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-rw-r--r--drivers/iio/accel/mma9551_core.c810
1 files changed, 810 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..c34c5ce81
--- /dev/null
+++ b/drivers/iio/accel/mma9551_core.c
@@ -0,0 +1,810 @@
+/*
+ * Common code for Freescale MMA955x Intelligent Sensor Platform drivers
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/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);
+ *val = be16_to_cpu(v);
+
+ return ret;
+}
+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);
+ *val = be16_to_cpu(v);
+
+ return ret;
+}
+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");