Re: [PATCH RFC 03/10] drm/panel: Add LGD panel driver for Sony Xperia XZ3

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 5/29/2023 3:18 PM, Dmitry Baryshkov wrote:
> On 30/05/2023 00:07, Marijn Suijten wrote:
> > On 2023-05-22 15:58:56, Dmitry Baryshkov wrote:
> > > On Mon, 22 May 2023 at 12:04, Neil Armstrong 
> > > <neil.armstrong@xxxxxxxxxx> wrote:
> > > > On 22/05/2023 03:16, Dmitry Baryshkov wrote:
> > > > > On 22/05/2023 00:23, Marijn Suijten wrote:
> > > > > > Sony provides an unlabeled LGD + Atmel maXTouch assembly in its 
> > > > > > Xperia
> > > > > > XZ3 (tama akatsuki) phone, with custom DCS commands to match.
> > > > > >
> > > > > > This panel features Display Stream Compression 1.1.
> > > > > >
> > > > > > Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> > > > > > ---
> > > > > >    drivers/gpu/drm/panel/Kconfig                   |  11 +
> > > > > >    drivers/gpu/drm/panel/Makefile                  |   1 +
> > > > > >    drivers/gpu/drm/panel/panel-sony-akatsuki-lgd.c | 362 
> > > > > > ++++++++++++++++++++++++
> > > > > >    3 files changed, 374 insertions(+)
> > > > > >
> > > > > > diff --git a/drivers/gpu/drm/panel/Kconfig 
> > > > > > b/drivers/gpu/drm/panel/Kconfig
> > > > > > index 67ef898d133f2..18bd116e78a71 100644
> > > > > > --- a/drivers/gpu/drm/panel/Kconfig
> > > > > > +++ b/drivers/gpu/drm/panel/Kconfig
> > > > > > @@ -706,6 +706,17 @@ config DRM_PANEL_SONY_ACX565AKM
> > > > > >          Say Y here if you want to enable support for the Sony 
> > > > > > ACX565AKM
> > > > > >          800x600 3.5" panel (found on the Nokia N900).
> > > > > > +config DRM_PANEL_SONY_AKATSUKI_LGD
> > > > > > +    tristate "Sony Xperia XZ3 LGD panel"
> > > > > > +    depends on GPIOLIB && OF
> > > > > > +    depends on DRM_MIPI_DSI
> > > > > > +    depends on BACKLIGHT_CLASS_DEVICE
> > > > > > +    help
> > > > > > +      Say Y here if you want to enable support for the Sony 
> > > > > > Xperia XZ3
> > > > > > +      1440x2880@60 6.0" OLED DSI cmd mode panel produced by LG 
> > > > > > Display.
> > > > > > +
> > > > > > +      This panel uses Display Stream Compression 1.1.
> > > > > > +
> > > > > >    config DRM_PANEL_SONY_TD4353_JDI
> > > > > >        tristate "Sony TD4353 JDI panel"
> > > > > >        depends on GPIOLIB && OF
> > > > > > diff --git a/drivers/gpu/drm/panel/Makefile 
> > > > > > b/drivers/gpu/drm/panel/Makefile
> > > > > > index ff169781e82d7..85133f73558f3 100644
> > > > > > --- a/drivers/gpu/drm/panel/Makefile
> > > > > > +++ b/drivers/gpu/drm/panel/Makefile
> > > > > > @@ -71,6 +71,7 @@ obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += 
> > > > > > panel-sitronix-st7701.o
> > > > > >    obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7703) += panel-sitronix-st7703.o
> > > > > >    obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += 
> > > > > > panel-sitronix-st7789v.o
> > > > > >    obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
> > > > > > +obj-$(CONFIG_DRM_PANEL_SONY_AKATSUKI_LGD) += 
> > > > > > panel-sony-akatsuki-lgd.o
> > > > > >    obj-$(CONFIG_DRM_PANEL_SONY_TD4353_JDI) += panel-sony-td4353-jdi.o
> > > > > >    obj-$(CONFIG_DRM_PANEL_SONY_TULIP_TRULY_NT35521) += 
> > > > > > panel-sony-tulip-truly-nt35521.o
> > > > > >    obj-$(CONFIG_DRM_PANEL_TDO_TL070WSH30) += panel-tdo-tl070wsh30.o
> > > > > > diff --git a/drivers/gpu/drm/panel/panel-sony-akatsuki-lgd.c 
> > > > > > b/drivers/gpu/drm/panel/panel-sony-akatsuki-lgd.c
> > > > > > new file mode 100644
> > > > > > index 0000000000000..f55788f963dab
> > > > > > --- /dev/null
> > > > > > +++ b/drivers/gpu/drm/panel/panel-sony-akatsuki-lgd.c
> > > > > > @@ -0,0 +1,362 @@
> > > > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > > > +/*
> > > > > > + * Copyright (c) 2023 Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> > > > > > + *
> > > > > > + * Based on Sony Downstream's "Atmel LGD ID5" Akatsuki panel dtsi.
> > > > > > + */
> > > > > > +
> > > > > > +#include <linux/backlight.h>
> > > > > > +#include <linux/delay.h>
> > > > > > +#include <linux/gpio/consumer.h>
> > > > > > +#include <linux/module.h>
> > > > > > +#include <linux/of.h>
> > > > > > +#include <linux/of_device.h>
> > > > > > +#include <linux/regulator/consumer.h>
> > > > > > +
> > > > > > +#include <video/mipi_display.h>
> > > > > > +
> > > > > > +#include <drm/drm_mipi_dsi.h>
> > > > > > +#include <drm/drm_modes.h>
> > > > > > +#include <drm/drm_panel.h>
> > > > > > +#include <drm/drm_probe_helper.h>
> > > > > > +#include <drm/display/drm_dsc.h>
> > > > > > +#include <drm/display/drm_dsc_helper.h>
> > > > > > +
> > > > > > +struct sony_akatsuki_lgd {
> > > > > > +    struct drm_panel panel;
> > > > > > +    struct mipi_dsi_device *dsi;
> > > > > > +    struct regulator *vddio;
