Merge tag 'iio-for-3.17b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second round of new drivers and cleanups for IIO in the 3.17 cycle.

New drivers
* mcp4902, mcp4912 and mcp4922 SPI DAC driver.
* max1027, max1029 and max1031 SPI ADC driver.

Cleanups
* cm32181 - use devm APIs to simplify error paths.
* ak8975 - use devm APIs to simplify error paths.
* ad9850 - drop some unused defines and an unnecessary goto.
* hmc5843 - add missing devices to the device id table and the documentation.
* ad9832 - small formatting cleanups.
* sca3000 - hide direct use of the stufftoread element by adding a
    data_available function.  This is a precursor for the addition of buffer
    watermarks to the subsystem but stands as a good cleanup on its own.

15 files changed, 814 insertions, 73 deletions

diff --git a/Documentation/devicetree/bindings/iio/adc/max1027-adc.txt b/Documentation/devicetree/bindings/iio/adc/max1027-adc.txt
new file mode 100644
index 000000000000..a8770cc6bcad
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/max1027-adc.txt
@@ -0,0 +1,22 @@
+* Maxim 1027/1029/1031 Analog to Digital Converter (ADC)
+
+Required properties:
+  - compatible: Should be "maxim,max1027" or "maxim,max1029" or "maxim,max1031"
+  - reg: SPI chip select number for the device
+  - interrupt-parent: phandle to the parent interrupt controller
+  see: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+  - interrupts: IRQ line for the ADC
+  see: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+
+Recommended properties:
+- spi-max-frequency: Definition as per
+                     Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Example:
+adc@0 {
+        compatible = "maxim,max1027";
+        reg = <0>;
+        interrupt-parent = <&gpio5>;
+        interrupts = <15 IRQ_TYPE_EDGE_RISING>;
+        spi-max-frequency = <1000000>;
+};
diff --git a/Documentation/devicetree/bindings/iio/magnetometer/hmc5843.txt b/Documentation/devicetree/bindings/iio/magnetometer/hmc5843.txt
index 90d5f34db04e..b8cbdd517abc 100644
--- a/Documentation/devicetree/bindings/iio/magnetometer/hmc5843.txt
+++ b/Documentation/devicetree/bindings/iio/magnetometer/hmc5843.txt
@@ -3,6 +3,9 @@
 Required properties:
 
   - compatible : should be "honeywell,hmc5843"
+  Other models which are supported with driver are:
+        "honeywell,hmc5883"
+        "honeywell,hmc5883l"
   - reg : the I2C address of the magnetometer - typically 0x1e
 
 Optional properties:
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index a80d23628f14..20a7073f1dd6 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -131,6 +131,15 @@ config LP8788_ADC
         help
           Say yes here to build support for TI LP8788 ADC.
 
