Hi,

On Saturday 12 December 2015 17:14:24 Jonathan Cameron wrote:
> On 06/12/15 19:52, Markus Pargmann wrote:
> > This is a conversion queue driver for the mx25 SoC. It uses the central
> > ADC which is used by two seperate independent queues. This driver
> > prepares different conversion configurations for each possible input.
> > For a conversion it creates a conversionqueue of one item with the
> conversion queue
> > correct configuration for the chosen channel. It then executes the queue
> > once and disables the conversion queue afterwards.
> > 
> > The reference voltages are configurable through devicetree subnodes,
> > depending on the connections of the ADC inputs.
> > 
> > Signed-off-by: Markus Pargmann <m...@pengutronix.de>
> > Signed-off-by: Denis Carikli <de...@eukrea.com>
> A couple of little bits inline.  Fix the return of 0 on fail in probe
> and you can add

Thanks, I fixed all your comments for the next version.

Best Regards,

Markus

> 
> Acked-by: Jonathan Cameron <ji...@kernel.org>
> > ---
> > 
> > Notes:
> >     Changes in v7:
> >      - Remove separate functions mx25_gcq_disable/enable_eoq() as they were 
> > used at
> >        only one position
> >      - Enforce an external reference regulator if one of the conversions 
> > uses it as
> >        reference. The devm_regulator_get() call was moved into
> >        mx25_gcq_setup_cfgs() to be able to acquire the reference regulator 
> > when
> >        necessary.
> >      - Store indio_dev as platform driver data instead of the private data. 
> > This
> >        was changed in probe() and remove().
> >     
> >     Changes in v6:
> >      - Added defines for a complete list of references in the dt binding 
> > macros
> > 
> >  drivers/iio/adc/Kconfig         |   7 +
> >  drivers/iio/adc/Makefile        |   1 +
> >  drivers/iio/adc/fsl-imx25-gcq.c | 415 
> > ++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 423 insertions(+)
> >  create mode 100644 drivers/iio/adc/fsl-imx25-gcq.c
> > 
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index 7868c744fd4b..73145c53ec2c 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -183,6 +183,13 @@ config EXYNOS_ADC
> >       To compile this driver as a module, choose M here: the module will be
> >       called exynos_adc.
> >  
> > +config FSL_MX25_ADC
> > +   tristate "Freescale MX25 ADC driver"
> > +   depends on MFD_MX25_TSADC
> > +   help
> > +     Generic Conversion Queue driver used for general purpose ADC in the
> > +     MX25. This driver supports single measurements using the MX25 ADC.
> > +
> >  config HI8435
> >     tristate "Holt Integrated Circuits HI-8435 threshold detector"
> >     select IIO_TRIGGERED_EVENT
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> > index 99b37a963a1e..2fe9b78e4b02 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -19,6 +19,7 @@ obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
> >  obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
> >  obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
> >  obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
> > +obj-$(CONFIG_FSL_MX25_ADC) += fsl-imx25-gcq.o
> >  obj-$(CONFIG_HI8435) += hi8435.o
> >  obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> >  obj-$(CONFIG_MAX1027) += max1027.o
> > diff --git a/drivers/iio/adc/fsl-imx25-gcq.c 
> > b/drivers/iio/adc/fsl-imx25-gcq.c
> > new file mode 100644
> > index 000000000000..eb9570876291
> > --- /dev/null
> > +++ b/drivers/iio/adc/fsl-imx25-gcq.c
> > @@ -0,0 +1,415 @@
> > +/*
> > + * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann 
> > <m...@pengutronix.de>
> > + *
> > + * This program is free software; you can redistribute it and/or modify it 
> > under
> > + * the terms of the GNU General Public License version 2 as published by 
> > the
> > + * Free Software Foundation.
> > + *
> > + * This is the driver for the imx25 GCQ (Generic Conversion Queue)
> > + * connected to the imx25 ADC.
