On 04/05/17 13:13, Eugen Hristev wrote: > Added support for the external hardware trigger on pin ADTRG, > integrated the three possible edge triggers into the subsystem > and created buffer management for data retrieval > > Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> > --- > Changes in v2: > - Moved buffer allocation and freeing into the preenable and postdisable > callbacks. > We have a total of scan bytes that can vary a lot depending on each channel > enabled at a certain point. How much? Having dynamic allocations are likely to prove just as costly as you'll almost always end up allocating a lot more than you ask for. I'm counting worst case of 18x 2byte channels + timestamp = 48 bytes. A quick google suggests you'll always allocate 32 bytes whatever with slab (lower for slob). So not a huge saving... Worth the hassle? > - made the at91 trigger list part of state structure > - made the iio trigger list preallocated in state structure > - moved irq enabling/disabling into the try_reenable callback I'd have liked a little explanation on why we need to explicitly disable the irq. It will have little effect it if triggers too often as the trigger consumers are all oneshot anyway. > - on trigger disable must write disable registries as well Basically looks good. A few questions inline. Jonathan > > drivers/iio/adc/at91-sama5d2_adc.c | 231 ++++++++++++++++++++++++++++++++++++- > 1 file changed, 228 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c > index e10dca3..11f5570 100644 > --- a/drivers/iio/adc/at91-sama5d2_adc.c > +++ b/drivers/iio/adc/at91-sama5d2_adc.c > @@ -23,8 +23,15 @@ > #include <linux/platform_device.h> > #include <linux/sched.h> > #include <linux/wait.h> > +#include <linux/slab.h> > + > #include <linux/iio/iio.h> > #include <linux/iio/sysfs.h> > +#include <linux/iio/buffer.h> > +#include <linux/iio/trigger.h> > +#include <linux/iio/trigger_consumer.h> > +#include <linux/iio/triggered_buffer.h> > + > #include <linux/regulator/consumer.h> > > /* Control Register */ > @@ -132,6 +139,17 @@ > #define AT91_SAMA5D2_PRESSR 0xbc > /* Trigger Register */ > #define AT91_SAMA5D2_TRGR 0xc0 > +/* Mask for TRGMOD field of TRGR register */ > +#define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0) > +/* No trigger, only software trigger can start conversions */ > +#define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0 > +/* Trigger Mode external trigger rising edge */ > +#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1 > +/* Trigger Mode external trigger falling edge */ > +#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2 > +/* Trigger Mode external trigger any edge */ > +#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3 > + > /* Correction Select Register */ > #define AT91_SAMA5D2_COSR 0xd0 > /* Correction Value Register */ > @@ -145,14 +163,20 @@ > /* Version Register */ > #define AT91_SAMA5D2_VERSION 0xfc > > +#define AT91_SAMA5D2_HW_TRIG_CNT 3 > +#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12 > +#define AT91_SAMA5D2_DIFF_CHAN_CNT 6 > + > #define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \ > { \ > .type = IIO_VOLTAGE, \ > .channel = num, \ > .address = addr, \ > + .scan_index = num, \ > .scan_type = { \ > .sign = 'u', \ > .realbits = 12, \ > + .storagebits = 16, \ > }, \ > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > @@ -168,9 +192,11 @@ > .channel = num, \ > .channel2 = num2, \ > .address = addr, \ > + .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT, \ > .scan_type = { \ > .sign = 's', \ > .realbits = 12, \ > + .storagebits = 16, \ > }, \ > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > @@ -188,18 +214,25 @@ struct at91_adc_soc_info { > unsigned max_sample_rate; > }; > > +struct at91_adc_trigger { > + char *name; > + unsigned int trgmod_value; > +}; > + > struct at91_adc_state { > void __iomem *base; > int irq; > struct clk *per_clk; > struct regulator *reg; > struct regulator *vref; > + u16 *buffer; > int vref_uv; > const struct iio_chan_spec *chan; > bool conversion_done; > u32 conversion_value; > struct at91_adc_soc_info soc_info; > wait_queue_head_t wq_data_available; > + struct iio_trigger *trig[AT91_SAMA5D2_HW_TRIG_CNT]; > /* > * lock to prevent concurrent 'single conversion' requests through > * sysfs. > @@ -207,6 +240,21 @@ struct at91_adc_state { > struct mutex lock; > }; > > +static const struct at91_adc_trigger at91_adc_trigger_list[] = { > + { > + .name = "external-rising", > + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE, > + }, > + { > + .name = "external-falling", > + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL, > + }, > + { > + .name = "external-any", > + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY, > + }, Hmm. Should this be a userspace configurable option? Feels rather like it is an element of the hardware - reflecting the characteristics of some hardware device sat on the pin. > +}; > + > static const struct iio_chan_spec at91_adc_channels[] = { > AT91_SAMA5D2_CHAN_SINGLE(0, 0x50), > AT91_SAMA5D2_CHAN_SINGLE(1, 0x54), > @@ -226,8 +274,168 @@ static const struct iio_chan_spec at91_adc_channels[] = { > AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68), > AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70), > AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78), > + IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_SINGLE_CHAN_CNT > + + AT91_SAMA5D2_DIFF_CHAN_CNT + 1), > }; > > +static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) > +{ > + struct iio_dev *indio = iio_trigger_get_drvdata(trig); > + struct