Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 808 insertions, 0 deletions

diff --git a/drivers/iio/accel/mma9551_core.c b/drivers/iio/accel/mma9551_core.c
new file mode 100644
index 000000000..9bb5c2fea
--- /dev/null
+++ b/drivers/iio/accel/mma9551_core.c
@@ -0,0 +1,808 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Common code for Freescale MMA955x Intelligent Sensor Platform drivers
+ * Copyright (c) 2014, Intel Corporation.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/pm_runtime.h>
+#include "mma9551_core.h"
+
+/* Command masks for mailbox write command */
+#define MMA9551_CMD_READ_VERSION_INFO	0x00
+#define MMA9551_CMD_READ_CONFIG		0x10
+#define MMA9551_CMD_WRITE_CONFIG	0x20
+#define MMA9551_CMD_READ_STATUS		0x30
+
+/* Mailbox read command */
+#define MMA9551_RESPONSE_COCO		BIT(7)
+
+/* Error-Status codes returned in mailbox read command */
+#define MMA9551_MCI_ERROR_NONE			0x00
+#define MMA9551_MCI_ERROR_PARAM			0x04
+#define MMA9551_MCI_INVALID_COUNT		0x19
+#define MMA9551_MCI_ERROR_COMMAND		0x1C
+#define MMA9551_MCI_ERROR_INVALID_LENGTH	0x21
+#define MMA9551_MCI_ERROR_FIFO_BUSY		0x22
+#define MMA9551_MCI_ERROR_FIFO_ALLOCATED	0x23
+#define MMA9551_MCI_ERROR_FIFO_OVERSIZE		0x24
+
+/* GPIO Application */
+#define MMA9551_GPIO_POL_MSB		0x08
+#define MMA9551_GPIO_POL_LSB		0x09
+
+/* Sleep/Wake application */
+#define MMA9551_SLEEP_CFG		0x06
+#define MMA9551_SLEEP_CFG_SNCEN		BIT(0)
+#define MMA9551_SLEEP_CFG_FLEEN		BIT(1)
+#define MMA9551_SLEEP_CFG_SCHEN		BIT(2)
+
+/* AFE application */
+#define MMA9551_AFE_X_ACCEL_REG		0x00
+#define MMA9551_AFE_Y_ACCEL_REG		0x02
+#define MMA9551_AFE_Z_ACCEL_REG		0x04
+
+/* Reset/Suspend/Clear application */
+#define MMA9551_RSC_RESET		0x00
+#define MMA9551_RSC_OFFSET(mask)	(3 - (ffs(mask) - 1) / 8)
+#define MMA9551_RSC_VAL(mask)		(mask >> (((ffs(mask) - 1) / 8) * 8))
+
+/*
+ * A response is composed of:
+ * - control registers: MB0-3
+ * - data registers: MB4-31
+ *
+ * A request is composed of:
+ * - mbox to write to (always 0)
+ * - control registers: MB1-4
+ * - data registers: MB5-31
+ */
+#define MMA9551_MAILBOX_CTRL_REGS	4
+#define MMA9551_MAX_MAILBOX_DATA_REGS	28
+#define MMA9551_MAILBOX_REGS		32
+
+#define MMA9551_I2C_READ_RETRIES	5
+#define MMA9551_I2C_READ_DELAY	50	/* us */
+
+struct mma9551_mbox_request {
+	u8 start_mbox;		/* Always 0. */
+	u8 app_id;
+	/*
+	 * See Section 5.3.1 of the MMA955xL Software Reference Manual.
+	 *
+	 * Bit 7: reserved, always 0
+	 * Bits 6-4: command
+	 * Bits 3-0: upper bits of register offset
+	 */
+	u8 cmd_off;
+	u8 lower_off;
+	u8 nbytes;
+	u8 buf[MMA9551_MAX_MAILBOX_DATA_REGS - 1];
+} __packed;
+
+struct mma9551_mbox_response {
+	u8 app_id;
+	/*
+	 * See Section 5.3.3 of the MMA955xL Software Reference Manual.
