Re: [PATCH 08/18] dmaengine: bcm2835: pass dma_chan to generic functions

Frank Li
2024-06-05T18:05:38Z

On Fri, May 24, 2024 at 07:26:52PM +0100, Dave Stevenson wrote:
> From: Stefan Wahren <stefan.wahren@i2se.com>
>
> In preparation to support more platforms pass the dma_chan to the
> generic functions. This provides access to the DMA device and possible
> platform specific data.

why need this change? you can easy convert between dma_chan and
bcm2835_chan.

>
> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
> ---
> drivers/dma/bcm2835-dma.c | 24 ++++++++++++++----------
> 1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
> index e2f9c8692e6b..aefaa1f01d7f 100644
> --- a/drivers/dma/bcm2835-dma.c
> +++ b/drivers/dma/bcm2835-dma.c
> @@ -288,12 +288,13 @@ static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
> }
>
> static bool
> -bcm2835_dma_create_cb_set_length(struct bcm2835_chan *chan,
> +bcm2835_dma_create_cb_set_length(struct dma_chan *chan,
> struct bcm2835_dma_cb *control_block,
> size_t len, size_t period_len,
> size_t *total_len)
> {
> - size_t max_len = bcm2835_dma_max_frame_length(chan);
> + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
> + size_t max_len = bcm2835_dma_max_frame_length(c);
>
> /* set the length taking lite-channel limitations into account */
> control_block->length = min_t(u32, len, max_len);
> @@ -417,7 +418,7 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
> /* set up length in control_block if requested */
> if (buf_len) {
> /* calculate length honoring period_length */
> - if (bcm2835_dma_create_cb_set_length(c, control_block,
> + if (bcm2835_dma_create_cb_set_length(chan, control_block,
> len, period_len,
> &total_len)) {
> /* add extrainfo bits in info */
> @@ -485,8 +486,9 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
> }
> }
>
> -static void bcm2835_dma_abort(struct bcm2835_chan *c)
> +static void bcm2835_dma_abort(struct dma_chan *chan)
> {
> + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
> void __iomem *chan_base = c->chan_base;
> long int timeout = 10000;
>
> @@ -513,8 +515,9 @@ static void bcm2835_dma_abort(struct bcm2835_chan *c)
> writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
> }
>
> -static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
> +static void bcm2835_dma_start_desc(struct dma_chan *chan)
> {
> + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
> struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
> struct bcm2835_desc *d;
>
> @@ -533,7 +536,8 @@ static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
>
> static irqreturn_t bcm2835_dma_callback(int irq, void *data)
> {
> - struct bcm2835_chan *c = data;
> + struct dma_chan *chan = data;
> + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
> struct bcm2835_desc *d;
> unsigned long flags;
>
> @@ -566,7 +570,7 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
> vchan_cyclic_callback(&d->vd);
> } else if (!readl(c->chan_base + BCM2835_DMA_ADDR)) {
> vchan_cookie_complete(&c->desc->vd);
> - bcm2835_dma_start_desc(c);
> + bcm2835_dma_start_desc(chan);
> }
> }
>
> @@ -594,7 +598,7 @@ static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan)
> }
>
> return request_irq(c->irq_number, bcm2835_dma_callback,
> - c->irq_flags, "DMA IRQ", c);
> + c->irq_flags, "DMA IRQ", chan);
> }
>
> static void bcm2835_dma_free_chan_resources(struct dma_chan *chan)
> @@ -682,7 +686,7 @@ static void bcm2835_dma_issue_pending(struct dma_chan *chan)
>
> spin_lock_irqsave(&c->vc.lock, flags);
> if (vchan_issue_pending(&c->vc) && !c->desc)
> - bcm2835_dma_start_desc(c);
> + bcm2835_dma_start_desc(chan);
>
> spin_unlock_irqrestore(&c->vc.lock, flags);
> }
> @@ -846,7 +850,7 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan)
> if (c->desc) {
> vchan_terminate_vdesc(&c->desc->vd);
> c->desc = NULL;
> - bcm2835_dma_abort(c);
> + bcm2835_dma_abort(chan);
> }
>
> vchan_get_all_descriptors(&c->vc, &head);
> --
> 2.34.1
>