Re: [PATCH v10 16/17] media: platform: Add mali-c55 parameters video node

Dan Scally
2025-06-30T10:41:04Z

Hi Sakari

On 29/06/2025 12:27, Sakari Ailus wrote:
> Hi Daniel,
>
> On 6/24/25 13:21, Daniel Scally wrote:
>> +static void mali_c55_params_buf_queue(struct vb2_buffer *vb)
>> +{
>> +    struct mali_c55_params *params = vb2_get_drv_priv(vb->vb2_queue);
>> +    struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>> +    struct mali_c55_params_buf *buf = to_mali_c55_params_buf(vbuf);
>> +    struct mali_c55 *mali_c55 = params->mali_c55;
>> +    struct mali_c55_params_buffer *config;
>> +    struct list_head *queue;
>> +    size_t block_offset = 0;
>> +    size_t max_offset;
>> +
>> +    /*
>> +     * Before accepting the buffer we should check that the data within it
>> +     * is valid.
>> +     */
>> +    config = vb2_plane_vaddr(vb, 0);
>> +
>> +    if (config->total_size > MALI_C55_PARAMS_MAX_SIZE) {
>> +        dev_dbg(mali_c55->dev, "Invalid parameters buffer size %u\n",
>> +            config->total_size);
>> +        goto err_buffer_done;
>> +    }
>> +
>> +    /* Currently only v1 is supported */
>> +    if (config->version != MALI_C55_PARAM_BUFFER_V1) {
>> +        dev_dbg(mali_c55->dev, "Invalid parameters version\n");
>> +        goto err_buffer_done;
>> +    }
>> +
>> +    max_offset = config->total_size - sizeof(struct mali_c55_params_block_header);
>> +    while (block_offset < max_offset) {
>> +        const struct mali_c55_block_handler *block_handler;
>> +        union mali_c55_params_block block;
>> +
>> +        block = (union mali_c55_params_block)
>> +             &config->data[block_offset];
>> +
>> +        if (block.header->type >= ARRAY_SIZE(mali_c55_block_handlers)) {
>> +            dev_dbg(mali_c55->dev, "Invalid parameters block type\n");
>> +            goto err_buffer_done;
>> +        }
>> +
>> +        if (block_offset + block.header->size > config->total_size) {
>> +            dev_dbg(mali_c55->dev, "Parameters block too large\n");
>> +            goto err_buffer_done;
>> +        }
>> +
>> +        block_handler = &mali_c55_block_handlers[block.header->type];
>> +
>> +        /*
>> +         * Userspace can optionally omit all but the header of a block
>> +         * if it only intends to disable the block.
>> +         */
>> +        if (block.header->size != block_handler->size &&
>> +            block.header->size != sizeof(*block.header)) {
>> +            dev_dbg(mali_c55->dev, "Invalid parameters block size\n");
>> +            goto err_buffer_done;
>> +        }
>> +
>> +        block_offset += block.header->size;
>
> I recall discussing with Jacopo in the context of another ISP driver (Rockchip?) that this piece
> of non-trivial code should make it into the framework side before a next driver using it has been
> added. What's the status of that? Same for other related bits.
Ah-ha. OK - let me talk to Jacopo about that
>
>> +    }
>> +
>> +    vb2_set_plane_payload(vb, 0, sizeof(struct mali_c55_params_buffer));
>> +
>> +    /*
>> +     * Copy the parameters buffer provided by userspace to the internal
>> +     * scratch buffer. This protects against the chance of userspace making
>> +     * changed to the buffer content whilst the driver processes it.
>> +     */
>> +    memcpy(buf->config, config, sizeof(*config));
>> +
>> +    queue = mali_c55->inline_mode ? &params->buffers.queue :
>> +                    &params->buffers.pending;
>> +
>> +    spin_lock(&params->buffers.lock);
>> +    list_add_tail(&buf->queue, queue);
>> +    spin_unlock(&params->buffers.lock);
>> +
>> +    media_jobs_try_queue_job(mali_c55->sched, MEDIA_JOB_TYPE_PIPELINE_PULSE);
>> +
>> +    return;
>> +
>> +err_buffer_done:
>> +    vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
>> +}
>
> ...
