[media] cec: Kconfig cleanup

The Kconfig options for the CEC subsystem were a bit messy. In
addition there were two cec sources (cec-edid.c and cec-notifier.c)
that were outside of the media/cec directory, which was weird.

Move those sources to media/cec as well.

The cec-edid and cec-notifier functionality is now part of the cec
module and these are no longer separate modules.

Also remove the MEDIA_CEC_EDID config option and include it with the
main CEC config option (which defined CEC_EDID anyway).

Added static inlines to cec-edid.h for dummy functions when CEC_CORE
isn't defined.

CEC drivers should now depend on CEC_CORE.

CEC drivers that need the cec-notifier functionality must explicitly
select CEC_NOTIFIER.

The s5p-cec and stih-cec drivers depended on VIDEO_DEV instead of
CEC_CORE, fix that as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

4 files changed, 314 insertions, 3 deletions

diff --git a/drivers/media/cec/Kconfig b/drivers/media/cec/Kconfig
new file mode 100644
index 000000000000..24b53187ee52
--- /dev/null
+++ b/drivers/media/cec/Kconfig
@@ -0,0 +1,13 @@
+config CEC_CORE
+	tristate
+	depends on MEDIA_CEC_SUPPORT
+	default y
+
+config MEDIA_CEC_NOTIFIER
+	bool
+
+config MEDIA_CEC_DEBUG
+	bool "HDMI CEC debugfs interface"
+	depends on MEDIA_CEC_SUPPORT && DEBUG_FS
+	---help---
+	  Turns on the DebugFS interface for CEC devices.
diff --git a/drivers/media/cec/Makefile b/drivers/media/cec/Makefile
index d6686337275f..402a6c62a3e8 100644
--- a/drivers/media/cec/Makefile
+++ b/drivers/media/cec/Makefile
@@ -1,5 +1,7 @@
-cec-objs := cec-core.o cec-adap.o cec-api.o
+cec-objs := cec-core.o cec-adap.o cec-api.o cec-edid.o
 
