[PATCH v2 25/50] drm/omap: hdmi4: Rework EDID read to isolate data read

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: dri-devel@lists.freedesktop.org
Cc: Maxime Ripard <maxime.ripard@bootlin.com>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Sean Paul <sean@poorly.run>,
	Sebastian Reichel <sebastian.reichel@collabora.com>
Subject: [PATCH v2 25/50] drm/omap: hdmi4: Rework EDID read to isolate data read
Date: Tue, 20 Aug 2019 04:16:56 +0300	[thread overview]
Message-ID: <20190820011721.30136-26-laurent.pinchart@ideasonboard.com> (raw)
In-Reply-To: <20190820011721.30136-1-laurent.pinchart@ideasonboard.com>

In preparation of adding DRM bridge support to the hdmi4 encoder code,
rework the EDID read to isolate data read.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/omapdrm/dss/hdmi4.c      | 94 +++++++++++++++---------
 drivers/gpu/drm/omapdrm/dss/hdmi4_core.c | 59 +++------------
 drivers/gpu/drm/omapdrm/dss/hdmi4_core.h |  4 +-
 3 files changed, 73 insertions(+), 84 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4.c b/drivers/gpu/drm/omapdrm/dss/hdmi4.c
index e15fa3862922..37536b9f3114 100644
--- a/drivers/gpu/drm/omapdrm/dss/hdmi4.c
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi4.c
@@ -272,23 +272,6 @@ static int hdmi_dump_regs(struct seq_file *s, void *p)
 	return 0;
 }
 
-static int read_edid(struct omap_hdmi *hdmi, u8 *buf, int len)
-{
-	int r;
-
-	mutex_lock(&hdmi->lock);
-
-	r = hdmi_runtime_get(hdmi);
-	BUG_ON(r);
-
-	r = hdmi4_read_edid(&hdmi->core,  buf, len);
-
-	hdmi_runtime_put(hdmi);
-	mutex_unlock(&hdmi->lock);
-
-	return r;
-}
-
 static void hdmi_start_audio_stream(struct omap_hdmi *hd)
 {
 	hdmi_wp_audio_enable(&hd->wp, true);
@@ -407,10 +390,8 @@ static void hdmi_disconnect(struct omap_dss_device *src,
 
 #define MAX_EDID	512
 
-static struct edid *hdmi_read_edid(struct omap_dss_device *dssdev)
+static struct edid *hdmi_read_edid_data(struct omap_hdmi *hdmi)
 {
-	struct omap_hdmi *hdmi = dssdev_to_hdmi(dssdev);
-	bool need_enable;
 	u8 *edid;
 	int r;
 
@@ -418,32 +399,79 @@ static struct edid *hdmi_read_edid(struct omap_dss_device *dssdev)
 	if (!edid)
 		return NULL;
 
+	r = hdmi4_core_ddc_read(&hdmi->core, edid, 0, EDID_LENGTH);
+	if (r)
+		goto error;
+
+	if (edid[0x7e] > 0) {
+		char checksum = 0;
+		unsigned int i;
+
+		r = hdmi4_core_ddc_read(&hdmi->core, edid + EDID_LENGTH, 1,
+					EDID_LENGTH);
+		if (r)
+			goto error;
+
+		for (i = 0; i < EDID_LENGTH; ++i)
+			checksum += edid[EDID_LENGTH + i];
+
+		if (checksum != 0) {
+			DSSERR("E-EDID checksum failed!!\n");
+			goto error;
+		}
+	}
+
+	return (struct edid *)edid;
+
+error:
+	kfree(edid);
+	return NULL;
+}
+
+static struct edid *hdmi_read_edid(struct omap_dss_device *dssdev)
+{
+	struct omap_hdmi *hdmi = dssdev_to_hdmi(dssdev);
+	struct edid *edid = NULL;
+	unsigned int cec_addr;
+	bool need_enable;
+	int r;
+
 	need_enable = hdmi->core_enabled == false;
 
 	if (need_enable) {
 		r = hdmi4_core_enable(&hdmi->core);
-		if (r) {
-			kfree(edid);
+		if (r)
 			return NULL;
-		}
 	}
 
-	r = read_edid(hdmi, edid, MAX_EDID);
-	if (r < 0) {
-		kfree(edid);
-		edid = NULL;
+	mutex_lock(&hdmi->lock);
+	r = hdmi_runtime_get(hdmi);
+	BUG_ON(r);
+
+	r = hdmi4_core_ddc_init(&hdmi->core);
+	if (r)
+		goto done;
+
+	edid = hdmi_read_edid_data(hdmi);
+
+done:
+	hdmi_runtime_put(hdmi);
+	mutex_unlock(&hdmi->lock);
+
+	if (edid && edid->extensions) {
+		unsigned int len = (edid->extensions + 1) * EDID_LENGTH;
+
+		cec_addr = cec_get_edid_phys_addr((u8 *)edid, len, NULL);
 	} else {
-		unsigned int cec_addr;
-
-		cec_addr = r >= 256 ? cec_get_edid_phys_addr(edid, r, NULL)
-			 : CEC_PHYS_ADDR_INVALID;
-		hdmi4_cec_set_phys_addr(&hdmi->core, cec_addr);
+		cec_addr = CEC_PHYS_ADDR_INVALID;
 	}
 
+	hdmi4_cec_set_phys_addr(&hdmi->core, cec_addr);
+
 	if (need_enable)
 		hdmi4_core_disable(&hdmi->core);
 