>
>> +static bool mali_c55_params_job_ready(void *data)
>> +{
>> +    struct mali_c55_params *params = data;
>> +
>> +    if (IS_ERR_OR_NULL(media_pad_remote_pad_unique(&params->pad)))
>> +        return true;
>> +
>> +    guard(spinlock)(&params->buffers.lock);
>> +
>> +    if (list_empty(&params->buffers.pending))
>> +        return false;
>
>     return !list_empty(...);
Nice
>
>> +
>> +    return true;
>> +}
>> +
>> +static void mali_c55_params_job_queue(void *data)
>> +{
>> +    struct mali_c55_params *params = data;
>> +    struct mali_c55_params_buf *buf;
>> +
>> +    if (IS_ERR_OR_NULL(media_pad_remote_pad_unique(&params->pad)))
>> +        return;
>> +
>> +    guard(spinlock)(&params->buffers.lock);
>> +    buf = list_first_entry(&params->buffers.pending,
>> +                   struct mali_c55_params_buf, queue);
>> +    list_move_tail(&buf->queue, &params->buffers.queue);
>> +}
>> +
>> +static void mali_c55_params_job_abort(void *data)
>> +{
>> +    struct mali_c55_params *params = data;
>> +    struct mali_c55_params_buf *buf;
>> +
>> +    guard(spinlock)(&params->buffers.lock);
>> +    buf = list_last_entry(&params->buffers.queue,
>> +                  struct mali_c55_params_buf, queue);
>> +
>> +    if (buf)
>> +        list_move(&buf->queue, &params->buffers.pending);
>> +}
>> +
>> +static void mali_c55_params_run_step(void *data)
>> +{
>> +    struct mali_c55_params *params = data;
>> +    struct mali_c55 *mali_c55 = params->mali_c55;
>> +
>> +    mali_c55_params_write_config(mali_c55);
>> +}
>> +
>> +static int mali_c55_params_job_add_steps(struct media_job *job, void *data)
>> +{
>> +    return media_jobs_add_job_step(job, mali_c55_params_run_step, data,
>> +                       MEDIA_JOBS_FL_STEP_FROM_FRONT, 0);
>> +}
>> +
>> +static struct media_job_contributor_ops mali_c55_params_media_job_ops = {
>
> const
>
>> +    .add_steps    = mali_c55_params_job_add_steps,
>> +    .ready        = mali_c55_params_job_ready,
>> +    .queue        = mali_c55_params_job_queue,
>> +    .abort        = mali_c55_params_job_abort
>> +};
>> +
>> +void mali_c55_params_write_config(struct mali_c55 *mali_c55)
>> +{
>> +    struct mali_c55_params *params = &mali_c55->params;
>> +    struct mali_c55_params_buffer *config;
>> +    struct mali_c55_params_buf *buf;
>> +    size_t block_offset = 0;
>> +    size_t max_offset;
>> +
>> +    spin_lock(&params->buffers.lock);
>> +
>> +    buf = list_first_entry_or_null(&params->buffers.queue,
>> +                       struct mali_c55_params_buf, queue);
>> +    if (buf)
>> +        list_del(&buf->queue);
>> +    spin_unlock(&params->buffers.lock);
>
> scoped_guard here?

Yep will do

>
>> +
>> +    if (!buf)
>> +        return;
>> +
>> +    buf->vb.sequence = mali_c55->isp.frame_sequence;
>> +    config = buf->config;
>> +
>> +    max_offset = config->total_size - sizeof(struct mali_c55_params_block_header);
>> +
>> +    /*
>> +     * Walk the list of parameter blocks and process them. No validation is
>> +     * done here, as the contents of the config buffer are already checked
>> +     * when the buffer is queued.
