[PATCH 29/54] drm/amd/display: Linux set/read lane settings through debugfs
Harry Wentland
harry.wentland at amd.com
Tue Jul 10 00:37:07 UTC 2018
From: Hersen Wu <hersenxs.wu at amd.com>
function: get current DP PHY settings: voltage swing, pre-emphasis,
post-cursor2 (defined by VESA DP specification)
valid values: voltage swing: 0,1,2,3 pre-emphasis : 0,1,2,3
post cursor2 : 0,1,2,3
debugfs file phy_setings is located at /sys/kernel/debug/dri/0/DP-x
there will be directories, like DP-1, DP-2,DP-3, etc. for DP display
--- to figure out which DP-x is the display for DP to be check,
cd DP-x
ls -ll
There should be debugfs file, like link_settings, phy_settings.
cat link_settings
from lane_count, link_rate to figure which DP-x is for display to be
worked on
--- to get current DP PHY settings,
cat phy_settings
--- to change DP PHY settings,
echo <voltage_swing> <pre-emphasis> <post_cursor2> > phy_settings
for examle, to change voltage swing to 2, pre-emphasis to 3,
post_cursor2 to 0,
echo 2 3 0 > phy_settings
--- to check if change be applied, get current phy settings by
cat phy_settings
--- in case invalid values are set by user, like
echo 1 4 0 > phy_settings
HW will NOT be programmed by these settings.
cat phy_settings will show the previous valid settings.
Signed-off-by: Hersen Wu <hersenxs.wu at amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland at amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu at amd.com>
---
.../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 266 ++++++++++++++----
1 file changed, 207 insertions(+), 59 deletions(-)
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 8ddbf219dd23..f20ba9d1c9e2 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
@@ -26,7 +26,6 @@
#include <linux/debugfs.h>
#include "dc.h"
-
#include "amdgpu.h"
#include "amdgpu_dm.h"
#include "amdgpu_dm_debugfs.h"
@@ -46,7 +45,7 @@
*
* --- to get dp configuration
*
- * xxd -l 300 phy_settings
+ * cat link_settings
*
* It will list current, verified, reported, preferred dp configuration.
* current -- for current video mode
@@ -56,7 +55,7 @@
*
* --- set (or force) dp configuration
*
- * echo <lane_count> <link_rate>
+ * echo <lane_count> <link_rate> > link_settings
*
* for example, to force to 2 lane, 2.7GHz,
* echo 4 0xa > link_settings
@@ -67,7 +66,7 @@
* done. please check link settings after force operation to see if HW get
* programming.
*
- * xxd -l 300 link_settings
+ * cat link_settings
*
* check current and preferred settings.
*
@@ -79,13 +78,13 @@ static ssize_t dp_link_settings_read(struct file *f, char __user *buf,
struct dc_link *link = connector->dc_link;
char *rd_buf = NULL;
char *rd_buf_ptr = NULL;
- uint32_t rd_buf_size = 320;
- int bytes_to_user;
+ const uint32_t rd_buf_size = 100;
+ uint32_t result = 0;
uint8_t str_len = 0;
int r;
- if (size == 0)
- return 0;
+ if (*pos & 3 || size & 3)
+ return -EINVAL;
rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
if (!rd_buf)
@@ -98,39 +97,44 @@ static ssize_t dp_link_settings_read(struct file *f, char __user *buf,
link->cur_link_settings.lane_count,
link->cur_link_settings.link_rate,
link->cur_link_settings.link_spread);
- rd_buf_ptr = rd_buf_ptr + str_len;
+ rd_buf_ptr += str_len;
str_len = strlen("Verified: %d %d %d ");
snprintf(rd_buf_ptr, str_len, "Verified: %d %d %d ",
link->verified_link_cap.lane_count,
link->verified_link_cap.link_rate,
link->verified_link_cap.link_spread);
- rd_buf_ptr = rd_buf_ptr + str_len;
+ rd_buf_ptr += str_len;
str_len = strlen("Reported: %d %d %d ");