+config MAX1027
+        tristate "Maxim max1027 ADC driver"
+        depends on SPI
+        select IIO_BUFFER
+        select IIO_TRIGGERED_BUFFER
+        help
+          Say yes here to build support for Maxim SPI ADC models
+          max1027, max1029 and max1031.
+
 config MAX1363
         tristate "Maxim max1363 ADC driver"
         depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 9d60f2deaaaf..38cf5c3f5631 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
+obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
new file mode 100644
index 000000000000..87ee1c7d0b54
--- /dev/null
+++ b/drivers/iio/adc/max1027.c
@@ -0,0 +1,521 @@
+ /*
+  * iio/adc/max1027.c
+  * Copyright (C) 2014 Philippe Reynes
+  *
+  * based on linux/drivers/iio/ad7923.c
+  * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
+  * Copyright 2012 CS Systemes d'Information
+  *
+  * 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.
+  *
+  * max1027.c
+  *
+  * Partial support for max1027 and similar chips.
+  */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MAX1027_CONV_REG  BIT(7)
+#define MAX1027_SETUP_REG BIT(6)
+#define MAX1027_AVG_REG   BIT(5)
+#define MAX1027_RST_REG   BIT(4)
+
+/* conversion register */
+#define MAX1027_TEMP      BIT(0)
+#define MAX1027_SCAN_0_N  (0x00 << 1)
+#define MAX1027_SCAN_N_M  (0x01 << 1)
+#define MAX1027_SCAN_N    (0x02 << 1)
+#define MAX1027_NOSCAN    (0x03 << 1)
+#define MAX1027_CHAN(n)   ((n) << 3)
+
+/* setup register */
+#define MAX1027_UNIPOLAR  0x02
+#define MAX1027_BIPOLAR   0x03
+#define MAX1027_REF_MODE0 (0x00 << 2)
+#define MAX1027_REF_MODE1 (0x01 << 2)
+#define MAX1027_REF_MODE2 (0x02 << 2)
+#define MAX1027_REF_MODE3 (0x03 << 2)
+#define MAX1027_CKS_MODE0 (0x00 << 4)
+#define MAX1027_CKS_MODE1 (0x01 << 4)
+#define MAX1027_CKS_MODE2 (0x02 << 4)
+#define MAX1027_CKS_MODE3 (0x03 << 4)
+
+/* averaging register */
+#define MAX1027_NSCAN_4   0x00
+#define MAX1027_NSCAN_8   0x01
+#define MAX1027_NSCAN_12  0x02
+#define MAX1027_NSCAN_16  0x03
+#define MAX1027_NAVG_4    (0x00 << 2)
+#define MAX1027_NAVG_8    (0x01 << 2)
+#define MAX1027_NAVG_16   (0x02 << 2)
+#define MAX1027_NAVG_32   (0x03 << 2)
+#define MAX1027_AVG_EN    BIT(4)
+
+enum max1027_id {
+        max1027,
+        max1029,
+        max1031,
+};
+
+static const struct spi_device_id max1027_id[] = {
+        {"max1027", max1027},
+        {"max1029", max1029},
+        {"max1031", max1031},
+        {}
+};
+MODULE_DEVICE_TABLE(spi, max1027_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id max1027_adc_dt_ids[] = {
+        { .compatible = "maxim,max1027" },
+        { .compatible = "maxim,max1029" },
+        { .compatible = "maxim,max1031" },
+        {},
+};
+MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids);
+#endif
+
+#define MAX1027_V_CHAN(index)                                           \
+        {                                                               \
+                .type = IIO_VOLTAGE,                                    \
+                .indexed = 1,                                           \
+                .channel = index,                                       \
+                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
+                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+                .scan_index = index + 1,                                \
+                .scan_type = {                                          \
+                        .sign = 'u',                                    \
+                        .realbits = 10,                                 \
+                        .storagebits = 16,                              \
+                        .shift = 2,                                     \
+                        .endianness = IIO_BE,                           \
+                },                                                      \
+        }
+
+#define MAX1027_T_CHAN                                                  \
+        {                                                               \
+                .type = IIO_TEMP,                                       \
+                .channel = 0,                                           \
+                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
+                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+                .scan_index = 0,                                        \
+                .scan_type = {                                          \