>> +     */
>> +    while (block_offset < max_offset) {
>> +        const struct mali_c55_block_handler *block_handler;
>> +        union mali_c55_params_block block;
>> +
>> +        block = (union mali_c55_params_block)
>> +             &config->data[block_offset];
>> +
>> +        /* We checked the array index already in .buf_queue() */
>> +        block_handler = &mali_c55_block_handlers[block.header->type];
>> +        block_handler->handler(mali_c55, block);
>> +
>> +        block_offset += block.header->size;
>> +    }
>> +
>> +    vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
>> +}
>> +
>> +void mali_c55_unregister_params(struct mali_c55 *mali_c55)
>> +{
>> +    struct mali_c55_params *params = &mali_c55->params;
>> +
>> +    if (!video_is_registered(&params->vdev))
>> +        return;
>> +
>> +    vb2_video_unregister_device(&params->vdev);
>> +    media_entity_cleanup(&params->vdev.entity);
>> +    mutex_destroy(&params->lock);
>> +}
>> +
>> +int mali_c55_register_params(struct mali_c55 *mali_c55)
>> +{
>> +    struct mali_c55_params *params = &mali_c55->params;
>> +    struct video_device *vdev = &params->vdev;
>> +    struct vb2_queue *vb2q = &params->queue;
>> +    int ret;
>> +
>> +    mutex_init(&params->lock);
>> +    INIT_LIST_HEAD(&params->buffers.queue);
>> +    INIT_LIST_HEAD(&params->buffers.pending);
>> +    spin_lock_init(&params->buffers.lock);
>> +
>> +    params->pad.flags = MEDIA_PAD_FL_SOURCE;
>> +    ret = media_entity_pads_init(&params->vdev.entity, 1, &params->pad);
>> +    if (ret)
>> +        goto err_destroy_mutex;
>> +
>> +    vb2q->type = V4L2_BUF_TYPE_META_OUTPUT;
>> +    vb2q->io_modes = VB2_MMAP | VB2_DMABUF;
>> +    vb2q->drv_priv = params;
>> +    vb2q->mem_ops = &vb2_dma_contig_memops;
>> +    vb2q->ops = &mali_c55_params_vb2_ops;
>> +    vb2q->buf_struct_size = sizeof(struct mali_c55_params_buf);
>> +    vb2q->min_queued_buffers = 1;
>> +    vb2q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
>> +    vb2q->lock = &params->lock;
>> +    vb2q->dev = mali_c55->dev;
>> +
>> +    ret = vb2_queue_init(vb2q);
>> +    if (ret) {
>> +        dev_err(mali_c55->dev, "params vb2 queue init failed\n");
>> +        goto err_cleanup_entity;
>> +    }
>> +
>> +    strscpy(params->vdev.name, "mali-c55 3a params",
>> +        sizeof(params->vdev.name));
>> +    vdev->release = video_device_release_empty;
>> +    vdev->fops = &mali_c55_params_v4l2_fops;
>> +    vdev->ioctl_ops = &mali_c55_params_v4l2_ioctl_ops;
>> +    vdev->lock = &params->lock;
>> +    vdev->v4l2_dev = &mali_c55->v4l2_dev;
>> +    vdev->queue = &params->queue;
>> +    vdev->device_caps = V4L2_CAP_META_OUTPUT | V4L2_CAP_STREAMING |
>> +                V4L2_CAP_IO_MC;
>> +    vdev->vfl_dir = VFL_DIR_TX;
>> +    video_set_drvdata(vdev, params);
>> +
>> +    ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
>> +    if (ret) {
>> +        dev_err(mali_c55->dev,
>> +            "failed to register params video device\n");
>> +        goto err_release_vb2q;
>> +    }
>> +
>> +    ret = media_jobs_register_job_contributor(mali_c55->sched,
>> +                          &mali_c55_params_media_job_ops,
>> +                          params,
>> +                          MEDIA_JOB_TYPE_PIPELINE_PULSE);