snprintf(rd_buf_ptr, str_len, "Reported: %d %d %d ",
link->reported_link_cap.lane_count,
link->reported_link_cap.link_rate,
link->reported_link_cap.link_spread);
- rd_buf_ptr = rd_buf_ptr + str_len;
+ rd_buf_ptr += str_len;
str_len = strlen("Preferred: %d %d %d ");
- snprintf(rd_buf_ptr, str_len, "Preferred: %d %d %d ",
+ snprintf(rd_buf_ptr, str_len, "Preferred: %d %d %d\n",
link->preferred_link_setting.lane_count,
link->preferred_link_setting.link_rate,
link->preferred_link_setting.link_spread);
- r = copy_to_user(buf, rd_buf, rd_buf_size);
+ while (size) {
+ if (*pos >= rd_buf_size)
+ break;
- bytes_to_user = rd_buf_size - r;
+ r = put_user(*(rd_buf + result), buf);
+ if (r)
+ return r; /* r = -EFAULT */
- if (r > rd_buf_size) {
- bytes_to_user = 0;
- DRM_DEBUG_DRIVER("data not copy to user");
+ buf += 1;
+ size -= 1;
+ *pos += 1;
+ result += 1;
}
kfree(rd_buf);
- return bytes_to_user;
+ return result;
}
static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
@@ -142,7 +146,7 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
struct dc_link_settings prefer_link_settings;
char *wr_buf = NULL;
char *wr_buf_ptr = NULL;
- uint32_t wr_buf_size = 40;
+ const uint32_t wr_buf_size = 40;
int r;
int bytes_from_user;
char *sub_str;
@@ -153,11 +157,11 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
bool valid_input = false;
if (size == 0)
- return 0;
+ return -EINVAL;
wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL);
if (!wr_buf)
- return 0;
+ return -EINVAL;
wr_buf_ptr = wr_buf;
r = copy_from_user(wr_buf_ptr, buf, wr_buf_size);
@@ -166,7 +170,7 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
if (r >= wr_buf_size) {
kfree(wr_buf);
DRM_DEBUG_DRIVER("user data not read\n");
- return 0;
+ return -EINVAL;
}
bytes_from_user = wr_buf_size - r;
@@ -181,16 +185,13 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
r = kstrtol(sub_str, 16, ¶m[param_index]);
if (r)
- DRM_DEBUG_DRIVER(" -EINVAL convert error happens!\n");
+ DRM_DEBUG_DRIVER("string to int convert error code: %d\n", r);
param_index++;
while (isspace(*wr_buf_ptr))
wr_buf_ptr++;
}
- DRM_DEBUG_DRIVER("Lane_count: %lx\n", param[0]);
- DRM_DEBUG_DRIVER("link_rate: %lx\n", param[1]);
-
switch (param[0]) {
case LANE_COUNT_ONE:
case LANE_COUNT_TWO:
@@ -213,9 +214,10 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
break;
}
- if (!valid_input) {
+ if (!valid_input || (param[0] > link->reported_link_cap.lane_count) ||
+ (param[1] > link->reported_link_cap.link_rate)) {
kfree(wr_buf);
- DRM_DEBUG_DRIVER("Invalid Input value exceed No HW will be programmed\n");
+ DRM_DEBUG_DRIVER("Invalid Input value No HW will be programmed\n");
return bytes_from_user;
}
@@ -229,36 +231,190 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
dc_link_set_preferred_link_settings(dc, &prefer_link_settings, link);
kfree(wr_buf);
-
return bytes_from_user;
}
-static ssize_t dp_voltage_swing_debugfs_read(struct file *f, char __user *buf,
+/* function: get current DP PHY settings: voltage swing, pre-emphasis,
+ * post-cursor2 (defined by VESA DP specification)
+ *
+ * valid values
+ * voltage swing: 0,1,2,3
+ * pre-emphasis : 0,1,2,3
+ * post cursor2 : 0,1,2,3
+ *
+ *
+ * how to use this debugfs
+ *
+ * debugfs is located at /sys/kernel/debug/dri/0/DP-x
+ *
+ * there will be directories, like DP-1, DP-2,DP-3, etc. for DP display
+ *
+ * To figure out which DP-x is the display for DP to be check,
+ * cd DP-x
+ * ls -ll
+ * There should be debugfs file, like link_settings, phy_settings.
