root/drivers/input/misc/drv2665.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * DRV2665 haptics driver family
 *
 * Author: Dan Murphy <dmurphy@ti.com>
 *
 * Copyright: (C) 2015 Texas Instruments, Inc.
 */

#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>

/* Control registers */
#define DRV2665_STATUS  0x00
#define DRV2665_CTRL_1  0x01
#define DRV2665_CTRL_2  0x02
#define DRV2665_FIFO    0x0b

/* Status Register */
#define DRV2665_FIFO_FULL               BIT(0)
#define DRV2665_FIFO_EMPTY              BIT(1)

/* Control 1 Register */
#define DRV2665_25_VPP_GAIN             0x00
#define DRV2665_50_VPP_GAIN             0x01
#define DRV2665_75_VPP_GAIN             0x02
#define DRV2665_100_VPP_GAIN            0x03
#define DRV2665_DIGITAL_IN              0xfc
#define DRV2665_ANALOG_IN               BIT(2)

/* Control 2 Register */
#define DRV2665_BOOST_EN                BIT(1)
#define DRV2665_STANDBY                 BIT(6)
#define DRV2665_DEV_RST                 BIT(7)
#define DRV2665_5_MS_IDLE_TOUT          0x00
#define DRV2665_10_MS_IDLE_TOUT         0x04
#define DRV2665_15_MS_IDLE_TOUT         0x08
#define DRV2665_20_MS_IDLE_TOUT         0x0c

/**
 * struct drv2665_data -
 * @input_dev: Pointer to the input device
 * @client: Pointer to the I2C client
 * @regmap: Register map of the device
 * @work: Work item used to off load the enable/disable of the vibration
 * @regulator: Pointer to the regulator for the IC
 */
struct drv2665_data {
        struct input_dev *input_dev;
        struct i2c_client *client;
        struct regmap *regmap;
        struct work_struct work;
        struct regulator *regulator;
};

/* 8kHz Sine wave to stream to the FIFO */
static const u8 drv2665_sine_wave_form[] = {
        0x00, 0x10, 0x20, 0x2e, 0x3c, 0x48, 0x53, 0x5b, 0x61, 0x65, 0x66,
        0x65, 0x61, 0x5b, 0x53, 0x48, 0x3c, 0x2e, 0x20, 0x10,
        0x00, 0xf0, 0xe0, 0xd2, 0xc4, 0xb8, 0xad, 0xa5, 0x9f, 0x9b, 0x9a,
        0x9b, 0x9f, 0xa5, 0xad, 0xb8, 0xc4, 0xd2, 0xe0, 0xf0, 0x00,
};

static const struct reg_default drv2665_reg_defs[] = {
        { DRV2665_STATUS, 0x02 },
        { DRV2665_CTRL_1, 0x28 },
        { DRV2665_CTRL_2, 0x40 },
        { DRV2665_FIFO, 0x00 },
};

static void drv2665_worker(struct work_struct *work)
{
        struct drv2665_data *haptics =
                                container_of(work, struct drv2665_data, work);
        unsigned int read_buf;
        int error;

        error = regmap_read(haptics->regmap, DRV2665_STATUS, &read_buf);
        if (error) {
                dev_err(&haptics->client->dev,
                        "Failed to read status: %d\n", error);
                return;
        }

        if (read_buf & DRV2665_FIFO_EMPTY) {
                error = regmap_bulk_write(haptics->regmap,
                                          DRV2665_FIFO,
                                          drv2665_sine_wave_form,
                                          ARRAY_SIZE(drv2665_sine_wave_form));
                if (error) {
                        dev_err(&haptics->client->dev,
                                "Failed to write FIFO: %d\n", error);
                        return;
                }
        }
}

static int drv2665_haptics_play(struct input_dev *input, void *data,
                                struct ff_effect *effect)
{
        struct drv2665_data *haptics = input_get_drvdata(input);

        schedule_work(&haptics->work);

        return 0;
}

static void drv2665_close(struct input_dev *input)
{
        struct drv2665_data *haptics = input_get_drvdata(input);
        int error;

        cancel_work_sync(&haptics->work);

        error = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
                                   DRV2665_STANDBY, DRV2665_STANDBY);
        if (error)
                dev_err(&haptics->client->dev,
                        "Failed to enter standby mode: %d\n", error);
}

static const struct reg_sequence drv2665_init_regs[] = {
        { DRV2665_CTRL_2, 0 | DRV2665_10_MS_IDLE_TOUT },
        { DRV2665_CTRL_1, DRV2665_25_VPP_GAIN },
};

static int drv2665_init(struct drv2665_data *haptics)
{
        int error;

        error = regmap_register_patch(haptics->regmap,
                                      drv2665_init_regs,
                                      ARRAY_SIZE(drv2665_init_regs));
        if (error) {
                dev_err(&haptics->client->dev,
                        "Failed to write init registers: %d\n",
                        error);
                return error;
        }

        return 0;
}

static const struct regmap_config drv2665_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,