+                        .sign = 'u',                                    \
+                        .realbits = 12,                                 \
+                        .storagebits = 16,                              \
+                        .endianness = IIO_BE,                           \
+                },                                                      \
+        }
+
+static const struct iio_chan_spec max1027_channels[] = {
+        MAX1027_T_CHAN,
+        MAX1027_V_CHAN(0),
+        MAX1027_V_CHAN(1),
+        MAX1027_V_CHAN(2),
+        MAX1027_V_CHAN(3),
+        MAX1027_V_CHAN(4),
+        MAX1027_V_CHAN(5),
+        MAX1027_V_CHAN(6),
+        MAX1027_V_CHAN(7)
+};
+
+static const struct iio_chan_spec max1029_channels[] = {
+        MAX1027_T_CHAN,
+        MAX1027_V_CHAN(0),
+        MAX1027_V_CHAN(1),
+        MAX1027_V_CHAN(2),
+        MAX1027_V_CHAN(3),
+        MAX1027_V_CHAN(4),
+        MAX1027_V_CHAN(5),
+        MAX1027_V_CHAN(6),
+        MAX1027_V_CHAN(7),
+        MAX1027_V_CHAN(8),
+        MAX1027_V_CHAN(9),
+        MAX1027_V_CHAN(10),
+        MAX1027_V_CHAN(11)
+};
+
+static const struct iio_chan_spec max1031_channels[] = {
+        MAX1027_T_CHAN,
+        MAX1027_V_CHAN(0),
+        MAX1027_V_CHAN(1),
+        MAX1027_V_CHAN(2),
+        MAX1027_V_CHAN(3),
+        MAX1027_V_CHAN(4),
+        MAX1027_V_CHAN(5),
+        MAX1027_V_CHAN(6),
+        MAX1027_V_CHAN(7),
+        MAX1027_V_CHAN(8),
+        MAX1027_V_CHAN(9),
+        MAX1027_V_CHAN(10),
+        MAX1027_V_CHAN(11),
+        MAX1027_V_CHAN(12),
+        MAX1027_V_CHAN(13),
+        MAX1027_V_CHAN(14),
+        MAX1027_V_CHAN(15)
+};
+
+static const unsigned long max1027_available_scan_masks[] = {
+        0x000001ff,
+        0x00000000,
+};
+
+static const unsigned long max1029_available_scan_masks[] = {
+        0x00001fff,
+        0x00000000,
+};
+
+static const unsigned long max1031_available_scan_masks[] = {
+        0x0001ffff,
+        0x00000000,
+};
+
+struct max1027_chip_info {
+        const struct iio_chan_spec *channels;
+        unsigned int num_channels;
+        const unsigned long *available_scan_masks;
+};
+
+static const struct max1027_chip_info max1027_chip_info_tbl[] = {
+        [max1027] = {
+                .channels = max1027_channels,
+                .num_channels = ARRAY_SIZE(max1027_channels),
+                .available_scan_masks = max1027_available_scan_masks,
+        },
+        [max1029] = {
+                .channels = max1029_channels,
+                .num_channels = ARRAY_SIZE(max1029_channels),
+                .available_scan_masks = max1029_available_scan_masks,
+        },
+        [max1031] = {
+                .channels = max1031_channels,
+                .num_channels = ARRAY_SIZE(max1031_channels),
+                .available_scan_masks = max1031_available_scan_masks,
+        },
+};
+
+struct max1027_state {
+        const struct max1027_chip_info  *info;
+        struct spi_device               *spi;
+        struct iio_trigger              *trig;
+        __be16                          *buffer;
+        struct mutex                    lock;
+
+        u8                              reg ____cacheline_aligned;
+};
+
+static int max1027_read_single_value(struct iio_dev *indio_dev,
+                                     struct iio_chan_spec const *chan,
+                                     int *val)
+{
+        int ret;
+        struct max1027_state *st = iio_priv(indio_dev);
+
+        if (iio_buffer_enabled(indio_dev)) {
+                dev_warn(&indio_dev->dev, "trigger mode already enabled");
+                return -EBUSY;
+        }
+
+        /* Start acquisition on conversion register write */
+        st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
+        ret = spi_write(st->spi, &st->reg, 1);
+        if (ret < 0) {
+                dev_err(&indio_dev->dev,
+                        "Failed to configure setup register\n");
+                return ret;
+        }
+
+        /* Configure conversion register with the requested chan */
+        st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
+                  MAX1027_NOSCAN | !!(chan->type == IIO_TEMP);
+        ret = spi_write(st->spi, &st->reg, 1);
+        if (ret < 0) {
+                dev_err(&indio_dev->dev,
+                        "Failed to configure conversion register\n");
+                return ret;
+        }
+
+        /*
+         * For an unknown reason, when we use the mode "10" (write
