On May 29, 2014 10:22:00 PM GMT+01:00, Philippe Reynes <tremyfr@xxxxxxxx> wrote:
>This driver add partial support of the
>maxim 1027/1029/1031. Differential mode is not
>supported.
>
>It was tested on armadeus apf27 board.
>
>Signed-off-by: Philippe Reynes <tremyfr@xxxxxxxx>
One last thing from me.
>---
> .../devicetree/bindings/iio/adc/max1027-adc.txt | 22 +
> drivers/iio/adc/Kconfig | 9 +
> drivers/iio/adc/Makefile | 1 +
>drivers/iio/adc/max1027.c | 518
>++++++++++++++++++++
> 4 files changed, 550 insertions(+), 0 deletions(-)
>create mode 100644
>Documentation/devicetree/bindings/iio/adc/max1027-adc.txt
> create mode 100644 drivers/iio/adc/max1027.c
>
>Changelog:
>v3: (thanks Hartmut Knaack, Lars-Peter Clausen and Jonathan Cameron for
>the feedback)
>- move to drivers/iio/adc (was in staging)
>- clean binding doc
>- drop empty update_scan_mode callback
>- add a lock around single channel read code
>- remove useless wrappers around spi_write and spi_read
>- fix available scan mask (a bit was missing)
>- remove useless header
>- some others little cleanp
>
>v2: (thanks Hartmut Knaack and Jonathan Cameron for the feedback)
>- really use devm_*
>- use demux magic
>- use spi_read and spi_write (instead of spi_sync)
>- use define for register (instead of hardcoded value)
>
>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 0000000..a8770cc
>--- /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/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>index 24c28e3..517f886 100644
>--- a/drivers/iio/adc/Kconfig
>+++ b/drivers/iio/adc/Kconfig
>@@ -119,6 +119,15 @@ 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 ab346d8..daac784 100644
>--- a/drivers/iio/adc/Makefile
>+++ b/drivers/iio/adc/Makefile
>@@ -14,6 +14,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
> obj-$(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 0000000..6323510
>--- /dev/null
>+++ b/drivers/iio/adc/max1027.c
>@@ -0,0 +1,518 @@
>+ /*
>+ * 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 0x80
>+#define MAX1027_SETUP_REG 0x40
>+#define MAX1027_AVG_REG 0x20
>+#define MAX1027_RST_REG 0x10
>+
>+/* conversion register */
>+#define MAX1027_TEMP 0x01
>+#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 (0x01 << 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(index) \
>+ { \
>+ .type = IIO_TEMP, \
>+ .channel = index, \
>+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
>+ .scan_index = index, \
>+ .scan_type = { \
>+ .sign = 'u', \
>+ .realbits = 12, \
>+ .storagebits = 16, \
>+ .endianness = IIO_BE, \
>+ }, \
>+ }
>+
>+static const struct iio_chan_spec max1027_channels[] = {
>+ MAX1027_T_CHAN(0),
>+ 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(0),
>+ 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(0),
>+ 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 unsigned long max1027_available_scan_masks[] = {
>+ 0x000001ff,
>+ 0x00000000,
>+};
>+
>+static unsigned long max1029_available_scan_masks[] = {
>+ 0x00001fff,
>+ 0x00000000,
>+};
>+
>+static unsigned long max1031_available_scan_masks[] = {
>+ 0x0001ffff,
>+ 0x00000000,
>+};
>+
>+struct max1027_chip_info {
>+ const struct iio_chan_spec *channels;
>+ unsigned int num_channels;
>+ 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 {
>+ struct max1027_chip_info *info;
>+ struct spi_device *spi;
>+ struct iio_trigger *trig;
>+ u16 *buffer;
>+ struct mutex lock;
>+};
>+
>+static int max1027_read_single_value(struct iio_dev *indio_dev,
>+ struct iio_chan_spec const *chan,
>+ int *val)
>+{
>+ int ret;
>+ unsigned char reg;
>+ struct max1027_state *st = iio_priv(indio_dev);
>+
>+ if (iio_buffer_enabled(indio_dev)) {
>+ dev_warn(&indio_dev->dev, "trigger mode already enabled");
>+ return -EIO;
>+ }
>+
>+ /* Start acquisition on conversion register write */
>+ reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
>+ ret = spi_write(st->spi, (void *)®, 1);
>+ if (ret < 0) {
>+ dev_err(&indio_dev->dev,
>+ "Failed to configure setup register\n");
>+ return ret;
>+ }
>+
>+ /* Configure conversion register with the requested chan */
>+ reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel)
>+ | MAX1027_NOSCAN | !!(chan->type == IIO_TEMP);
>+ ret = spi_write(st->spi, (void *)®, 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 it 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)
>+{
>+ unsigned char val;
>+ struct max1027_state *st = iio_priv(indio_dev);
>+
>+ if (readval != NULL)
>+ return -EINVAL;
>+
>+ val = (unsigned char)writeval;
>+ return spi_write(st->spi, (void *)&val, 1);
>+}
>+
>+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);
>+ unsigned char reg;
>+ int ret;
>+
>+ if (state) {
>+ /* Start acquisition on cnvst */
>+ reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 | MAX1027_REF_MODE2;
>+ ret = spi_write(st->spi, (void *)®, 1);
>+ if (ret < 0)
>+ return ret;
>+
>+ /* Scan from 0 to max */
>+ reg = MAX1027_CONV_REG | MAX1027_CHAN(0)
>+ | MAX1027_SCAN_N_M | MAX1027_TEMP;
>+ ret = spi_write(st->spi, (void *)®, 1);
>+ if (ret < 0)
>+ return ret;
>+ } else {
>+ /* Start acquisition on conversion register write */
>+ reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 | MAX1027_REF_MODE2;
>+ ret = spi_write(st->spi, (void *)®, 1);
>+ if (ret < 0)
>+ return ret;
>+ }
>+
>+ return 0;
>+}
>+
This is a very common case so we have a generic function for it so use that...