-ifeq ($(CONFIG_MEDIA_CEC_SUPPORT),y)
-  obj-$(CONFIG_MEDIA_SUPPORT) += cec.o
+ifeq ($(CONFIG_MEDIA_CEC_NOTIFIER),y)
+  cec-objs += cec-notifier.o
 endif
+
+obj-$(CONFIG_CEC_CORE) += cec.o
diff --git a/drivers/media/cec/cec-edid.c b/drivers/media/cec/cec-edid.c
new file mode 100644
index 000000000000..c63dc81d2a29
--- /dev/null
+++ b/drivers/media/cec/cec-edid.c
@@ -0,0 +1,167 @@
+/*
+ * cec-edid - HDMI Consumer Electronics Control EDID & CEC helper functions
+ *
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <media/cec-edid.h>
+
+/*
+ * This EDID is expected to be a CEA-861 compliant, which means that there are
+ * at least two blocks and one or more of the extensions blocks are CEA-861
+ * blocks.
+ *
+ * The returned location is guaranteed to be < size - 1.
+ */
+static unsigned int cec_get_edid_spa_location(const u8 *edid, unsigned int size)
+{
+	unsigned int blocks = size / 128;
+	unsigned int block;
+	u8 d;
+
+	/* Sanity check: at least 2 blocks and a multiple of the block size */
+	if (blocks < 2 || size % 128)
+		return 0;
+
+	/*
+	 * If there are fewer extension blocks than the size, then update
+	 * 'blocks'. It is allowed to have more extension blocks than the size,
+	 * since some hardware can only read e.g. 256 bytes of the EDID, even
+	 * though more blocks are present. The first CEA-861 extension block
+	 * should normally be in block 1 anyway.
+	 */
+	if (edid[0x7e] + 1 < blocks)
+		blocks = edid[0x7e] + 1;
+
+	for (block = 1; block < blocks; block++) {
+		unsigned int offset = block * 128;
+
+		/* Skip any non-CEA-861 extension blocks */
+		if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
+			continue;
+
+		/* search Vendor Specific Data Block (tag 3) */
+		d = edid[offset + 2] & 0x7f;
+		/* Check if there are Data Blocks */
+		if (d <= 4)
+			continue;
+		if (d > 4) {
+			unsigned int i = offset + 4;
+			unsigned int end = offset + d;
+
+			/* Note: 'end' is always < 'size' */
+			do {
+				u8 tag = edid[i] >> 5;
+				u8 len = edid[i] & 0x1f;
+
+				if (tag == 3 && len >= 5 && i + len <= end &&
+				    edid[i + 1] == 0x03 &&
+				    edid[i + 2] == 0x0c &&
+				    edid[i + 3] == 0x00)
+					return i + 4;
+				i += len + 1;
+			} while (i < end);
+		}
+	}
+	return 0;
+}
+
+u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
+			   unsigned int *offset)
+{
+	unsigned int loc = cec_get_edid_spa_location(edid, size);
+
+	if (offset)
+		*offset = loc;
+	if (loc == 0)
+		return CEC_PHYS_ADDR_INVALID;
+	return (edid[loc] << 8) | edid[loc + 1];
+}
+EXPORT_SYMBOL_GPL(cec_get_edid_phys_addr);
+
+void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr)
+{
+	unsigned int loc = cec_get_edid_spa_location(edid, size);
+	u8 sum = 0;
+	unsigned int i;
+
+	if (loc == 0)
+		return;
+	edid[loc] = phys_addr >> 8;
+	edid[loc + 1] = phys_addr & 0xff;
+	loc &= ~0x7f;
+
+	/* update the checksum */
+	for (i = loc; i < loc + 127; i++)
+		sum += edid[i];
+	edid[i] = 256 - sum;
+}
+EXPORT_SYMBOL_GPL(cec_set_edid_phys_addr);
+
+u16 cec_phys_addr_for_input(u16 phys_addr, u8 input)
+{
+	/* Check if input is sane */
+	if (WARN_ON(input == 0 || input > 0xf))
+		return CEC_PHYS_ADDR_INVALID;
+
+	if (phys_addr == 0)
+		return input << 12;
+
+	if ((phys_addr & 0x0fff) == 0)
+		return phys_addr | (input << 8);
+
+	if ((phys_addr & 0x00ff) == 0)
+		return phys_addr | (input << 4);
+
+	if ((phys_addr & 0x000f) == 0)
+		return phys_addr | input;
+
+	/*
+	 * All nibbles are used so no valid physical addresses can be assigned
+	 * to the input.
+	 */
+	return CEC_PHYS_ADDR_INVALID;
+}
+EXPORT_SYMBOL_GPL(cec_phys_addr_for_input);
+
+int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port)
+{
+	int i;
+
+	if (parent)
+		*parent = phys_addr;
+	if (port)
+		*port = 0;
+	if (phys_addr == CEC_PHYS_ADDR_INVALID)
+		return 0;
+	for (i = 0; i < 16; i += 4)
+		if (phys_addr & (0xf << i))
+			break;
+	if (i == 16)
+		return 0;
+	if (parent)
+		*parent = phys_addr & (0xfff0 << i);
+	if (port)
+		*port = (phys_addr >> i) & 0xf;
+	for (i += 4; i < 16; i += 4)
+		if ((phys_addr & (0xf << i)) == 0)
+			return -EINVAL;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cec_phys_addr_validate);
diff --git a/drivers/media/cec/cec-notifier.c b/drivers/media/cec/cec-notifier.c
new file mode 100644
index 000000000000..5f5209a73665
--- /dev/null
+++ b/drivers/media/cec/cec-notifier.c
@@ -0,0 +1,129 @@
+/*
+ * cec-notifier.c - notify CEC drivers of physical address changes
+ *
+ * Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
+ * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/kref.h>
+
+#include <media/cec-notifier.h>
+#include <drm/drm_edid.h>
+
+struct cec_notifier {
+	struct mutex lock;
+	struct list_head head;
+	struct kref kref;
+	struct device *dev;
+	struct cec_adapter *cec_adap;
+	void (*callback)(struct cec_adapter *adap, u16 pa);
+
+	u16 phys_addr;
+};
+
+static LIST_HEAD(cec_notifiers);
+static DEFINE_MUTEX(cec_notifiers_lock);
+
+struct cec_notifier *cec_notifier_get(struct device *dev)
+{
+	struct cec_notifier *n;
+
+	mutex_lock(&cec_notifiers_lock);
+	list_for_each_entry(n, &cec_notifiers, head) {
+		if (n->dev == dev) {
+			kref_get(&n->kref);
+			mutex_unlock(&cec_notifiers_lock);
+			return n;
+		}
+	}
+	n = kzalloc(sizeof(*n), GFP_KERNEL);
+	if (!n)
+		goto unlock;
+	n->dev = dev;
+	n->phys_addr = CEC_PHYS_ADDR_INVALID;
+	mutex_init(&n->lock);
+	kref_init(&n->kref);
+	list_add_tail(&n->head, &cec_notifiers);
+unlock:
+	mutex_unlock(&cec_notifiers_lock);
+	return n;
+}
+EXPORT_SYMBOL_GPL(cec_notifier_get);
+
+static void cec_notifier_release(struct kref *kref)
+{
+	struct cec_notifier *n =
+		container_of(kref, struct cec_notifier, kref);
+
+	list_del(&n->head);
+	kfree(n);
+}
+
+void cec_notifier_put(struct cec_notifier *n)
+{
+	mutex_lock(&cec_notifiers_lock);
+	kref_put(&n->kref, cec_notifier_release);
+	mutex_unlock(&cec_notifiers_lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_put);
+
+void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
+{
+	mutex_lock(&n->lock);
+	n->phys_addr = pa;
+	if (n->callback)
+		n->callback(n->cec_adap, n->phys_addr);
+	mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr);
+
+void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
+					  const struct edid *edid)
+{
+	u16 pa = CEC_PHYS_ADDR_INVALID;
+
+	if (edid && edid->extensions)
+		pa = cec_get_edid_phys_addr((const u8 *)edid,
+				EDID_LENGTH * (edid->extensions + 1), NULL);
+	cec_notifier_set_phys_addr(n, pa);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr_from_edid);
+
+void cec_notifier_register(struct cec_notifier *n,
+			   struct cec_adapter *adap,
+			   void (*callback)(struct cec_adapter *adap, u16 pa))
+{
+	kref_get(&n->kref);
+	mutex_lock(&n->lock);
+	n->cec_adap = adap;
+	n->callback = callback;
+	n->callback(adap, n->phys_addr);
+	mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_register);
+
+void cec_notifier_unregister(struct cec_notifier *n)
+{
+	mutex_lock(&n->lock);
+	n->callback = NULL;
+	mutex_unlock(&n->lock);
+	cec_notifier_put(n);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_unregister);