+         * conversion register), the interrupt doesn't occur every time.
+         * So we just wait 1 ms.
+         */
+        mdelay(1);
+
+        /* Read result */
+        ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
+        if (ret < 0)
+                return ret;
+
+        *val = be16_to_cpu(st->buffer[0]);
+
+        return IIO_VAL_INT;
+}
+
+static int max1027_read_raw(struct iio_dev *indio_dev,
+                            struct iio_chan_spec const *chan,
+                            int *val, int *val2, long mask)
+{
+        int ret = 0;
+        struct max1027_state *st = iio_priv(indio_dev);
+
+        mutex_lock(&st->lock);
+
+        switch (mask) {
+        case IIO_CHAN_INFO_RAW:
+                ret = max1027_read_single_value(indio_dev, chan, val);
+                break;
+        case IIO_CHAN_INFO_SCALE:
+                switch (chan->type) {
+                case IIO_TEMP:
+                        *val = 1;
+                        *val2 = 8;
+                        ret = IIO_VAL_FRACTIONAL;
+                        break;
+                case IIO_VOLTAGE:
+                        *val = 2500;
+                        *val2 = 10;
+                        ret = IIO_VAL_FRACTIONAL_LOG2;
+                        break;
+                default:
+                        ret = -EINVAL;
+                        break;
+                }
+                break;
+        default:
+                ret = -EINVAL;
+                break;
+        }
+
+        mutex_unlock(&st->lock);
+
+        return ret;
+}
+
+static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,
+                                      unsigned reg, unsigned writeval,
+                                      unsigned *readval)
+{
+        struct max1027_state *st = iio_priv(indio_dev);
+        u8 *val = (u8 *)st->buffer;
+
+        if (readval != NULL)
+                return -EINVAL;
+
+        *val = (u8)writeval;
+        return spi_write(st->spi, val, 1);
+}
+
+static int max1027_validate_trigger(struct iio_dev *indio_dev,
+                                    struct iio_trigger *trig)
+{
+        struct max1027_state *st = iio_priv(indio_dev);
+
+        if (st->trig != trig)
+                return -EINVAL;
+
+        return 0;
+}
+
+static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+        struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+        struct max1027_state *st = iio_priv(indio_dev);
+        int ret;
+
+        if (state) {
+                /* Start acquisition on cnvst */
+                st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
+                          MAX1027_REF_MODE2;
+                ret = spi_write(st->spi, &st->reg, 1);
+                if (ret < 0)
+                        return ret;
+
+                /* Scan from 0 to max */
+                st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) |
+                          MAX1027_SCAN_N_M | MAX1027_TEMP;
+                ret = spi_write(st->spi, &st->reg, 1);
+                if (ret < 0)
+                        return ret;
+        } else {
+                /* Start acquisition on conversion register write */
+                st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 |
+                          MAX1027_REF_MODE2;
+                ret = spi_write(st->spi, &st->reg, 1);
+                if (ret < 0)
+                        return ret;
+        }
+
+        return 0;
+}
+
+static int max1027_validate_device(struct iio_trigger *trig,
+                                   struct iio_dev *indio_dev)
+{
+        struct iio_dev *indio = iio_trigger_get_drvdata(trig);
+
+        if (indio != indio_dev)
+                return -EINVAL;
+
+        return 0;
+}
+
+static irqreturn_t max1027_trigger_handler(int irq, void *private)
+{
+        struct iio_poll_func *pf = (struct iio_poll_func *)private;
+        struct iio_dev *indio_dev = pf->indio_dev;
+        struct max1027_state *st = iio_priv(indio_dev);
+
+        pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private);
+
+        /* fill buffer with all channel */
+        spi_read(st->spi, st->buffer, indio_dev->masklength * 2);
+
+        iio_push_to_buffers(indio_dev, st->buffer);
+
+        iio_trigger_notify_done(indio_dev->trig);
+
+        return IRQ_HANDLED;
+}
+
+static const struct iio_trigger_ops max1027_trigger_ops = {
+        .owner = THIS_MODULE,
+        .validate_device = &max1027_validate_device,
