lkml.org 
[lkml]   [2016]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH v2] dmaengine: DW DMAC: split pdata to hardware properties and platform quirks
From
Date
On Thu, 2016-10-27 at 18:34 +0300, Eugeniy Paltsev wrote:
> This patch is to address a proposal by Andy in this thread:
> http://www.spinics.net/lists/dmaengine/msg11506.html
> Split platform data to actual hardware properties, and platform
> quirks.
> Now we able to use quirks and hardware properties separately from
> different sources (pdata, device tree or autoconfig registers)
>

Thanks for an update, my comments below.

> ---
> Changes for v2:
>    - use separate bool values for quirks in "dw_dma_platform_data"
> instead of
>      common bit field.

>    - convert device tree properties reading to unified device property
> API.

This should be a separate patch.

>
> I was wrong about DW_DMA_IS_SOFT_LLP flag - it is used to check about
> ongoing soft llp transfer. So DW_DMA_IS_SOFT_LLP flag and "dwc-
> >nollp" 
> variable have different functions and I couldn't just get rid of "dwc-
> >nollp"
> and use DW_DMA_IS_SOFT_LLP flag instead. So I left "dwc->nollp"
> untouched.

So, then perhaps we may convert it to another flag let's say
DW_DMA_IS_LLP_SUPPORTED.

But this is other story independent of the subject.

> --- a/drivers/dma/dw/core.c
> +++ b/drivers/dma/dw/core.c
> @@ -1452,9 +1452,24 @@ int dw_dma_probe(struct dw_dma_chip *chip)
>   dw->regs = chip->regs;
>   chip->dw = dw;
>  
> + /* Reassign the platform data pointer */
> + pdata = dw->pdata;
> +
>   pm_runtime_get_sync(chip->dev);
>  
> - if (!chip->pdata) {
> + if ((!chip->pdata) || (chip->pdata && chip->pdata-
> >only_quirks_used)) {

It's simple as
if (!chip->pdata || chip->pdata->only_quirks_used)

> + if (!chip->pdata) {
> + /*
> +  * Fill quirks with the default values in
> case of
> +  * pdata absence.
> +  */
> + pdata->is_private = true;
> + pdata->is_memcpy = true;
> + } else {
> + pdata->is_private = chip->pdata->is_private;
> + pdata->is_memcpy = chip->pdata->is_memcpy;
> + }

Would we leave the first part in the place it is now and add new piece
after?

> +
>   dw_params = dma_readl(dw, DW_PARAMS);
>   dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
>  
> @@ -1464,9 +1479,6 @@ int dw_dma_probe(struct dw_dma_chip *chip)
>   goto err_pdata;
>   }
>  
> - /* Reassign the platform data pointer */
> - pdata = dw->pdata;
> -
>   /* Get hardware configuration parameters */
>   pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN
> & 7) + 1;
>   pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER
> & 3) + 1;
> @@ -1477,8 +1489,6 @@ int dw_dma_probe(struct dw_dma_chip *chip)
>   pdata->block_size = dma_readl(dw, MAX_BLK_SIZE);
>  
>   /* Fill platform data with the default values */
> - pdata->is_private = true;
> - pdata->is_memcpy = true;
>   pdata->chan_allocation_order =
> CHAN_ALLOCATION_ASCENDING;
>   pdata->chan_priority = CHAN_PRIORITY_ASCENDING;

...like

/* Apply platform defined quirks */
if (chip->data && chip->data->only_quirks_used) {
...
}


> - if (of_property_read_u32(np, "dma-channels", &nr_channels))
> - return NULL;
> + if (device_property_read_bool(dev, "is-private"))

As I mentioned above, please do a separate patch for this.

> @@ -183,7 +186,7 @@ static int dw_probe(struct platform_device *pdev)
>  
>   pdata = dev_get_platdata(dev);
>   if (!pdata)
> - pdata = dw_dma_parse_dt(pdev);
> + pdata = dw_dma_parse_dt(dev);

Perhaps you might rename the function to something like

dw_dma_parse_properties(dev);

> + * @only_quirks_used: Only read quirks (like "is_private" or
> "is_memcpy") from
> + * platform data structure. Read other parameters from device
> tree
> + * node (if exists) or from hardware autoconfig registers.

Can you somehow be more clear that all listed quirks will be copied from
platform data.

>   * @is_nollp: The device channels does not support multi block
> transfers.
>   * @chan_allocation_order: Allocate channels starting from 0 or 7
>   * @chan_priority: Set channel priority increasing from 0 to 7 or 7
> to 0.
> @@ -52,6 +55,7 @@ struct dw_dma_platform_data {
>   unsigned int nr_channels;
>   bool is_private;
>   bool is_memcpy;

> + bool only_quirks_used;

Perhaps add if at the end of quirk list and name just 

>   bool is_nollp;

...here

bool use_quirks;

>  #define CHAN_ALLOCATION_ASCENDING 0 /* zero to seven */
>  #define CHAN_ALLOCATION_DESCENDING 1 /* seven to zero
> */
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

\
 
 \ /
  Last update: 2016-10-27 17:56    [W:0.069 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site