On Monday 04 February 2013 03:35 PM, Marcus Lorentzon wrote:
On 02/02/2013 12:35 AM, Laurent Pinchart wrote:
Hi Marcus,
On Tuesday 08 January 2013 18:08:19 Marcus Lorentzon wrote:
On 01/08/2013 05:36 PM, Tomasz Figa wrote:
On Tuesday 08 of January 2013 11:12:26 Marcus Lorentzon wrote:
[...]
But it is not perfect. After a couple of products we realized that
most
panel drivers want an easy way to send a bunch of init commands in one
go. So I think it should be an op for sending an array of commands at
once. Something like
struct dsi_cmd {
enum mipi_pkt_type type; /* MIPI DSI, DCS, SetPacketLen, ... */
u8 cmd;
int dataLen;
u8 *data;
}
struct dsi_ops {
int dsi_write(source, int num_cmds, struct dsi_cmd *cmds);
...
}
Do you have DSI IP(s) that can handle a list of commands ? Or would
all DSI
transmitter drivers need to iterate over the commands manually ? In
the later
case a lower-level API might be easier to implement in DSI transmitter
drivers. Helper functions could provide the higher-level API you
proposed.
The HW has a FIFO, so it can handle a few. Currently we use the low
level type of call with one call per command. But we have found DSI
command mode panels that don't accept any commands during the "update"
(write start+continues). And so we must use a mutex/state machine to
exclude any async calls to send DSI commands during update. But if you
need to send more than one command per frame this will be hard (like
CABC and backlight commands). It will be a ping pong between update and
command calls. One option is to expose the mutex to the caller so it can
make many calls before the next update grabs the mutex again.
So maybe we could create a helper that handle the op for list of
commands and another op for single command that you actually have to
implement.
fyi, the DSI IP on OMAP3+ SoCs also has a FIFO. It can provide
interrupts after each command is pushed out, and also when the FIFO gets
empty(all commands are pushed). The only thing to take care is to not
overflow FIFO.
DSI video mode panels generally have a few dozen internal registers
which need to be configured via DSI commands. It's more fast(and
convenient) to configure a handful of internal registers in one shot,
and then perform a single BTA to know from the panel whether the
commands were received correctly.
Regards,
Archit
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