[PATCH v2 14/17] drm/msm/dpu: add the writeback connector layer

[Dmitry Baryshkov]

On 20/04/2022 22:10, Abhinav Kumar wrote:
> 
> 
> On 4/20/2022 12:52 AM, Dmitry Baryshkov wrote:
>> On 20/04/2022 04:46, Abhinav Kumar wrote:
>>> Introduce the dpu_writeback module which serves as the
>>> interface between dpu operations and the drm_writeback.
>>>
>>> This module manages the connector related operations for
>>> dpu writeback.
>>>
>>> changes in v2:
>>>     - start using drm_writeback_connector_init_with_encoder()
>>>     - drop unnecessary arguments from dpu_writeback_init()
>>>     - rebase on msm-next tip and remove usage of priv->connectors
>>>
>>> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
>>> ---
>>>   drivers/gpu/drm/msm/Makefile                  |  1 +
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 68 
>>> +++++++++++++++++++++++++++
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h | 25 ++++++++++
>>>   3 files changed, 94 insertions(+)
>>>   create mode 100644 drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
>>>   create mode 100644 drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
>>>
>>> diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
>>> index 0387f22..66395ee 100644
>>> --- a/drivers/gpu/drm/msm/Makefile
>>> +++ b/drivers/gpu/drm/msm/Makefile
>>> @@ -80,6 +80,7 @@ msm-$(CONFIG_DRM_MSM_DPU) += \
>>>       disp/dpu1/dpu_plane.o \
>>>       disp/dpu1/dpu_rm.o \
>>>       disp/dpu1/dpu_vbif.o \
>>> +    disp/dpu1/dpu_writeback.o
>>>   msm-$(CONFIG_DRM_MSM_MDSS) += \
>>>       msm_mdss.o \
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
>>> new file mode 100644
>>> index 0000000..526d884
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
>>> @@ -0,0 +1,68 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>>> reserved.
>>> + */
>>> +
>>> +#include "dpu_writeback.h"
>>> +
>>> +static int dpu_wb_conn_get_modes(struct drm_connector *connector)
>>> +{
>>> +    struct drm_device *dev = connector->dev;
>>> +
>>> +    return drm_add_modes_noedid(connector, dev->mode_config.max_width,
>>> +            dev->mode_config.max_height);
>>> +}
>>> +
>>> +static const struct drm_connector_funcs dpu_wb_conn_funcs = {
>>> +    .reset = drm_atomic_helper_connector_reset,
>>> +    .fill_modes = drm_helper_probe_single_connector_modes,
>>> +    .destroy = drm_connector_cleanup,
>>> +    .atomic_duplicate_state = 
>>> drm_atomic_helper_connector_duplicate_state,
>>> +    .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>>> +};
>>> +
>>> +static int dpu_wb_conn_prepare_job(struct drm_writeback_connector 
>>> *connector,
>>> +        struct drm_writeback_job *job)
>>> +{
>>> +    if (!job->fb)
>>> +        return 0;
>>> +
>>> +    dpu_encoder_prepare_wb_job(connector->encoder, job);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static void dpu_wb_conn_cleanup_job(struct drm_writeback_connector 
>>> *connector,
>>> +        struct drm_writeback_job *job)
>>> +{
>>> +    if (!job->fb)
>>> +        return;
>>> +
>>> +    dpu_encoder_cleanup_wb_job(connector->encoder, job);
>>> +}
>>> +
>>> +static const struct drm_connector_helper_funcs 
>>> dpu_wb_conn_helper_funcs = {
>>> +    .get_modes = dpu_wb_conn_get_modes,
>>> +    .prepare_writeback_job = dpu_wb_conn_prepare_job,
>>> +    .cleanup_writeback_job = dpu_wb_conn_cleanup_job,
>>> +};
>>> +
>>> +int dpu_writeback_init(struct drm_device *dev, struct drm_encoder *enc,
>>> +        const u32 *format_list, u32 num_formats)
>>> +{
>>> +    struct dpu_wb_connector *dpu_wb_conn;
>>> +    int rc = 0;
>>> +
>>> +    dpu_wb_conn = devm_kzalloc(dev->dev, sizeof(*dpu_wb_conn), 
>>> GFP_KERNEL);
>>> +
>>> +    drm_connector_helper_add(&dpu_wb_conn->base.base, 
>>> &dpu_wb_conn_helper_funcs);
>>> +
>>> +    /* DPU initializes the encoder and sets it up completely for 
>>> writeback
>>> +     * cases and hence should use the new API 
>>> drm_writeback_connector_init_with_encoder
>>> +     * to initialize the writeback connector
>>> +     */
>>> +    rc = drm_writeback_connector_init_with_encoder(dev, 
>>> &dpu_wb_conn->base, enc,
>>> +            &dpu_wb_conn_funcs, format_list, num_formats);
>>> +
>>> +    return rc;
>>> +}
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
>>> new file mode 100644
>>> index 0000000..05aff05
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
>>> @@ -0,0 +1,25 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>>> reserved.
>>> + */
>>> +
>>> +#ifndef _DPU_WRITEBACK_H
>>> +#define _DPU_WRITEBACK_H
>>> +
>>> +#include <drm/drm_crtc.h>
>>> +#include <drm/drm_file.h>
>>> +#include <drm/drm_probe_helper.h>
>>> +#include <drm/drm_writeback.h>
>>> +
>>> +#include "msm_drv.h"
>>> +#include "dpu_kms.h"
>>> +#include "dpu_encoder_phys.h"
>>> +
>>> +struct dpu_wb_connector {
>>> +    struct drm_writeback_connector base;
>>> +};
>>
>> Do you plan to add more fields to this struct? If not, we can probably 
>> drop it and use struct drm_writeback_connector directly.
> 
> Glad you asked about it. I was expecting this question because it looks 
> like a very "light" struct.
> 
> Yes, we do plan to expand this as we will keep adding writeback features 
> sequentially now to make it ready for this to be absorbed downstream 
> completely.

Then a separate struct is fine with me.

> 
>>
>>> +
>>> +int dpu_writeback_init(struct drm_device *dev, struct drm_encoder *enc,
>>> +        const u32 *format_list, u32 num_formats);
>>> +
>>> +#endif /*_DPU_WRITEBACK_H */
>>
>>


-- 
With best wishes
Dmitry