+        .set_trigger_state = &max1027_set_trigger_state,
+};
+
+static const struct iio_info max1027_info = {
+        .driver_module = THIS_MODULE,
+        .read_raw = &max1027_read_raw,
+        .validate_trigger = &max1027_validate_trigger,
+        .debugfs_reg_access = &max1027_debugfs_reg_access,
+};
+
+static int max1027_probe(struct spi_device *spi)
+{
+        int ret;
+        struct iio_dev *indio_dev;
+        struct max1027_state *st;
+
+        pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi);
+
+        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+        if (indio_dev == NULL) {
+                pr_err("Can't allocate iio device\n");
+                return -ENOMEM;
+        }
+
+        spi_set_drvdata(spi, indio_dev);
+
+        st = iio_priv(indio_dev);
+        st->spi = spi;
+        st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+        mutex_init(&st->lock);
+
+        indio_dev->name = spi_get_device_id(spi)->name;
+        indio_dev->dev.parent = &spi->dev;
+        indio_dev->info = &max1027_info;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+        indio_dev->channels = st->info->channels;
+        indio_dev->num_channels = st->info->num_channels;
+        indio_dev->available_scan_masks = st->info->available_scan_masks;
+
+        st->buffer = devm_kmalloc(&indio_dev->dev,
+                                  indio_dev->num_channels * 2,
+                                  GFP_KERNEL);
+        if (st->buffer == NULL) {
+                dev_err(&indio_dev->dev, "Can't allocate bufffer\n");
+                return -ENOMEM;
+        }
+
+        ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+                                         &max1027_trigger_handler, NULL);
+        if (ret < 0) {
+                dev_err(&indio_dev->dev, "Failed to setup buffer\n");
+                return ret;
+        }
+
+        st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
+                                                        indio_dev->name);
+        if (st->trig == NULL) {
+                ret = -ENOMEM;
+                dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n");
+                goto fail_trigger_alloc;
+        }
+
+        st->trig->ops = &max1027_trigger_ops;
+        st->trig->dev.parent = &spi->dev;
+        iio_trigger_set_drvdata(st->trig, indio_dev);
+        iio_trigger_register(st->trig);
+
+        ret = devm_request_threaded_irq(&spi->dev, spi->irq,
+                                        iio_trigger_generic_data_rdy_poll,
+                                        NULL,
+                                        IRQF_TRIGGER_FALLING,
+                                        spi->dev.driver->name, st->trig);
+        if (ret < 0) {
+                dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n");
+                goto fail_dev_register;
+        }
+
+        /* Disable averaging */
+        st->reg = MAX1027_AVG_REG;
+        ret = spi_write(st->spi, &st->reg, 1);
+        if (ret < 0) {
+                dev_err(&indio_dev->dev, "Failed to configure averaging register\n");
+                goto fail_dev_register;
+        }
+
+        ret = iio_device_register(indio_dev);
+        if (ret < 0) {
+                dev_err(&indio_dev->dev, "Failed to register iio device\n");
+                goto fail_dev_register;
+        }
+
+        return 0;
+
+fail_dev_register:
+fail_trigger_alloc:
+        iio_triggered_buffer_cleanup(indio_dev);
+
+        return ret;
+}
+
+static int max1027_remove(struct spi_device *spi)
+{
+        struct iio_dev *indio_dev = spi_get_drvdata(spi);
+
+        pr_debug("%s: remove(spi = 0x%p)\n", __func__, spi);
+
+        iio_device_unregister(indio_dev);
+        iio_triggered_buffer_cleanup(indio_dev);
+
+        return 0;
+}
+
+static struct spi_driver max1027_driver = {
+        .driver = {
+                .name   = "max1027",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = max1027_probe,
+        .remove         = max1027_remove,
+        .id_table       = max1027_id,
+};
+module_spi_driver(max1027_driver);
+
+MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>");
+MODULE_DESCRIPTION("MAX1027/MAX1029/MAX1031 ADC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index f378ca8033db..f278eff42a4c 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -163,4 +163,14 @@ config MCP4725
           To compile this driver as a module, choose M here: the module
           will be called mcp4725.
 
