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Commit e170adcb authored by Ben Dooks's avatar Ben Dooks Committed by Ben Dooks
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ARM: S3C: Add ADC synchronous read call. 



To add HWMON support, we need a synchronous read() call that blocks
until completion. Add the client that is being service to the select
and convert callbacks to make the code easier.

Signed-off-by: default avatarBen Dooks <ben@simtec.co.uk>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent 885f9ebe

arch/arm/plat-s3c/include/plat/adc.h

+6 −2
Original line number Diff line number Diff line
@@ -19,10 +19,14 @@ struct s3c_adc_client; 
extern int s3c_adc_start(struct s3c_adc_client *client,

			 unsigned int channel, unsigned int nr_samples);



extern int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch);



extern struct s3c_adc_client *

	s3c_adc_register(struct platform_device *pdev,

			 void (*select)(unsigned selected),

			 void (*conv)(unsigned d0, unsigned d1,

			 void (*select)(struct s3c_adc_client *client,

					unsigned selected),

			 void (*conv)(struct s3c_adc_client *client,

				      unsigned d0, unsigned d1,

				      unsigned *samples_left),

			 unsigned int is_ts);

arch/arm/plat-s3c24xx/adc.c

+53 −11
Original line number Diff line number Diff line
@@ -39,13 +39,16 @@ 
struct s3c_adc_client {

	struct platform_device	*pdev;

	struct list_head	 pend;

	wait_queue_head_t	*wait;



	unsigned int		 nr_samples;

	int			 result;

	unsigned char		 is_ts;

	unsigned char		 channel;



	void	(*select_cb)(unsigned selected);

	void	(*convert_cb)(unsigned val1, unsigned val2,

	void	(*select_cb)(struct s3c_adc_client *c, unsigned selected);

	void	(*convert_cb)(struct s3c_adc_client *c,

			      unsigned val1, unsigned val2,

			      unsigned *samples_left);

};
@@ -81,7 +84,7 @@ static inline void s3c_adc_select(struct adc_device *adc, 
{

	unsigned con = readl(adc->regs + S3C2410_ADCCON);



	client->select_cb(1);

	client->select_cb(client, 1);



	con &= ~S3C2410_ADCCON_MUXMASK;

	con &= ~S3C2410_ADCCON_STDBM;
@@ -153,25 +156,61 @@ int s3c_adc_start(struct s3c_adc_client *client, 
}

EXPORT_SYMBOL_GPL(s3c_adc_start);



static void s3c_adc_default_select(unsigned select)

static void s3c_convert_done(struct s3c_adc_client *client,

			     unsigned v, unsigned u, unsigned *left)

{

	client->result = v;

	wake_up(client->wait);

}



int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)

{

	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);

	int ret;



	client->convert_cb = s3c_convert_done;

	client->wait = &wake;

	client->result = -1;



	ret = s3c_adc_start(client, ch, 1);

	if (ret < 0)

		goto err;



	ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);

	if (client->result < 0) {

		ret = -ETIMEDOUT;

		goto err;

	}



	client->convert_cb = NULL;

	return client->result;



err:

	return ret;

}

EXPORT_SYMBOL_GPL(s3c_adc_convert);



static void s3c_adc_default_select(struct s3c_adc_client *client,

				   unsigned select)

{

}



struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,

					void (*select)(unsigned int selected),

					void (*conv)(unsigned d0, unsigned d1,

					void (*select)(struct s3c_adc_client *client,

						       unsigned int selected),

					void (*conv)(struct s3c_adc_client *client,

						     unsigned d0, unsigned d1,

						     unsigned *samples_left),

					unsigned int is_ts)

{

	struct s3c_adc_client *client;



	WARN_ON(!pdev);

	WARN_ON(!conv);



	if (!select)

		select = s3c_adc_default_select;



	if (!conv || !pdev)

	if (!pdev)

		return ERR_PTR(-EINVAL);



	client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
@@ -230,16 +269,19 @@ static irqreturn_t s3c_adc_irq(int irq, void *pw) 
	adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);



	client->nr_samples--;

	(client->convert_cb)(data0 & 0x3ff, data1 & 0x3ff, &client->nr_samples);



	if (client->convert_cb)

		(client->convert_cb)(client, data0 & 0x3ff, data1 & 0x3ff,

				     &client->nr_samples);



	if (client->nr_samples > 0) {

		/* fire another conversion for this */



		client->select_cb(1);

		client->select_cb(client, 1);

		s3c_adc_convert(adc);

	} else {

		local_irq_save(flags);

		(client->select_cb)(0);

		(client->select_cb)(client, 0);

		adc->cur = NULL;



		s3c_adc_try(adc);