[PATCH i-g-t v2 19/26] lib/unigraf: Add helpers to read and write edid

[Louis Chauvet]

Read and writing EDID on unigraf can be useful to emulate different
screens, add helpers to read and write them.

There is a limitation on the libTSI.so, it is only possible to read EDID
using buffers of size multiple of 128 bytes, and there is no way to query
the actual EDID size. The current implementation can only read EDID up to
2048 bytes.
---
 lib/unigraf/unigraf.c | 25 +++++++++++++++++++++++++
 lib/unigraf/unigraf.h | 21 +++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/lib/unigraf/unigraf.c b/lib/unigraf/unigraf.c
index 15ded642c2fc6900a6722bdeb62c7126b23e9cee..6df48da4672c1774bd85125076fcc63e9891b6cc 100644
--- a/lib/unigraf/unigraf.c
+++ b/lib/unigraf/unigraf.c
@@ -281,6 +281,31 @@ void unigraf_require_device(void)
 	igt_require(unigraf_open_device());
 }
 
+struct edid *unigraf_read_edid(uint32_t stream, uint32_t *edid_size)
+{
+	void *edid;
+
+	igt_assert(unigraf_device);
+	unigraf_debug("Read EDID for stream %d...\n", stream);
+
+	edid = malloc(2048);
+	memset(edid, 0, 2048);
+
+	unigraf_write(TSI_EDID_SELECT_STREAM, &stream, sizeof(stream));
+	*edid_size = unigraf_assert(TSIX_TS_GetConfigItem(unigraf_device, TSI_EDID_TE_INPUT, edid, 2048));
+
+	return edid;
+}
+
+void unigraf_write_edid(uint32_t stream, const struct edid *edid, uint32_t edid_size)
+{
+	igt_assert(unigraf_device);
+	unigraf_debug("Write EDID for stream %d...\n", stream);
+
+	unigraf_write(TSI_EDID_SELECT_STREAM, &stream, edid_size);
+	unigraf_write(TSI_EDID_TE_INPUT, edid, 2048);
+}
+
 void unigraf_hpd_assert(void)
 {
 	int d = 1;
diff --git a/lib/unigraf/unigraf.h b/lib/unigraf/unigraf.h
index 6ecd1248cdd70a2af99ae09ae19f9fc8c061ff56..e843aa8f2badddcfaeceb8773d5ad19e572e37d9 100644
--- a/lib/unigraf/unigraf.h
+++ b/lib/unigraf/unigraf.h
@@ -45,6 +45,27 @@ bool unigraf_open_device(void);
  */
 void unigraf_require_device(void);
 
+/**
+ * unigraf_read_edid() - Read the EDID from the specified input
+ * @dev: The device handle
+ * @stream: The stream ID to read the EDID from
+ * @edid_size: Pointer to an integer where the size of the EDID will be stored
+ *
+ * Returns: A pointer to the EDID structure, or NULL if the operation failed. The caller
+ * is responsible to free this pointer.
+ */
+struct edid *unigraf_read_edid(uint32_t stream, uint32_t *edid_size);
+
+/**
+ * unigraf_write_edid() - Write EDID data to the specified stream
+ * @stream: The stream ID to write the EDID to
+ * @edid: Pointer to the EDID structure to write
+ * @edid_size: Size of the EDID data in bytes
+ *
+ * This function writes the provided EDID data to the specified stream.
+ */
+void unigraf_write_edid(uint32_t stream, const struct edid *edid, uint32_t edid_size);
+
 /**
  * unigraf_hpd_deassert() - Deassert Hot Plug Detect signal
  *

-- 
2.50.0