+	 *
+	 * Bit 7: COCO
+	 * Bits 6-0: Error code.
+	 */
+	u8 coco_err;
+	u8 nbytes;
+	u8 req_bytes;
+	u8 buf[MMA9551_MAX_MAILBOX_DATA_REGS];
+} __packed;
+
+struct mma9551_version_info {
+	__be32 device_id;
+	u8 rom_version[2];
+	u8 fw_version[2];
+	u8 hw_version[2];
+	u8 fw_build[2];
+};
+
+static int mma9551_transfer(struct i2c_client *client,
+			    u8 app_id, u8 command, u16 offset,
+			    u8 *inbytes, int num_inbytes,
+			    u8 *outbytes, int num_outbytes)
+{
+	struct mma9551_mbox_request req;
+	struct mma9551_mbox_response rsp;
+	struct i2c_msg in, out;
+	u8 req_len, err_code;
+	int ret, retries;
+
+	if (offset >= 1 << 12) {
+		dev_err(&client->dev, "register offset too large\n");
+		return -EINVAL;
+	}
+
+	req_len = 1 + MMA9551_MAILBOX_CTRL_REGS + num_inbytes;
+	req.start_mbox = 0;
+	req.app_id = app_id;
+	req.cmd_off = command | (offset >> 8);
+	req.lower_off = offset;
+
+	if (command == MMA9551_CMD_WRITE_CONFIG)
+		req.nbytes = num_inbytes;
+	else
+		req.nbytes = num_outbytes;
+	if (num_inbytes)
+		memcpy(req.buf, inbytes, num_inbytes);
+
+	out.addr = client->addr;
+	out.flags = 0;
+	out.len = req_len;
+	out.buf = (u8 *)&req;
+
+	ret = i2c_transfer(client->adapter, &out, 1);
+	if (ret < 0) {
+		dev_err(&client->dev, "i2c write failed\n");
+		return ret;
+	}
+
+	retries = MMA9551_I2C_READ_RETRIES;
+	do {
+		udelay(MMA9551_I2C_READ_DELAY);
+
+		in.addr = client->addr;
+		in.flags = I2C_M_RD;
+		in.len = sizeof(rsp);
+		in.buf = (u8 *)&rsp;
+
+		ret = i2c_transfer(client->adapter, &in, 1);
+		if (ret < 0) {
+			dev_err(&client->dev, "i2c read failed\n");
+			return ret;
+		}
+
+		if (rsp.coco_err & MMA9551_RESPONSE_COCO)
+			break;
+	} while (--retries > 0);
+
+	if (retries == 0) {
+		dev_err(&client->dev,
+			"timed out while waiting for command response\n");
+		return -ETIMEDOUT;
+	}
+
+	if (rsp.app_id != app_id) {
+		dev_err(&client->dev,
+			"app_id mismatch in response got %02x expected %02x\n",
+			rsp.app_id, app_id);
+		return -EINVAL;
+	}
+
+	err_code = rsp.coco_err & ~MMA9551_RESPONSE_COCO;
+	if (err_code != MMA9551_MCI_ERROR_NONE) {
+		dev_err(&client->dev, "read returned error %x\n", err_code);
+		return -EINVAL;
+	}
+
+	if (rsp.nbytes != rsp.req_bytes) {
+		dev_err(&client->dev,
+			"output length mismatch got %d expected %d\n",
+			rsp.nbytes, rsp.req_bytes);
+		return -EINVAL;
+	}
+
+	if (num_outbytes)
+		memcpy(outbytes, rsp.buf, num_outbytes);
+
+	return 0;
+}
+
+/**
+ * mma9551_read_config_byte() - read 1 configuration byte
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @val:	Pointer to store value read
+ *
+ * Read one configuration byte from the device using MMA955xL command format.