> > + */
> > +
> > +#include <dt-bindings/iio/adc/fsl-imx25-gcq.h>
> > +#include <linux/clk.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/mfd/imx25-tsadc.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> > +
> > +#define MX25_GCQ_TIMEOUT (msecs_to_jiffies(2000))
> > +
> > +static const char * const driver_name = "mx25-gcq";
> > +
> > +enum mx25_gcq_cfgs {
> > +   MX25_CFG_XP = 0,
> > +   MX25_CFG_YP,
> > +   MX25_CFG_XN,
> > +   MX25_CFG_YN,
> > +   MX25_CFG_WIPER,
> > +   MX25_CFG_INAUX0,
> > +   MX25_CFG_INAUX1,
> > +   MX25_CFG_INAUX2,
> > +   MX25_NUM_CFGS,
> > +};
> > +
> > +struct mx25_gcq_priv {
> > +   struct regmap *regs;
> > +   struct completion completed;
> > +   struct clk *clk;
> > +   int irq;
> > +   struct regulator *vref[4];
> > +   u32 channel_vref_mv[MX25_NUM_CFGS];
> > +};
> > +
> > +#define MX25_CQG_CHAN(chan, id) {\
> > +   .type = IIO_VOLTAGE,\
> > +   .indexed = 1,\
> > +   .channel = chan,\
> > +   .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> > +                         BIT(IIO_CHAN_INFO_SCALE),\
> > +   .datasheet_name = id,\
> > +}
> > +
> > +static const struct iio_chan_spec mx25_gcq_channels[MX25_NUM_CFGS] = {
> > +   MX25_CQG_CHAN(MX25_CFG_XP, "xp"),
> > +   MX25_CQG_CHAN(MX25_CFG_YP, "yp"),
> > +   MX25_CQG_CHAN(MX25_CFG_XN, "xn"),
> > +   MX25_CQG_CHAN(MX25_CFG_YN, "yn"),
> > +   MX25_CQG_CHAN(MX25_CFG_WIPER, "wiper"),
> > +   MX25_CQG_CHAN(MX25_CFG_INAUX0, "inaux0"),
> > +   MX25_CQG_CHAN(MX25_CFG_INAUX1, "inaux1"),
> > +   MX25_CQG_CHAN(MX25_CFG_INAUX2, "inaux2"),
> > +};
> > +
> > +static const char * const mx25_gcq_refp_names[] = {
> > +   [MX25_ADC_REFP_YP] = "yp",
> > +   [MX25_ADC_REFP_XP] = "xp",
> > +   [MX25_ADC_REFP_INT] = "int",
> > +   [MX25_ADC_REFP_EXT] = "ext",
> > +};
> > +
> > +static irqreturn_t mx25_gcq_irq(int irq, void *data)
> > +{
> > +   struct mx25_gcq_priv *priv = data;
> > +   u32 stats;
> > +
> > +   regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
> > +
> > +   if (stats & MX25_ADCQ_SR_EOQ) {
> > +           regmap_update_bits(priv->regs, MX25_ADCQ_MR,
> > +                              MX25_ADCQ_MR_EOQ_IRQ, MX25_ADCQ_MR_EOQ_IRQ);
> > +           complete(&priv->completed);
> > +   }
> > +
> > +   /* Disable conversion queue run */
> > +   regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
> > +
> > +   /* Acknowledge all possible irqs */
> > +   regmap_write(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
> > +                MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR |
> > +                MX25_ADCQ_SR_EOQ | MX25_ADCQ_SR_PD);
> > +
> > +   return IRQ_HANDLED;
> > +}
> > +
> > +static int mx25_gcq_get_raw_value(struct device *dev,
> > +                             struct iio_chan_spec const *chan,
> > +                             struct mx25_gcq_priv *priv,
> > +                             int *val)
> > +{
> > +   long timeout;
> > +   u32 data;
> > +
> > +   /* Setup the configuration we want to use */
> > +   regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