+ * cat link_settings
+ * from lane_count, link_rate to figure which DP-x is for display to be worked
+ * on
+ *
+ * To get current DP PHY settings,
+ * cat phy_settings
+ *
+ * To change DP PHY settings,
+ * echo <voltage_swing> <pre-emphasis> <post_cursor2> > phy_settings
+ * for examle, to change voltage swing to 2, pre-emphasis to 3, post_cursor2 to
+ * 0,
+ * echo 2 3 0 > phy_settings
+ *
+ * To check if change be applied, get current phy settings by
+ * cat phy_settings
+ *
+ * In case invalid values are set by user, like
+ * echo 1 4 0 > phy_settings
+ *
+ * HW will NOT be programmed by these settings.
+ * cat phy_settings will show the previous valid settings.
+ */
+static ssize_t dp_phy_settings_read(struct file *f, char __user *buf,
size_t size, loff_t *pos)
{
- /* TODO: create method to read voltage swing */
- return 1;
-}
+ struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
+ struct dc_link *link = connector->dc_link;
+ char *rd_buf = NULL;
+ const uint32_t rd_buf_size = 20;
+ uint32_t result = 0;
+ int r;
-static ssize_t dp_voltage_swing_debugfs_write(struct file *f, const char __user *buf,
- size_t size, loff_t *pos)
-{
- /* TODO: create method to write voltage swing */
- return 1;
-}
+ if (*pos & 3 || size & 3)
+ return -EINVAL;
-static ssize_t dp_pre_emphasis_debugfs_read(struct file *f, char __user *buf,
- size_t size, loff_t *pos)
-{
- /* TODO: create method to read pre-emphasis */
- return 1;
+ rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
+ if (!rd_buf)
+ return -EINVAL;
+
+ snprintf(rd_buf, rd_buf_size, " %d %d %d ",
+ link->cur_lane_setting.VOLTAGE_SWING,
+ link->cur_lane_setting.PRE_EMPHASIS,
+ link->cur_lane_setting.POST_CURSOR2);
+
+ while (size) {
+ if (*pos >= rd_buf_size)
+ break;
+
+ r = put_user((*(rd_buf + result)), buf);
+ if (r)
+ return r; /* r = -EFAULT */
+
+ buf += 1;
+ size -= 1;
+ *pos += 1;
+ result += 1;
+ }
+
+ kfree(rd_buf);
+ return result;
}
-static ssize_t dp_pre_emphasis_debugfs_write(struct file *f, const char __user *buf,
+static ssize_t dp_phy_settings_write(struct file *f, const char __user *buf,
size_t size, loff_t *pos)
{
- /* TODO: create method to write pre-emphasis */
- return 1;
+ struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
+ struct dc_link *link = connector->dc_link;
+ struct dc *dc = (struct dc *)link->dc;
+ char *wr_buf = NULL;
+ char *wr_buf_ptr = NULL;
+ uint32_t wr_buf_size = 40;
+ int r;
+ int bytes_from_user;
+ char *sub_str;
+ uint8_t param_index = 0;
+ long param[3];
+ const char delimiter[3] = {' ', '\n', '\0'};
+ bool use_prefer_link_setting;
+ struct link_training_settings link_lane_settings;
+
+ if (size == 0)
+ return 0;
+
+ wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL);
+ if (!wr_buf)
+ return 0;
+ wr_buf_ptr = wr_buf;
+
+ r = copy_from_user(wr_buf_ptr, buf, wr_buf_size);
+
+ /* r is bytes not be copied */
+ if (r >= wr_buf_size) {
+ kfree(wr_buf);
+ DRM_DEBUG_DRIVER("user data not be read\n");
+ return 0;
+ }
+
+ bytes_from_user = wr_buf_size - r;
+