+ * Commands to the MMA955xL platform consist of a write followed
+ * by one or more reads.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_config_byte(struct i2c_client *client, u8 app_id,
+			     u16 reg, u8 *val)
+{
+	return mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
+				reg, NULL, 0, val, 1);
+}
+EXPORT_SYMBOL(mma9551_read_config_byte);
+
+/**
+ * mma9551_write_config_byte() - write 1 configuration byte
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @val:	Value to write
+ *
+ * Write one configuration byte from the device using MMA955xL command format.
+ * Commands to the MMA955xL platform consist of a write followed by one or
+ * more reads.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_write_config_byte(struct i2c_client *client, u8 app_id,
+			      u16 reg, u8 val)
+{
+	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG, reg,
+				&val, 1, NULL, 0);
+}
+EXPORT_SYMBOL(mma9551_write_config_byte);
+
+/**
+ * mma9551_read_status_byte() - read 1 status byte
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @val:	Pointer to store value read
+ *
+ * Read one status byte from the device using MMA955xL command format.
+ * Commands to the MMA955xL platform consist of a write followed by one or
+ * more reads.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_status_byte(struct i2c_client *client, u8 app_id,
+			     u16 reg, u8 *val)
+{
+	return mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
+				reg, NULL, 0, val, 1);
+}
+EXPORT_SYMBOL(mma9551_read_status_byte);
+
+/**
+ * mma9551_read_config_word() - read 1 config word
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @val:	Pointer to store value read
+ *
+ * Read one configuration word from the device using MMA955xL command format.
+ * Commands to the MMA955xL platform consist of a write followed by one or
+ * more reads.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_config_word(struct i2c_client *client, u8 app_id,
+			     u16 reg, u16 *val)
+{
+	int ret;
+	__be16 v;
+
+	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
+			       reg, NULL, 0, (u8 *)&v, 2);
+	if (ret < 0)
+		return ret;
+
+	*val = be16_to_cpu(v);
+
+	return 0;
+}
+EXPORT_SYMBOL(mma9551_read_config_word);
+
+/**
+ * mma9551_write_config_word() - write 1 config word
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @val:	Value to write
+ *
+ * Write one configuration word from the device using MMA955xL command format.
+ * Commands to the MMA955xL platform consist of a write followed by one or
+ * more reads.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_write_config_word(struct i2c_client *client, u8 app_id,
+			      u16 reg, u16 val)
+{
+	__be16 v = cpu_to_be16(val);
+
+	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG, reg,
+				(u8 *)&v, 2, NULL, 0);
+}
+EXPORT_SYMBOL(mma9551_write_config_word);
+
+/**
+ * mma9551_read_status_word() - read 1 status word
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @val:	Pointer to store value read
+ *
+ * Read one status word from the device using MMA955xL command format.
+ * Commands to the MMA955xL platform consist of a write followed by one or
+ * more reads.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_status_word(struct i2c_client *client, u8 app_id,
+			     u16 reg, u16 *val)
+{
+	int ret;
+	__be16 v;
+
+	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
+			       reg, NULL, 0, (u8 *)&v, 2);
+	if (ret < 0)
+		return ret;
+
+	*val = be16_to_cpu(v);
+
+	return 0;
+}
+EXPORT_SYMBOL(mma9551_read_status_word);
+
+/**
+ * mma9551_read_config_words() - read multiple config words
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @len:	Length of array to read (in words)
+ * @buf:	Array of words to read
+ *
+ * Read multiple configuration registers (word-sized registers).
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_config_words(struct i2c_client *client, u8 app_id,
+			      u16 reg, u8 len, u16 *buf)
+{
+	int ret, i;
+	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];
+
+	if (len > ARRAY_SIZE(be_buf)) {
+		dev_err(&client->dev, "Invalid buffer size %d\n", len);
+		return -EINVAL;
+	}
+
+	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
+			       reg, NULL, 0, (u8 *)be_buf, len * sizeof(u16));
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < len; i++)
+		buf[i] = be16_to_cpu(be_buf[i]);
+
+	return 0;
+}
+EXPORT_SYMBOL(mma9551_read_config_words);
+
+/**
+ * mma9551_read_status_words() - read multiple status words
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @len:	Length of array to read (in words)
+ * @buf:	Array of words to read
+ *
+ * Read multiple status registers (word-sized registers).