+config MCP4922
+        tristate "MCP4902, MCP4912, MCP4922 DAC driver"
+        depends on SPI
+        help
+          Say yes here to build the driver for the Microchip MCP4902
+          MCP4912, and MCP4922 DAC devices.
+
+          To compile this driver as a module, choose M here: the module
+          will be called mcp4922.
+
 endmenu
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index bb84ad64463f..10107640bb46 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_AD5686) += ad5686.o
 obj-$(CONFIG_AD7303) += ad7303.o
 obj-$(CONFIG_MAX517) += max517.o
 obj-$(CONFIG_MCP4725) += mcp4725.o
+obj-$(CONFIG_MCP4922) += mcp4922.o
diff --git a/drivers/iio/dac/mcp4922.c b/drivers/iio/dac/mcp4922.c
new file mode 100644
index 000000000000..92cf4ca6981d
--- /dev/null
+++ b/drivers/iio/dac/mcp4922.c
@@ -0,0 +1,216 @@
+/*
+ * mcp4922.c
+ *
+ * Driver for Microchip Digital to Analog Converters.
+ * Supports MCP4902, MCP4912, and MCP4922.
+ *
+ * Copyright (c) 2014 EMAC Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/regulator/consumer.h>
+#include <linux/bitops.h>
+
+#define MCP4922_NUM_CHANNELS    2
+
+enum mcp4922_supported_device_ids {
+        ID_MCP4902,
+        ID_MCP4912,
+        ID_MCP4922,
+};
+
+struct mcp4922_state {
+        struct spi_device *spi;
+        unsigned int value[MCP4922_NUM_CHANNELS];
+        unsigned int vref_mv;
+        struct regulator *vref_reg;
+        u8 mosi[2] ____cacheline_aligned;
+};
+
+#define MCP4922_CHAN(chan, bits) {                      \
+        .type = IIO_VOLTAGE,                            \
+        .output = 1,                                    \
+        .indexed = 1,                                   \
+        .channel = chan,                                \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
+        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+        .scan_type = {                                  \
+                .sign = 'u',                            \
+                .realbits = (bits),                     \
+                .storagebits = 16,                      \
+                .shift = 12 - (bits),                   \
+        },                                              \
+}
+
+static int mcp4922_spi_write(struct mcp4922_state *state, u8 addr, u32 val)
+{
+        state->mosi[1] = val & 0xff;
+        state->mosi[0] = (addr == 0) ? 0x00 : 0x80;
+        state->mosi[0] |= 0x30 | ((val >> 8) & 0x0f);
+
+        return spi_write(state->spi, state->mosi, 2);
+}
+
+static int mcp4922_read_raw(struct iio_dev *indio_dev,
+                struct iio_chan_spec const *chan,
+                int *val,
+                int *val2,
+                long mask)
+{
+        struct mcp4922_state *state = iio_priv(indio_dev);
+
+        switch (mask) {
+        case IIO_CHAN_INFO_RAW:
+                *val = state->value[chan->channel];
+                return IIO_VAL_INT;
+        case IIO_CHAN_INFO_SCALE:
+                *val = state->vref_mv;
+                *val2 = chan->scan_type.realbits;
+                return IIO_VAL_FRACTIONAL_LOG2;
+        default:
+                return -EINVAL;
+        }
+}
+
+static int mcp4922_write_raw(struct iio_dev *indio_dev,
+                struct iio_chan_spec const *chan,
+                int val,
+                int val2,
+                long mask)
+{
+        struct mcp4922_state *state = iio_priv(indio_dev);
+
+        if (val2 != 0)
+                return -EINVAL;
+
+        switch (mask) {
+        case IIO_CHAN_INFO_RAW:
+                if (val > GENMASK(chan->scan_type.realbits-1, 0))
+                        return -EINVAL;
+                val <<= chan->scan_type.shift;
+                state->value[chan->channel] = val;
+                return mcp4922_spi_write(state, chan->channel, val);
+        default:
+                return -EINVAL;
+        }
+}
+
+static const struct iio_chan_spec mcp4922_channels[3][MCP4922_NUM_CHANNELS] = {
+        [ID_MCP4902] = { MCP4922_CHAN(0, 8),    MCP4922_CHAN(1, 8) },
+        [ID_MCP4912] = { MCP4922_CHAN(0, 10),   MCP4922_CHAN(1, 10) },
+        [ID_MCP4922] = { MCP4922_CHAN(0, 12),   MCP4922_CHAN(1, 12) },
+};
+
+static const struct iio_info mcp4922_info = {
+        .read_raw = &mcp4922_read_raw,
+        .write_raw = &mcp4922_write_raw,
+        .driver_module = THIS_MODULE,
+};
+
+static int mcp4922_probe(struct spi_device *spi)
+{
+        struct iio_dev *indio_dev;
+        struct mcp4922_state *state;
+        const struct spi_device_id *id;
+        int ret;
+
+        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
+        if (indio_dev == NULL)
+                return -ENOMEM;
+
+        state = iio_priv(indio_dev);
+        state->spi = spi;
+        state->vref_reg = devm_regulator_get(&spi->dev, "vref");
+        if (IS_ERR(state->vref_reg)) {
+                dev_err(&spi->dev, "Vref regulator not specified\n");
+                return PTR_ERR(state->vref_reg);
+        }
+
+        ret = regulator_enable(state->vref_reg);
+        if (ret) {
+                dev_err(&spi->dev, "Failed to enable vref regulator: %d\n",
+                                ret);
+                return ret;
+        }
+
+        ret = regulator_get_voltage(state->vref_reg);
+        if (ret < 0) {
+                dev_err(&spi->dev, "Failed to read vref regulator: %d\n",
+                                ret);
+                goto error_disable_reg;
+        }
+        state->vref_mv = ret / 1000;
+
+        spi_set_drvdata(spi, indio_dev);
+        id = spi_get_device_id(spi);
+        indio_dev->dev.parent = &spi->dev;
+        indio_dev->info = &mcp4922_info;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+        indio_dev->channels = mcp4922_channels[id->driver_data];
+        indio_dev->num_channels = MCP4922_NUM_CHANNELS;
+        indio_dev->name = id->name;
+
+        ret = iio_device_register(indio_dev);
+        if (ret) {
+                dev_err(&spi->dev, "Failed to register iio device: %d\n",
+                                ret);
+                goto error_disable_reg;
+        }
+
+        return 0;
+
+error_disable_reg:
+        regulator_disable(state->vref_reg);
+
+        return ret;
+}
+
+static int mcp4922_remove(struct spi_device *spi)
+{
+        struct iio_dev *indio_dev = spi_get_drvdata(spi);
+        struct mcp4922_state *state;
+
+        iio_device_unregister(indio_dev);
+        state = iio_priv(indio_dev);
+        regulator_disable(state->vref_reg);
+
+        return 0;
+}
+
+static const struct spi_device_id mcp4922_id[] = {
+        {"mcp4902", ID_MCP4902},
+        {"mcp4912", ID_MCP4912},
+        {"mcp4922", ID_MCP4922},
+        {}
+};
+MODULE_DEVICE_TABLE(spi, mcp4922_id);
+
+static struct spi_driver mcp4922_driver = {
+        .driver = {
+                   .name = "mcp4922",
+                   .owner = THIS_MODULE,
+                   },
+        .probe = mcp4922_probe,
+        .remove = mcp4922_remove,
+        .id_table = mcp4922_id,
+};
+module_spi_driver(mcp4922_driver);
+
+MODULE_AUTHOR("Michael Welling <mwelling@ieee.org>");
+MODULE_DESCRIPTION("Microchip MCP4902, MCP4912, MCP4922 DAC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 36b1ae92e239..2952ee038477 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -39,10 +39,7 @@ static bool iio_buffer_is_active(struct iio_buffer *buf)
 
