Re: [PATCH 2/3] dma/ti: convert k3-udma to module

[Kevin Hilman <khilman@baylibre.com>]

Péter Ujfalusi <peter.ujfalusi@gmail.com> writes:

> On 9/26/22 21:18, Kevin Hilman wrote:
>> Currently k3-udma driver is built as separate platform drivers with a
>> shared probe and identical code path, just differnet platform data.
>> 
>> To enable to build as module, convert the separate platform driver
>> into a single module_platform_driver with the data selection done via
>> compatible string and of_match.  The separate of_match tables are also
>> combined into a single table to avoid the multiple calls to
>> of_match_node()
>> 
>> Since all modern TI platforms using this are DT enabled, the removal
>> of separate platform_drivers shoul should nave no functional change.
>> 
>> Signed-off-by: Kevin Hilman <khilman@baylibre.com>
>> ---
>>  drivers/dma/ti/Kconfig        |  4 ++--
>>  drivers/dma/ti/k3-udma-glue.c |  5 ++++-
>>  drivers/dma/ti/k3-udma.c      | 40 +++++------------------------------
>>  3 files changed, 11 insertions(+), 38 deletions(-)
>> 
>> diff --git a/drivers/dma/ti/Kconfig b/drivers/dma/ti/Kconfig
>> index 79618fac119a..f196be3b222f 100644
>> --- a/drivers/dma/ti/Kconfig
>> +++ b/drivers/dma/ti/Kconfig
>> @@ -35,7 +35,7 @@ config DMA_OMAP
>>  	  DMA engine is found on OMAP and DRA7xx parts.
>>  
>>  config TI_K3_UDMA
>> -	bool "Texas Instruments UDMA support"
>> +	tristate "Texas Instruments UDMA support"
>>  	depends on ARCH_K3
>>  	depends on TI_SCI_PROTOCOL
>>  	depends on TI_SCI_INTA_IRQCHIP
>> @@ -48,7 +48,7 @@ config TI_K3_UDMA
>>  	  DMA engine is used in AM65x and j721e.
>>  
>>  config TI_K3_UDMA_GLUE_LAYER
>> -	bool "Texas Instruments UDMA Glue layer for non DMAengine users"
>> +	tristate "Texas Instruments UDMA Glue layer for non DMAengine users"
>>  	depends on ARCH_K3
>>  	depends on TI_K3_UDMA
>>  	help
>> diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
>> index 4fdd9f06b723..c29de4695ae7 100644
>> --- a/drivers/dma/ti/k3-udma-glue.c
>> +++ b/drivers/dma/ti/k3-udma-glue.c
>> @@ -6,6 +6,7 @@
>>   *
>>   */
>>  
>> +#include <linux/module.h>
>>  #include <linux/atomic.h>
>>  #include <linux/delay.h>
>>  #include <linux/dma-mapping.h>
>> @@ -1433,4 +1434,6 @@ static int __init k3_udma_glue_class_init(void)
>>  {
>>  	return class_register(&k3_udma_glue_devclass);
>>  }
>> -arch_initcall(k3_udma_glue_class_init);
>> +
>> +module_init(k3_udma_glue_class_init);
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
>> index 2f0d2c68c93c..7239ff31c8c5 100644
>> --- a/drivers/dma/ti/k3-udma.c
>> +++ b/drivers/dma/ti/k3-udma.c
>> @@ -5,6 +5,7 @@
>>   */
>>  
>>  #include <linux/kernel.h>
>> +#include <linux/module.h>
>>  #include <linux/delay.h>
>>  #include <linux/dmaengine.h>
>>  #include <linux/dma-mapping.h>
>> @@ -4318,18 +4319,10 @@ static const struct of_device_id udma_of_match[] = {
>>  		.compatible = "ti,j721e-navss-mcu-udmap",
>>  		.data = &j721e_mcu_data,
>>  	},
>> -	{ /* Sentinel */ },
>> -};
>> -
>> -static const struct of_device_id bcdma_of_match[] = {
>>  	{
>>  		.compatible = "ti,am64-dmss-bcdma",
>>  		.data = &am64_bcdma_data,
>>  	},
>> -	{ /* Sentinel */ },
>> -};
>> -
>> -static const struct of_device_id pktdma_of_match[] = {
>>  	{
>>  		.compatible = "ti,am64-dmss-pktdma",
>>  		.data = &am64_pktdma_data,
>> @@ -5254,14 +5247,9 @@ static int udma_probe(struct platform_device *pdev)
>>  		return -ENOMEM;
>>  
>>  	match = of_match_node(udma_of_match, dev->of_node);
>> -	if (!match)
>> -		match = of_match_node(bcdma_of_match, dev->of_node);
>>  	if (!match) {
>> -		match = of_match_node(pktdma_of_match, dev->of_node);
>> -		if (!match) {
>> -			dev_err(dev, "No compatible match found\n");
>> -			return -ENODEV;
>> -		}
>> +		dev_err(dev, "No compatible match found\n");
>> +		return -ENODEV;
>>  	}
>>  	ud->match_data = match->data;
>>  
>> @@ -5494,27 +5482,9 @@ static struct platform_driver udma_driver = {
>>  	},
>>  	.probe		= udma_probe,
>>  };
>> -builtin_platform_driver(udma_driver);
>>  
>> -static struct platform_driver bcdma_driver = {
>> -	.driver = {
>> -		.name	= "ti-bcdma",
>> -		.of_match_table = bcdma_of_match,
>> -		.suppress_bind_attrs = true,
>> -	},
>> -	.probe		= udma_probe,
>> -};
>> -builtin_platform_driver(bcdma_driver);
>> -
>> -static struct platform_driver pktdma_driver = {
>> -	.driver = {
>> -		.name	= "ti-pktdma",
>> -		.of_match_table = pktdma_of_match,
>> -		.suppress_bind_attrs = true,
>> -	},
>> -	.probe		= udma_probe,
>> -};
>> -builtin_platform_driver(pktdma_driver);
>> +module_platform_driver(udma_driver);

> I did liked the 'hack' that the dev_* prints contained the actual type
> of the DMA (udma/bcdma/pktdma), but it is not working via modules,
> unless the driver init parts are split out and the bulk is kept as a
> library.
>
> I had this half way implemented in my wip, but never got the chance to
> finalize it.

I guess that could always be done as a second path if needed, but I
wanted to keep this module conversion as simple as possible at first.

> But, one can get the info via the address, so...

Shall I take this "so..." as an acked-by?  ;)

Kevin