Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 377 insertions, 0 deletions

diff --git a/kernel/drivers/iio/dac/ad5504.c b/kernel/drivers/iio/dac/ad5504.c
new file mode 100644
index 000000000..581ec141d
--- /dev/null
+++ b/kernel/drivers/iio/dac/ad5504.c
@@ -0,0 +1,377 @@
+/*
+ * AD5504, AD5501 High Voltage Digital to Analog Converter
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/dac/ad5504.h>
+
+#define AD5504_RES_MASK			GENMASK(11, 0)
+#define AD5504_CMD_READ			BIT(15)
+#define AD5504_CMD_WRITE		0
+#define AD5504_ADDR(addr)		((addr) << 12)
+
+/* Registers */
+#define AD5504_ADDR_NOOP		0
+#define AD5504_ADDR_DAC(x)		((x) + 1)
+#define AD5504_ADDR_ALL_DAC		5
+#define AD5504_ADDR_CTRL		7
+
+/* Control Register */
+#define AD5504_DAC_PWR(ch)		((ch) << 2)
+#define AD5504_DAC_PWRDWN_MODE(mode)	((mode) << 6)
+#define AD5504_DAC_PWRDN_20K		0
+#define AD5504_DAC_PWRDN_3STATE		1
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @spi:			spi_device
+ * @reg:		supply regulator
+ * @vref_mv:		actual reference voltage used
+ * @pwr_down_mask	power down mask
+ * @pwr_down_mode	current power down mode
+ * @data:		transfer buffer
+ */
+struct ad5504_state {
+	struct spi_device		*spi;
+	struct regulator		*reg;
+	unsigned short			vref_mv;
+	unsigned			pwr_down_mask;
+	unsigned			pwr_down_mode;
+
+	__be16				data[2] ____cacheline_aligned;
+};
+
+/**
+ * ad5504_supported_device_ids:
+ */
+
+enum ad5504_supported_device_ids {
+	ID_AD5504,
+	ID_AD5501,
+};
+
+static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val)
+{
+	st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) |
+			      (val & AD5504_RES_MASK));
+
+	return spi_write(st->spi, &st->data[0], 2);
+}
+
+static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
+{
+	int ret;
+	struct spi_transfer t = {
+	    .tx_buf = &st->data[0],
+	    .rx_buf = &st->data[1],
+	    .len = 2,
+	};
+
+	st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
+	ret = spi_sync_transfer(st->spi, &t, 1);
+	if (ret < 0)
+		return ret;
+
+	return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
+}
+
+static int ad5504_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad5504_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		ret = ad5504_spi_read(st, chan->address);
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->vref_mv;
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+	return -EINVAL;
+}
+
+static int ad5504_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct ad5504_state *st = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val >= (1 << chan->scan_type.realbits) || val < 0)
+			return -EINVAL;
+
+		return ad5504_spi_write(st, chan->address, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const char * const ad5504_powerdown_modes[] = {
+	"20kohm_to_gnd",
+	"three_state",
+};
+
+static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan)
+{
+	struct ad5504_state *st = iio_priv(indio_dev);
+
+	return st->pwr_down_mode;
+}
+
+static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, unsigned int mode)
+{
+	struct ad5504_state *st = iio_priv(indio_dev);
+
+	st->pwr_down_mode = mode;
+
+	return 0;
+}
+
+static const struct iio_enum ad5504_powerdown_mode_enum = {
+	.items = ad5504_powerdown_modes,
+	.num_items = ARRAY_SIZE(ad5504_powerdown_modes),
+	.get = ad5504_get_powerdown_mode,
+	.set = ad5504_set_powerdown_mode,
+};
+
+static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+	struct ad5504_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n",
+			!(st->pwr_down_mask & (1 << chan->channel)));
+}
+
+static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
+	size_t len)
+{
+	bool pwr_down;
+	int ret;
+	struct ad5504_state *st = iio_priv(indio_dev);
+
+	ret = strtobool(buf, &pwr_down);
+	if (ret)
+		return ret;
+
+	if (pwr_down)
+		st->pwr_down_mask |= (1 << chan->channel);
+	else
+		st->pwr_down_mask &= ~(1 << chan->channel);
+
+	ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
+				AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