-	return (struct edid *)edid;
+	return edid;
 }
 
 static void hdmi_lost_hotplug(struct omap_dss_device *dssdev)
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4_core.c b/drivers/gpu/drm/omapdrm/dss/hdmi4_core.c
index 5d5d5588ebc1..62175e85f0ef 100644
--- a/drivers/gpu/drm/omapdrm/dss/hdmi4_core.c
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi4_core.c
@@ -32,7 +32,7 @@ static inline void __iomem *hdmi_av_base(struct hdmi_core_data *core)
 	return core->base + HDMI_CORE_AV;
 }
 
-static int hdmi_core_ddc_init(struct hdmi_core_data *core)
+int hdmi4_core_ddc_init(struct hdmi_core_data *core)
 {
 	void __iomem *base = core->base;
 
@@ -74,13 +74,11 @@ static int hdmi_core_ddc_init(struct hdmi_core_data *core)
 	return 0;
 }
 
-static int hdmi_core_ddc_edid(struct hdmi_core_data *core,
-		u8 *pedid, int ext)
+int hdmi4_core_ddc_read(void *data, u8 *buf, unsigned int block, size_t len)
 {
+	struct hdmi_core_data *core = data;
 	void __iomem *base = core->base;
 	u32 i;
-	char checksum;
-	u32 offset = 0;
 
 	/* HDMI_CORE_DDC_STATUS_IN_PROG */
 	if (hdmi_wait_for_bit_change(base, HDMI_CORE_DDC_STATUS,
@@ -89,24 +87,21 @@ static int hdmi_core_ddc_edid(struct hdmi_core_data *core,
 		return -ETIMEDOUT;
 	}
 
-	if (ext % 2 != 0)
-		offset = 0x80;
-
 	/* Load Segment Address Register */
-	REG_FLD_MOD(base, HDMI_CORE_DDC_SEGM, ext / 2, 7, 0);
+	REG_FLD_MOD(base, HDMI_CORE_DDC_SEGM, block / 2, 7, 0);
 
 	/* Load Slave Address Register */
 	REG_FLD_MOD(base, HDMI_CORE_DDC_ADDR, 0xA0 >> 1, 7, 1);
 
 	/* Load Offset Address Register */
-	REG_FLD_MOD(base, HDMI_CORE_DDC_OFFSET, offset, 7, 0);
+	REG_FLD_MOD(base, HDMI_CORE_DDC_OFFSET, block % 2 ? 0x80 : 0, 7, 0);
 
 	/* Load Byte Count */
-	REG_FLD_MOD(base, HDMI_CORE_DDC_COUNT1, 0x80, 7, 0);
+	REG_FLD_MOD(base, HDMI_CORE_DDC_COUNT1, len, 7, 0);
 	REG_FLD_MOD(base, HDMI_CORE_DDC_COUNT2, 0x0, 1, 0);
 
 	/* Set DDC_CMD */
-	if (ext)
+	if (block)
 		REG_FLD_MOD(base, HDMI_CORE_DDC_CMD, 0x4, 3, 0);
 	else
 		REG_FLD_MOD(base, HDMI_CORE_DDC_CMD, 0x2, 3, 0);
@@ -122,7 +117,7 @@ static int hdmi_core_ddc_edid(struct hdmi_core_data *core,
 		return -EIO;
 	}
 
-	for (i = 0; i < 0x80; ++i) {
+	for (i = 0; i < len; ++i) {
 		int t;
 
 		/* IN_PROG */
@@ -141,48 +136,12 @@ static int hdmi_core_ddc_edid(struct hdmi_core_data *core,
 			udelay(1);
 		}
 
-		pedid[i] = REG_GET(base, HDMI_CORE_DDC_DATA, 7, 0);
-	}
-
-	checksum = 0;
-	for (i = 0; i < 0x80; ++i)
-		checksum += pedid[i];
-
-	if (checksum != 0) {
-		DSSERR("E-EDID checksum failed!!\n");
-		return -EIO;
+		buf[i] = REG_GET(base, HDMI_CORE_DDC_DATA, 7, 0);
 	}
 
 	return 0;
 }
 
-int hdmi4_read_edid(struct hdmi_core_data *core, u8 *edid, int len)
-{
-	int r, l;
-
-	if (len < 128)
-		return -EINVAL;
-
-	r = hdmi_core_ddc_init(core);
-	if (r)
-		return r;
-
-	r = hdmi_core_ddc_edid(core, edid, 0);
-	if (r)
-		return r;
-
-	l = 128;
-
-	if (len >= 128 * 2 && edid[0x7e] > 0) {
-		r = hdmi_core_ddc_edid(core, edid + 0x80, 1);
-		if (r)
-			return r;
-		l += 128;
-	}
-
-	return l;
-}
-
 static void hdmi_core_init(struct hdmi_core_video_config *video_cfg)
 {
 	DSSDBG("Enter hdmi_core_init\n");
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4_core.h b/drivers/gpu/drm/omapdrm/dss/hdmi4_core.h
index 11c4b7ba1eee..dc64ae2aa300 100644
--- a/drivers/gpu/drm/omapdrm/dss/hdmi4_core.h
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi4_core.h
@@ -249,7 +249,9 @@ struct hdmi_core_packet_enable_repeat {
 	u32	generic_pkt_repeat;
 };
 
-int hdmi4_read_edid(struct hdmi_core_data *core, u8 *edid, int len);
+int hdmi4_core_ddc_init(struct hdmi_core_data *core);
+int hdmi4_core_ddc_read(void *data, u8 *buf, unsigned int block, size_t len);
+
 void hdmi4_configure(struct hdmi_core_data *core, struct hdmi_wp_data *wp,
 		struct hdmi_config *cfg);
 void hdmi4_core_dump(struct hdmi_core_data *core, struct seq_file *s);
-- 
Regards,

Laurent Pinchart

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