// SPDX-License-Identifier: GPL-2.0
/*
 * CS40L50 Advanced Haptic Driver with waveform memory,
 * integrated DSP, and closed-loop algorithms
 *
 * Copyright 2024 Cirrus Logic, Inc.
 *
 * Author: James Ogletree <james.ogletree@cirrus.com>
 */

#include <linux/bitfield.h>
#include <linux/input.h>
#include <linux/mfd/cs40l50.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>

/* Wavetables */
#define CS40L50_RAM_INDEX_START         0x1000000
#define CS40L50_RAM_INDEX_END           0x100007F
#define CS40L50_RTH_INDEX_START         0x1400000
#define CS40L50_RTH_INDEX_END           0x1400001
#define CS40L50_ROM_INDEX_START         0x1800000
#define CS40L50_ROM_INDEX_END           0x180001A
#define CS40L50_TYPE_PCM                8
#define CS40L50_TYPE_PWLE               12
#define CS40L50_PCM_ID                  0x0
#define CS40L50_OWT_CUSTOM_DATA_SIZE    2
#define CS40L50_CUSTOM_DATA_MASK        0xFFFFU

/* DSP */
#define CS40L50_GPIO_BASE               0x2804140
#define CS40L50_OWT_BASE                0x2805C34
#define CS40L50_OWT_SIZE                0x2805C38
#define CS40L50_OWT_NEXT                0x2805C3C
#define CS40L50_EFFECTS_MAX             1

/* GPIO */
#define CS40L50_GPIO_NUM_MASK           GENMASK(14, 12)
#define CS40L50_GPIO_EDGE_MASK          BIT(15)
#define CS40L50_GPIO_MAPPING_NONE       0
#define CS40L50_GPIO_DISABLE            0x1FF

enum cs40l50_bank_type {
        CS40L50_WVFRM_BANK_RAM,
        CS40L50_WVFRM_BANK_ROM,
        CS40L50_WVFRM_BANK_OWT,
        CS40L50_WVFRM_BANK_NUM,
};

/* Describes an area in DSP memory populated by effects */
struct cs40l50_bank {
        enum cs40l50_bank_type type;
        u32 base_index;
        u32 max_index;
};

struct cs40l50_effect {
        enum cs40l50_bank_type type;
        struct list_head list;
        u32 gpio_reg;
        u32 index;
        int id;
};

/* Describes haptic interface of loaded DSP firmware */
struct cs40l50_vibra_dsp {
        struct cs40l50_bank *banks;
        u32 gpio_base_reg;
        u32 owt_offset_reg;
        u32 owt_size_reg;
        u32 owt_base_reg;
        u32 push_owt_cmd;
        u32 delete_owt_cmd;
        u32 stop_cmd;
        int (*write)(struct device *dev, struct regmap *regmap, u32 val);
};

/* Describes configuration and state of haptic operations */
struct cs40l50_vibra {
        struct device *dev;
        struct regmap *regmap;
        struct input_dev *input;
        struct workqueue_struct *vib_wq;
        struct list_head effect_head;
        struct cs40l50_vibra_dsp dsp;
};

struct cs40l50_work {
        struct cs40l50_vibra *vib;
        struct ff_effect *effect;
        struct work_struct work;
        s16 *custom_data;
        int custom_len;
        int count;
        int error;
};

static struct cs40l50_bank cs40l50_banks[] = {
        {
                .type =         CS40L50_WVFRM_BANK_RAM,
                .base_index =   CS40L50_RAM_INDEX_START,
                .max_index =    CS40L50_RAM_INDEX_END,
        },
        {
                .type =         CS40L50_WVFRM_BANK_ROM,
                .base_index =   CS40L50_ROM_INDEX_START,
                .max_index =    CS40L50_ROM_INDEX_END,
        },
        {
                .type =         CS40L50_WVFRM_BANK_OWT,
                .base_index =   CS40L50_RTH_INDEX_START,
                .max_index =    CS40L50_RTH_INDEX_END,
        },
};

static struct cs40l50_vibra_dsp cs40l50_dsp = {
        .banks =                cs40l50_banks,
        .gpio_base_reg =        CS40L50_GPIO_BASE,
        .owt_base_reg =         CS40L50_OWT_BASE,
        .owt_offset_reg =       CS40L50_OWT_NEXT,
        .owt_size_reg =         CS40L50_OWT_SIZE,
        .push_owt_cmd =         CS40L50_OWT_PUSH,
        .delete_owt_cmd =       CS40L50_OWT_DELETE,
        .stop_cmd =             CS40L50_STOP_PLAYBACK,
        .write =                cs40l50_dsp_write,
};

static struct cs40l50_effect *cs40l50_find_effect(int id, struct list_head *effect_head)
{
        struct cs40l50_effect *effect;

        list_for_each_entry(effect, effect_head, list)
                if (effect->id == id)
                        return effect;

        return NULL;
}

static int cs40l50_effect_bank_set(struct cs40l50_work *work_data,
                                   struct cs40l50_effect *effect)
{
        s16 bank_type = work_data->custom_data[0] & CS40L50_CUSTOM_DATA_MASK;

