Hi Vinod,
On Fri, Sep 02, 2016 at 04:55:32PM +0530, Vinod Koul wrote:
> On Thu, Sep 01, 2016 at 03:43:16PM -0700, Nicolin Chen wrote:
>
> > +#define ADMA_CH_CTRL_MODE_ONCE (1 << 8)
>
> BIT(8)? You should change the existing ones too :)
Ah..right...Will change them all in the v2.
> > #define ADMA_CH_CTRL_MODE_CONTINUOUS (2 << 8)
> > +#define ADMA_CH_CTRL_MODE_LINKED_LIST (4 << 8)
> > #define ADMA_CH_CTRL_FLOWCTRL_EN BIT(1)
> >
> > #define ADMA_CH_CONFIG 0x28
> > @@ -111,6 +115,7 @@ struct tegra_adma_desc {
> > size_t buf_len;
> > size_t period_len;
> > size_t num_periods;
> > + bool cyclic;
>
> Okay, i think this should be a separate preparatory patch
Hmm..I could do that, but the driver only had a cyclic support
so the boolean property here would look useless without having
the prep_dma_memcpy().
> > case DMA_DEV_TO_MEM:
> > adma_dir = ADMA_CH_CTRL_DIR_AHUB2MEM;
> > burst_size = fls(tdc->sconfig.src_maxburst);
> > - ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(desc->num_periods - 1);
> > - ch_regs->ctrl = ADMA_CH_CTRL_RX_REQ(tdc->sreq_index);
> > + ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(num_periods - 1);
> > + ch_regs->ctrl = ADMA_CH_CTRL_RX_REQ(tdc->sreq_index) |
> > + ADMA_CH_CTRL_MODE_CONTINUOUS |
> > + ADMA_CH_CTRL_FLOWCTRL_EN;
>
> why is this changing?
The reference manual says M2M is non-flow controlled, and it
would not use the MODE_CONTINUOUS but MODE_ONCE, I should have
mentioned this in the commit log though.
> > +static struct dma_async_tx_descriptor *tegra_adma_prep_dma_memcpy(
> > + struct dma_chan *dc, dma_addr_t dest, dma_addr_t src,
> > + size_t buf_len, unsigned long flags)
> > +{
> > + struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
> > + struct device *dev = dc->device->dev;
> > + struct tegra_adma_desc *desc = NULL;
> > +
> > + dev_dbg(dev, "%s channel: %d src=0x%llx dst=0x%llx len=%zu\n",
> > + __func__, dc->chan_id, (unsigned long long)src,
> > + (unsigned long long)dest, buf_len);
> > +
> > + if (unlikely(!tdc || !buf_len))
> > + return NULL;
> > +
> > + desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
> > + if (!desc)
> > + return NULL;
> > +
> > + desc->num_periods = 1;
> > + desc->buf_len = buf_len;
> > + desc->period_len = buf_len;
>
> should we perhaps rename this to length rather than period?
The MODE_ONCE should support multiple buffers/chunks/periods
as well according to the reference manual but I just couldn't
make that work and the manual doesn't provide much detail.
I think it could be better to have a TODO comment here.
Thank you
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