Hi Archit,
Thank you for the patch.
On Friday 02 August 2013 19:33:38 Archit Taneja wrote:
> The primary function of VPDMA is to move data between external memory and
> internal processing modules(in our case, VPE) that source or sink data.
> VPDMA is capable of buffering this data and then delivering the data as
> demanded to the modules as programmed. The modules that source or sink data
> are referred to as clients or ports. A channel is setup inside the VPDMA to
> connect a specific memory buffer to a specific client. The VPDMA
> centralizes the DMA control functions and buffering required to allow all
> the clients to minimize the effect of long latency times.
>
> Add the following to the VPDMA helper:
>
> - A data struct which describe VPDMA channels. For now, these channels are
> the ones used only by VPE, the list of channels will increase when
> VIP(Video Input Port) also uses the VPDMA library. This channel information
> will be used to populate fields required by data descriptors.
>
> - Data structs which describe the different data types supported by VPDMA.
> This data type information will be used to populate fields required by data
> descriptors and used by the VPE driver to map a V4L2 format to the
> corresponding VPDMA data type.
>
> - Provide VPDMA register offset definitions, functions to read, write and
> modify VPDMA registers.
>
> - Functions to create and submit a VPDMA list. A list is a group of
> descriptors that makes up a set of DMA transfers that need to be completed.
> Each descriptor will either perform a DMA transaction to fetch input
> buffers and write to output buffers(data descriptors), or configure the
> MMRs of sub blocks of VPE(configuration descriptors), or provide control
> information to VPDMA (control descriptors).
>
> - Functions to allocate, map and unmap buffers needed for the descriptor
> list, payloads containing MMR values and motion vector buffers. These use
> the DMA mapping APIs to ensure exclusive access to VPDMA.
>
> - Functions to enable VPDMA interrupts. VPDMA can trigger an interrupt on
> the VPE interrupt line when a descriptor list is parsed completely and the
> DMA transactions are completed. This requires masking the events in VPDMA
> registers and configuring some top level VPE interrupt registers.
>
> - Enable some VPDMA specific parameters: frame start event(when to start DMA
> for a client) and line mode(whether each line fetched should be mirrored or
> not).
>
> - Function to load firmware required by VPDMA. VPDMA requires a firmware for
> it's internal list manager. We add the required request_firmware apis to
> fetch this firmware from user space.
>
> - Function to dump VPDMA registers.
>
> - A function to initialize VPDMA, this will be called by the VPE driver with
> it's platform device pointer, this function will take care of loading VPDMA
> firmware and returning a handle back to the VPE driver. The VIP driver will
> also call the same init function to initialize it's own VPDMA instance.
>
> Signed-off-by: Archit Taneja <archit@xxxxxx>
> ---
> drivers/media/platform/ti-vpe/vpdma.c | 589 ++++++++++++++++++++++++++
> drivers/media/platform/ti-vpe/vpdma.h | 154 ++++++++
> drivers/media/platform/ti-vpe/vpdma_priv.h | 119 ++++++
> 3 files changed, 862 insertions(+)
> create mode 100644 drivers/media/platform/ti-vpe/vpdma.c
> create mode 100644 drivers/media/platform/ti-vpe/vpdma.h
> create mode 100644 drivers/media/platform/ti-vpe/vpdma_priv.h
>
> diff --git a/drivers/media/platform/ti-vpe/vpdma.c
> b/drivers/media/platform/ti-vpe/vpdma.c new file mode 100644
> index 0000000..b15b3dd
> --- /dev/null
> +++ b/drivers/media/platform/ti-vpe/vpdma.c
> @@ -0,0 +1,589 @@
[snip]
> +static int get_field(u32 value, u32 mask, int shift)
> +{
> + return (value & (mask << shift)) >> shift;
> +}
> +
> +static int get_field_reg(struct vpdma_data *vpdma, int offset,
> + u32 mask, int shift)
I would call this read_field_reg().
