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Message-ID: <1160ec55-2ce3-cc0e-3b59-5fec1f1e5809@linaro.org>
Date:   Wed, 31 May 2023 02:16:50 +0300
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Subject: Re: [PATCH RFC 03/10] drm/panel: Add LGD panel driver for Sony Xperia
 XZ3
Content-Language: en-GB
To:     Marijn Suijten <marijn.suijten@somainline.org>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>
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>
 <00d30c09-d622-11c1-2e07-44a798659982@quicinc.com>
 <2zwamlkhtcuu3c7lithcipb3h46gjg7zsefnhdinmsjwkjxrcc@jbj7ak2mdgeu>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <2zwamlkhtcuu3c7lithcipb3h46gjg7zsefnhdinmsjwkjxrcc@jbj7ak2mdgeu>
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On 30/05/2023 21:13, Marijn Suijten wrote:
> On 2023-05-30 10:54:17, Abhinav Kumar 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.
> 
> All four panel drivers in this series have a `post-panel-on` separation
> (containing _just_ the panel_on DCS) and should be implemented with a
> separate .enable callback.
> 
> More importantly: is the API to enable/disable, and separately
> prepare/unprepare the panel exposed to userspace?  And is there an app
> (maybe as part of mesa/drm where modetest lives) that is able to trigger
> these calls to test adequate behaviour?  In the past I've seen panels
> working, until my userspace suspends and turn the panel off, where it
> never comes back up properly after.

No. The prepare/enable (and disable/unrepare) translate to the bridge's 
pre_enable/enable and disable/post_disable callbacks, which are a part 
of modesetting. One can not call them separately.


-- 
With best wishes
Dmitry