On Sun, Aug 08, 2021 at 09:44:57PM +0800, Shawn Guo wrote:
On Wed, Aug 04, 2021 at 02:09:19PM +0200, Stephan Gerhold wrote:
On Wed, Aug 04, 2021 at 04:13:52PM +0800, Shawn Guo wrote:
- ...
- nt_dcs_write(0xb1, 0x6c, 0x21);
- nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x00, 0x00);
- nt_dcs_write(0x35, 0x00);
- nt_gen_write(0x11, 0x00);
- msleep(120);
- nt_gen_write(0x29, 0x00);
- usleep_range(1000, 1500);
- nt_dcs_write(0x53, 0x24);
Did you mix up "nt_dcs_write" and "nt_gen_write" here? The nt_gen_write(0x11, 0x00); looks like MIPI_DCS_EXIT_SLEEP_MODE and the nt_gen_write(0x29, 0x00); looks like MIPI_DCS_SET_DISPLAY_ON.
For reference you can pull your original reference DTB from Sony through my panel driver generator: https://github.com/msm8916-mainline/linux-mdss-dsi-panel-driver-generator
Wow, very nice! It really deserves wider spread!
It produces the following (I compiled "msm8939-kanuti_tulip.dtb" from https://github.com/sonyxperiadev/kernel/tree/aosp/LA.BR.1.3.3_rb2.14, not sure if that is right):
// ... dsi_generic_write_seq(dsi, 0x35, 0x00);
ret = mipi_dsi_dcs_exit_sleep_mode(dsi); if (ret < 0) { dev_err(dev, "Failed to exit sleep mode: %d\n", ret); return ret; } msleep(120);
ret = mipi_dsi_dcs_set_display_on(dsi); if (ret < 0) { dev_err(dev, "Failed to set display on: %d\n", ret); return ret; } usleep_range(1000, 2000);
dsi_generic_write_seq(dsi, 0x53, 0x24);
Which also suggests that generic and DCS writes are mixed up here.
Note however that you could not use the generated driver as-is, because Sony seems to use their own display driver instead of Qualcomm's and some things seem to be different.
I re-created the driver using your generator. With modeling the 5v control GPIOs with regulators and adding backlight-gpios support, the driver works quite nicely, except the following two problems:
- I have to drop the MIPI_DSI_MODE_LPM configuration from .update_status hook. Otherwise brightness did not get updated to panel.
---8<------ diff --git a/drivers/gpu/drm/panel/panel-sony-tulip-truly-nt35521.c b/drivers/gpu/drm/panel/panel-sony-tulip-truly-nt35521.c index 31e5f942a039..eba926c6f722 100644 --- a/drivers/gpu/drm/panel/panel-sony-tulip-truly-nt35521.c +++ b/drivers/gpu/drm/panel/panel-sony-tulip-truly-nt35521.c @@ -420,33 +420,23 @@ static int truly_nt35521_bl_update_status(struct backlight_device *bl) u16 brightness = backlight_get_brightness(bl); int ret;
dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness); if (ret < 0) return ret;dsi->mode_flags |= MIPI_DSI_MODE_LPM;return 0;} ------>8---
I have to admit I don't know much about Low Power Mode vs High Speed Mode. As long it works it is good I guess :-)
- The driver works good, if the kernel is launched via "fastboot boot". But if the kernel is flashed to eMMC and launched by bootloader with splash screen, kernel will fail to bring up the panel. After kernel boots up, a blank & unblank cycle can get panel work though.
The problem 2) is not driver generator related. @Konrad, did you see it on asus-z00t-tm5p5-n35596 driver?
Do you have CONFIG_DRM_MSM=y (built-in) instead of =m (module) maybe? I think a similar issue exists on MSM8916 but it does not happen for some reason if CONFIG_DRM_MSM=m instead of =y. Somehow having it load later during the boot process fixes some things there.
Thanks, Stephan