 static bool iio_buffer_data_available(struct iio_buffer *buf)
 {
-        if (buf->access->data_available)
-                return buf->access->data_available(buf);
-
-        return buf->stufftoread;
+        return buf->access->data_available(buf);
 }
 
 /**
diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index d976e6ce60db..ad36b294e4d5 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -331,7 +331,7 @@ static int cm32181_probe(struct i2c_client *client,
                 return ret;
         }
 
-        ret = iio_device_register(indio_dev);
+        ret = devm_iio_device_register(&client->dev, indio_dev);
         if (ret) {
                 dev_err(&client->dev,
                         "%s: regist device failed\n",
@@ -342,14 +342,6 @@ static int cm32181_probe(struct i2c_client *client,
         return 0;
 }
 
-static int cm32181_remove(struct i2c_client *client)
-{
-        struct iio_dev *indio_dev = i2c_get_clientdata(client);
-
-        iio_device_unregister(indio_dev);
-        return 0;
-}
-
 static const struct i2c_device_id cm32181_id[] = {
         { "cm32181", 0 },
         { }
@@ -370,7 +362,6 @@ static struct i2c_driver cm32181_driver = {
         },
         .id_table       = cm32181_id,
         .probe          = cm32181_probe,
-        .remove         = cm32181_remove,
 };
 
 module_i2c_driver(cm32181_driver);
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index ea08313af0d2..a2357921d761 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -165,7 +165,7 @@ static int ak8975_setup_irq(struct ak8975_data *data)
         else
                 irq = gpio_to_irq(data->eoc_gpio);
 
-        rc = request_irq(irq, ak8975_irq_handler,
+        rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
                          IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                          dev_name(&client->dev), data);
         if (rc < 0) {
@@ -513,21 +513,21 @@ static int ak8975_probe(struct i2c_client *client,
         /* We may not have a GPIO based IRQ to scan, that is fine, we will
            poll if so */
         if (gpio_is_valid(eoc_gpio)) {
-                err = gpio_request_one(eoc_gpio, GPIOF_IN, "ak_8975");
+                err = devm_gpio_request_one(&client->dev, eoc_gpio,
+                                                        GPIOF_IN, "ak_8975");
                 if (err < 0) {
                         dev_err(&client->dev,
                                 "failed to request GPIO %d, error %d\n",
                                                         eoc_gpio, err);
-                        goto exit;
+                        return err;
                 }
         }
 
         /* Register with IIO */
-        indio_dev = iio_device_alloc(sizeof(*data));
-        if (indio_dev == NULL) {
-                err = -ENOMEM;
-                goto exit_gpio;
-        }
+        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+        if (indio_dev == NULL)
+                return -ENOMEM;
+
         data = iio_priv(indio_dev);
         i2c_set_clientdata(client, indio_dev);
 
@@ -542,17 +542,16 @@ static int ak8975_probe(struct i2c_client *client,
                 name = (char *) id->name;
         } else if (ACPI_HANDLE(&client->dev))
                 name = ak8975_match_acpi_device(&client->dev, &data->chipset);
-        else {
-                err = -ENOSYS;
-                goto exit_free_iio;
-        }
+        else
+                return -ENOSYS;
+
         dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
 
         /* Perform some basic start-of-day setup of the device. */
         err = ak8975_setup(client);
         if (err < 0) {
                 dev_err(&client->dev, "AK8975 initialization fails\n");
-                goto exit_free_iio;
+                return err;
         }
 
         data->client = client;
@@ -564,37 +563,9 @@ static int ak8975_probe(struct i2c_client *client,
         indio_dev->info = &ak8975_info;
         indio_dev->modes = INDIO_DIRECT_MODE;
         indio_dev->name = name;
-        err = iio_device_register(indio_dev);
+        err = devm_iio_device_register(&client->dev, indio_dev);
         if (err < 0)
-                goto exit_free_iio;
-
-        return 0;
-
-exit_free_iio:
-        iio_device_free(indio_dev);
-        if (data->eoc_irq)
-                free_irq(data->eoc_irq, data);
-exit_gpio:
-        if (gpio_is_valid(eoc_gpio))
-                gpio_free(eoc_gpio);
-exit:
-        return err;
-}
-
-static int ak8975_remove(struct i2c_client *client)
-{
-        struct iio_dev *indio_dev = i2c_get_clientdata(client);
-        struct ak8975_data *data = iio_priv(indio_dev);
-
-        iio_device_unregister(indio_dev);
-
-        if (data->eoc_irq)
-                free_irq(data->eoc_irq, data);
-
-        if (gpio_is_valid(data->eoc_gpio))
-                gpio_free(data->eoc_gpio);
-
-        iio_device_free(indio_dev);
+                return err;
 
         return 0;
 }
@@ -621,7 +592,6 @@ static struct i2c_driver ak8975_driver = {
                 .acpi_match_table = ACPI_PTR(ak_acpi_match),
         },
         .probe          = ak8975_probe,
-        .remove         = ak8975_remove,
         .id_table       = ak8975_id,
 };
 module_i2c_driver(ak8975_driver);
diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c
index 198710651e0e..33f0e9235be7 100644
--- a/drivers/staging/iio/accel/sca3000_ring.c
+++ b/drivers/staging/iio/accel/sca3000_ring.c
@@ -141,6 +141,11 @@ static int sca3000_ring_get_bytes_per_datum(struct iio_buffer *r)
         return 6;
 }
 
