Merge tag 'staging-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver tree changes from Greg KH:
 "Here's the big drivers/staging/ update for 3.14-rc1

  Lots and lots of cleanups, IIO driver updates are also mixed in here
  due to the subsystem still crossing staging and drivers/iio/, and the
  dwc2 driver is moved out of staging.  There's a new driver (rts5208),
  which ends up making us adding more lines than removing, but overall
  there was lots of work toward moving code out of here, which was good

  All of this has been in linux-next with no reported issues"

* tag 'staging-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1084 commits)
  lustre: delete linux/lustre_debug.h
  staging: lustre: remove some unused debug macros
  usb: dwc2: move device tree bindings doc to correct place
  staging: vt6656: sparse fixes: iwctl_giwgenie use memcpy.
  staging: vt6656: sparse fixes: iwctl_siwgenie use memcpy.
  staging: vt6656: sparse fixes ethtool_ioctl Use struct ifreq *
  staging: vt6656: sparse fixes: dpc.c missing dpc.h
  staging: lustre: libcfs_debug: small whitespace cleanups
  staging: lustre: libcfs_debug.h: remove extra blank lines
  staging: lustre: libcfs_debug.h: Align backslashes in macros
  staging: lustre: libcfs_debug.h: align define values
  staging: tidspbridge: adjust error return code (bugfix)
  Staging: rts5139: rts51x_card: fixed style issues
  staging: wlags49_h2: Fix "do not use C99 //" in wl_cs.h, wl_enc.h wl_main.h and wl_wext.h
  Staging: rtl8188eu: Fixed "foo * bar" related coding style issues
  Staging: rtl8188eu: Fixed required spaces after ',' and around '=' and '=='
  staging: vt6655: Fix memory leak in wpa_ioctl()
  imx-drm: parallel-display: honor 'native-mode' property when selecting video mode from DT
  staging: drm/imx: don't drop crtc offsets when doing pageflip
  staging: drm/imx: handle framebuffer offsets correctly
  ...