iio_trigger_generic_data_poll
Note that the private data is the trigger structure rather than the iio_Dev
Also if this only works of the buffer is enabled you need to enforce that using the relevant call backs... Validate_device and validate_trigger. Probably start by only letting the device and trigger bind.
One day we will work out a clean way of falling back to polled reads if using any other trigger!
>+static irqreturn_t max1027_interrupt_handler(int irq, void *private)
>+{
>+ struct iio_dev *indio_dev = (struct iio_dev *)private;
>+
>+ pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private);
>+
>+ if (iio_buffer_enabled(indio_dev))
>+ iio_trigger_poll(indio_dev->trig, iio_get_time_ns());
>+
>+ return IRQ_HANDLED;
>+}
>+
>+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_with_timestamp(indio_dev, st->buffer,
>+ iio_get_time_ns());
>+
>+ iio_trigger_notify_done(indio_dev->trig);
>+
>+ return IRQ_HANDLED;
>+}
>+
>+static const struct iio_trigger_ops max1027_trigger_ops = {
>+ .owner = THIS_MODULE,
>+ .set_trigger_state = &max1027_set_trigger_state,
>+};
>+
>+static const struct iio_info max1027_info = {
>+ .driver_module = THIS_MODULE,
>+ .read_raw = &max1027_read_raw,
>+ .debugfs_reg_access = &max1027_debugfs_reg_access,
>+};
>+
>+static int max1027_probe(struct spi_device *spi)
>+{
>+ int err;
>+ unsigned char reg;
>+ struct iio_dev *indio_dev;
>+ struct max1027_state *st;
>+
>+ pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi);
>+
>+ /* allocate iio device */
>+ 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->buffer = NULL;
>+ st->info = (struct max1027_chip_info *)
>+ &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
>+
>+ mutex_init(&st->lock);
>+
>+ /* request irq */
>+ err = devm_request_threaded_irq(&spi->dev, spi->irq,
>+ max1027_interrupt_handler,
>+ NULL,
>+ IRQF_TRIGGER_FALLING,
>+ spi->dev.driver->name, indio_dev);
>+ if (err < 0) {
>+ dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n");
>+ return err;
>+ }
>+
>+ 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;
>+
>+ /* Allocate buffer (data) */
>+ 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;
>+ }
>+
>+ /* Allocate buffer */
>+ err = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
>+ &max1027_trigger_handler, NULL);
>+ if (err < 0) {
>+ dev_err(&indio_dev->dev, "Failed to setup buffer\n");
>+ return err;
>+ }
>+
>+ /* Allocate trigger */
>+ st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
>+ indio_dev->name);
>+ if (st->trig == NULL) {
>+ err = -ENOMEM;
>+ dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n");
>+ goto fail_trigger_alloc;
>+ }
>+
>+ /* configure and register trigger */
>+ 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);
>+
>+ /* Disable averaging */
>+ reg = MAX1027_AVG_REG;
>+ err = spi_write(st->spi, (void *)®, 1);
>+ if (err < 0) {
>+ dev_err(&indio_dev->dev, "Failed to configure averaging
>register\n");
>+ goto fail_dev_register;
>+ }
>+
>+ /* Register the device */
>+ err = iio_device_register(indio_dev);
>+ if (err < 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 err;
>+}
>+
>+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@xxxxxxxx>");
>+MODULE_DESCRIPTION("MAX1027/MAX1029/MAX1031 ADC");
>+MODULE_LICENSE("GPL v2");
--
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