> > +                MX25_ADCQ_ITEM(0, chan->channel));
> > +
> > +   regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_EOQ_IRQ, 0);
> > +
> > +   /* Trigger queue for one run */
> > +   regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS,
> > +                      MX25_ADCQ_CR_FQS);
> > +
> > +   timeout = wait_for_completion_interruptible_timeout(
> > +           &priv->completed, MX25_GCQ_TIMEOUT);
> > +   if (timeout < 0) {
> > +           dev_err(dev, "ADC wait for measurement failed\n");
> > +           return timeout;
> > +   } else if (timeout == 0) {
> > +           dev_err(dev, "ADC timed out\n");
> > +           return -ETIMEDOUT;
> > +   }
> > +
> > +   regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
> > +
> > +   *val = MX25_ADCQ_FIFO_DATA(data);
> > +
> > +   return IIO_VAL_INT;
> > +}
> > +
> > +static int mx25_gcq_read_raw(struct iio_dev *indio_dev,
> > +                        struct iio_chan_spec const *chan, int *val,
> > +                        int *val2, long mask)
> > +{
> > +   struct mx25_gcq_priv *priv = iio_priv(indio_dev);
> > +   int ret;
> > +
> > +   switch (mask) {
> > +   case IIO_CHAN_INFO_RAW:
> > +           mutex_lock(&indio_dev->mlock);
> > +           ret = mx25_gcq_get_raw_value(&indio_dev->dev, chan, priv, val);
> > +           mutex_unlock(&indio_dev->mlock);
> > +           return ret;
> > +
> > +   case IIO_CHAN_INFO_SCALE:
> > +           *val = priv->channel_vref_mv[chan->channel];
> > +           *val2 = 12;
> > +           return IIO_VAL_FRACTIONAL_LOG2;
> > +
> > +   default:
> > +           return -EINVAL;
> > +   }
> > +}
> > +
> > +static const struct iio_info mx25_gcq_iio_info = {
> > +   .read_raw = mx25_gcq_read_raw,
> > +};
> > +
> > +static const struct regmap_config mx25_gcq_regconfig = {
> > +   .max_register = 0x5c,
> > +   .reg_bits = 32,
> > +   .val_bits = 32,
> > +   .reg_stride = 4,
> > +};
> > +
> > +static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
> > +                          struct mx25_gcq_priv *priv)
> > +{
> > +   struct device_node *np = pdev->dev.of_node;
> > +   struct device_node *child;
> > +   struct device *dev = &pdev->dev;
> > +   unsigned int refp_used[4] = {};
> > +   int ret, i;
> > +
> > +   /*
> > +    * Setup all configurations registers with a default conversion
> > +    * configuration for each input
> > +    */
> > +   for (i = 0; i < MX25_NUM_CFGS; ++i)
> > +           regmap_write(priv->regs, MX25_ADCQ_CFG(i),
> > +                        MX25_ADCQ_CFG_YPLL_OFF |
> > +                        MX25_ADCQ_CFG_XNUR_OFF |
> > +                        MX25_ADCQ_CFG_XPUL_OFF |
> > +                        MX25_ADCQ_CFG_REFP_INT |
> > +                        MX25_ADCQ_CFG_IN(i) |
> > +                        MX25_ADCQ_CFG_REFN_NGND2);
> > +
> > +   /*
> > +    * First get all regulators to store them in channel_vref_mv if
> > +    * necessary. Later we use that information for proper IIO scale
> > +    * information.