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_status_words(struct i2c_client *client, u8 app_id,
+			      u16 reg, u8 len, u16 *buf)
+{
+	int ret, i;
+	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];
+
+	if (len > ARRAY_SIZE(be_buf)) {
+		dev_err(&client->dev, "Invalid buffer size %d\n", len);
+		return -EINVAL;
+	}
+
+	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
+			       reg, NULL, 0, (u8 *)be_buf, len * sizeof(u16));
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < len; i++)
+		buf[i] = be16_to_cpu(be_buf[i]);
+
+	return 0;
+}
+EXPORT_SYMBOL(mma9551_read_status_words);
+
+/**
+ * mma9551_write_config_words() - write multiple config words
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @len:	Length of array to write (in words)
+ * @buf:	Array of words to write
+ *
+ * Write multiple configuration registers (word-sized registers).
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_write_config_words(struct i2c_client *client, u8 app_id,
+			       u16 reg, u8 len, u16 *buf)
+{
+	int i;
+	__be16 be_buf[(MMA9551_MAX_MAILBOX_DATA_REGS - 1) / 2];
+
+	if (len > ARRAY_SIZE(be_buf)) {
+		dev_err(&client->dev, "Invalid buffer size %d\n", len);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < len; i++)
+		be_buf[i] = cpu_to_be16(buf[i]);
+
+	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG,
+				reg, (u8 *)be_buf, len * sizeof(u16), NULL, 0);
+}
+EXPORT_SYMBOL(mma9551_write_config_words);
+
+/**
+ * mma9551_update_config_bits() - update bits in register
+ * @client:	I2C client
+ * @app_id:	Application ID
+ * @reg:	Application register
+ * @mask:	Mask for the bits to update
+ * @val:	Value of the bits to update
+ *
+ * Update bits in the given register using a bit mask.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_update_config_bits(struct i2c_client *client, u8 app_id,
+			       u16 reg, u8 mask, u8 val)
+{
+	int ret;
+	u8 tmp, orig;
+
+	ret = mma9551_read_config_byte(client, app_id, reg, &orig);
+	if (ret < 0)
+		return ret;
+
+	tmp = orig & ~mask;
+	tmp |= val & mask;
+
+	if (tmp == orig)
+		return 0;
+
+	return mma9551_write_config_byte(client, app_id, reg, tmp);
+}
+EXPORT_SYMBOL(mma9551_update_config_bits);
+
+/**
+ * mma9551_gpio_config() - configure gpio
+ * @client:	I2C client
+ * @pin:	GPIO pin to configure
+ * @app_id:	Application ID
+ * @bitnum:	Bit number of status register being assigned to the GPIO pin.
+ * @polarity:	The polarity parameter is described in section 6.2.2, page 66,
+ *		of the Software Reference Manual.  Basically, polarity=0 means
+ *		the interrupt line has the same value as the selected bit,
+ *		while polarity=1 means the line is inverted.
+ *
+ * Assign a bit from an application’s status register to a specific GPIO pin.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_gpio_config(struct i2c_client *client, enum mma9551_gpio_pin pin,
+			u8 app_id, u8 bitnum, int polarity)
+{
+	u8 reg, pol_mask, pol_val;
+	int ret;
+
+	if (pin > mma9551_gpio_max) {
+		dev_err(&client->dev, "bad GPIO pin\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Pin 6 is configured by regs 0x00 and 0x01, pin 7 by 0x02 and
+	 * 0x03, and so on.