> +{
> + return get_field(read_reg(vpdma, offset), mask, shift);
> +}
> +
> +static void insert_field(u32 *valp, u32 field, u32 mask, int shift)
> +{
> + u32 val = *valp;
> +
> + val &= ~(mask << shift);
> + val |= (field & mask) << shift;
> + *valp = val;
> +}
get_field() and insert_field() are used in a single location, you can manually
inline them.
> +static void insert_field_reg(struct vpdma_data *vpdma, int offset, u32
> field,
> + u32 mask, int shift)
> +{
> + u32 val = read_reg(vpdma, offset);
> +
> + insert_field(&val, field, mask, shift);
> +
> + write_reg(vpdma, offset, val);
> +}
[snip]
> +/*
> + * Allocate a DMA buffer
> + */
> +int vpdma_buf_alloc(struct vpdma_buf *buf, size_t size)
> +{
> + buf->size = size;
> + buf->mapped = 0;
> + buf->addr = kzalloc(size, GFP_KERNEL);
You should use the dma allocation API (depending on your needs,
dma_alloc_coherent for instance) to allocate DMA-able buffers.
> + if (!buf->addr)
> + return -ENOMEM;
> +
> + WARN_ON((u32) buf->addr & VPDMA_DESC_ALIGN);
> +
> + return 0;
> +}
> +
> +void vpdma_buf_free(struct vpdma_buf *buf)
> +{
> + WARN_ON(buf->mapped != 0);
> + kfree(buf->addr);
> + buf->addr = NULL;
> + buf->size = 0;
> +}
> +
> +/*
> + * map a DMA buffer, enabling DMA access
> + */
> +void vpdma_buf_map(struct vpdma_data *vpdma, struct vpdma_buf *buf)
> +{
> + struct device *dev = &vpdma->pdev->dev;
> +
> + WARN_ON(buf->mapped != 0);
> + buf->dma_addr = dma_map_single(dev, buf->addr, buf->size,
> + DMA_TO_DEVICE);
> + buf->mapped = 1;
> + BUG_ON(dma_mapping_error(dev, buf->dma_addr));
BUG_ON() is too harsh, you should return a proper error instead.
> +}
> +
> +/*
> + * unmap a DMA buffer, disabling DMA access and
> + * allowing the main processor to acces the data
> + */
> +void vpdma_buf_unmap(struct vpdma_data *vpdma, struct vpdma_buf *buf)
> +{
> + struct device *dev = &vpdma->pdev->dev;
> +
> + if (buf->mapped)
> + dma_unmap_single(dev, buf->dma_addr, buf->size, DMA_TO_DEVICE);
> +
> + buf->mapped = 0;
> +}
> +
> +/*
> + * create a descriptor list, the user of this list will append
> configuration,
> + * contorl and data descriptors to this list, this list will be submitted
s/contorl/control/
> to
> + * VPDMA. VPDMA's list parser will go through each descriptor and perform
> + * the required DMA operations
> + */
> +int vpdma_create_desc_list(struct vpdma_desc_list *list, size_t size, int
> type)
> +{
> + int r;
> +
> + r = vpdma_buf_alloc(&list->buf, size);
> + if (r)
> + return r;
> +
> + list->next = list->buf.addr;
> +
> + list->type = type;
> +
> + return 0;
> +}
> +
> +/*
> + * once a descriptor list is parsed by VPDMA, we reset the list by emptying
> it,
> + * to allow new descriptors to be added to the list.
> + */
> +void vpdma_reset_desc_list(struct vpdma_desc_list *list)
> +{
> + list->next = list->buf.addr;
> +}
> +
> +/*
> + * free the buffer allocated fot the VPDMA descriptor list, this should be
> + * called when the user doesn't want to use VPDMA any more.
> + */
> +void vpdma_free_desc_list(struct vpdma_desc_list *list)
> +{
> + vpdma_buf_free(&list->buf);
> +
> + list->next = NULL;
> +}
> +
> +static int vpdma_list_busy(struct vpdma_data *vpdma, int list_num)
Should the function return a bool instead of an int ?