at91_adc_state *st = iio_priv(indio); > + u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR); > + u8 bit; > + int i; > + > + /* clear TRGMOD */ > + status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK; > + > + if (state) > + for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT; i++) { > + if (!strstr(trig->name, > + at91_adc_trigger_list[i].name)) { > + status |= at91_adc_trigger_list[i].trgmod_value; > + break; > + } > + } > + > + /* set/unset hw trigger */ > + at91_adc_writel(st, AT91_SAMA5D2_TRGR, status); > + > + for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) { > + struct iio_chan_spec const *chan = indio->channels + bit; > + > + if (state) { > + at91_adc_writel(st, AT91_SAMA5D2_CHER, > + BIT(chan->channel)); > + at91_adc_writel(st, AT91_SAMA5D2_IER, > + BIT(chan->channel)); > + } else { > + at91_adc_writel(st, AT91_SAMA5D2_IDR, > + BIT(chan->channel)); > + at91_adc_writel(st, AT91_SAMA5D2_CHDR, > + BIT(chan->channel)); > + } > + } > + > + return 0; > +} > + > +static int at91_adc_reenable_trigger(struct iio_trigger *trig) > +{ > + struct iio_dev *indio = iio_trigger_get_drvdata(trig); > + struct at91_adc_state *st = iio_priv(indio); > + > + enable_irq(st->irq); > + return 0; > +} > + > +static const struct iio_trigger_ops at91_adc_trigger_ops = { > + .owner = THIS_MODULE, > + .set_trigger_state = &at91_adc_configure_trigger, > + .try_reenable = &at91_adc_reenable_trigger, > +}; > + > +static int at91_adc_buffer_preenable(struct iio_dev *indio_dev) > +{ > + struct at91_adc_state *st = iio_priv(indio_dev); > + > + st->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);Why allocate it here? Presumably the biggest it can get is fairly small? Unless very large, just make sure you allocate enough directly in st in the first place. > + > + if (!st->buffer) > + return -ENOMEM; > + > + return 0; > +} > + > +static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev) > +{ > + struct at91_adc_state *st = iio_priv(indio_dev); > + > + kfree(st->buffer); > + > + return 0; > +} > + > +static const struct iio_buffer_setup_ops at91_buffer_setup_ops = { > + .preenable = &at91_adc_buffer_preenable, > + .postenable = &iio_triggered_buffer_postenable, > + .predisable = &iio_triggered_buffer_predisable, > + .postdisable = &at91_adc_buffer_postdisable, > +}; > + > +static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio, > + char *trigger_name) > +{ > + struct iio_trigger *trig; > + int ret; > + > + trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name, > + indio->id, trigger_name); > + if (!trig) > + return NULL; > + > + trig->dev.parent = indio->dev.parent; > + iio_trigger_set_drvdata(trig, indio); > + trig->ops = &at91_adc_trigger_ops; > + > + ret = devm_iio_trigger_register(&indio->dev, trig); > + > + if (ret) > + return NULL; > + > + return trig; > +} > + > +static int at91_adc_trigger_init(struct iio_dev *indio) > +{ > + struct at91_adc_state *st = iio_priv(indio); > + int i; > + > + for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT; i++) { > + st->trig[i] = at91_adc_allocate_trigger(indio, > + at91_adc_trigger_list[i].name); > + if (!st->trig[i]) { > + dev_err(&indio->dev, > + "could not allocate trigger %d\n", i); > + return -ENOMEM; > + } > + } > + > + return 0; > +} > + > +static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > +{ > + struct iio_poll_func *pf = p; > + struct iio_dev *indio = pf->indio_dev; > + struct at91_adc_state *st = iio_priv(indio); > + int i = 0; > + u8 bit; > + > + for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) { > + struct iio_chan_spec const *chan = indio->channels + bit; > + > + st->buffer[i] = at91_adc_readl(st, chan->address); > + i++; > + } > + > + iio_push_to_buffers_with_timestamp(indio, st->buffer, pf->timestamp); > + > + iio_trigger_notify_done(indio->trig); > + > + /* Needed to ACK the DRDY interruption */ > + at91_adc_readl(st, AT91_SAMA5D2_LCDR); > + > + return IRQ_HANDLED; > +} > + > +static int at91_adc_buffer_init(struct iio_dev *indio) > +{ > + return devm_iio_triggered_buffer_setup(&indio->dev, indio, > + &iio_pollfunc_store_time, > + &at91_adc_trigger_handler, &at91_buffer_setup_ops); > +} > + > static unsigned at91_adc_startup_time(unsigned startup_time_min, > unsigned adc_clk_khz) > { > @@ -293,14 +501,19 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private) > u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR); > u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR); > > - if (status & imr) { > + if (!(status & imr)) > + return IRQ_NONE; > + > + if (iio_buffer_enabled(indio)) { > + disable_irq_nosync(irq); > + iio_trigger_poll(indio->trig); > + } else { > st->conversion_value = at91_adc_readl(st, st->chan->address); > st->conversion_done = true; > wake_up_interruptible(&st->wq_data_available); > - return IRQ_HANDLED; > } > > - return IRQ_NONE; > + return IRQ_HANDLED; > } > > static int at91_adc_read_raw(struct iio_dev *indio_dev, > @@ -499,6 +712,18 @@ static int at91_adc_probe(struct platform_device *pdev) > > platform_set_drvdata(pdev, indio_dev); > > + ret = at91_adc_buffer_init(indio_dev); > + if (ret < 0) { > + dev_err(&pdev->dev, "couldn't initialize the buffer.\n"); > + goto per_clk_disable_unprepare; > + } > + > + ret = at91_adc_trigger_init(indio_dev); > + if (ret < 0) { > + dev_err(&pdev->dev, "couldn't setup the triggers.\n"); > + goto per_clk_disable_unprepare; > + } > + > ret = iio_device_register(indio_dev); > if (ret < 0) > goto per_clk_disable_unprepare; > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html