+	 */
+	reg = pin * 2;
+
+	ret = mma9551_write_config_byte(client, MMA9551_APPID_GPIO,
+					reg, app_id);
+	if (ret < 0) {
+		dev_err(&client->dev, "error setting GPIO app_id\n");
+		return ret;
+	}
+
+	ret = mma9551_write_config_byte(client, MMA9551_APPID_GPIO,
+					reg + 1, bitnum);
+	if (ret < 0) {
+		dev_err(&client->dev, "error setting GPIO bit number\n");
+		return ret;
+	}
+
+	switch (pin) {
+	case mma9551_gpio6:
+		reg = MMA9551_GPIO_POL_LSB;
+		pol_mask = 1 << 6;
+		break;
+	case mma9551_gpio7:
+		reg = MMA9551_GPIO_POL_LSB;
+		pol_mask = 1 << 7;
+		break;
+	case mma9551_gpio8:
+		reg = MMA9551_GPIO_POL_MSB;
+		pol_mask = 1 << 0;
+		break;
+	case mma9551_gpio9:
+		reg = MMA9551_GPIO_POL_MSB;
+		pol_mask = 1 << 1;
+		break;
+	}
+	pol_val = polarity ? pol_mask : 0;
+
+	ret = mma9551_update_config_bits(client, MMA9551_APPID_GPIO, reg,
+					 pol_mask, pol_val);
+	if (ret < 0)
+		dev_err(&client->dev, "error setting GPIO polarity\n");
+
+	return ret;
+}
+EXPORT_SYMBOL(mma9551_gpio_config);
+
+/**
+ * mma9551_read_version() - read device version information
+ * @client:	I2C client
+ *
+ * Read version information and print device id and firmware version.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_read_version(struct i2c_client *client)
+{
+	struct mma9551_version_info info;
+	int ret;
+
+	ret = mma9551_transfer(client, MMA9551_APPID_VERSION, 0x00, 0x00,
+			       NULL, 0, (u8 *)&info, sizeof(info));
+	if (ret < 0)
+		return ret;
+
+	dev_info(&client->dev, "device ID 0x%x, firmware version %02x.%02x\n",
+		 be32_to_cpu(info.device_id), info.fw_version[0],
+		 info.fw_version[1]);
+
+	return 0;
+}
+EXPORT_SYMBOL(mma9551_read_version);
+
+/**
+ * mma9551_set_device_state() - sets HW power mode
+ * @client:	I2C client
+ * @enable:	Use true to power on device, false to cause the device
+ *		to enter sleep.
+ *
+ * Set power on/off for device using the Sleep/Wake Application.
+ * When enable is true, power on chip and enable doze mode.
+ * When enable is false, enter sleep mode (device remains in the
+ * lowest-power mode).
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_set_device_state(struct i2c_client *client, bool enable)
+{
+	return mma9551_update_config_bits(client, MMA9551_APPID_SLEEP_WAKE,
+					  MMA9551_SLEEP_CFG,
+					  MMA9551_SLEEP_CFG_SNCEN |
+					  MMA9551_SLEEP_CFG_FLEEN |
+					  MMA9551_SLEEP_CFG_SCHEN,
+					  enable ? MMA9551_SLEEP_CFG_SCHEN |
+					  MMA9551_SLEEP_CFG_FLEEN :
+					  MMA9551_SLEEP_CFG_SNCEN);
+}
+EXPORT_SYMBOL(mma9551_set_device_state);
+
+/**
+ * mma9551_set_power_state() - sets runtime PM state
+ * @client:	I2C client
+ * @on:		Use true to power on device, false to power off
+ *
+ * Resume or suspend the device using Runtime PM.
+ * The device will suspend after the autosuspend delay.
