1 files changed, 104 insertions, 0 deletions
diff --git a/include/media/cec-edid.h b/include/media/cec-edid.h
new file mode 100644
index 000000000000..bdf731ecba1a
--- /dev/null
+++ b/include/media/cec-edid.h
@@ -0,0 +1,104 @@
+/*
+ * cec-edid - HDMI Consumer Electronics Control & EDID helpers
+ *
+ * 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.
+ */
+
+#ifndef _MEDIA_CEC_EDID_H
+#define _MEDIA_CEC_EDID_H
+
+#include <linux/types.h>
+
+#define CEC_PHYS_ADDR_INVALID		0xffff
+#define cec_phys_addr_exp(pa) \
+	((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
+
+/**
+ * cec_get_edid_phys_addr() - find and return the physical address
+ *
+ * @edid:	pointer to the EDID data
+ * @size:	size in bytes of the EDID data
+ * @offset:	If not %NULL then the location of the physical address
+ *		bytes in the EDID will be returned here. This is set to 0
+ *		if there is no physical address found.
+ *
+ * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
+ */
+u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
+			   unsigned int *offset);
+
+/**
+ * cec_set_edid_phys_addr() - find and set the physical address
+ *
+ * @edid:	pointer to the EDID data
+ * @size:	size in bytes of the EDID data
+ * @phys_addr:	the new physical address
+ *
+ * This function finds the location of the physical address in the EDID
+ * and fills in the given physical address and updates the checksum
+ * at the end of the EDID block. It does nothing if the EDID doesn't
+ * contain a physical address.
+ */
+void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);
+
+/**
+ * cec_phys_addr_for_input() - calculate the PA for an input
+ *
+ * @phys_addr:	the physical address of the parent
+ * @input:	the number of the input port, must be between 1 and 15
+ *
+ * This function calculates a new physical address based on the input
+ * port number. For example:
+ *
+ * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
+ *
+ * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
+ *
+ * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
+ *
+ * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
+ *
+ * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
+ */
+u16 cec_phys_addr_for_input(u16 phys_addr, u8 input);
+
+/**
+ * cec_phys_addr_validate() - validate a physical address from an EDID
+ *
+ * @phys_addr:	the physical address to validate
+ * @parent:	if not %NULL, then this is filled with the parents PA.
+ * @port:	if not %NULL, then this is filled with the input port.
+ *
+ * This validates a physical address as read from an EDID. If the
+ * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
+ * then it will return -EINVAL.
+ *
+ * The parent PA is passed into %parent and the input port is passed into
+ * %port. For example:
+ *
+ * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
+ *
+ * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
+ *
+ * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
+ *
+ * PA = f.f.f.f: has parent f.f.f.f and input port 0.
+ *
+ * Return: 0 if the PA is valid, -EINVAL if not.
+ */
+int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);
+
+#endif /* _MEDIA_CEC_EDID_H */