> +{
> + u32 sync_reg = read_reg(vpdma, VPDMA_LIST_STAT_SYNC);
> +
> + return (sync_reg >> (list_num + 16)) & 0x01;
You could shorten that as
return read_reg(vpdma, VPDMA_LIST_STAT_SYNC) & BIT(list_num + 16);
> +}
> +
> +/*
> + * submit a list of DMA descriptors to the VPE VPDMA, do not wait for
> completion
> + */
> +int vpdma_submit_descs(struct vpdma_data *vpdma, struct vpdma_desc_list
> *list)
> +{
> + /* we always use the first list */
> + int list_num = 0;
> + int list_size;
> +
> + if (vpdma_list_busy(vpdma, list_num))
> + return -EBUSY;
> +
> + /* 16-byte granularity */
> + list_size = (list->next - list->buf.addr) >> 4;
> +
> + write_reg(vpdma, VPDMA_LIST_ADDR, (u32) list->buf.dma_addr);
> + wmb();
> + write_reg(vpdma, VPDMA_LIST_ATTR,
> + (list_num << VPDMA_LIST_NUM_SHFT) |
> + (list->type << VPDMA_LIST_TYPE_SHFT) |
> + list_size);
> +
> + return 0;
> +}
> +
> +/* set or clear the mask for list complete interrupt */
> +void vpdma_enable_list_complete_irq(struct vpdma_data *vpdma, int list_num,
> + bool enable)
> +{
> + u32 val;
> +
> + val = read_reg(vpdma, VPDMA_INT_LIST0_MASK);
> + if (enable)
> + val |= (1 << (list_num * 2));
> + else
> + val &= ~(1 << (list_num * 2));
> + write_reg(vpdma, VPDMA_INT_LIST0_MASK, val);
> +}
> +
> +/* clear previosuly occured list intterupts in the LIST_STAT register */
> +void vpdma_clear_list_stat(struct vpdma_data *vpdma)
> +{
> + write_reg(vpdma, VPDMA_INT_LIST0_STAT,
> + read_reg(vpdma, VPDMA_INT_LIST0_STAT));
> +}
> +
> +/*
> + * configures the output mode of the line buffer for the given client, the
> + * line buffer content can either be mirrored(each line repeated twice) or
> + * passed to the client as is
> + */
> +void vpdma_set_line_mode(struct vpdma_data *vpdma, int line_mode,
> + enum vpdma_channel chan)
> +{
> + int client_cstat = chan_info[chan].cstat_offset;
> +
> + insert_field_reg(vpdma, client_cstat, line_mode,
> + VPDMA_CSTAT_LINE_MODE_MASK, VPDMA_CSTAT_LINE_MODE_SHIFT);
> +}
> +
> +/*
> + * configures the event which should trigger VPDMA transfer for the given
> + * client
> + */
> +void vpdma_set_frame_start_event(struct vpdma_data *vpdma,
> + enum vpdma_frame_start_event fs_event,
> + enum vpdma_channel chan)
> +{
> + int client_cstat = chan_info[chan].cstat_offset;
> +
> + insert_field_reg(vpdma, client_cstat, fs_event,
> + VPDMA_CSTAT_FRAME_START_MASK, VPDMA_CSTAT_FRAME_START_SHIFT);
> +}
> +
> +static void vpdma_firmware_cb(const struct firmware *f, void *context)
> +{
> + struct vpdma_data *vpdma = context;
> + struct vpdma_buf fw_dma_buf;
> + int i, r;
> +
> + dev_dbg(&vpdma->pdev->dev, "firmware callback\n");
> +
> + if (!f || !f->data) {
> + dev_err(&vpdma->pdev->dev, "couldn't get firmware\n");
> + return;
> + }
> +
> + /* already initialized */
> + if (get_field_reg(vpdma, VPDMA_LIST_ATTR, VPDMA_LIST_RDY_MASK,
> + VPDMA_LIST_RDY_SHFT)) {
