On 06/12/2015 03:58 PM, Vinod Koul wrote:
Sorry this slipped thru
I was away for a week anyways ;)
Thinking about it again, I think we should coverge to two APIs and mark the legacy depracuated and look to convert folks and phase that out
Currently, w/o this series we have these APIs: /* to be used with DT/ACPI */ dma_request_slave_channel(dev, name) /* NULL on failure */ dma_request_slave_channel_reason(dev, name) /* error code on failure */
/* Legacy mode only - no DT/ACPI lookup */ dma_request_channel(mask, fn, fn_param) /* NULL on failure */
/* to be used with DT/ACPI or legacy boot */ dma_request_slave_channel_compat(mask, fn, fn_param, dev, name) /* NULL on failure */
To request _any_ channel to be used for memcpy one has to use dma_request_channel(mask, NULL, NULL);
If I did not missed something.
As we need different types of parameters for DT/ACPI and legacy (non DT/ACPI lookup) and the good API names are already taken, we might need to settle:
/* to be used with DT/ACPI */ dma_request_slave_channel(dev, name) /* error code on failure */ - Convert users to check IS_ERR_OR_NULL() instead against NULL - Mark dma_request_slave_channel_reason() deprecated and convert the current users
/* to be used with DT/ACPI or legacy boot */ dma_request_slave_channel_compat(mask, fn, fn_param, dev, name) /* error code on failure */ - Convert users to check IS_ERR_OR_NULL() instead against NULL - Do not try legacy mode if either OF or ACPI failed because of real error
/* Legacy mode only - no DT/ACPI lookup */ dma_request_channel_legacy(mask, fn, fn_param) /* error code on failure */ - convert users of dma_request_channel() - mark dma_request_channel() deprecated
/* to be used to get a channel for memcpy for example */ dma_request_any_channel(mask) /* error code on failure */ - Convert current dma_request_channel(mask, NULL, NULL) users I know, any of the other function could be prepared to handle this when parameters are missing, but it is a bit cleaner to have separate API for this.
It would be nice to find another name for the dma_request_slave_channel_compat() so with the new name we could have chance to rearrange the parameters: (dev, name, mask, fn, fn_param)
We would end up with the following APIs, all returning with error code on failure: dma_request_slave_channel(dev, name); dma_request_channel_legacy(mask, fn, fn_param); dma_request_slave_channel_compat(mask, fn, fn_param, dev, name); dma_request_any_channel(mask);
What do you think?