path: root/drivers/iio/accel/mma9553.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Freescale MMA9553L Intelligent Pedometer driver
 * Copyright (c) 2014, Intel Corporation.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/pm_runtime.h>
#include "mma9551_core.h"

#define MMA9553_DRV_NAME			"mma9553"
#define MMA9553_IRQ_NAME			"mma9553_event"

/* Pedometer configuration registers (R/W) */
#define MMA9553_REG_CONF_SLEEPMIN		0x00
#define MMA9553_REG_CONF_SLEEPMAX		0x02
#define MMA9553_REG_CONF_SLEEPTHD		0x04
#define MMA9553_MASK_CONF_WORD			GENMASK(15, 0)

#define MMA9553_REG_CONF_CONF_STEPLEN		0x06
#define MMA9553_MASK_CONF_CONFIG		BIT(15)
#define MMA9553_MASK_CONF_ACT_DBCNTM		BIT(14)
#define MMA9553_MASK_CONF_SLP_DBCNTM		BIT(13)
#define MMA9553_MASK_CONF_STEPLEN		GENMASK(7, 0)

#define MMA9553_REG_CONF_HEIGHT_WEIGHT		0x08
#define MMA9553_MASK_CONF_HEIGHT		GENMASK(15, 8)
#define MMA9553_MASK_CONF_WEIGHT		GENMASK(7, 0)

#define MMA9553_REG_CONF_FILTER			0x0A
#define MMA9553_MASK_CONF_FILTSTEP		GENMASK(15, 8)
#define MMA9553_MASK_CONF_MALE			BIT(7)
#define MMA9553_MASK_CONF_FILTTIME		GENMASK(6, 0)

#define MMA9553_REG_CONF_SPEED_STEP		0x0C
#define MMA9553_MASK_CONF_SPDPRD		GENMASK(15, 8)
#define MMA9553_MASK_CONF_STEPCOALESCE		GENMASK(7, 0)

#define MMA9553_REG_CONF_ACTTHD			0x0E
#define MMA9553_MAX_ACTTHD			GENMASK(15, 0)

/* Pedometer status registers (R-only) */
#define MMA9553_REG_STATUS			0x00
#define MMA9553_MASK_STATUS_MRGFL		BIT(15)
#define MMA9553_MASK_STATUS_SUSPCHG		BIT(14)
#define MMA9553_MASK_STATUS_STEPCHG		BIT(13)
#define MMA9553_MASK_STATUS_ACTCHG		BIT(12)
#define MMA9553_MASK_STATUS_SUSP		BIT(11)
#define MMA9553_MASK_STATUS_ACTIVITY		GENMASK(10, 8)
#define MMA9553_MASK_STATUS_VERSION		GENMASK(7, 0)

#define MMA9553_REG_STEPCNT			0x02
#define MMA9553_REG_DISTANCE			0x04
#define MMA9553_REG_SPEED			0x06
#define MMA9553_REG_CALORIES			0x08
#define MMA9553_REG_SLEEPCNT			0x0A

/* Pedometer events are always mapped to this pin. */
#define MMA9553_DEFAULT_GPIO_PIN	mma9551_gpio6
#define MMA9553_DEFAULT_GPIO_POLARITY	0

/* Bitnum used for GPIO configuration = bit number in high status byte */
#define MMA9553_STATUS_TO_BITNUM(bit)	(ffs(bit) - 9)
#define MMA9553_MAX_BITNUM		MMA9553_STATUS_TO_BITNUM(BIT(16))

#define MMA9553_DEFAULT_SAMPLE_RATE	30	/* Hz */

/*
 * The internal activity level must be stable for ACTTHD samples before
 * ACTIVITY is updated. The ACTIVITY variable contains the current activity
 * level and is updated every time a step is detected or once a second
 * if there are no steps.
 */
#define MMA9553_ACTIVITY_THD_TO_SEC(thd) ((thd) / MMA9553_DEFAULT_SAMPLE_RATE)
#define MMA9553_ACTIVITY_SEC_TO_THD(sec) ((sec) * MMA9553_DEFAULT_SAMPLE_RATE)

/*
 * Autonomously suspend pedometer if acceleration vector magnitude
 * is near 1g (4096 at 0.244 mg/LSB resolution) for 30 seconds.
 */
#define MMA9553_DEFAULT_SLEEPMIN	3688	/* 0,9 g */
#define MMA9553_DEFAULT_SLEEPMAX	4508	/* 1,1 g */
#define MMA9553_DEFAULT_SLEEPTHD	(MMA9553_DEFAULT_SAMPLE_RATE * 30)

#define MMA9553_CONFIG_RETRIES		2

/* Status register - activity field  */
enum activity_level {
	ACTIVITY_UNKNOWN,
	ACTIVITY_REST,
	ACTIVITY_WALKING,
	ACTIVITY_JOGGING,
	ACTIVITY_RUNNING,
};

static struct mma9553_event_info {
	enum iio_chan_type type;
	enum iio_modifier mod;
	enum iio_event_direction dir;
} mma9553_events_info[] = {
	{
		.type = IIO_STEPS,
		.mod = IIO_NO_MOD,
		.dir = IIO_EV_DIR_NONE,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_STILL,
		.dir = IIO_EV_DIR_RISING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_STILL,
		.dir = IIO_EV_DIR_FALLING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_WALKING,
		.dir = IIO_EV_DIR_RISING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_WALKING,
		.dir = IIO_EV_DIR_FALLING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_JOGGING,
		.dir = IIO_EV_DIR_RISING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_JOGGING,
		.dir = IIO_EV_DIR_FALLING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_RUNNING,
		.dir = IIO_EV_DIR_RISING,
	},
	{
		.type = IIO_ACTIVITY,
		.mod = IIO_MOD_RUNNING,
		.dir = IIO_EV_DIR_FALLING,
	},
};

#define MMA9553_EVENTS_INFO_SIZE ARRAY_SIZE(mma9553_events_info)

struct mma9553_event {
	struct mma9553_event_info *info;
	bool enabled;
};

struct mma9553_conf_regs {
	u16 sleepmin;
	u16 sleepmax;
	u16 sleepthd;
	u16 config;
	u16 height_weight;
	u16 filter;
	u16 speed_step;
	u16 actthd;
} __packed;

struct mma9553_data {
	struct i2c_client *client;
	/*
	 * 1. Serialize access to HW (requested by mma9551_core API).
	 * 2. Serialize sequences that power on/off the device and access HW.
	 */
	struct mutex mutex;
	struct mma9553_conf_regs conf;
	struct mma9553_event events[MMA9553_EVENTS_INFO_SIZE];
	int num_events;
	u8 gpio_bitnum