Merge tag 'iio-for-4.9b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of iio new device support, features and cleanups for the 4.9 cycle.

New device support
* ad8801 dac
  - new driver supporting ad8801 and ad8803 DACs.
* adc12138
  - new driver supporting TI adc12130/adc12132 and adc12138 ADCs.
* ltc2485 adc
  - new driver
* mxc6255
  - add support for the mxc6225 part name and fixup the ID check so it works.
* vz89x VOC sensor
  - add support for the vz89te part which drops the voc_short channel and adds
    CRCs compared to other supported parts.

New features
* core
  - immutable triggers.  These effectively grant exclusive control over a
    trigger. The typical usecase is a device representing an analog part
    (perhaps a MUX) that needs to control the sampling of a downstream
    ADC.
  - resource managed trigger registration and triggered_buffer_init.
  - iio_push_event now protected against case of the event interface
    registration not having yet occured.  Only matters if an interrupt
    can occur during this window - might happen on shared interrupt lines.
  - helper to let a driver query if the trigger it is using is provided by
    itself (using the convention of both device and trigger having the same
    parent).
* tools
  - iio-utils. Used channel modifier scaling in preference to generic scaling
    when both exist.
* at91-adc
  - Add support for touchscreen switches closure time needed by some newer
    parts.
* stx104
  - support the ADC channels on this ADC/DAC board. As these are the primary
    feature of the board also move the driver to the iio/adc directory.
* sx9500
  - device tree bindings.

Cleanups / Fixes
* ad5755
  - fix an off-by-one on devnr limit check (introduced earlier this cycle)
* ad7266
  - drop NULL check on devm_regulator_get_optional as it can't return NULL.
* ak8974
  - avoid an unused functional warning due to rework in PM core code.
  - remove .owner field setting as done by i2c_core.
* ina2xx
  - clear out a left over debug field from chip global data.
* hid-sensors
  - avoid an unused functional warning due to rework in PM core code.
* maxim-thermocouple
  - fix non static symbol warnings.
* ms5611
  - fetch and enable regulators unconditionally when they aren't optional.
* sca3000
  - whitespace cleanup.
* st_sensors
  - fetch and enable regulators unconditionally rather than having them
    supported as optional regulators (missunderstanding on my part amongst
    others a while back)
  - followup to previous patch fixes error checking on the regulators.
  - mark symbols static where possible.
  - use the 'is it my trigger' help function.  This prevents the odd case
    of another device triggering from the st-sensors trigger whilst the
    st-sensors trigger is itself not using it but rather using say an hrtimer.
* ti-ads1015
  - add missing of_node_put.
* vz89x
  - rework to all support of new devices.
  - prevent reading of a corrupted buffer.
  - fixup a return value of 0/1 in a bool returning function.

Address updates
- Vlad Dogaru email address change.

1 files changed, 148 insertions, 0 deletions

diff --git a/drivers/iio/adc/ltc2485.c b/drivers/iio/adc/ltc2485.c
new file mode 100644
index 000000000000..eab91f12454a
--- /dev/null
+++ b/drivers/iio/adc/ltc2485.c
@@ -0,0 +1,148 @@
+/*
+ * ltc2485.c - Driver for Linear Technology LTC2485 ADC
+ *
+ * Copyright (C) 2016 Alison Schofield <amsfield22@gmail.com>
+ *
+ * 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.
+ *
+ * Datasheet: http://cds.linear.com/docs/en/datasheet/2485fd.pdf
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+/* Power-on configuration: rejects both 50/60Hz, operates at 1x speed */
+#define LTC2485_CONFIG_DEFAULT		0
+
+struct ltc2485_data {
+	struct i2c_client	*client;
+	ktime_t			time_prev;	/* last conversion */
+};
+
+static void ltc2485_wait_conv(struct ltc2485_data *data)
+{
+	const unsigned int conv_time = 147;	/* conversion time ms */
+	unsigned int time_elapsed;
+
+	/* delay if conversion time not passed since last read or write */
+	time_elapsed = ktime_ms_delta(ktime_get(), data->time_prev);
+
+	if (time_elapsed < conv_time)
+		msleep(conv_time - time_elapsed);
+}
+
+static int ltc2485_read(struct ltc2485_data *data, int *val)
+{
+	struct i2c_client *client = data->client;
+	__be32 buf = 0;
+	int ret;
+
+	ltc2485_wait_conv(data);
+
+	ret = i2c_master_recv(client, (char *)&buf, 4);
+	if (ret < 0)  {
+		dev_err(&client->dev, "i2c_master_recv failed\n");
+		return ret;
+	}
+	data->time_prev = ktime_get();
+	*val = sign_extend32(be32_to_cpu(buf) >> 6, 24);
+
+	return ret;
+}
+
+static int ltc2485_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct ltc2485_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (mask == IIO_CHAN_INFO_RAW) {
+		ret = ltc2485_read(data, val);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+
+	} else if (mask == IIO_CHAN_INFO_SCALE) {
+		*val = 5000;			/* on board vref millivolts */
+		*val2 = 25;			/* 25 (24 + sign) data bits */
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	} else {
+		return -EINVAL;
+	}
+}
+
+static const struct iio_chan_spec ltc2485_channel[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)
+	},
+};
+
+static const struct iio_info ltc2485_info = {
+	.read_raw = ltc2485_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int ltc2485_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct ltc2485_data *data;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
+				     I2C_FUNC_SMBUS_WRITE_BYTE))
+		return -EOPNOTSUPP;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = id->name;
+	indio_dev->info = &ltc2485_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ltc2485_channel;
+	indio_dev->num_channels = ARRAY_SIZE(ltc2485_channel);
+
+	ret = i2c_smbus_write_byte(data->client, LTC2485_CONFIG_DEFAULT);
+	if (ret < 0)
+		return ret;
+
+	data->time_prev = ktime_get();
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id ltc2485_id[] = {
+	{ "ltc2485", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ltc2485_id);
+
+static struct i2c_driver ltc2485_driver = {
+	.driver = {
+		.name = "ltc2485",
+	},
+	.probe = ltc2485_probe,
+	.id_table = ltc2485_id,
+};
+module_i2c_driver(ltc2485_driver);
+
+MODULE_AUTHOR("Alison Schofield <amsfield22@gmail.com>");
+MODULE_DESCRIPTION("Linear Technology LTC2485 ADC driver");
+MODULE_LICENSE("GPL v2");