> > +    */
> > +   priv->vref[MX25_ADC_REFP_INT] = NULL;
> > +   priv->vref[MX25_ADC_REFP_EXT] =
> > +           devm_regulator_get_optional(&pdev->dev, "vref-ext");
> > +   priv->vref[MX25_ADC_REFP_XP] =
> > +           devm_regulator_get_optional(&pdev->dev, "vref-xp");
> > +   priv->vref[MX25_ADC_REFP_YP] =
> > +           devm_regulator_get_optional(&pdev->dev, "vref-yp");
> > +
> > +   for_each_child_of_node(np, child) {
> > +           u32 reg;
> > +           u32 refp = MX25_ADCQ_CFG_REFP_INT;
> > +           u32 refn = MX25_ADCQ_CFG_REFN_NGND2;
> > +
> > +           ret = of_property_read_u32(child, "reg", &reg);
> > +           if (ret) {
> > +                   dev_err(dev, "Failed to get reg property\n");
> > +                   return ret;
> > +           }
> > +
> > +           if (reg >= MX25_NUM_CFGS) {
> > +                   dev_err(dev,
> > +                           "reg value is greater than the number of 
> > available configuration registers\n");
> > +                   return -EINVAL;
> > +           }
> > +
> > +           of_property_read_u32(child, "fsl,adc-refp", &refp);
> > +           of_property_read_u32(child, "fsl,adc-refn", &refn);
> > +
> > +           switch (refp) {
> > +           case MX25_ADC_REFP_EXT:
> > +           case MX25_ADC_REFP_XP:
> > +           case MX25_ADC_REFP_YP:
> > +                   if (IS_ERR(priv->vref[refp])) {
> > +                           dev_err(dev, "Error, trying to use external 
> > voltage reference without a vref-%s regulator.",
> > +                                   mx25_gcq_refp_names[refp]);
> > +                           return PTR_ERR(priv->vref[refp]);
> > +                   }
> > +                   priv->channel_vref_mv[reg] =
> > +                           regulator_get_voltage(priv->vref[refp]);
> > +                   /* Conversion from uV to mV */
> > +                   do_div(priv->channel_vref_mv[reg], 1000);
> > +                   break;
> > +           case MX25_ADC_REFP_INT:
> > +                   priv->channel_vref_mv[reg] = 2500;
> > +                   break;
> > +           default:
> > +                   dev_err(dev, "Invalid positive reference %d\n", refp);
> > +                   return -EINVAL;
> > +           }
> > +
> > +           ++refp_used[refp];
> > +
> > +           /*
> > +            * Shift the read values to the correct positions within the
> > +            * register.
> > +            */
> > +           refp = MX25_ADCQ_CFG_REFP(refp);
> > +           refn = MX25_ADCQ_CFG_REFN(refn);
> > +
> > +           if ((refp & MX25_ADCQ_CFG_REFP_MASK) != refp) {
> > +                   dev_err(dev, "Invalid fsl,adc-refp property value\n");
> > +                   return -EINVAL;
> > +           }
> > +           if ((refn & MX25_ADCQ_CFG_REFN_MASK) != refn) {
> > +                   dev_err(dev, "Invalid fsl,adc-refn property value\n");
> > +                   return -EINVAL;
> > +           }
> > +
> > +           regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg),
> > +                              MX25_ADCQ_CFG_REFP_MASK |
> > +                              MX25_ADCQ_CFG_REFN_MASK,
> > +                              refp | refn);
> > +   }
> > +   regmap_update_bits(priv->regs, MX25_ADCQ_CR,
> > +                      MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST,
> > +                      MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST);
> > +
> > +   regmap_write(priv->regs, MX25_ADCQ_CR,
> > +                MX25_ADCQ_CR_PDMSK | MX25_ADCQ_CR_QSM_FQS);
> > +
> > +   /* Remove unused regulators */
> > +   for (i = 0; i != 4; ++i) {
> > +           if (!refp_used[i]) {
> > +                   if (!IS_ERR_OR_NULL(priv->vref[i]))
> > +                           devm_regulator_put(priv->vref[i]);
> > +                   priv->vref[i] = NULL;
> > +           }
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> > +static int mx25_gcq_probe(struct platform_device *pdev)
> > +{
> > +   struct iio_dev *indio_dev;
> > +   struct mx25_gcq_priv *priv;
> > +   struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
> > +   struct device *dev = &pdev->dev;
> > +   struct resource *res;
> > +   void __iomem *mem;
> > +   int ret;
> > +   int i;
> > +
> > +   indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
> > +   if (!indio_dev)
> > +           return -ENOMEM;
> > +
> > +   priv = iio_priv(indio_dev);
> > +
> > +   res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +   mem = devm_ioremap_resource(dev, res);
> > +   if (IS_ERR(mem))
> > +           return PTR_ERR(mem);
> > +
> > +   priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_gcq_regconfig);
> > +   if (IS_ERR(priv->regs)) {
> > +           dev_err(dev, "Failed to initialize regmap\n");
> > +           return PTR_ERR(priv->regs);
> > +   }
> > +
> > +   init_completion(&priv->completed);
> > +
> > +   ret = mx25_gcq_setup_cfgs(pdev, priv);
> > +   if (ret)
> > +           return ret;
> > +
> > +   for (i = 0; i != 4; ++i) {
> > +           if (!priv->vref[i])
> > +                   continue;
> > +
> > +           ret = regulator_enable(priv->vref[i]);
> > +           if (ret)
> > +                   goto err_regulator_disable;
> > +   }
> > +
> > +   priv->clk = tsadc->clk;
> > +   ret = clk_prepare_enable(priv->clk);
> > +   if (ret) {
> > +           dev_err(dev, "Failed to enable clock\n");
> > +           goto err_vref_disable;
> > +   }
> > +
> > +   priv->irq = platform_get_irq(pdev, 0);
> > +   if (priv->irq <= 0) {
> > +           dev_err(dev, "Failed to get IRQ\n");
> > +           ret = priv->irq;
> If it is zero you'll return 0 from probe (success)
> whilst actually failing.  