> > > > > > +    struct gpio_desc *reset_gpio;
> > > > > > +    bool prepared;
> > > > > > +};
> > > > > > +
> > > > > > +static inline struct sony_akatsuki_lgd 
> > > > > > *to_sony_akatsuki_lgd(struct drm_panel *panel)
> > > > > > +{
> > > > > > +    return container_of(panel, struct sony_akatsuki_lgd, panel);
> > > > > > +}
> > > > > > +
> > > > > > +static int sony_akatsuki_lgd_on(struct sony_akatsuki_lgd *ctx)
> > > > > > +{
> > > > > > +    struct mipi_dsi_device *dsi = ctx->dsi;
> > > > > > +    struct device *dev = &dsi->dev;
> > > > > > +    int ret;
> > > > > > +
> > > > > > +    dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> > > > > > +
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0x7f, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf0, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf1, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf2, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0x02, 0x01);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0x59, 0x01);
> > > > > > +    /* Enable backlight control */
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY, 
> > > > > > BIT(5));
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0x57, 0x20, 0x80, 0xde, 0x60, 0x00);
> > > > > > +
> > > > > > +    ret = mipi_dsi_dcs_set_column_address(dsi, 0, 1440 - 1);
> > > > > > +    if (ret < 0) {
> > > > > > +        dev_err(dev, "Failed to set column address: %d\n", ret);
> > > > > > +        return ret;
> > > > > > +    }
> > > > > > +
> > > > > > +    ret = mipi_dsi_dcs_set_page_address(dsi, 0, 2880 - 1);
> > > > > > +    if (ret < 0) {
> > > > > > +        dev_err(dev, "Failed to set page address: %d\n", ret);
> > > > > > +        return ret;
> > > > > > +    }
> > > > > > +
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, MIPI_DCS_WRITE_POWER_SAVE, 0x00);
> > > > > > +
> > > > > > +    ret = mipi_dsi_dcs_set_tear_on(dsi, 
> > > > > > MIPI_DSI_DCS_TEAR_MODE_VBLANK);
> > > > > > +    if (ret < 0) {
> > > > > > +        dev_err(dev, "Failed to set tear on: %d\n", ret);
> > > > > > +        return ret;
> > > > > > +    }
> > > > > > +
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0x7f, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf0, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf1, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf2, 0x5a, 0x5a);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xb0, 0x03);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf6, 0x04);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xb0, 0x05);
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xf6, 0x01, 0x7f, 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);
> > > > > > +
> > > > > > +    mipi_dsi_dcs_write_seq(dsi, 0xe3, 0xac, 0x19, 0x34, 0x14, 0x7d);
> > > > > > +
> > > > > > +    ret = mipi_dsi_dcs_set_display_on(dsi);
> > > > > > +    if (ret < 0) {
> > > > > > +        dev_err(dev, "Failed to turn display on: %d\n", ret);
> > > > > > +        return ret;
> > > > > > +    }
> > > > >
> > > > > My usual question: should the mipi_dsi_dcs_exit_sleep_mode() / 
> > > > > mipi_dsi_dcs_set_display_on() be moved from prepare() to enable() 
> > > > > part?
> > > >
> > > >
> > > > No, prepare is called before the video stream is started and when 
> > > > display is still in LPM mode and the mode hasn't been set.
> > >
> > > Yes, that's my point. Shouldn't we enable the panel _after_ starting 
> > > the stream?
> >
> > I have never investigated what it takes to split these functions, but
> > some of these panels do show some corruption at startup which may be
> > circumvented by powering the panel on after starting the video stream?
> >
> > I'm just not sure where to make the split: downstream does describe a
> > qcom,mdss-dsi-on-command and qcom,mdss-dsi-post-panel-on-command, where
> > the latter only contains set_display_on() (not exit_sleep_mode()).
> > It is documented like:
> >
> >      same as "qcom,mdss-dsi-on-command" except commands are sent after
> >      displaying an image."
> >
> > So this seems like the right way to split them up, I'll test this out on
> > all submitted panel drivers.
>
> Interesting enough, Neil suggested that sending all the commands during 
> pre_enable() is the correct sequence (especially for VIDEO mode panels), 
> since not all DSI hosts can send commands after switching to the VIDEO 
> mode.

I agree with Neil here.

Yes, it does seem natural to think that sending the video stream before 
sending the on commands would avoid any potential corruption / garbage 
screen issues.

But even from panel side should allow that. I have seen panel ON 
sequences where some explicitly ask for ON commands before the video stream.

So, we cannot really generalize it and needs to be treated on a 
host-to-host and panel-to-panel basis.