+ while (isspace(*wr_buf_ptr))
+ wr_buf_ptr++;
+
+ while ((*wr_buf_ptr != '\0') && (param_index < 3)) {
+
+ sub_str = strsep(&wr_buf_ptr, delimiter);
+
+ r = kstrtol(sub_str, 16, ¶m[param_index]);
+
+ if (r)
+ DRM_DEBUG_DRIVER("string to int convert error code: %d\n", r);
+
+ param_index++;
+ while (isspace(*wr_buf_ptr))
+ wr_buf_ptr++;
+ }
+
+ if ((param[0] > VOLTAGE_SWING_MAX_LEVEL) ||
+ (param[1] > PRE_EMPHASIS_MAX_LEVEL) ||
+ (param[2] > POST_CURSOR2_MAX_LEVEL)) {
+ kfree(wr_buf);
+ DRM_DEBUG_DRIVER("Invalid Input No HW will be programmed\n");
+ return bytes_from_user;
+ }
+
+ /* get link settings: lane count, link rate */
+ use_prefer_link_setting =
+ ((link->preferred_link_setting.link_rate != LINK_RATE_UNKNOWN) &&
+ (link->test_pattern_enabled));
+
+ memset(&link_lane_settings, 0, sizeof(link_lane_settings));
+
+ if (use_prefer_link_setting) {
+ link_lane_settings.link_settings.lane_count =
+ link->preferred_link_setting.lane_count;
+ link_lane_settings.link_settings.link_rate =
+ link->preferred_link_setting.link_rate;
+ link_lane_settings.link_settings.link_spread =
+ link->preferred_link_setting.link_spread;
+ } else {
+ link_lane_settings.link_settings.lane_count =
+ link->cur_link_settings.lane_count;
+ link_lane_settings.link_settings.link_rate =
+ link->cur_link_settings.link_rate;
+ link_lane_settings.link_settings.link_spread =
+ link->cur_link_settings.link_spread;
+ }
+
+ /* apply phy settings from user */
+ for (r = 0; r < link_lane_settings.link_settings.lane_count; r++) {
+ link_lane_settings.lane_settings[r].VOLTAGE_SWING =
+ (enum dc_voltage_swing) (param[0]);
+ link_lane_settings.lane_settings[r].PRE_EMPHASIS =
+ (enum dc_pre_emphasis) (param[1]);
+ link_lane_settings.lane_settings[r].POST_CURSOR2 =
+ (enum dc_post_cursor2) (param[2]);
+ }
+
+ /* program ASIC registers and DPCD registers */
+ dc_link_set_drive_settings(dc, &link_lane_settings, link);
+
+ kfree(wr_buf);
+ return bytes_from_user;
}
/* function description
@@ -483,17 +639,10 @@ static const struct file_operations dp_link_settings_debugfs_fops = {
.llseek = default_llseek
};
-static const struct file_operations dp_voltage_swing_fops = {
- .owner = THIS_MODULE,
- .read = dp_voltage_swing_debugfs_read,
- .write = dp_voltage_swing_debugfs_write,
- .llseek = default_llseek
-};
-
-static const struct file_operations dp_pre_emphasis_fops = {
+static const struct file_operations dp_phy_settings_debugfs_fop = {
.owner = THIS_MODULE,
- .read = dp_pre_emphasis_debugfs_read,
- .write = dp_pre_emphasis_debugfs_write,
+ .read = dp_phy_settings_read,
+ .write = dp_phy_settings_write,
.llseek = default_llseek
};
@@ -508,8 +657,7 @@ static const struct {
const struct file_operations *fops;
} dp_debugfs_entries[] = {
{"link_settings", &dp_link_settings_debugfs_fops},
- {"voltage_swing", &dp_voltage_swing_fops},
- {"pre_emphasis", &dp_pre_emphasis_fops},
+ {"phy_settings", &dp_phy_settings_debugfs_fop},
{"test_pattern", &dp_phy_test_pattern_fops}
};
--
2.17.1
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