From 23cdad3360a39b1b81e1068b1027db25c9e16d97 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 29 Jul 2013 13:48:01 -0700 Subject: [PATCH] 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: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das16.c | 95 +++----------------------- 1 file changed, 9 insertions(+), 86 deletions(-) diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c index 593ec3866146..2dd03da22a2e 100644 --- a/drivers/staging/comedi/drivers/das16.c +++ b/drivers/staging/comedi/drivers/das16.c @@ -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->timer_running = 1; + devpriv->timer.expires = jiffies + timer_period(); + add_timer(&devpriv->timer); + 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; + init_timer(&(devpriv->timer)); + devpriv->timer.function = das16_timer_interrupt; + devpriv->timer.data = (unsigned long)dev; ret = comedi_alloc_subdevices(dev, 5); if (ret) -- 2.30.2