+static bool sca3000_ring_buf_data_available(struct iio_buffer *r)
+{
+        return r->stufftoread;
+}
+
 static IIO_BUFFER_ENABLE_ATTR;
 static IIO_BUFFER_LENGTH_ATTR;
 
@@ -274,6 +279,7 @@ static const struct iio_buffer_access_funcs sca3000_ring_access_funcs = {
         .read_first_n = &sca3000_read_first_n_hw_rb,
         .get_length = &sca3000_ring_get_length,
         .get_bytes_per_datum = &sca3000_ring_get_bytes_per_datum,
+        .data_available = sca3000_ring_buf_data_available,
         .release = sca3000_ring_release,
 };
 
diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index c7d0307c8e76..b7c8351ce2ff 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -57,7 +57,7 @@ static int ad9832_write_frequency(struct ad9832_state *st,
 }
 
 static int ad9832_write_phase(struct ad9832_state *st,
-                                  unsigned long addr, unsigned long phase)
+                              unsigned long addr, unsigned long phase)
 {
         if (phase > (1 << AD9832_PHASE_BITS))
                 return -EINVAL;
@@ -72,10 +72,8 @@ static int ad9832_write_phase(struct ad9832_state *st,
         return spi_sync(st->spi, &st->phase_msg);
 }
 
-static ssize_t ad9832_write(struct device *dev,
-                struct device_attribute *attr,
-                const char *buf,
-                size_t len)
+static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
+                            const char *buf, size_t len)
 {
         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
         struct ad9832_state *st = iio_priv(indio_dev);
@@ -109,11 +107,11 @@ static ssize_t ad9832_write(struct device *dev,
                 ret = spi_sync(st->spi, &st->msg);
                 break;
         case AD9832_FREQ_SYM:
-                if (val == 1)
+                if (val == 1) {
                         st->ctrl_fp |= AD9832_FREQ;
-                else if (val == 0)
+                } else if (val == 0) {
                         st->ctrl_fp &= ~AD9832_FREQ;
-                else {
+                } else {
                         ret = -EINVAL;
                         break;
                 }
diff --git a/drivers/staging/iio/frequency/ad9850.c b/drivers/staging/iio/frequency/ad9850.c
index af877ff680e9..8727933cafcf 100644
--- a/drivers/staging/iio/frequency/ad9850.c
+++ b/drivers/staging/iio/frequency/ad9850.c
@@ -21,9 +21,6 @@
 
 #define DRV_NAME "ad9850"
 
-#define value_mask (u16)0xf000
-#define addr_shift 12
-
 /* Register format: 4 bits addr + 12 bits value */
 struct ad9850_config {
         u8 control[5];
@@ -50,9 +47,6 @@ static ssize_t ad9850_set_parameter(struct device *dev,
         mutex_lock(&st->lock);
 
         ret = spi_sync_transfer(st->sdev, &xfer, 1);
-        if (ret)
-                goto error_ret;
-error_ret:
         mutex_unlock(&st->lock);
 
         return ret ? ret : len;
diff --git a/drivers/staging/iio/magnetometer/hmc5843.c b/drivers/staging/iio/magnetometer/hmc5843.c
index d4f4dd90c699..f595fdcc79b0 100644
--- a/drivers/staging/iio/magnetometer/hmc5843.c
+++ b/drivers/staging/iio/magnetometer/hmc5843.c
@@ -630,7 +630,9 @@ static const struct i2c_device_id hmc5843_id[] = {
 MODULE_DEVICE_TABLE(i2c, hmc5843_id);
 
 static const struct of_device_id hmc5843_of_match[] = {
-        { .compatible = "honeywell,hmc5843" },
+        { .compatible = "honeywell,hmc5843", .data = (void *)HMC5843_ID },
+        { .compatible = "honeywell,hmc5883", .data = (void *)HMC5883_ID },
+        { .compatible = "honeywell,hmc5883l", .data = (void *)HMC5883L_ID },
         {}
 };
 MODULE_DEVICE_TABLE(of, hmc5843_of_match);