From 3f56e5514bfd99aaba649e4af6b11a11b731d3a2 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Tue, 9 Apr 2024 12:46:10 +0300
Subject: drm/edid: add drm_edid_print_product_id()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add a function to print a decoded EDID vendor and product id to a drm
printer, optionally with the raw data.

v2:
- refactor date printing
- use seq_buf to avoid kasprintf() (Ville)
- handle week == 0 (Ville)
- use be16_to_cpu() on manufacturer_name

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Melissa Wen <mwen@igalia.com> # v1
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/32bbc83ee6557809ef6d7a5edb1bc8ef4d56d10f.1712655867.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

(limited to 'drivers')

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 626a0e24e66a..1400722ae3fe 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -29,12 +29,14 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/byteorder/generic.h>
 #include <linux/cec.h>
 #include <linux/hdmi.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/seq_buf.h>
 #include <linux/slab.h>
 #include <linux/vga_switcheroo.h>
 
@@ -2771,6 +2773,48 @@ void drm_edid_get_product_id(const struct drm_edid *drm_edid,
 }
 EXPORT_SYMBOL(drm_edid_get_product_id);
 
+static void decode_date(struct seq_buf *s, const struct drm_edid_product_id *id)
+{
+	int week = id->week_of_manufacture;
+	int year = id->year_of_manufacture + 1990;
+
+	if (week == 0xff)
+		seq_buf_printf(s, "model year: %d", year);
+	else if (!week)
+		seq_buf_printf(s, "year of manufacture: %d", year);
+	else
+		seq_buf_printf(s, "week/year of manufacture: %d/%d", week, year);
+}
+
+/**
+ * drm_edid_print_product_id - Print decoded product id to printer
+ * @p: drm printer
+ * @id: EDID product id
+ * @raw: If true, also print the raw hex
+ *
+ * See VESA E-EDID 1.4 section 3.4.
+ */
+void drm_edid_print_product_id(struct drm_printer *p,
+			       const struct drm_edid_product_id *id, bool raw)
+{
+	DECLARE_SEQ_BUF(date, 40);
+	char vend[4];
+
+	drm_edid_decode_mfg_id(be16_to_cpu(id->manufacturer_name), vend);
+
+	decode_date(&date, id);
+
+	drm_printf(p, "manufacturer name: %s, product code: %u, serial number: %u, %s\n",
+		   vend, le16_to_cpu(id->product_code),
+		   le32_to_cpu(id->serial_number), seq_buf_str(&date));
+
+	if (raw)
+		drm_printf(p, "raw product id: %*ph\n", (int)sizeof(*id), id);
+
+	WARN_ON(seq_buf_has_overflowed(&date));
+}
+EXPORT_SYMBOL(drm_edid_print_product_id);
+
 /**
  * drm_edid_get_panel_id - Get a panel's ID from EDID
  * @drm_edid: EDID that contains panel ID.
-- 
cgit