// SPDX-License-Identifier: GPL-2.0-only
/*
 * VTI CMA3000_D0x Accelerometer driver
 *
 * Copyright (C) 2010 Texas Instruments
 * Author: Hemanth V <hemanthv@ti.com>
 */

#include <linux/export.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input/cma3000.h>
#include <linux/module.h>

#include "cma3000_d0x.h"

#define CMA3000_WHOAMI      0x00
#define CMA3000_REVID       0x01
#define CMA3000_CTRL        0x02
#define CMA3000_STATUS      0x03
#define CMA3000_RSTR        0x04
#define CMA3000_INTSTATUS   0x05
#define CMA3000_DOUTX       0x06
#define CMA3000_DOUTY       0x07
#define CMA3000_DOUTZ       0x08
#define CMA3000_MDTHR       0x09
#define CMA3000_MDFFTMR     0x0A
#define CMA3000_FFTHR       0x0B

#define CMA3000_RANGE2G    (1 << 7)
#define CMA3000_RANGE8G    (0 << 7)
#define CMA3000_BUSI2C     (0 << 4)
#define CMA3000_MODEMASK   (7 << 1)
#define CMA3000_GRANGEMASK (1 << 7)

#define CMA3000_STATUS_PERR    1
#define CMA3000_INTSTATUS_FFDET (1 << 2)

/* Settling time delay in ms */
#define CMA3000_SETDELAY    30

/* Delay for clearing interrupt in us */
#define CMA3000_INTDELAY    44


/*
 * Bit weights in mg for bit 0, other bits need
 * multiply factor 2^n. Eight bit is the sign bit.
 */
#define BIT_TO_2G  18
#define BIT_TO_8G  71

struct cma3000_accl_data {
        const struct cma3000_bus_ops *bus_ops;
        const struct cma3000_platform_data *pdata;

        struct device *dev;
        struct input_dev *input_dev;

        int bit_to_mg;
        int irq;

        int g_range;
        u8 mode;

        struct mutex mutex;
        bool opened;
        bool suspended;
};

#define CMA3000_READ(data, reg, msg) \
        (data->bus_ops->read(data->dev, reg, msg))
#define CMA3000_SET(data, reg, val, msg) \
        ((data)->bus_ops->write(data->dev, reg, val, msg))

/*
 * Conversion for each of the eight modes to g, depending
 * on G range i.e 2G or 8G. Some modes always operate in
 * 8G.
 */

static int mode_to_mg[8][2] = {
        { 0, 0 },
        { BIT_TO_8G, BIT_TO_2G },
        { BIT_TO_8G, BIT_TO_2G },
        { BIT_TO_8G, BIT_TO_8G },
        { BIT_TO_8G, BIT_TO_8G },
        { BIT_TO_8G, BIT_TO_2G },
        { BIT_TO_8G, BIT_TO_2G },
        { 0, 0},
};

static void decode_mg(struct cma3000_accl_data *data, int *datax,
                                int *datay, int *dataz)
{
        /* Data in 2's complement, convert to mg */
        *datax = ((s8)*datax) * data->bit_to_mg;
        *datay = ((s8)*datay) * data->bit_to_mg;
        *dataz = ((s8)*dataz) * data->bit_to_mg;
}

static irqreturn_t cma3000_thread_irq(int irq, void *dev_id)
{
        struct cma3000_accl_data *data = dev_id;
        int datax, datay, dataz, intr_status;
        u8 ctrl, mode, range;

        intr_status = CMA3000_READ(data, CMA3000_INTSTATUS, "interrupt status");
        if (intr_status < 0)
                return IRQ_NONE;