        .max_register = DRV2665_FIFO,
        .reg_defaults = drv2665_reg_defs,
        .num_reg_defaults = ARRAY_SIZE(drv2665_reg_defs),
        .cache_type = REGCACHE_NONE,
};

static int drv2665_probe(struct i2c_client *client)
{
        struct drv2665_data *haptics;
        int error;

        haptics = devm_kzalloc(&client->dev, sizeof(*haptics), GFP_KERNEL);
        if (!haptics)
                return -ENOMEM;

        haptics->regulator = devm_regulator_get(&client->dev, "vbat");
        if (IS_ERR(haptics->regulator)) {
                error = PTR_ERR(haptics->regulator);
                dev_err(&client->dev,
                        "unable to get regulator, error: %d\n", error);
                return error;
        }

        haptics->input_dev = devm_input_allocate_device(&client->dev);
        if (!haptics->input_dev) {
                dev_err(&client->dev, "Failed to allocate input device\n");
                return -ENOMEM;
        }

        haptics->input_dev->name = "drv2665:haptics";
        haptics->input_dev->dev.parent = client->dev.parent;
        haptics->input_dev->close = drv2665_close;
        input_set_drvdata(haptics->input_dev, haptics);
        input_set_capability(haptics->input_dev, EV_FF, FF_RUMBLE);

        error = input_ff_create_memless(haptics->input_dev, NULL,
                                        drv2665_haptics_play);
        if (error) {
                dev_err(&client->dev, "input_ff_create() failed: %d\n",
                        error);
                return error;
        }

        INIT_WORK(&haptics->work, drv2665_worker);

        haptics->client = client;
        i2c_set_clientdata(client, haptics);

        haptics->regmap = devm_regmap_init_i2c(client, &drv2665_regmap_config);
        if (IS_ERR(haptics->regmap)) {
                error = PTR_ERR(haptics->regmap);
                dev_err(&client->dev, "Failed to allocate register map: %d\n",
                        error);
                return error;
        }

        error = drv2665_init(haptics);
        if (error) {
                dev_err(&client->dev, "Device init failed: %d\n", error);
                return error;
        }

        error = input_register_device(haptics->input_dev);
        if (error) {
                dev_err(&client->dev, "couldn't register input device: %d\n",
                        error);
                return error;
        }

        return 0;
}

static int drv2665_suspend(struct device *dev)
{
        struct drv2665_data *haptics = dev_get_drvdata(dev);
        int error;

        guard(mutex)(&haptics->input_dev->mutex);

        if (input_device_enabled(haptics->input_dev)) {
                error = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
                                           DRV2665_STANDBY, DRV2665_STANDBY);
                if (error) {
                        dev_err(dev, "Failed to set standby mode\n");
                        regulator_disable(haptics->regulator);
                        return error;
                }

                error = regulator_disable(haptics->regulator);
                if (error) {
                        dev_err(dev, "Failed to disable regulator\n");
                        regmap_update_bits(haptics->regmap,
                                           DRV2665_CTRL_2,
                                           DRV2665_STANDBY, 0);
                        return error;
                }
        }

        return 0;
}

static int drv2665_resume(struct device *dev)
{
        struct drv2665_data *haptics = dev_get_drvdata(dev);
        int error;

        guard(mutex)(&haptics->input_dev->mutex);

        if (input_device_enabled(haptics->input_dev)) {
                error = regulator_enable(haptics->regulator);
                if (error) {
                        dev_err(dev, "Failed to enable regulator\n");
                        return error;
                }

                error = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
                                           DRV2665_STANDBY, 0);
                if (error) {
                        dev_err(dev, "Failed to unset standby mode\n");
                        regulator_disable(haptics->regulator);
                        return error;
                }

        }

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(drv2665_pm_ops, drv2665_suspend, drv2665_resume);

static const struct i2c_device_id drv2665_id[] = {
        { "drv2665" },
        { }
};
MODULE_DEVICE_TABLE(i2c, drv2665_id);

#ifdef CONFIG_OF
static const struct of_device_id drv2665_of_match[] = {
        { .compatible = "ti,drv2665", },
        { }
};
MODULE_DEVICE_TABLE(of, drv2665_of_match);
#endif

static struct i2c_driver drv2665_driver = {
        .probe          = drv2665_probe,
        .driver         = {
                .name   = "drv2665-haptics",
                .of_match_table = of_match_ptr(drv2665_of_match),
                .pm     = pm_sleep_ptr(&drv2665_pm_ops),
        },
        .id_table = drv2665_id,
};
module_i2c_driver(drv2665_driver);

MODULE_DESCRIPTION("TI DRV2665 haptics driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");