Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754299AbbHHO34 (ORCPT ); Sat, 8 Aug 2015 10:29:56 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:58790 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754102AbbHHO3y (ORCPT ); Sat, 8 Aug 2015 10:29:54 -0400 Subject: Re: [PATCH v2] iio: adc: vf610: Add IIO buffer support for Vybrid ADC To: Sanchayan Maity , linux-iio@vger.kernel.org References: <1bb1f290da601bbda41875a92ba6e983b423d7b0.1438775572.git.maitysanchayan@gmail.com> Cc: stefan@agner.ch, B38611@freescale.com, hofrat@osadl.org, sanjeev_sharma@mentor.com, fabio.estevam@freescale.com, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, antoine.tenart@free-electrons.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Jonathan Cameron Message-ID: <55C6125B.1060103@kernel.org> Date: Sat, 8 Aug 2015 15:29:47 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <1bb1f290da601bbda41875a92ba6e983b423d7b0.1438775572.git.maitysanchayan@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8970 Lines: 275 On 05/08/15 13:10, Sanchayan Maity wrote: > This patch adds support for IIO buffer to the Vybrid ADC driver. > IIO triggered buffer infrastructure along with iio sysfs trigger > is used to leverage continuous sampling support provided by the > ADC block. Looking good. Just a couple more bits and pieces inline from me. One or two of which aren't corrected from Peter's review of v1. I will want Fugang Dong's ack / review tag on the final version before applying it however. This driver is some distance form my area of expertise! Jonathan > > Signed-off-by: Sanchayan Maity > --- > drivers/iio/adc/Kconfig | 4 ++ > drivers/iio/adc/vf610_adc.c | 107 +++++++++++++++++++++++++++++++++++++++++--- > 2 files changed, 105 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 7c55658..4661241 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -337,6 +337,10 @@ config TWL6030_GPADC > config VF610_ADC > tristate "Freescale vf610 ADC driver" > depends on OF > + select IIO_BUFFER > + select IIO_TRIGGER > + select IIO_SYSFS_TRIGGER Unless I missed something there is no dependency on this particular trigger (it just happens to be the one you've been testing with I guess). Could be driven from a hardware trigger belonging to another device for example. > + select IIO_TRIGGERED_BUFFER > help > Say yes here to support for Vybrid board analog-to-digital converter. > Since the IP is used for i.MX6SLX, the driver also support i.MX6SLX. > diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c > index 23b8fb9..97cb2ed 100644 > --- a/drivers/iio/adc/vf610_adc.c > +++ b/drivers/iio/adc/vf610_adc.c > @@ -34,8 +34,11 @@ > #include > > #include > +#include > #include > -#include > +#include > +#include > +#include > > /* This will be the driver name the kernel reports */ > #define DRIVER_NAME "vf610-adc" > @@ -170,6 +173,7 @@ struct vf610_adc { > u32 sample_freq_avail[5]; > > struct completion completion; > + u16 buffer[2]; Note the requirements on the buffer provided to iio_push_to_buffers_with_timestamp Needs to be u16 buffer[8] to allow for the aligned 64bit (4 word) timestamp. Peter pointed this out in his follow up email and you said you'd implement it.. Guessing this got lost somewhere. > }; > > static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 }; > @@ -505,12 +509,22 @@ static const struct iio_chan_spec_ext_info vf610_ext_info[] = { > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ > BIT(IIO_CHAN_INFO_SAMP_FREQ), \ > .ext_info = vf610_ext_info, \ > + .address = (_idx), \ > + .scan_index = (_idx), \ > + .scan_type.sign = 'u', \ > + .scan_type.realbits = 12, \ > + .scan_type.storagebits = 16, \ > } > > #define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) { \ > .type = (_chan_type), \ > .channel = (_idx), \ > .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ > + .address = (_idx), \ > + .scan_index = (_idx), \ .scan_type = { .sign = 'u', etc. Peter picked up on this.. > + .scan_type.sign = 'u', \ > + .scan_type.realbits = 12, \ > + .scan_type.storagebits = 16, \ > } > > static const struct iio_chan_spec vf610_adc_iio_channels[] = { > @@ -531,6 +545,7 @@ static const struct iio_chan_spec vf610_adc_iio_channels[] = { > VF610_ADC_CHAN(14, IIO_VOLTAGE), > VF610_ADC_CHAN(15, IIO_VOLTAGE), > VF610_ADC_TEMPERATURE_CHAN(26, IIO_TEMP), > + IIO_CHAN_SOFT_TIMESTAMP(32), It's bit extreme throwing it out at scan_index 32. Is there a reason to think that migh be neccesary? Mind you, why is the temperature channel down at 26? Are we dealing with a set of reserved real channels inbetween? > /* sentinel */ > }; > > @@ -559,13 +574,20 @@ static int vf610_adc_read_data(struct vf610_adc *info) > > static irqreturn_t vf610_adc_isr(int irq, void *dev_id) > { > - struct vf610_adc *info = (struct vf610_adc *)dev_id; > + struct iio_dev *indio_dev = (struct iio_dev *)dev_id; > + struct vf610_adc *info = iio_priv(indio_dev); > int coco; > > coco = readl(info->regs + VF610_REG_ADC_HS); > if (coco & VF610_ADC_HS_COCO0) { > info->value = vf610_adc_read_data(info); I'd be tempted to make the non buffered path also use info->bufffer[0] and drop info->value entirely. A more invasive patch, but a cleaner resulting code (slightly!) > - complete(&info->completion); > + if (iio_buffer_enabled(indio_dev)) { > + info->buffer[0] = info->value; > + iio_push_to_buffers_with_timestamp(indio_dev, > + info->buffer, iio_get_time_ns()); > + iio_trigger_notify_done(indio_dev->trig); > + } else > + complete(&info->completion); > } > > return IRQ_HANDLED; > @@ -612,6 +634,9 @@ static int vf610_read_raw(struct iio_dev *indio_dev, > switch (mask) { > case IIO_CHAN_INFO_RAW: > case IIO_CHAN_INFO_PROCESSED: To avoid possible races this check should be done under the mlock. > + if (iio_buffer_enabled(indio_dev)) > + return -EBUSY; > + > mutex_lock(&indio_dev->mlock); > reinit_completion(&info->completion); > > @@ -694,6 +719,68 @@ static int vf610_write_raw(struct iio_dev *indio_dev, > return -EINVAL; > } > > +static int vf610_adc_buffer_postenable(struct iio_dev *indio_dev) > +{ > + struct vf610_adc *info = iio_priv(indio_dev); > + unsigned int channel; > + int ret; > + int val; > + > + ret = iio_triggered_buffer_postenable(indio_dev); > + if (ret) > + return ret; > + > + val = readl(info->regs + VF610_REG_ADC_GC); > + val |= VF610_ADC_ADCON; > + writel(val, info->regs + VF610_REG_ADC_GC); > + > + channel = find_first_bit(indio_dev->active_scan_mask, > + indio_dev->masklength); > + > + val = VF610_ADC_ADCHC(channel); > + val |= VF610_ADC_AIEN; > + > + writel(val, info->regs + VF610_REG_ADC_HC0); > + > + return 0; > +} > + > +static int vf610_adc_buffer_postdisable(struct iio_dev *indio_dev) > +{ > + struct vf610_adc *info = iio_priv(indio_dev); > + unsigned int hc_cfg = 0; > + int val; > + > + val = readl(info->regs + VF610_REG_ADC_GC); > + val &= ~VF610_ADC_ADCON; > + writel(val, info->regs + VF610_REG_ADC_GC); > + > + hc_cfg |= VF610_ADC_CONV_DISABLE; > + hc_cfg &= ~VF610_ADC_AIEN; > + > + writel(hc_cfg, info->regs + VF610_REG_ADC_HC0); > + > + return 0; > +} > + > +static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { > + .postenable = &vf610_adc_buffer_postenable, > + .predisable = &iio_triggered_buffer_predisable, > + .postdisable = &vf610_adc_buffer_postdisable, > + .validate_scan_mask = &iio_validate_scan_mask_onehot, > +}; > + > +static int vf610_adc_buffer_init(struct iio_dev *indio_dev) > +{ > + return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, > + NULL, &iio_triggered_buffer_setup_ops); > +} > + > +static void vf610_adc_buffer_remove(struct iio_dev *indio_dev) > +{ > + iio_triggered_buffer_cleanup(indio_dev); > +} These to wrappers seem a little superflous. I'd have just put the code inline, but it's obviously a matter of personal taste and I don't care that much! > + > static int vf610_adc_reg_access(struct iio_dev *indio_dev, > unsigned reg, unsigned writeval, > unsigned *readval) > @@ -753,7 +840,7 @@ static int vf610_adc_probe(struct platform_device *pdev) > > ret = devm_request_irq(info->dev, irq, > vf610_adc_isr, 0, > - dev_name(&pdev->dev), info); > + dev_name(&pdev->dev), indio_dev); > if (ret < 0) { > dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq); > return ret; > @@ -806,15 +893,22 @@ static int vf610_adc_probe(struct platform_device *pdev) > vf610_adc_cfg_init(info); > vf610_adc_hw_init(info); > > + ret = vf610_adc_buffer_init(indio_dev); > + if (ret < 0) { > + dev_err(&pdev->dev, "Couldn't initialise the buffer\n"); > + goto error_iio_device_register; > + } > + > ret = iio_device_register(indio_dev); > if (ret) { > dev_err(&pdev->dev, "Couldn't register the device.\n"); > - goto error_iio_device_register; > + goto error_adc_buffer_init; > } > > return 0; > > - > +error_adc_buffer_init: > + vf610_adc_buffer_remove(indio_dev); > error_iio_device_register: > clk_disable_unprepare(info->clk); > error_adc_clk_enable: > @@ -829,6 +923,7 @@ static int vf610_adc_remove(struct platform_device *pdev) > struct vf610_adc *info = iio_priv(indio_dev); > > iio_device_unregister(indio_dev); > + vf610_adc_buffer_remove(indio_dev); > regulator_disable(info->vref); > clk_disable_unprepare(info->clk); > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/