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 <maitysancha...@gmail.com>
> ---
> 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 <linux/err.h>
>
> #include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> #include <linux/iio/sysfs.h>
> -#include <linux/iio/driver.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
>
> /* 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);
>
>
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