Commit e8314d7d authored by Peter Rosin's avatar Peter Rosin Committed by Mark Brown
Browse files

misc: atmel-ssc: register as sound DAI if #sound-dai-cells is present 



The SSC is currently not usable with the ASoC simple-audio-card, as
every SSC audio user has to build a platform driver that may do as
little as calling atmel_ssc_set_audio/atmel_ssc_put_audio (which
allocates the SSC and registers a DAI with the ASoC subsystem).

So, have that happen automatically, if the #sound-dai-cells property
is present in devicetree, which it has to be anyway for simple audio
card to work.

Signed-off-by: default avatarPeter Rosin <peda@axentia.se>
Acked-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent a5de5b74

Documentation/devicetree/bindings/misc/atmel-ssc.txt

+2 −0
Original line number Diff line number Diff line
@@ -24,6 +24,8 @@ Optional properties: 
       this parameter to choose where the clock from.

     - By default the clock is from TK pin, if the clock from RK pin, this

       property is needed.

  - #sound-dai-cells: Should contain <0>.

     - This property makes the SSC into an automatically registered DAI.



Examples:

- PDC transfer:

drivers/misc/atmel-ssc.c

+50 −0
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 


#include <linux/of.h>



#include "../../sound/soc/atmel/atmel_ssc_dai.h"



/* Serialize access to ssc_list and user count */

static DEFINE_SPINLOCK(user_lock);

static LIST_HEAD(ssc_list);
@@ -145,6 +147,49 @@ static inline const struct atmel_ssc_platform_data * __init 
		platform_get_device_id(pdev)->driver_data;

}



#ifdef CONFIG_SND_ATMEL_SOC_SSC

static int ssc_sound_dai_probe(struct ssc_device *ssc)

{

	struct device_node *np = ssc->pdev->dev.of_node;

	int ret;

	int id;



	ssc->sound_dai = false;



	if (!of_property_read_bool(np, "#sound-dai-cells"))

		return 0;



	id = of_alias_get_id(np, "ssc");

	if (id < 0)

		return id;



	ret = atmel_ssc_set_audio(id);

	ssc->sound_dai = !ret;



	return ret;

}



static void ssc_sound_dai_remove(struct ssc_device *ssc)

{

	if (!ssc->sound_dai)

		return;



	atmel_ssc_put_audio(of_alias_get_id(ssc->pdev->dev.of_node, "ssc"));

}

#else

static inline int ssc_sound_dai_probe(struct ssc_device *ssc)

{

	if (of_property_read_bool(ssc->pdev->dev.of_node, "#sound-dai-cells"))

		return -ENOTSUPP;



	return 0;

}



static inline void ssc_sound_dai_remove(struct ssc_device *ssc)

{

}

#endif



static int ssc_probe(struct platform_device *pdev)

{

	struct resource *regs;
@@ -204,6 +249,9 @@ static int ssc_probe(struct platform_device *pdev) 
	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",

			ssc->regs, ssc->irq);



	if (ssc_sound_dai_probe(ssc))

		dev_err(&pdev->dev, "failed to auto-setup ssc for audio\n");



	return 0;

}
@@ -211,6 +259,8 @@ static int ssc_remove(struct platform_device *pdev) 
{

	struct ssc_device *ssc = platform_get_drvdata(pdev);



	ssc_sound_dai_remove(ssc);



	spin_lock(&user_lock);

	list_del(&ssc->list);

	spin_unlock(&user_lock);

include/linux/atmel-ssc.h

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ struct ssc_device { 
	int			user;

	int			irq;

	bool			clk_from_rk_pin;

	bool			sound_dai;

};



struct ssc_device * __must_check ssc_request(unsigned int ssc_num);

CRA Git | Maintained and supported by SUSTech CRA and CCSE