samsung-sm8650/android_kernel_samsung_sm8650-modules
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

disp: msm: dp: read DPCD registers using debugfs

Browse Source 
This change adds support for reading the byte at specific DPCD
addresses for physical monitors, similar to the way it is already done in
sim mode.

The read address is taken to be the last written address. Reads return a
single byte unless the address is 0, in which case 20 bytes are returned
to preserve the original functionality.

Change-Id: I43c44d81758c156257bd5dba6bb8f9c08ac948eb
Signed-off-by: Alex Danila <eadanila@codeaurora.org>
This commit is contained in:
Alex Danila
2021-08-26 09:12:34 -04:00
parent 3a2c526376
commit d521b12b69
1 changed files with 16 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
msm/dp/dp_debug.c
View File

@@ -212,7 +212,7 @@ static ssize_t dp_debug_write_dpcd(struct file *file,
size = min_t(size_t, count, SZ_2K);
if (size <= 4)
if (size < 4)
goto bail;
buf = kzalloc(size, GFP_KERNEL);
@@ -231,9 +231,10 @@ static ssize_t dp_debug_write_dpcd(struct file *file,
DP_ERR("offset kstrtoint error\n");
goto bail;
}
debug->dpcd_offset = offset;
size -= 4;
if (size == 0)
if (size < char_to_nib)
goto bail;
dpcd_size = size / char_to_nib;
@@ -277,7 +278,6 @@ static ssize_t dp_debug_write_dpcd(struct file *file,
dp_sim_write_dpcd_reg(debug->sim_bridge,
dpcd, dpcd_buf_index, offset);
debug->dpcd_offset = offset;
debug->dpcd_size = dpcd_buf_index;
bail:
@@ -315,21 +315,27 @@ static ssize_t dp_debug_read_dpcd(struct file *file,
/*
* In simulation mode, this function returns the last written DPCD node.
* For a real monitor plug in, it always dumps the first 16 DPCD registers.
* For a real monitor plug in, it dumps the first byte at the last written DPCD address
* unless the address is 0, in which case the first 20 bytes are dumped
*/
if (debug->dp_debug.sim_mode) {
dp_sim_read_dpcd_reg(debug->sim_bridge, dpcd, debug->dpcd_size, debug->dpcd_offset);
} else {
debug->dpcd_size = sizeof(debug->panel->dpcd);
debug->dpcd_offset = 0;
memcpy(dpcd, debug->panel->dpcd, debug->dpcd_size);
if (debug->dpcd_offset) {
debug->dpcd_size = 1;
if (drm_dp_dpcd_read(debug->aux->drm_aux, debug->dpcd_offset, dpcd,
debug->dpcd_size) != 1)
goto bail;
} else {
debug->dpcd_size = sizeof(debug->panel->dpcd);
memcpy(dpcd, debug->panel->dpcd, debug->dpcd_size);
}
}
len += scnprintf(buf, buf_size, "%04x: ", debug->dpcd_offset);
len += scnprintf(buf + len , buf_size - len, "%04x: ", debug->dpcd_offset);
while (offset < debug->dpcd_size)
len += scnprintf(buf + len, buf_size - len, "%02x ",
dpcd[debug->dpcd_offset + offset++]);
len += scnprintf(buf + len, buf_size - len, "%02x ", dpcd[offset++]);
kfree(dpcd);