iio:pressure: initial zpa2326 barometer support

Introduce driver for Murata ZPA2326 pressure and temperature sensor:
http://www.murata.com/en-us/products/productdetail?partno=ZPA2326-0311A-R

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/pressure/zpa2326.h b/drivers/iio/pressure/zpa2326.h
new file mode 100644
index 0000000..05d3e1e
--- /dev/null
+++ b/drivers/iio/pressure/zpa2326.h
@@ -0,0 +1,89 @@
+/*
+ * Murata ZPA2326 pressure and temperature sensor IIO driver
+ *
+ * Copyright (c) 2016 Parrot S.A.
+ *
+ * Author: Gregor Boirie <gregor.boirie@parrot.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.
+ *
+ * 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.
+ */
+
+#ifndef _ZPA2326_H
+#define _ZPA2326_H
+
+/* Register map. */
+#define ZPA2326_REF_P_XL_REG              (0x8)
+#define ZPA2326_REF_P_L_REG               (0x9)
+#define ZPA2326_REF_P_H_REG               (0xa)
+#define ZPA2326_DEVICE_ID_REG             (0xf)
+#define ZPA2326_DEVICE_ID                 (0xb9)
+#define ZPA2326_RES_CONF_REG              (0x10)
+#define ZPA2326_CTRL_REG0_REG             (0x20)
+#define ZPA2326_CTRL_REG0_ONE_SHOT        BIT(0)
+#define ZPA2326_CTRL_REG0_ENABLE          BIT(1)
+#define ZPA2326_CTRL_REG1_REG             (0x21)
+#define ZPA2326_CTRL_REG1_MASK_DATA_READY BIT(2)
+#define ZPA2326_CTRL_REG2_REG             (0x22)
+#define ZPA2326_CTRL_REG2_SWRESET         BIT(2)
+#define ZPA2326_CTRL_REG3_REG             (0x23)
+#define ZPA2326_CTRL_REG3_ODR_SHIFT       (4)
+#define ZPA2326_CTRL_REG3_ENABLE_MEAS     BIT(7)
+#define ZPA2326_INT_SOURCE_REG            (0x24)
+#define ZPA2326_INT_SOURCE_DATA_READY     BIT(2)
+#define ZPA2326_THS_P_LOW_REG             (0x25)
+#define ZPA2326_THS_P_HIGH_REG            (0x26)
+#define ZPA2326_STATUS_REG                (0x27)
+#define ZPA2326_STATUS_P_DA               BIT(1)
+#define ZPA2326_STATUS_FIFO_E             BIT(2)
+#define ZPA2326_STATUS_P_OR               BIT(5)
+#define ZPA2326_PRESS_OUT_XL_REG          (0x28)
+#define ZPA2326_PRESS_OUT_L_REG           (0x29)
+#define ZPA2326_PRESS_OUT_H_REG           (0x2a)
+#define ZPA2326_TEMP_OUT_L_REG            (0x2b)
+#define ZPA2326_TEMP_OUT_H_REG            (0x2c)
+
+struct device;
+struct regmap;
+
+bool zpa2326_isreg_writeable(struct device *dev, unsigned int reg);
+bool zpa2326_isreg_readable(struct device *dev, unsigned int reg);
+bool zpa2326_isreg_precious(struct device *dev, unsigned int reg);
+
+/**
+ * zpa2326_probe() - Instantiate and register core ZPA2326 IIO device
+ * @parent: Hardware sampling device the created IIO device will be a child of.
+ * @name:   Arbitrary name to identify the device.
+ * @irq:    Interrupt line, negative if none.
+ * @hwid:   Expected device hardware id.
+ * @regmap: Registers map used to abstract underlying bus accesses.
+ *
+ * Return: Zero when successful, a negative error code otherwise.
+ */
+int zpa2326_probe(struct device        *parent,
+		  const char           *name,
+		  int                   irq,
+		  unsigned int          hwid,
+		  struct regmap        *regmap);
+
+/**
+ * zpa2326_remove() - Unregister and destroy core ZPA2326 IIO device.
+ * @parent: Hardware sampling device the IIO device to remove is a child of.
+ */
+void zpa2326_remove(const struct device *parent);
+
+#ifdef CONFIG_PM
+#include <linux/pm.h>
+extern const struct dev_pm_ops zpa2326_pm_ops;
+#define ZPA2326_PM_OPS (&zpa2326_pm_ops)
+#else
+#define ZPA2326_PM_OPS (NULL)
+#endif
+
+#endif