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_set_power_state(struct i2c_client *client, bool on)
+{
+#ifdef CONFIG_PM
+	int ret;
+
+	if (on)
+		ret = pm_runtime_get_sync(&client->dev);
+	else {
+		pm_runtime_mark_last_busy(&client->dev);
+		ret = pm_runtime_put_autosuspend(&client->dev);
+	}
+
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"failed to change power state to %d\n", on);
+		if (on)
+			pm_runtime_put_noidle(&client->dev);
+
+		return ret;
+	}
+#endif
+
+	return 0;
+}
+EXPORT_SYMBOL(mma9551_set_power_state);
+
+/**
+ * mma9551_sleep() - sleep
+ * @freq:	Application frequency
+ *
+ * Firmware applications run at a certain frequency on the
+ * device. Sleep for one application cycle to make sure the
+ * application had time to run once and initialize set values.
+ */
+void mma9551_sleep(int freq)
+{
+	int sleep_val = 1000 / freq;
+
+	if (sleep_val < 20)
+		usleep_range(sleep_val * 1000, 20000);
+	else
+		msleep_interruptible(sleep_val);
+}
+EXPORT_SYMBOL(mma9551_sleep);
+
+/**
+ * mma9551_read_accel_chan() - read accelerometer channel
+ * @client:	I2C client
+ * @chan:	IIO channel
+ * @val:	Pointer to the accelerometer value read
+ * @val2:	Unused
+ *
+ * Read accelerometer value for the specified channel.
+ *
+ * Locking note: This function must be called with the device lock held.
+ * Locking is not handled inside the function. Callers should ensure they
+ * serialize access to the HW.
+ *
+ * Returns: IIO_VAL_INT on success, negative value on failure.
+ */
+int mma9551_read_accel_chan(struct i2c_client *client,
+			    const struct iio_chan_spec *chan,
+			    int *val, int *val2)
+{
+	u16 reg_addr;
+	s16 raw_accel;
+	int ret;
+
+	switch (chan->channel2) {
+	case IIO_MOD_X:
+		reg_addr = MMA9551_AFE_X_ACCEL_REG;
+		break;
+	case IIO_MOD_Y:
+		reg_addr = MMA9551_AFE_Y_ACCEL_REG;
+		break;
+	case IIO_MOD_Z:
+		reg_addr = MMA9551_AFE_Z_ACCEL_REG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = mma9551_set_power_state(client, true);
+	if (ret < 0)
+		return ret;
+
+	ret = mma9551_read_status_word(client, MMA9551_APPID_AFE,
+				       reg_addr, &raw_accel);
+	if (ret < 0)
+		goto out_poweroff;
+
+	*val = raw_accel;
+
+	ret = IIO_VAL_INT;
+
+out_poweroff:
+	mma9551_set_power_state(client, false);
+	return ret;
+}
+EXPORT_SYMBOL(mma9551_read_accel_chan);
+
+/**
+ * mma9551_read_accel_scale() - read accelerometer scale
+ * @val:	Pointer to the accelerometer scale (int value)
+ * @val2:	Pointer to the accelerometer scale (micro value)
+ *
+ * Read accelerometer scale.
+ *
+ * Returns: IIO_VAL_INT_PLUS_MICRO.
+ */
+int mma9551_read_accel_scale(int *val, int *val2)
+{
+	*val = 0;
+	*val2 = 2440;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+EXPORT_SYMBOL(mma9551_read_accel_scale);
+
+/**
+ * mma9551_app_reset() - reset application
+ * @client:	I2C client
+ * @app_mask:	Application to reset
+ *
+ * Reset the given application (using the Reset/Suspend/Clear
+ * Control Application)
+ *
+ * Returns: 0 on success, negative value on failure.
+ */
+int mma9551_app_reset(struct i2c_client *client, u32 app_mask)
+{
+	return mma9551_write_config_byte(client, MMA9551_APPID_RSC,
+					 MMA9551_RSC_RESET +
+					 MMA9551_RSC_OFFSET(app_mask),
+					 MMA9551_RSC_VAL(app_mask));
+}
+EXPORT_SYMBOL(mma9551_app_reset);
+
+MODULE_AUTHOR("Irina Tirdea <irina.tirdea@intel.com>");
+MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MMA955xL sensors core");