[igt-dev] [v8 1/3] lib/dsc: add helpers for vdsc fractional bpp debugfs entry

[Swati Sharma]

Helper functions are added for getting/setting VDSC Fractional BPP
debugfs entry.

v2: -improved func description (Ankit)
    -increased buff size (Ankit)
    -asserted bpp_prec (Ankit)
v3: -return 0 on success instead of 1 (Jouni)
v4: -rebase
v5: -alignment fixes (Ankit)

Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 lib/igt_dsc.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_dsc.h |   6 +++
 2 files changed, 109 insertions(+)

diff --git a/lib/igt_dsc.c b/lib/igt_dsc.c
index 76a420c10..61d619a4a 100644
--- a/lib/igt_dsc.c
+++ b/lib/igt_dsc.c
@@ -205,3 +205,106 @@ int igt_force_dsc_output_format(int drmfd, char *connector_name,
 
 	return write_dsc_debugfs(drmfd, connector_name, "i915_dsc_output_format", buf);
 }
+
+/*
+ * igt_get_dsc_fractional_bpp_supported:
+ * @drmfd: A drm file descriptor
+ * @connector_name: Name of the libdrm connector we're going to use
+ *
+ * Returns: DSC BPP precision supported by the sink.
+ * 	    Precision value of
+ * 		16 => 1/16
+ * 		8  => 1/8
+ * 		1  => fractional bpp not supported
+ */
+int igt_get_dsc_fractional_bpp_supported(int drmfd, char *connector_name)
+{
+	char file_name[128] = {0};
+	char buf[512];
+	char *start_loc;
+	int bpp_prec;
+
+	sprintf(file_name, "%s/i915_dsc_fec_support", connector_name);
+	igt_debugfs_read(drmfd, file_name, buf);
+
+	igt_assert(start_loc = strstr(buf, "DSC_Sink_BPP_Precision: "));
+	igt_assert_eq(sscanf(start_loc, "DSC_Sink_BPP_Precision: %d", &bpp_prec), 1);
+	igt_assert(bpp_prec > 0);
+
+	return bpp_prec;
+}
+
+/*
+ * igt_is_dsc_fractional_bpp_supported_by_sink:
+ * @drmfd: A drm file descriptor
+ * @connector_name: Name of the libdrm connector we're going to use
+ *
+ * Returns: True if DSC fractional bpp is supported for the given connector,
+ * false otherwise.
+ */
+bool igt_is_dsc_fractional_bpp_supported_by_sink(int drmfd, char *connector_name)
+{
+	int bpp_prec;
+
+	bpp_prec = igt_get_dsc_fractional_bpp_supported(drmfd, connector_name);
+
+	if (bpp_prec == 1)
+		return false;
+
+	return true;
+}
+
+static bool check_dsc_fractional_bpp_debugfs(int drmfd, char *connector_name,
+					     const char *check_str)
+{
+	char file_name[128] = {0};
+	char buf[512];
+
+	sprintf(file_name, "%s/i915_dsc_fractional_bpp", connector_name);
+
+	igt_debugfs_read(drmfd, file_name, buf);
+
+	return strstr(buf, check_str);
+}
+
+/*
+ * igt_is_force_dsc_fractional_bpp_enabled:
+ * @drmfd: A drm file descriptor
+ * @connector_name: Name of the libdrm connector we're going to use
+ *
+ * Returns: True if DSC Fractional BPP is force enabled (via debugfs) for the given connector,
+ * false otherwise.
+ */
+bool igt_is_force_dsc_fractional_bpp_enabled(int drmfd, char *connector_name)
+{
+	return check_dsc_fractional_bpp_debugfs(drmfd, connector_name, "Force_DSC_Fractional_BPP_Enable: yes");
+}
+
+/*
+ * igt_force_dsc_fractional_bpp_enable:
+ * @drmfd: A drm file descriptor
+ * @connector_name: Name of the libdrm connector we're going to use
+ *
+ * Returns: 0 on success or negative error code, in case of failure.
+ */
+int igt_force_dsc_fractional_bpp_enable(int drmfd, char *connector_name)
+{
+	return write_dsc_debugfs(drmfd, connector_name, "i915_dsc_fractional_bpp", "1");
+}
+
+/*
+ * igt_get_dsc_fractional_bpp_debugfs_fd:
+ * @drmfd: A drm file descriptor
+ * @connector_name: Name of the libdrm connector we're going to use
+ *
+ * Returns: fd of the DSC Fractional BPP debugfs for the given connector,
+ * else returns -1.
+ */
+int igt_get_dsc_fractional_bpp_debugfs_fd(int drmfd, char *connector_name)
+{
+	char file_name[128] = {0};
+
+	sprintf(file_name, "%s/i915_dsc_fractional_bpp", connector_name);
+
+	return openat(igt_debugfs_dir(drmfd), file_name, O_WRONLY);
+}
diff --git a/lib/igt_dsc.h b/lib/igt_dsc.h
index b58743b5f..7ab0917ec 100644
--- a/lib/igt_dsc.h
+++ b/lib/igt_dsc.h
@@ -8,6 +8,7 @@
 
 #include "igt_fb.h"
 #include "igt_kms.h"
+#include "igt_core.h"
 
 bool igt_is_dsc_supported_by_source(int drmfd);
 bool igt_is_dsc_supported_by_sink(int drmfd, char *connector_name);
@@ -21,5 +22,10 @@ bool igt_is_dsc_output_format_supported_by_sink(int drmfd, char *connector_name,
 						enum dsc_output_format output_format);
 int igt_force_dsc_output_format(int drmfd, char *connector_name,
 				enum dsc_output_format output_format);
+bool igt_is_dsc_fractional_bpp_supported_by_sink(int drmfd, char *connector_name);
+int igt_get_dsc_fractional_bpp_supported(int drmfd, char *connector_name);
+bool igt_is_force_dsc_fractional_bpp_enabled(int drmfd, char *connector_name);
+int igt_force_dsc_fractional_bpp_enable(int drmfd, char *connector_name);
+int igt_get_dsc_fractional_bpp_debugfs_fd(int drmfd, char *connector_name);
 
 #endif
-- 
2.25.1