Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752026AbdFTQzX (ORCPT ); Tue, 20 Jun 2017 12:55:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:44500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751028AbdFTQzV (ORCPT ); Tue, 20 Jun 2017 12:55:21 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80DDB2397B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jic23@kernel.org Date: Tue, 20 Jun 2017 17:55:15 +0100 From: Jonathan Cameron To: Eugen Hristev Cc: , , , , , , , , Subject: Re: [PATCH v5 4/4] iio: adc: at91-sama5d2_adc: add hw trigger and buffer support Message-ID: <20170620175515.0cae41ed@kernel.org> In-Reply-To: <1497533097-12052-5-git-send-email-eugen.hristev@microchip.com> References: <1497533097-12052-1-git-send-email-eugen.hristev@microchip.com> <1497533097-12052-5-git-send-email-eugen.hristev@microchip.com> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-unknown-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12932 Lines: 413 On Thu, 15 Jun 2017 16:24:57 +0300 Eugen Hristev wrote: > Added support for the external hardware trigger on pin ADTRG, > integrated the three possible edges into the driver > and created buffer management for data retrieval > > Signed-off-by: Eugen Hristev > Acked-by: Ludovic Desroches Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > Changes in v5: > - Moved DRDY ack in tryreenable function > - Used PTR_ERR to pass error code to probe > > Changes in v4: > - Used iio claim direct to make sure buffer is not enabled when someone might > try to use a software triggered conversion > > Changes in v3: > - No longer have all three possible triggers registered in the subsystem and > available in the sysfs. Only registering one trigger, and the possible edge > is being read from the device tree. In the device tree, any possible edge > can be set. There are three already made nodes for each possible edge which > can be selected. > - Fixed a bug where software triggered conversion could be started even if > the hardware trigger was enabled. > - Preallocate enough space for the buffer, considering all the channels > and timestamp > > 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. > - 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 > - on trigger disable must write disable registries as well > > drivers/iio/adc/at91-sama5d2_adc.c | 237 ++++++++++++++++++++++++++++++++++++- > 1 file changed, 232 insertions(+), 5 deletions(-) > > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c > index e10dca3..1773a5d 100644 > --- a/drivers/iio/adc/at91-sama5d2_adc.c > +++ b/drivers/iio/adc/at91-sama5d2_adc.c > @@ -25,6 +25,10 @@ > #include > #include > #include > +#include > +#include > +#include > +#include > #include > > /* Control Register */ > @@ -132,6 +136,17 @@ > #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 +160,29 @@ > /* 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 > + > +/* > + * Maximum number of bytes to hold conversion from all channels > + * plus the timestamp > + */ > +#define AT91_BUFFER_MAX_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \ > + AT91_SAMA5D2_DIFF_CHAN_CNT) * 2 + 8) > + > +#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2) > + > #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 +198,11 @@ > .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), \ > @@ -188,6 +220,12 @@ struct at91_adc_soc_info { > unsigned max_sample_rate; > }; > > +struct at91_adc_trigger { > + char *name; > + unsigned int trgmod_value; > + unsigned int edge_type; > +}; > + > struct at91_adc_state { > void __iomem *base; > int irq; > @@ -195,11 +233,14 @@ struct at91_adc_state { > struct regulator *reg; > struct regulator *vref; > int vref_uv; > + struct iio_trigger *trig; > + const struct at91_adc_trigger *selected_trig; > 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; > + u16 buffer[AT91_BUFFER_MAX_HWORDS]; > /* > * lock to prevent concurrent 'single conversion' requests through > * sysfs. > @@ -207,6 +248,24 @@ 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, > + .edge_type = IRQ_TYPE_EDGE_RISING, > + }, > + { > + .name = "external_falling", > + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL, > + .edge_type = IRQ_TYPE_EDGE_FALLING, > + }, > + { > + .name = "external_any", > + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY, > + .edge_type = IRQ_TYPE_EDGE_BOTH, > + }, > +}; > + > static const struct iio_chan_spec at91_adc_channels[] = { > AT91_SAMA5D2_CHAN_SINGLE(0, 0x50), > AT91_SAMA5D2_CHAN_SINGLE(1, 0x54), > @@ -226,8 +285,128 @@ 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; > + > + /* clear TRGMOD */ > + status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK; > + > + if (state) > + status |= st->selected_trig->trgmod_value; > + > + /* 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); > + > + /* Needed to ACK the DRDY interruption */ > + at91_adc_readl(st, AT91_SAMA5D2_LCDR); > + 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 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 ERR_PTR(ret); > + > + return trig; > +} > + > +static int at91_adc_trigger_init(struct iio_dev *indio) > +{ > + struct at91_adc_state *st = iio_priv(indio); > + > + st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name); > + if (IS_ERR(st->trig)) { > + dev_err(&indio->dev, > + "could not allocate trigger\n"); > + return PTR_ERR(st->trig); > + } > + > + 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); > + > + 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, NULL); > +} > + > static unsigned at91_adc_startup_time(unsigned startup_time_min, > unsigned adc_clk_khz) > { > @@ -293,14 +472,18 @@ 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, > @@ -313,6 +496,11 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev, > > switch (mask) { > case IIO_CHAN_INFO_RAW: > + /* we cannot use software trigger if hw trigger enabled */ > + ret = iio_device_claim_direct_mode(indio_dev); > + if (ret) > + return ret; > + > mutex_lock(&st->lock); > > st->chan = chan; > @@ -344,6 +532,8 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev, > at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel)); > > mutex_unlock(&st->lock); > + > + iio_device_release_direct_mode(indio_dev); > return ret; > > case IIO_CHAN_INFO_SCALE: > @@ -391,7 +581,8 @@ static int at91_adc_probe(struct platform_device *pdev) > struct iio_dev *indio_dev; > struct at91_adc_state *st; > struct resource *res; > - int ret; > + int ret, i; > + u32 edge_type; > > indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st)); > if (!indio_dev) > @@ -432,6 +623,27 @@ static int at91_adc_probe(struct platform_device *pdev) > return ret; > } > > + ret = of_property_read_u32(pdev->dev.of_node, > + "atmel,trigger-edge-type", &edge_type); > + if (ret) { > + dev_err(&pdev->dev, > + "invalid or missing value for atmel,trigger-edge-type\n"); > + return ret; > + } > + > + st->selected_trig = NULL; > + > + for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT; i++) > + if (at91_adc_trigger_list[i].edge_type == edge_type) { > + st->selected_trig = &at91_adc_trigger_list[i]; > + break; > + } > + > + if (!st->selected_trig) { > + dev_err(&pdev->dev, "invalid external trigger edge value\n"); > + return -EINVAL; > + } > + > init_waitqueue_head(&st->wq_data_available); > mutex_init(&st->lock); > > @@ -499,10 +711,25 @@ 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; > > + dev_info(&pdev->dev, "setting up trigger as %s\n", > + st->selected_trig->name); > + > dev_info(&pdev->dev, "version: %x\n", > readl_relaxed(st->base + AT91_SAMA5D2_VERSION)); >