>> +    if (ret) {
>> +        dev_err(mali_c55->dev, "Failed to add media job setup func\n");
>> +        goto err_unregister_video_device;
>> +    }
>> +
>> +    params->mali_c55 = mali_c55;
>> +
>> +    return 0;
>> +
>> +err_unregister_video_device:
>> +    video_unregister_device(vdev);
>> +err_release_vb2q:
>> +    vb2_queue_release(vb2q);
>> +err_cleanup_entity:
>> +    media_entity_cleanup(&params->vdev.entity);
>> +err_destroy_mutex:
>> +    mutex_destroy(&params->lock);
>> +
>> +    return ret;
>> +}
>> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-registers.h
>> b/drivers/media/platform/arm/mali-c55/mali-c55-registers.h
>> index 58dd6ce556a096ede4d3a21e472fdb9ed1cf5de3..7bcb23d798ed2c3bdd90c15cf2e2084890449b6f 100644
>> --- a/drivers/media/platform/arm/mali-c55/mali-c55-registers.h
>> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-registers.h
>> @@ -159,6 +159,23 @@ enum mali_c55_interrupts {
>>   #define MALI_C55_BAYER_ORDER_GBRG            2
>>   #define MALI_C55_BAYER_ORDER_BGGR            3
>>   +#define MALI_C55_REG_METERING_CONFIG            0x18ed0
>> +#define MALI_C55_5BIN_HIST_DISABLE_MASK            BIT(0)
>> +#define MALI_C55_5BIN_HIST_SWITCH_MASK            GENMASK(2, 1)
>> +#define MALI_C55_5BIN_HIST_SWITCH(x)            ((x) << 1)
>> +#define MALI_C55_AF_DISABLE_MASK            BIT(4)
>> +#define MALI_C55_AF_SWITCH_MASK                BIT(5)
>> +#define MALI_C55_AWB_DISABLE_MASK            BIT(8)
>> +#define MALI_C55_AWB_SWITCH_MASK            BIT(9)
>> +#define MALI_C55_AWB_SWITCH(x)                ((x) << 9)
>> +#define MALI_C55_AEXP_HIST_DISABLE_MASK            BIT(12)
>> +#define MALI_C55_AEXP_HIST_DISABLE            (0x01 << 12)
>> +#define MALI_C55_AEXP_HIST_SWITCH_MASK            GENMASK(14, 13)
>> +#define MALI_C55_AEXP_HIST_SWITCH(x)            ((x) << 13)
>> +#define MALI_C55_AEXP_IHIST_DISABLE_MASK        BIT(16)
>> +#define MALI_C55_AEXP_IHIST_DISABLE            (0x01 << 12)
>> +#define MALI_C55_AEXP_SRC_MASK                BIT(24)
>> +
>>   #define MALI_C55_REG_TPG_CH0                0x18ed8
>>   #define MALI_C55_TEST_PATTERN_ON_OFF            BIT(0)
>>   #define MALI_C55_TEST_PATTERN_RGB_MASK            BIT(1)
>> @@ -179,6 +196,11 @@ enum mali_c55_interrupts {
>>   #define MALI_C55_REG_CONFIG_SPACES_OFFSET        0x0ab6c
>>   #define MALI_C55_CONFIG_SPACE_SIZE            0x1231c
>>   +#define MALI_C55_REG_DIGITAL_GAIN            0x1926c
>> +#define MALI_C55_DIGITAL_GAIN_MASK            GENMASK(12, 0)
>> +#define MALI_C55_REG_DIGITAL_GAIN_OFFSET        0x19270
>> +#define MALI_C55_DIGITAL_GAIN_OFFSET_MASK        GENMASK(19, 0)
>> +
>>   #define MALI_C55_REG_SINTER_CONFIG            0x19348
>>   #define MALI_C55_SINTER_VIEW_FILTER_MASK        GENMASK(1, 0)
>>   #define MALI_C55_SINTER_SCALE_MODE_MASK            GENMASK(3, 2)
>> @@ -192,6 +214,59 @@ enum mali_c55_interrupts {
>>   #define MALI_C55_TEMPER_DMA_WRITE_ON            BIT(0)
>>   #define MALI_C55_TEMPER_DMA_READ_ON            BIT(1)
>>   +/* Black Level Correction Configuration */
>> +#define MALI_C55_REG_SENSOR_OFF_PRE_SHA_00        0x1abcc
>> +#define MALI_C55_REG_SENSOR_OFF_PRE_SHA_01        0x1abd0
>> +#define MALI_C55_REG_SENSOR_OFF_PRE_SHA_10        0x1abd4
