From: David Francis <David.Francis@xxxxxxx>
[Why]
We need arbitrary read/write over DP AUX DPCD
for debugging
[How]
Three debugfs entries
Set the target address by writing to
"aux_dpcd_address"
(The first four bytes written are used)
Set the transaction size in bytes by writing to
"aux_dpcd_size"
(The first four bytes written are used)
Start a transaction by reading/writing
"aux_dpcd_data"
Do note: there is no concerrency protection at all
Accessing these entries in quick succession can lead
to strange behaviour
Change-Id: Ibf146c674fce12510fa20b28a976eb9986b341d4
Signed-off-by: David Francis <David.Francis@xxxxxxx>
Reviewed-by: Harry Wentland <Harry.Wentland@xxxxxxx>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 4 +
.../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 107 +++++++++++++++++-
3 files changed, 112 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 0d792a8a6871..7cd23e0f01a3 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4485,6 +4485,8 @@ static int amdgpu_dm_connector_init(struct amdgpu_display_manager *dm,
DRM_ERROR("Failed to create debugfs for connector");
goto out_free;
}
+ aconnector->debugfs_dpcd_address = 0;
+ aconnector->debugfs_dpcd_size = 0;
#endif
if (connector_type == DRM_MODE_CONNECTOR_DisplayPort
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 12e3b697ccef..0dadf15a59ce 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -238,6 +238,10 @@ struct amdgpu_dm_connector {
struct mutex hpd_lock;
bool fake_enable;
+#ifdef CONFIG_DEBUG_FS
+ uint32_t debugfs_dpcd_address;
+ uint32_t debugfs_dpcd_size;
+#endif
};
#define to_amdgpu_dm_connector(x) container_of(x, struct amdgpu_dm_connector, base)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 842ddd37fb81..1a9e3d3dfa38 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -29,6 +29,7 @@
#include "amdgpu.h"
#include "amdgpu_dm.h"
#include "amdgpu_dm_debugfs.h"
+#include "dm_helpers.h"
/* function description
* get/ set DP configuration: lane_count, link_rate, spread_spectrum
@@ -731,6 +732,88 @@ static ssize_t dp_sdp_message_debugfs_write(struct file *f, const char __user *b
DEFINE_SHOW_ATTRIBUTE(vrr_range);
+static ssize_t dp_dpcd_address_write(struct file *f, const char __user *buf,
+ size_t size, loff_t *pos)
+{
+ int r;
+ struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
+
+ if (size < sizeof(connector->debugfs_dpcd_address))
+ return 0;
+
+ r = copy_from_user(&connector->debugfs_dpcd_address,
+ buf, sizeof(connector->debugfs_dpcd_address));
+
+ return size - r;
+}
+
+static ssize_t dp_dpcd_size_write(struct file *f, const char __user *buf,
+ size_t size, loff_t *pos)
+{
+ int r;
+ struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
+
+ if (size < sizeof(connector->debugfs_dpcd_size))
+ return 0;
+
+ r = copy_from_user(&connector->debugfs_dpcd_size,
+ buf, sizeof(connector->debugfs_dpcd_size));
+
+ if (connector->debugfs_dpcd_size > 256)
+ connector->debugfs_dpcd_size = 0;
+
+ return size - r;
+}
+
+static ssize_t dp_dpcd_data_write(struct file *f, const char __user *buf,
+ size_t size, loff_t *pos)
+{
+ int r;
+ char *data;
+ struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
+ struct dc_link *link = connector->dc_link;
+ uint32_t write_size = connector->debugfs_dpcd_size;
+
+ if (size < write_size)
+ return 0;
+
+ data = kzalloc(write_size, GFP_KERNEL);
+ if (!data)
+ return 0;
+
+ r = copy_from_user(data, buf, write_size);
+
+ dm_helpers_dp_write_dpcd(link->ctx, link,
+ connector->debugfs_dpcd_address, data, write_size - r);
+ kfree(data);
+ return write_size - r;
+}
+
+static ssize_t dp_dpcd_data_read(struct file *f, char __user *buf,
+ size_t size, loff_t *pos)
+{
+ int r;
+ char *data;
+ struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
+ struct dc_link *link = connector->dc_link;
+ uint32_t read_size = connector->debugfs_dpcd_size;
+
+ if (size < read_size)
+ return 0;
+
+ data = kzalloc(read_size, GFP_KERNEL);
+ if (!data)
+ return 0;
+
+ dm_helpers_dp_read_dpcd(link->ctx, link,
+ connector->debugfs_dpcd_address, data, read_size);
+
+ r = copy_to_user(buf, data, read_size);
+
+ kfree(data);
+ return read_size - r;
+}
+
static const struct file_operations dp_link_settings_debugfs_fops = {
.owner = THIS_MODULE,
.read = dp_link_settings_read,
@@ -757,6 +840,25 @@ static const struct file_operations sdp_message_fops = {
.llseek = default_llseek
};
+static const struct file_operations dp_dpcd_address_debugfs_fops = {
+ .owner = THIS_MODULE,
+ .write = dp_dpcd_address_write,
+ .llseek = default_llseek
+};
+
+static const struct file_operations dp_dpcd_size_debugfs_fops = {
+ .owner = THIS_MODULE,
+ .write = dp_dpcd_size_write,
+ .llseek = default_llseek
+};
+
+static const struct file_operations dp_dpcd_data_debugfs_fops = {
+ .owner = THIS_MODULE,
+ .read = dp_dpcd_data_read,
+ .write = dp_dpcd_data_write,
+ .llseek = default_llseek
+};
+
static const struct {
char *name;
const struct file_operations *fops;
@@ -765,7 +867,10 @@ static const struct {
{"phy_settings", &dp_phy_settings_debugfs_fop},
{"test_pattern", &dp_phy_test_pattern_fops},
{"vrr_range", &vrr_range_fops},
- {"sdp_message", &sdp_message_fops}
+ {"sdp_message", &sdp_message_fops},
+ {"aux_dpcd_address", &dp_dpcd_address_debugfs_fops},
+ {"aux_dpcd_size", &dp_dpcd_size_debugfs_fops},
+ {"aux_dpcd_data", &dp_dpcd_data_debugfs_fops}
};
int connector_debugfs_init(struct amdgpu_dm_connector *connector)
--
2.17.1
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