1 files changed, 294 insertions, 0 deletions

diff --git a/drivers/iio/humidity/dht11.c b/drivers/iio/humidity/dht11.c
new file mode 100644
index 000000000000..d8771f546bf2
--- /dev/null
+++ b/drivers/iio/humidity/dht11.c
@@ -0,0 +1,294 @@
+/*
+ * DHT11/DHT22 bit banging GPIO driver
+ *
+ * Copyright (c) Harald Geyer <harald@ccbib.org>
+ *
+ * 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/err.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/sysfs.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+#include <linux/iio/iio.h>
+
+#define DRIVER_NAME	"dht11"
+
+#define DHT11_DATA_VALID_TIME	2000000000  /* 2s in ns */
+
+#define DHT11_EDGES_PREAMBLE 4
+#define DHT11_BITS_PER_READ 40
+#define DHT11_EDGES_PER_READ (2*DHT11_BITS_PER_READ + DHT11_EDGES_PREAMBLE + 1)
+
+/* Data transmission timing (nano seconds) */
+#define DHT11_START_TRANSMISSION	18  /* ms */
+#define DHT11_SENSOR_RESPONSE	80000
+#define DHT11_START_BIT		50000
+#define DHT11_DATA_BIT_LOW	27000
+#define DHT11_DATA_BIT_HIGH	70000
+
+struct dht11 {
+	struct device			*dev;
+
+	int				gpio;
+	int				irq;
+
+	struct completion		completion;
+
+	s64				timestamp;
+	int				temperature;
+	int				humidity;
+
+	/* num_edges: -1 means "no transmission in progress" */
+	int				num_edges;
+	struct {s64 ts; int value; }	edges[DHT11_EDGES_PER_READ];
+};
+
+static unsigned char dht11_decode_byte(int *timing, int threshold)
+{
+	unsigned char ret = 0;
+	int i;
+
+	for (i = 0; i < 8; ++i) {
+		ret <<= 1;
+		if (timing[i] >= threshold)
+			++ret;
+	}
+
+	return ret;
+}
+
+static int dht11_decode(struct dht11 *dht11, int offset)
+{
+	int i, t, timing[DHT11_BITS_PER_READ], threshold,
+		timeres = DHT11_SENSOR_RESPONSE;
+	unsigned char temp_int, temp_dec, hum_int, hum_dec, checksum;
+
+	/* Calculate timestamp resolution */
+	for (i = 0; i < dht11->num_edges; ++i) {
+		t = dht11->edges[i].ts - dht11->edges[i-1].ts;
+		if (t > 0 && t < timeres)
+			timeres = t;
+	}
+	if (2*timeres > DHT11_DATA_BIT_HIGH) {
+		pr_err("dht11: timeresolution %d too bad for decoding\n",
+			timeres);
+		return -EIO;
+	}
+	threshold = DHT11_DATA_BIT_HIGH / timeres;
+	if (DHT11_DATA_BIT_LOW/timeres + 1 >= threshold)
+		pr_err("dht11: WARNING: decoding ambiguous\n");
+
+	/* scale down with timeres and check validity */
+	for (i = 0; i < DHT11_BITS_PER_READ; ++i) {
+		t = dht11->edges[offset + 2*i + 2].ts -
+			dht11->edges[offset + 2*i + 1].ts;
+		if (!dht11->edges[offset + 2*i + 1].value)
+			return -EIO;  /* lost synchronisation */
+		timing[i] = t / timeres;
+	}
+
+	hum_int = dht11_decode_byte(timing, threshold);
+	hum_dec = dht11_decode_byte(&timing[8], threshold);
+	temp_int = dht11_decode_byte(&timing[16], threshold);
+	temp_dec = dht11_decode_byte(&timing[24], threshold);
+	checksum = dht11_decode_byte(&timing[32], threshold);
+
+	if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum)
+		return -EIO;
+
+	dht11->timestamp = iio_get_time_ns();
+	if (hum_int < 20) {  /* DHT22 */
+		dht11->temperature = (((temp_int & 0x7f) << 8) + temp_dec) *
+					((temp_int & 0x80) ? -100 : 100);
+		dht11->humidity = ((hum_int << 8) + hum_dec) * 100;
+	} else if (temp_dec == 0 && hum_dec == 0) {  /* DHT11 */
+		dht11->temperature = temp_int * 1000;
+		dht11->humidity = hum_int * 1000;
+	} else {
+		dev_err(dht11->dev,
+			"Don't know how to decode data: %d %d %d %d\n",
+			hum_int, hum_dec, temp_int, temp_dec);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int dht11_read_raw(struct iio_dev *iio_dev,
+			const struct iio_chan_spec *chan,
+			int *val, int *val2, long m)
+{
+	struct dht11 *dht11 = iio_priv(iio_dev);
+	int ret;
+
+	if (dht11->timestamp + DHT11_DATA_VALID_TIME < iio_get_time_ns()) {
+		reinit_completion(&dht11->completion);
+
+		dht11->num_edges = 0;
+		ret = gpio_direction_output(dht11->gpio, 0);
+		if (ret)
+			goto err;
+		msleep(DHT11_START_TRANSMISSION);
+		ret = gpio_direction_input(dht11->gpio);
+		if (ret)
+			goto err;
+
+		ret = wait_for_completion_killable_timeout(&dht11->completion,
+								 HZ);
+		if (ret == 0 && dht11->num_edges < DHT11_EDGES_PER_READ - 1) {
+			dev_err(&iio_dev->dev,
+					"Only %d signal edges detected\n",
+					dht11->num_edges);
+			ret = -ETIMEDOUT;
+		}
+		if (ret < 0)
+			goto err;
+
+		ret = dht11_decode(dht11,
+				dht11->num_edges == DHT11_EDGES_PER_READ ?
+					DHT11_EDGES_PREAMBLE :
+					DHT11_EDGES_PREAMBLE - 2);
+		if (ret)
+			goto err;
+	}
+
+	ret = IIO_VAL_INT;
+	if (chan->type == IIO_TEMP)
+		*val = dht11->temperature;
+	else if (chan->type == IIO_HUMIDITYRELATIVE)
+		*val = dht11->humidity;
+	else
+		ret = -EINVAL;
+err:
+	dht11->num_edges = -1;
+	return ret;
+}
+
+static const struct iio_info dht11_iio_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= dht11_read_raw,
+};
+
+/*
+ * IRQ handler called on GPIO edges
+*/
+static irqreturn_t dht11_handle_irq(int irq, void *data)
+{
+	struct iio_dev *iio = data;
+	struct dht11 *dht11 = iio_priv(iio);
+
+	/* TODO: Consider making the handler safe for IRQ sharing */
+	if (dht11->num_edges < DHT11_EDGES_PER_READ && dht11->num_edges >= 0) {
+		dht11->edges[dht11->num_edges].ts = iio_get_time_ns();
+		dht11->edges[dht11->num_edges++].value =
+						gpio_get_value(dht11->gpio);
+
+		if (dht11->num_edges >= DHT11_EDGES_PER_READ)
+			complete(&dht11->completion);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_chan_spec dht11_chan_spec[] = {
+	{ .type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), },
+	{ .type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), }
+};
+
+static const struct of_device_id dht11_dt_ids[] = {
+	{ .compatible = "dht11", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, dht11_dt_ids);
+
+static int dht11_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct dht11 *dht11;
+	struct iio_dev *iio;
+	int ret;
+
+	iio = devm_iio_device_alloc(dev, sizeof(*dht11));
+	if (!iio) {
+		dev_err(dev, "Failed to allocate IIO device\n");
+		return -ENOMEM;
+	}
+
+	dht11 = iio_priv(iio);
+	dht11->dev = dev;
+
+	dht11->gpio = ret = of_get_gpio(node, 0);
+	if (ret < 0)
+		return ret;
+	ret = devm_gpio_request_one(dev, dht11->gpio, GPIOF_IN, pdev->name);
+	if (ret)
+		return ret;
+
+	dht11->irq = gpio_to_irq(dht11->gpio);
+	if (dht11->irq < 0) {
+		dev_err(dev, "GPIO %d has no interrupt\n", dht11->gpio);
+		return -EINVAL;
+	}
+	ret = devm_request_irq(dev, dht11->irq, dht11_handle_irq,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				pdev->name, iio);
+	if (ret)
+		return ret;
+
+	dht11->timestamp = iio_get_time_ns() - DHT11_DATA_VALID_TIME - 1;
+	dht11->num_edges = -1;
+
+	platform_set_drvdata(pdev, iio);
+
+	init_completion(&dht11->completion);
+	iio->name = pdev->name;
+	iio->dev.parent = &pdev->dev;
+	iio->info = &dht11_iio_info;
+	iio->modes = INDIO_DIRECT_MODE;
+	iio->channels = dht11_chan_spec;
+	iio->num_channels = ARRAY_SIZE(dht11_chan_spec);
+
+	return devm_iio_device_register(dev, iio);
+}
+
+static struct platform_driver dht11_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = dht11_dt_ids,
+	},
+	.probe  = dht11_probe,
+};
+
+module_platform_driver(dht11_driver);
+
+MODULE_AUTHOR("Harald Geyer <harald@ccbib.org>");
+MODULE_DESCRIPTION("DHT11 humidity/temperature sensor driver");
+MODULE_LICENSE("GPL v2");