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Message-ID: <00d30c09-d622-11c1-2e07-44a798659982@quicinc.com>
Date:   Tue, 30 May 2023 10:54:17 -0700
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Subject: Re: [PATCH RFC 03/10] drm/panel: Add LGD panel driver for Sony Xperia
 XZ3
Content-Language: en-US
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Marijn Suijten <marijn.suijten@somainline.org>
CC:     <neil.armstrong@linaro.org>, Sam Ravnborg <sam@ravnborg.org>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Caleb Connolly <caleb@connolly.tech>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        "Andy Gross" <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        <~postmarketos/upstreaming@lists.sr.ht>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Martin Botka <martin.botka@somainline.org>,
        "Jami Kettunen" <jami.kettunen@somainline.org>,
        <dri-devel@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        Kuogee Hsieh <quic_khsieh@quicinc.com>,
        Jessica Zhang <quic_jesszhan@quicinc.com>
References: <20230521-drm-panels-sony-v1-0-541c341d6bee@somainline.org>
 <20230521-drm-panels-sony-v1-3-541c341d6bee@somainline.org>
 <ccc97880-8e74-b85b-9679-9c12c44c4b99@linaro.org>
 <71675a02-0801-62dc-2673-4a0907636b21@linaro.org>
 <CAA8EJpq=HZqiBZ6bpUNH47VmASuH+Mi5OD5BHmg0TPwtsKHf8w@mail.gmail.com>
 <oxgtbj7qmsdvz5gl4bud64jedmhdmvphjfge7uy6uwulefqfsa@pleslv2zgwbp>
 <ebc3ff33-6e4f-b107-33c6-f35b03307058@linaro.org>
From:   Abhinav Kumar <quic_abhinavk@quicinc.com>
In-Reply-To: <ebc3ff33-6e4f-b107-33c6-f35b03307058@linaro.org>
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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@linaro.org> 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@somainline.org>
>>>>>> ---
>>>>>>    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@somainline.org>
>>>>>> + *
>>>>>> + * 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.