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Commit 23cdad33 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: das16: "timer_mode" is always used for DMA 



As noted in the driver, a timer is always used by this driver to handle the
DMA due to buggy DMA controllers and the lack of a hardware fifo in some of
the supported boards.

Remove all the non-timer mode specific code.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7df68962

drivers/staging/comedi/drivers/das16.c

+9 −86
Original line number Diff line number Diff line
@@ -387,7 +387,6 @@ struct das16_private_struct { 


	struct timer_list timer;	/*  for timed interrupt */

	volatile short timer_running;

	volatile short timer_mode;	/*  true if using timer mode */



	unsigned long extra_iobase;

};
@@ -516,49 +515,6 @@ static int das16_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s, 
	return 0;

}



/* utility function that suggests a dma transfer size in bytes */

static unsigned int das16_suggest_transfer_size(struct comedi_device *dev,

						const struct comedi_cmd *cmd)

{

	struct das16_private_struct *devpriv = dev->private;

	unsigned int size;

	unsigned int freq;



	/* if we are using timer interrupt, we don't care how long it

	 * will take to complete transfer since it will be interrupted

	 * by timer interrupt */

	if (devpriv->timer_mode)

		return DAS16_DMA_SIZE;



	/* otherwise, we are relying on dma terminal count interrupt,

	 * so pick a reasonable size */

	if (cmd->convert_src == TRIG_TIMER)

		freq = 1000000000 / cmd->convert_arg;

	else if (cmd->scan_begin_src == TRIG_TIMER)

		freq = (1000000000 / cmd->scan_begin_arg) * cmd->chanlist_len;

	/*  return some default value */

	else

		freq = 0xffffffff;



	if (cmd->flags & TRIG_WAKE_EOS) {

		size = sample_size * cmd->chanlist_len;

	} else {

		/*  make buffer fill in no more than 1/3 second */

		size = (freq / 3) * sample_size;

	}



	/*  set a minimum and maximum size allowed */

	if (size > DAS16_DMA_SIZE)

		size = DAS16_DMA_SIZE - DAS16_DMA_SIZE % sample_size;

	else if (size < sample_size)

		size = sample_size;



	if (cmd->stop_src == TRIG_COUNT && size > devpriv->adc_byte_count)

		size = devpriv->adc_byte_count;



	return size;

}



static unsigned int das16_set_pacer(struct comedi_device *dev, unsigned int ns,

				    int rounding_flags)

{
@@ -585,13 +541,6 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s) 
	unsigned long flags;

	int range;



	if (devpriv->dma_chan == 0 || (dev->irq == 0

				       && devpriv->timer_mode == 0)) {

		comedi_error(dev,

				"irq (or use of 'timer mode') dma required to "

							"execute comedi_cmd");

		return -1;

	}

	if (cmd->flags & TRIG_RT) {

		comedi_error(dev, "isa dma transfers cannot be performed with "

							"TRIG_RT, aborting");
@@ -648,24 +597,16 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s) 
	devpriv->current_buffer = 0;

	set_dma_addr(devpriv->dma_chan,

		     devpriv->dma_buffer_addr[devpriv->current_buffer]);

	/*  set appropriate size of transfer */

	devpriv->dma_transfer_size = das16_suggest_transfer_size(dev, cmd);

	devpriv->dma_transfer_size = DAS16_DMA_SIZE;

	set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);

	enable_dma(devpriv->dma_chan);

	release_dma_lock(flags);



	/*  set up interrupt */

	if (devpriv->timer_mode) {

	devpriv->timer_running = 1;

	devpriv->timer.expires = jiffies + timer_period();

	add_timer(&devpriv->timer);

	devpriv->control_state &= ~DAS16_INTE;

	} else {

		/* clear interrupt bit */

		outb(0x00, dev->iobase + DAS16_STATUS);

		/* enable interrupts */

		devpriv->control_state |= DAS16_INTE;

	}

	devpriv->control_state |= DMA_ENABLE;

	devpriv->control_state &= ~PACING_MASK;

	if (cmd->convert_src == TRIG_EXT)
@@ -696,7 +637,7 @@ static int das16_cancel(struct comedi_device *dev, struct comedi_subdevice *s) 
		disable_dma(devpriv->dma_chan);



	/*  disable SW timer */

	if (devpriv->timer_mode && devpriv->timer_running) {

	if (devpriv->timer_running) {

		devpriv->timer_running = 0;

		del_timer(&devpriv->timer);

	}
@@ -864,7 +805,6 @@ static int disable_dma_on_even(struct comedi_device *dev) 


static void das16_interrupt(struct comedi_device *dev)

{

	const struct das16_board *board = comedi_board(dev);

	struct das16_private_struct *devpriv = dev->private;

	unsigned long dma_flags, spin_flags;

	struct comedi_subdevice *s = dev->read_subdev;
@@ -915,21 +855,12 @@ static void das16_interrupt(struct comedi_device *dev) 
	devpriv->current_buffer = (devpriv->current_buffer + 1) % 2;

	devpriv->adc_byte_count -= num_bytes;



	/*  figure out how many bytes for next transfer */

	if (cmd->stop_src == TRIG_COUNT && devpriv->timer_mode == 0 &&

	    devpriv->dma_transfer_size > devpriv->adc_byte_count)

		devpriv->dma_transfer_size = devpriv->adc_byte_count;



	/*  re-enable  dma */

	if ((async->events & COMEDI_CB_EOA) == 0) {

		set_dma_addr(devpriv->dma_chan,

			     devpriv->dma_buffer_addr[devpriv->current_buffer]);

		set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);

		enable_dma(devpriv->dma_chan);

		/* reenable conversions for das1600 mode, (stupid hardware) */

		if (board->size > 0x400 && devpriv->timer_mode == 0)

			outb(0x00, dev->iobase + DAS1600_CONV);



	}

	release_dma_lock(dma_flags);
@@ -1077,20 +1008,15 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	int ret;

	unsigned int irq;

	unsigned int dma_chan;

	int timer_mode;

	unsigned long flags;

	struct comedi_krange *user_ai_range, *user_ao_range;



#if 0

	irq = it->options[1];

	timer_mode = it->options[8];

#endif

	/* always use time_mode since using irq can drop samples while

	 * waiting for dma done interrupt (due to hardware limitations) */

	irq = 0;

	timer_mode = 1;

	if (timer_mode)

		irq = 0;



	/*  check that clock setting is valid */

	if (it->options[3]) {
@@ -1214,12 +1140,9 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
		user_ao_range->flags = UNIT_volt;

	}



	if (timer_mode) {

	init_timer(&(devpriv->timer));

	devpriv->timer.function = das16_timer_interrupt;

	devpriv->timer.data = (unsigned long)dev;

	}

	devpriv->timer_mode = timer_mode ? 1 : 0;



	ret = comedi_alloc_subdevices(dev, 5);

	if (ret)