> > +           goto err_clk_unprepare;
> > +   }
> > +
> > +   ret = request_irq(priv->irq, mx25_gcq_irq, 0, pdev->name, priv);
> > +   if (ret) {
> > +           dev_err(dev, "Failed requesting IRQ\n");
> > +           goto err_clk_unprepare;
> > +   }
> > +
> > +   indio_dev->dev.parent = &pdev->dev;
> > +   indio_dev->channels = mx25_gcq_channels;
> > +   indio_dev->num_channels = ARRAY_SIZE(mx25_gcq_channels);
> > +   indio_dev->info = &mx25_gcq_iio_info;
> > +   indio_dev->name = driver_name;
> > +
> > +   ret = iio_device_register(indio_dev);
> > +   if (ret) {
> > +           dev_err(dev, "Failed to register iio device\n");
> > +           goto err_irq_free;
> > +   }
> > +
> > +   platform_set_drvdata(pdev, indio_dev);
> > +
> > +   return 0;
> > +
> > +err_irq_free:
> > +   free_irq(priv->irq, (void *)priv);
> Cast to void * not needed. Any pointer can be implicitly be
> cast to void *
> 
> > +err_clk_unprepare:
> > +   clk_disable_unprepare(priv->clk);
> > +err_vref_disable:
> > +   i = 4;
> > +err_regulator_disable:
> > +   for (; i-- > 0;) {
> > +           if (priv->vref[i])
> > +                   regulator_disable(priv->vref[i]);
> > +   }
> > +   return ret;
> > +}
> > +
> > +static int mx25_gcq_remove(struct platform_device *pdev)
> > +{
> > +   struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > +   struct mx25_gcq_priv *priv = iio_priv(indio_dev);
> > +   int i;
> > +
> > +   iio_device_unregister(indio_dev);
> > +   free_irq(priv->irq, priv);
> > +   clk_disable_unprepare(priv->clk);
> > +   for (i = 4; i-- > 0;) {
> > +           if (priv->vref[i])
> > +                   regulator_disable(priv->vref[i]);
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> > +static const struct of_device_id mx25_gcq_ids[] = {
> > +   { .compatible = "fsl,imx25-gcq", },
> > +   { /* Sentinel */ }
> > +};
> > +
> > +static struct platform_driver mx25_gcq_driver = {
> > +   .driver         = {
> > +           .name   = "mx25-gcq",
> > +           .of_match_table = mx25_gcq_ids,
> > +   },
> > +   .probe          = mx25_gcq_probe,
> > +   .remove         = mx25_gcq_remove,
> > +};
> > +module_platform_driver(mx25_gcq_driver);
> > +
> > +MODULE_DESCRIPTION("ADC driver for Freescale mx25");
> > +MODULE_AUTHOR("Markus Pargmann <m...@pengutronix.de>");
> > +MODULE_LICENSE("GPL v2");
> > 
> 
> 
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