>> +#define MALI_C55_REG_SENSOR_OFF_PRE_SHA_11        0x1abd8
>> +#define MALI_C55_SENSOR_OFF_PRE_SHA_MASK        0xfffff
>> +
>> +/* Lens Mesh Shading Configuration */
>> +#define MALI_C55_REG_MESH_SHADING_TABLES        0x13074
>> +#define MALI_C55_REG_MESH_SHADING_CONFIG        0x1abfc
>> +#define MALI_C55_MESH_SHADING_ENABLE_MASK        BIT(0)
>> +#define MALI_C55_MESH_SHADING_MESH_SHOW_MASK        BIT(1)
>> +#define MALI_C55_MESH_SHADING_MESH_SHOW(x)        ((x) << 1)
>> +#define MALI_C55_MESH_SHADING_SCALE_MASK        GENMASK(4, 2)
>> +#define MALI_C55_MESH_SHADING_SCALE(x)            ((x) << 2)
>> +#define MALI_C55_MESH_SHADING_PAGE_R_MASK        GENMASK(9, 8)
>> +#define MALI_C55_MESH_SHADING_PAGE_R(x)            ((x) << 8)
>> +#define MALI_C55_MESH_SHADING_PAGE_G_MASK        GENMASK(11, 10)
>> +#define MALI_C55_MESH_SHADING_PAGE_G(x)            ((x) << 10)
>> +#define MALI_C55_MESH_SHADING_PAGE_B_MASK        GENMASK(13, 12)
>> +#define MALI_C55_MESH_SHADING_PAGE_B(x)            ((x) << 12)
>> +#define MALI_C55_MESH_SHADING_MESH_WIDTH_MASK GENMASK(21, 16)
>> +#define MALI_C55_MESH_SHADING_MESH_WIDTH(x)        ((x) << 16)
>> +#define MALI_C55_MESH_SHADING_MESH_HEIGHT_MASK GENMASK(29, 24)
>> +#define MALI_C55_MESH_SHADING_MESH_HEIGHT(x)        ((x) << 24)
>> +
>> +#define MALI_C55_REG_MESH_SHADING_ALPHA_BANK        0x1ac04
>> +#define MALI_C55_MESH_SHADING_ALPHA_BANK_R_MASK GENMASK(2, 0)
>> +#define MALI_C55_MESH_SHADING_ALPHA_BANK_G_MASK GENMASK(5, 3)
>> +#define MALI_C55_MESH_SHADING_ALPHA_BANK_G(x)        ((x) << 3)
>> +#define MALI_C55_MESH_SHADING_ALPHA_BANK_B_MASK GENMASK(8, 6)
>> +#define MALI_C55_MESH_SHADING_ALPHA_BANK_B(x)        ((x) << 6)
>> +#define MALI_C55_REG_MESH_SHADING_ALPHA            0x1ac08
>> +#define MALI_C55_MESH_SHADING_ALPHA_R_MASK        GENMASK(7, 0)
>> +#define MALI_C55_MESH_SHADING_ALPHA_G_MASK        GENMASK(15, 8)
>> +#define MALI_C55_MESH_SHADING_ALPHA_G(x)        ((x) << 8)
>> +#define MALI_C55_MESH_SHADING_ALPHA_B_MASK        GENMASK(23, 16)
>> +#define MALI_C55_MESH_SHADING_ALPHA_B(x)        ((x) << 16)
>> +#define MALI_C55_REG_MESH_SHADING_MESH_STRENGTH        0x1ac0c
>> +#define MALI_c55_MESH_STRENGTH_MASK            GENMASK(15, 0)
>> +
>> +/* AWB Gains Configuration */
>> +#define MALI_C55_REG_AWB_GAINS1                0x1ac10
>> +#define MALI_C55_AWB_GAIN00_MASK            GENMASK(11, 0)
>> +#define MALI_C55_AWB_GAIN01_MASK            GENMASK(27, 16)
>> +#define MALI_C55_AWB_GAIN01(x)                ((x) << 16)
>> +#define MALI_C55_REG_AWB_GAINS2                0x1ac14
>> +#define MALI_C55_AWB_GAIN10_MASK            GENMASK(11, 0)
>> +#define MALI_C55_AWB_GAIN11_MASK            GENMASK(27, 16)
>> +#define MALI_C55_AWB_GAIN11(x)                ((x) << 16)
>> +#define MALI_C55_REG_AWB_GAINS1_AEXP            0x1ac18
>> +#define MALI_C55_REG_AWB_GAINS2_AEXP            0x1ac1c
>> +
>>   /* Colour Correction Matrix Configuration */
>>   #define MALI_C55_REG_CCM_ENABLE                0x1b07c
>>   #define MALI_C55_CCM_ENABLE_MASK            BIT(0)
>> @@ -214,6 +289,59 @@ enum mali_c55_interrupts {
>>   #define MALI_C55_REG_CCM_ANTIFOG_OFFSET_B        0x1b0c8
>>   #define MALI_C55_CCM_ANTIFOG_OFFSET_MASK        GENMASK(11, 0)
>>   +/* AWB Statistics Configuration */