        /* Check if free fall is detected, report immediately */
        if (intr_status & CMA3000_INTSTATUS_FFDET) {
                input_report_abs(data->input_dev, ABS_MISC, 1);
                input_sync(data->input_dev);
        } else {
                input_report_abs(data->input_dev, ABS_MISC, 0);
        }

        datax = CMA3000_READ(data, CMA3000_DOUTX, "X");
        datay = CMA3000_READ(data, CMA3000_DOUTY, "Y");
        dataz = CMA3000_READ(data, CMA3000_DOUTZ, "Z");

        ctrl = CMA3000_READ(data, CMA3000_CTRL, "ctrl");
        mode = (ctrl & CMA3000_MODEMASK) >> 1;
        range = (ctrl & CMA3000_GRANGEMASK) >> 7;

        data->bit_to_mg = mode_to_mg[mode][range];

        /* Interrupt not for this device */
        if (data->bit_to_mg == 0)
                return IRQ_NONE;

        /* Decode register values to milli g */
        decode_mg(data, &datax, &datay, &dataz);

        input_report_abs(data->input_dev, ABS_X, datax);
        input_report_abs(data->input_dev, ABS_Y, datay);
        input_report_abs(data->input_dev, ABS_Z, dataz);
        input_sync(data->input_dev);

        return IRQ_HANDLED;
}

static int cma3000_reset(struct cma3000_accl_data *data)
{
        int val;

        /* Reset sequence */
        CMA3000_SET(data, CMA3000_RSTR, 0x02, "Reset");
        CMA3000_SET(data, CMA3000_RSTR, 0x0A, "Reset");
        CMA3000_SET(data, CMA3000_RSTR, 0x04, "Reset");

        /* Settling time delay */
        mdelay(10);

        val = CMA3000_READ(data, CMA3000_STATUS, "Status");
        if (val < 0) {
                dev_err(data->dev, "Reset failed\n");
                return val;
        }

        if (val & CMA3000_STATUS_PERR) {
                dev_err(data->dev, "Parity Error\n");
                return -EIO;
        }

        return 0;
}

static int cma3000_poweron(struct cma3000_accl_data *data)
{
        const struct cma3000_platform_data *pdata = data->pdata;
        u8 ctrl = 0;
        int ret;

        if (data->g_range == CMARANGE_2G) {
                ctrl = (data->mode << 1) | CMA3000_RANGE2G;
        } else if (data->g_range == CMARANGE_8G) {
                ctrl = (data->mode << 1) | CMA3000_RANGE8G;
        } else {
                dev_info(data->dev,
                         "Invalid G range specified, assuming 8G\n");
                ctrl = (data->mode << 1) | CMA3000_RANGE8G;
        }

        ctrl |= data->bus_ops->ctrl_mod;

        CMA3000_SET(data, CMA3000_MDTHR, pdata->mdthr,
                    "Motion Detect Threshold");
        CMA3000_SET(data, CMA3000_MDFFTMR, pdata->mdfftmr,
                    "Time register");
        CMA3000_SET(data, CMA3000_FFTHR, pdata->ffthr,
                    "Free fall threshold");
        ret = CMA3000_SET(data, CMA3000_CTRL, ctrl, "Mode setting");
        if (ret < 0)
                return -EIO;

        msleep(CMA3000_SETDELAY);

        return 0;
}

static int cma3000_poweroff(struct cma3000_accl_data *data)
{
        int ret;

        ret = CMA3000_SET(data, CMA3000_CTRL, CMAMODE_POFF, "Mode setting");
        msleep(CMA3000_SETDELAY);

        return ret;
}

static int cma3000_open(struct input_dev *input_dev)
{
        struct cma3000_accl_data *data = input_get_drvdata(input_dev);

        guard(mutex)(&data->mutex);

        if (!data->suspended)
                cma3000_poweron(data);

        data->opened = true;

        return 0;
}

static void cma3000_close(struct input_dev *input_dev)
{
        struct cma3000_accl_data *data = input_get_drvdata(input_dev);

        guard(mutex)(&data->mutex);

        if (!data->suspended)
                cma3000_poweroff(data);

        data->opened = false;
}

void cma3000_suspend(struct cma3000_accl_data *data)
{
        guard(mutex)(&data->mutex);

