[PATCH 3/3] drm/msm/dp: add a debugfs node for using tpg

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

DP test pattern generator is a very useful tool to debug issues
where monitor is showing incorrect output as it helps to isolate
whether the issue is due to rest of DPU pipeline or in the DP
controller itself. Expose a debugfs to use the TPG configuration
to help debug DP issues.

Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
---
 drivers/gpu/drm/msm/dp/dp_debug.c | 61 +++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_panel.h |  2 ++
 2 files changed, 63 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c
index 22fd946ee201..843fe77268f8 100644
--- a/drivers/gpu/drm/msm/dp/dp_debug.c
+++ b/drivers/gpu/drm/msm/dp/dp_debug.c
@@ -197,6 +197,65 @@ static const struct file_operations test_active_fops = {
 	.write = msm_dp_test_active_write
 };
 
+static ssize_t msm_dp_tpg_write(struct file *file, const char __user *ubuf,
+				size_t len, loff_t *offp)
+{
+	const struct msm_dp_debug_private *debug;
+	char *input_buffer;
+	int val;
+	int status = 0;
+	struct msm_dp_panel *dp_panel;
+
+	debug = ((struct seq_file *)file->private_data)->private;
+	dp_panel = debug->panel;
+
+	input_buffer = memdup_user_nul(ubuf, len);
+	if (IS_ERR(input_buffer))
+		return PTR_ERR(input_buffer);
+
+	status = kstrtoint(input_buffer, 10, &val);
+	if (status < 0) {
+		kfree(input_buffer);
+		return status;
+	}
+
+	msm_dp_panel_tpg_config(dp_panel, val);
+
+	dp_panel->tpg_enabled = val;
+
+	kfree(input_buffer);
+
+	*offp += len;
+	return len;
+}
+
+static int msm_dp_tpg_show(struct seq_file *f, void *data)
+{
+	struct msm_dp_debug_private *debug = f->private;
+	struct msm_dp_panel *dp_panel = debug->panel;
+
+	if (dp_panel->tpg_enabled)
+		seq_puts(f, "1");
+	else
+		seq_puts(f, "0");
+
+	return 0;
+}
+
+static int msm_dp_tpg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, msm_dp_tpg_show, inode->i_private);
+}
+
+static const struct file_operations msm_dp_tpg_fops = {
+	.owner = THIS_MODULE,
+	.open = msm_dp_tpg_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.write = msm_dp_tpg_write
+};
+
 int msm_dp_debug_init(struct device *dev, struct msm_dp_panel *panel,
 		  struct msm_dp_link *link,
 		  struct drm_connector *connector,
@@ -231,6 +290,8 @@ int msm_dp_debug_init(struct device *dev, struct msm_dp_panel *panel,
 		debugfs_create_file("dp_test_type", 0444,
 				    root,
 				    debug, &msm_dp_test_type_fops);
+
+		debugfs_create_file("dp_tpg", 0444, root, debug, &msm_dp_tpg_fops);
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
index 0e944db3adf2..7910b11fd685 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.h
+++ b/drivers/gpu/drm/msm/dp/dp_panel.h
@@ -50,6 +50,8 @@ struct msm_dp_panel {
 	u32 max_dp_link_rate;
 
 	u32 max_bw_code;
+
+	bool tpg_enabled;
 };
 
 int msm_dp_panel_init_panel_info(struct msm_dp_panel *msm_dp_panel);

-- 
2.34.1