>> +#define MALI_C55_REG_AWB_STATS_MODE            0x1b29c
>> +#define MALI_C55_AWB_STATS_MODE_MASK            BIT(0)
>> +#define MALI_C55_REG_AWB_WHITE_LEVEL            0x1b2a0
>> +#define MALI_C55_AWB_WHITE_LEVEL_MASK            GENMASK(9, 0)
>> +#define MALI_C55_REG_AWB_BLACK_LEVEL            0x1b2a4
>> +#define MALI_C55_AWB_BLACK_LEVEL_MASK            GENMASK(9, 0)
>> +#define MALI_C55_REG_AWB_CR_MAX                0x1b2a8
>> +#define MALI_C55_AWB_CR_MAX_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_CR_MIN                0x1b2ac
>> +#define MALI_C55_AWB_CR_MIN_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_CB_MAX                0x1b2b0
>> +#define MALI_C55_AWB_CB_MAX_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_CB_MIN                0x1b2b4
>> +#define MALI_C55_AWB_CB_MIN_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_NODES_USED            0x1b2c4
>> +#define MALI_C55_AWB_NODES_USED_HORIZ_MASK        GENMASK(7, 0)
>> +#define MALI_C55_AWB_NODES_USED_VERT_MASK        GENMASK(15, 8)
>> +#define MALI_C55_AWB_NODES_USED_VERT(x)            ((x) << 8)
>> +#define MALI_C55_REG_AWB_CR_HIGH            0x1b2c8
>> +#define MALI_C55_AWB_CR_HIGH_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_CR_LOW                0x1b2cc
>> +#define MALI_C55_AWB_CR_LOW_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_CB_HIGH            0x1b2d0
>> +#define MALI_C55_AWB_CB_HIGH_MASK            GENMASK(11, 0)
>> +#define MALI_C55_REG_AWB_CB_LOW                0x1b2d4
>> +#define MALI_C55_AWB_CB_LOW_MASK            GENMASK(11, 0)
>> +
>> +/* AEXP Metering Histogram Configuration */
>> +#define MALI_C55_REG_AEXP_HIST_BASE            0x1b730
>> +#define MALI_C55_REG_AEXP_IHIST_BASE            0x1bbac
>> +#define MALI_C55_AEXP_HIST_SKIP_OFFSET            0
>> +#define MALI_C55_AEXP_HIST_SKIP_X_MASK            GENMASK(2, 0)
>> +#define MALI_C55_AEXP_HIST_SKIP_X(x)            ((x) << 0)
>> +#define MALI_C55_AEXP_HIST_OFFSET_X_MASK        BIT(3)
>> +#define MALI_C55_AEXP_HIST_OFFSET_X(x)            ((x) << 3)
>> +#define MALI_C55_AEXP_HIST_SKIP_Y_MASK            GENMASK(6, 4)
>> +#define MALI_C55_AEXP_HIST_SKIP_Y(x)            ((x) << 4)
>> +#define MALI_C55_AEXP_HIST_OFFSET_Y_MASK        BIT(7)
>> +#define MALI_C55_AEXP_HIST_OFFSET_Y(x)            ((x) << 7)
>> +#define MALI_C55_AEXP_HIST_SCALE_OFFSET            4
>> +#define MALI_C55_AEXP_HIST_SCALE_BOTTOM_MASK        GENMASK(3, 0)
>> +#define MALI_C55_AEXP_HIST_SCALE_TOP_MASK        GENMASK(7, 4)
>> +#define MALI_C55_AEXP_HIST_SCALE_TOP(x)            ((x) << 4)
>> +#define MALI_C55_AEXP_HIST_PLANE_MODE_OFFSET        16
>> +#define MALI_C55_AEXP_HIST_PLANE_MODE_MASK        GENMASK(2, 0)
>> +#define MALI_C55_AEXP_HIST_NODES_USED_OFFSET        52
>> +#define MALI_C55_AEXP_HIST_NODES_USED_HORIZ_MASK    GENMASK(7, 0)
>> +#define MALI_C55_AEXP_HIST_NODES_USED_VERT_MASK GENMASK(15, 8)
>> +#define MALI_C55_AEXP_HIST_NODES_USED_VERT(x)        ((x) << 8)
>> +#define MALI_C55_AEXP_HIST_ZONE_WEIGHTS_OFFSET        56
>> +#define MALI_C55_AEXP_HIST_ZONE_WEIGHT_MASK        0x0f0f0f0f
>> +
>>   /*
>>    * The Mali-C55 ISP has up to two output pipes; known as full resolution and
>>    * down scaled. The register space for these is laid out identically, but offset
>>
>