Aaro,
On 19/11/2018 20.46, Aaro Koskinen wrote:
> Hi,
>
> On Mon, Nov 19, 2018 at 12:40:40PM +0200, Peter Ujfalusi wrote:
>> When the channel is configured for slave operation the LCH_TYPE needs to be
>> set to LCh-P. For memcpy channels the LCH_TYPE must be set to LCh-2D.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
>
> I don't have the documentation, but based on what omap_udc driver (still
> using the legacy OMAP DMA API) does this seems to be correct.
They are hard to fine, true. From the omap1710 TRM:
Logical channel types (LCh types) supported are:
- LCh-2D for nonsynchronized transfers (memory transfers, 1D and 2D)
- LCh-P for synchronized transfers (mostly peripheral transfers)
- LCh-PD similar to LCh-P but runs on a dedicated physical channel
- LCh-G for graphical transfers/operations
- LCh-D for display transfers
Looking at other part it looks like hat LCH-2D channel mode can happily
service a peripheral. LCH-P supports the same features as LCH-2D, but it
lacks support for Single/Double-indexed addressing mode on the
peripheral port side.
So, this patch might not be needed at all. Can you test the omap_udc
with s/OMAP_DMA_LCH_P/OMAP_DMA_LCH_2D
If USB works, then we can just drop this patch.
Note: if we ever need the port_window support in OMAP1 then we need
double indexing on the peripheral side.
> I tested the patch on Nokia 770 with MMC and couldn't see any negative
> impact.
>
> Tested-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
>
> A.
>
>> ---
>> drivers/dma/ti/omap-dma.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c
>> index a4a931ddf6f6..a18cfd497f04 100644
>> --- a/drivers/dma/ti/omap-dma.c
>> +++ b/drivers/dma/ti/omap-dma.c
>> @@ -185,6 +185,10 @@ enum {
>>
>> CLNK_CTRL_ENABLE_LNK = BIT(15),
>>
>> + /* OMAP1 only */
>> + LCH_CTRL_LCH_2D = 0,
>> + LCH_CTRL_LCH_P = 2,
>> +
>> CDP_DST_VALID_INC = 0 << 0,
>> CDP_DST_VALID_RELOAD = 1 << 0,
>> CDP_DST_VALID_REUSE = 2 << 0,
>> @@ -529,6 +533,7 @@ static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d)
>>
>> static void omap_dma_start_desc(struct omap_chan *c)
>> {
>> + struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
>> struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
>> struct omap_desc *d;
>> unsigned cxsa, cxei, cxfi;
>> @@ -570,6 +575,12 @@ static void omap_dma_start_desc(struct omap_chan *c)
>> omap_dma_chan_write(c, CSDP, d->csdp);
>> omap_dma_chan_write(c, CLNK_CTRL, d->clnk_ctrl);
>>
>> + if (dma_omap1() && !__dma_omap15xx(od->plat->dma_attr)) {
>> + if (is_slave_direction(d->dir))
>> + omap_dma_chan_write(c, LCH_CTRL, LCH_CTRL_LCH_P);
>> + else
>> + omap_dma_chan_write(c, LCH_CTRL, LCH_CTRL_LCH_2D);
>> + }
>> omap_dma_start_sg(c, d);
>> }
>>
>> --
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