        if (!data->suspended && data->opened)
                cma3000_poweroff(data);

        data->suspended = true;
}
EXPORT_SYMBOL(cma3000_suspend);


void cma3000_resume(struct cma3000_accl_data *data)
{
        guard(mutex)(&data->mutex);

        if (data->suspended && data->opened)
                cma3000_poweron(data);

        data->suspended = false;
}
EXPORT_SYMBOL(cma3000_resume);

struct cma3000_accl_data *cma3000_init(struct device *dev, int irq,
                                       const struct cma3000_bus_ops *bops)
{
        const struct cma3000_platform_data *pdata = dev_get_platdata(dev);
        struct cma3000_accl_data *data;
        struct input_dev *input_dev;
        int rev;
        int error;

        if (!pdata) {
                dev_err(dev, "platform data not found\n");
                error = -EINVAL;
                goto err_out;
        }


        /* if no IRQ return error */
        if (irq == 0) {
                error = -EINVAL;
                goto err_out;
        }

        data = kzalloc_obj(*data);
        input_dev = input_allocate_device();
        if (!data || !input_dev) {
                error = -ENOMEM;
                goto err_free_mem;
        }

        data->dev = dev;
        data->input_dev = input_dev;
        data->bus_ops = bops;
        data->pdata = pdata;
        data->irq = irq;
        mutex_init(&data->mutex);

        data->mode = pdata->mode;
        if (data->mode > CMAMODE_POFF) {
                data->mode = CMAMODE_MOTDET;
                dev_warn(dev,
                         "Invalid mode specified, assuming Motion Detect\n");
        }

        data->g_range = pdata->g_range;
        if (data->g_range != CMARANGE_2G && data->g_range != CMARANGE_8G) {
                dev_info(dev,
                         "Invalid G range specified, assuming 8G\n");
                data->g_range = CMARANGE_8G;
        }

        input_dev->name = "cma3000-accelerometer";
        input_dev->id.bustype = bops->bustype;
        input_dev->open = cma3000_open;
        input_dev->close = cma3000_close;

        input_set_abs_params(input_dev, ABS_X,
                        -data->g_range, data->g_range, pdata->fuzz_x, 0);
        input_set_abs_params(input_dev, ABS_Y,
                        -data->g_range, data->g_range, pdata->fuzz_y, 0);
        input_set_abs_params(input_dev, ABS_Z,
                        -data->g_range, data->g_range, pdata->fuzz_z, 0);
        input_set_abs_params(input_dev, ABS_MISC, 0, 1, 0, 0);

        input_set_drvdata(input_dev, data);

        error = cma3000_reset(data);
        if (error)
                goto err_free_mem;

        rev = CMA3000_READ(data, CMA3000_REVID, "Revid");
        if (rev < 0) {
                error = rev;
                goto err_free_mem;
        }

        pr_info("CMA3000 Accelerometer: Revision %x\n", rev);

        error = request_threaded_irq(irq, NULL, cma3000_thread_irq,
                                     pdata->irqflags | IRQF_ONESHOT,
                                     "cma3000_d0x", data);
        if (error) {
                dev_err(dev, "request_threaded_irq failed\n");
                goto err_free_mem;
        }

        error = input_register_device(data->input_dev);
        if (error) {
                dev_err(dev, "Unable to register input device\n");
                goto err_free_irq;
        }

        return data;

err_free_irq:
        free_irq(irq, data);
err_free_mem:
        input_free_device(input_dev);
        kfree(data);
err_out:
        return ERR_PTR(error);
}
EXPORT_SYMBOL(cma3000_init);

void cma3000_exit(struct cma3000_accl_data *data)
{
        free_irq(data->irq, data);
        input_unregister_device(data->input_dev);
        kfree(data);
}
EXPORT_SYMBOL(cma3000_exit);

MODULE_DESCRIPTION("CMA3000-D0x Accelerometer Driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");