+				AD5504_DAC_PWR(st->pwr_down_mask));
+
+	/* writes to the CTRL register must be followed by a NOOP */
+	ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);
+
+	return ret ? ret : len;
+}
+
+static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
+static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
+
+static struct attribute *ad5504_ev_attributes[] = {
+	&iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
+	&iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group ad5504_ev_attribute_group = {
+	.attrs = ad5504_ev_attributes,
+	.name = "events",
+};
+
+static irqreturn_t ad5504_event_handler(int irq, void *private)
+{
+	iio_push_event(private,
+		       IIO_UNMOD_EVENT_CODE(IIO_TEMP,
+					    0,
+					    IIO_EV_TYPE_THRESH,
+					    IIO_EV_DIR_RISING),
+		       iio_get_time_ns());
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info ad5504_info = {
+	.write_raw = ad5504_write_raw,
+	.read_raw = ad5504_read_raw,
+	.event_attrs = &ad5504_ev_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
+	{
+		.name = "powerdown",
+		.read = ad5504_read_dac_powerdown,
+		.write = ad5504_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
+	},
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5504_powerdown_mode_enum),
+	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
+	{ },
+};
+
+#define AD5504_CHANNEL(_chan) { \
+	.type = IIO_VOLTAGE, \
+	.indexed = 1, \
+	.output = 1, \
+	.channel = (_chan), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.address = AD5504_ADDR_DAC(_chan), \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 12, \
+		.storagebits = 16, \
+	}, \
+	.ext_info = ad5504_ext_info, \
+}
+
+static const struct iio_chan_spec ad5504_channels[] = {
+	AD5504_CHANNEL(0),
+	AD5504_CHANNEL(1),
+	AD5504_CHANNEL(2),
+	AD5504_CHANNEL(3),
+};
+
+static int ad5504_probe(struct spi_device *spi)
+{
+	struct ad5504_platform_data *pdata = spi->dev.platform_data;
+	struct iio_dev *indio_dev;
+	struct ad5504_state *st;
+	struct regulator *reg;
+	int ret, voltage_uv = 0;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+	reg = devm_regulator_get(&spi->dev, "vcc");
+	if (!IS_ERR(reg)) {
+		ret = regulator_enable(reg);
+		if (ret)
+			return ret;
+
+		ret = regulator_get_voltage(reg);
+		if (ret < 0)
+			goto error_disable_reg;
+
+		voltage_uv = ret;
+	}
+
+	spi_set_drvdata(spi, indio_dev);
+	st = iio_priv(indio_dev);
+	if (voltage_uv)
+		st->vref_mv = voltage_uv / 1000;
+	else if (pdata)
+		st->vref_mv = pdata->vref_mv;
+	else
+		dev_warn(&spi->dev, "reference voltage unspecified\n");
+
+	st->reg = reg;
+	st->spi = spi;
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(st->spi)->name;
+	indio_dev->info = &ad5504_info;
+	if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
+		indio_dev->num_channels = 1;
+	else
+		indio_dev->num_channels = 4;
+	indio_dev->channels = ad5504_channels;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	if (spi->irq) {
+		ret = devm_request_threaded_irq(&spi->dev, spi->irq,
+					   NULL,
+					   &ad5504_event_handler,
+					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					   spi_get_device_id(st->spi)->name,
+					   indio_dev);
+		if (ret)
+			goto error_disable_reg;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_disable_reg;
+
+	return 0;
+
+error_disable_reg:
+	if (!IS_ERR(reg))
+		regulator_disable(reg);
+
+	return ret;
+}
+
+static int ad5504_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad5504_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+
+	return 0;
+}
+
+static const struct spi_device_id ad5504_id[] = {
+	{"ad5504", ID_AD5504},
+	{"ad5501", ID_AD5501},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad5504_id);
+
+static struct spi_driver ad5504_driver = {
+	.driver = {
+		   .name = "ad5504",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = ad5504_probe,
+	.remove = ad5504_remove,
+	.id_table = ad5504_id,
+};
+module_spi_driver(ad5504_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
+MODULE_LICENSE("GPL v2");