> + vpdma->ready = true;
> + return;
> + }
> +
> + r = vpdma_buf_alloc(&fw_dma_buf, f->size);
> + if (r) {
> + dev_err(&vpdma->pdev->dev,
> + "failed to allocate dma buffer for firmware\n");
> + goto rel_fw;
> + }
> +
> + memcpy(fw_dma_buf.addr, f->data, f->size);
> +
> + vpdma_buf_map(vpdma, &fw_dma_buf);
> +
> + write_reg(vpdma, VPDMA_LIST_ADDR, (u32) fw_dma_buf.dma_addr);
> +
> + for (i = 0; i < 100; i++) { /* max 1 second */
> + msleep_interruptible(10);
> +
> + if (get_field_reg(vpdma, VPDMA_LIST_ATTR, VPDMA_LIST_RDY_MASK,
> + VPDMA_LIST_RDY_SHFT))
> + break;
> + }
> +
> + if (i == 100) {
> + dev_err(&vpdma->pdev->dev, "firmware upload failed\n");
> + goto free_buf;
> + }
> +
> + vpdma->ready = true;
> +
> +free_buf:
> + vpdma_buf_unmap(vpdma, &fw_dma_buf);
> +
> + vpdma_buf_free(&fw_dma_buf);
> +rel_fw:
> + release_firmware(f);
> +}
> +
> +static int vpdma_load_firmware(struct vpdma_data *vpdma)
> +{
> + int r;
> + struct device *dev = &vpdma->pdev->dev;
> +
> + r = request_firmware_nowait(THIS_MODULE, 1,
> + (const char *) VPDMA_FIRMWARE, dev, GFP_KERNEL, vpdma,
> + vpdma_firmware_cb);
Is there a reason not to use the synchronous interface ? That would simplify
both this code and the callers, as they won't have to check whether the
firmware has been correctly loaded.
> + if (r) {
> + dev_err(dev, "firmware not available %s\n", VPDMA_FIRMWARE);
> + return r;
> + } else {
> + dev_info(dev, "loading firmware %s\n", VPDMA_FIRMWARE);
> + }
> +
> + return 0;
> +}
> +
> +int vpdma_init(struct platform_device *pdev, struct vpdma_data **pvpdma)
As the function allocates the vpdma instance, I would call it vpdma_create()
and make it turn a struct vpdma_data *. You can then return error codes using
ERR_PTR().
> +{
> + struct resource *res;
> + struct vpdma_data *vpdma;
> + int r;
> +
> + dev_dbg(&pdev->dev, "vpdma_init\n");
> +
> + vpdma = devm_kzalloc(&pdev->dev, sizeof(*vpdma), GFP_KERNEL);
> + if (!vpdma) {
> + dev_err(&pdev->dev, "couldn't alloc vpdma_dev\n");
> + return -ENOMEM;
> + }
> +
> + vpdma->pdev = pdev;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vpdma");
> + if (res == NULL) {
> + dev_err(&pdev->dev, "missing platform resources data\n");
> + return -ENODEV;
> + }
> +
> + vpdma->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
You can use devm_ioremap_resource(). The function checks the res pointer and
prints error messages, so you can remove the res == NULL check above and the
dev_err() below.
> + if (!vpdma->base) {
> + dev_err(&pdev->dev, "failed to ioremap\n");
> + return -ENOMEM;
> + }
> +
> + r = vpdma_load_firmware(vpdma);
> + if (r) {
> + pr_err("failed to load firmware %s\n", VPDMA_FIRMWARE);
> + return r;
> + }
> +
> + *pvpdma = vpdma;
> +
> + return 0;
> +}
> +MODULE_FIRMWARE(VPDMA_FIRMWARE);
--
Regards,
Laurent Pinchart
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