put(child);
+			continue;
+		}
+
+		omapdss_walk_device(child, true);
+	}
+
+	while (!list_empty(&dss_conv_list)) {
+		struct dss_conv_node *n;
+
+		n = list_first_entry(&dss_conv_list, struct dss_conv_node,
+			list);
+
+		if (!n->root)
+			omapdss_omapify_node(n->node);
+
+		list_del(&n->list);
+		of_node_put(n->node);
+		kfree(n);
+	}
+
+	return 0;
+}
+
+subsys_initcall(omapdss_boot_init);