        if (bank_type >= CS40L50_WVFRM_BANK_NUM) {
                dev_err(work_data->vib->dev, "Invalid bank (%d)\n", bank_type);
                return -EINVAL;
        }

        if (work_data->custom_len > CS40L50_OWT_CUSTOM_DATA_SIZE)
                effect->type = CS40L50_WVFRM_BANK_OWT;
        else
                effect->type = bank_type;

        return 0;
}

static int cs40l50_effect_index_set(struct cs40l50_work *work_data,
                                    struct cs40l50_effect *effect)
{
        struct cs40l50_vibra *vib = work_data->vib;
        struct cs40l50_effect *owt_effect;
        u32 base_index, max_index;

        base_index = vib->dsp.banks[effect->type].base_index;
        max_index = vib->dsp.banks[effect->type].max_index;

        effect->index = base_index;

        switch (effect->type) {
        case CS40L50_WVFRM_BANK_OWT:
                list_for_each_entry(owt_effect, &vib->effect_head, list)
                        if (owt_effect->type == CS40L50_WVFRM_BANK_OWT)
                                effect->index++;
                break;
        case CS40L50_WVFRM_BANK_ROM:
        case CS40L50_WVFRM_BANK_RAM:
                effect->index += work_data->custom_data[1] & CS40L50_CUSTOM_DATA_MASK;
                break;
        default:
                dev_err(vib->dev, "Bank type %d not supported\n", effect->type);
                return -EINVAL;
        }

        if (effect->index > max_index || effect->index < base_index) {
                dev_err(vib->dev, "Index out of bounds: %u\n", effect->index);
                return -ENOSPC;
        }

        return 0;
}

static int cs40l50_effect_gpio_mapping_set(struct cs40l50_work *work_data,
                                           struct cs40l50_effect *effect)
{
        u16 gpio_edge, gpio_num, button = work_data->effect->trigger.button;
        struct cs40l50_vibra *vib = work_data->vib;

        if (button) {
                gpio_num = FIELD_GET(CS40L50_GPIO_NUM_MASK, button);
                gpio_edge = FIELD_GET(CS40L50_GPIO_EDGE_MASK, button);
                effect->gpio_reg = vib->dsp.gpio_base_reg + (gpio_num * 8) - gpio_edge;

                return regmap_write(vib->regmap, effect->gpio_reg, button);
        }

        effect->gpio_reg = CS40L50_GPIO_MAPPING_NONE;

        return 0;
}

struct cs40l50_owt_header {
        u32 type;
        u32 data_words;
        u32 offset;
} __packed;

static int cs40l50_upload_owt(struct cs40l50_work *work_data)
{
        u8 *new_owt_effect_data __free(kfree) = NULL;
        struct cs40l50_vibra *vib = work_data->vib;
        size_t len = work_data->custom_len * 2;
        struct cs40l50_owt_header header;
        u32 offset, size;
        int error;

        error = regmap_read(vib->regmap, vib->dsp.owt_size_reg, &size);
        if (error)
                return error;

        if ((size * sizeof(u32)) < sizeof(header) + len) {
                dev_err(vib->dev, "No space in open wavetable for effect\n");
                return -ENOSPC;
        }

        header.type = work_data->custom_data[0] == CS40L50_PCM_ID ? CS40L50_TYPE_PCM :
                                                                    CS40L50_TYPE_PWLE;
        header.offset = sizeof(header) / sizeof(u32);
        header.data_words = len / sizeof(u32);

        new_owt_effect_data = kmalloc(sizeof(header) + len, GFP_KERNEL);
        if (!new_owt_effect_data)
                return -ENOMEM;

        memcpy(new_owt_effect_data, &header, sizeof(header));
        memcpy(new_owt_effect_data + sizeof(header), work_data->custom_data, len);

        error = regmap_read(vib->regmap, vib->dsp.owt_offset_reg, &offset);
        if (error)
                return error;

        error = regmap_bulk_write(vib->regmap, vib->dsp.owt_base_reg +
                                  (offset * sizeof(u32)), new_owt_effect_data,
                                  sizeof(header) + len);
        if (error)
                return error;

        error = vib->dsp.write(vib->dev, vib->regmap, vib->dsp.push_owt_cmd);
        if (error)
                return error;

        return 0;
}

static void cs40l50_add_worker(struct work_struct *work)
{
        struct cs40l50_work *work_data = container_of(work, struct cs40l50_work, work);
        struct cs40l50_vibra *vib = work_data->vib;
        struct cs40l50_effect *effect;
        bool is_new = false;
        int error;

        error = pm_runtime_resume_and_get(vib->dev);
        if (error)
                goto err_exit;

        /* Update effect if already uploaded, otherwise create new effect */
        effect = cs40l50_find_effect(work_data->effect->id, &vib->effect_head);
        if (!effect) {
                effect = kzalloc_obj(*effect);
                if (!effect) {
                        error = -ENOMEM;
                        goto err_pm;
                }

                effect->id = work_data->effect->id;
                is_new = true;
        }

        error = cs40l50_effect_bank_set(work_data, effect);
        if (error)
                goto err_free;

        error = cs40l50_effect_index_set(work_data, effect);
        if (error)
                goto err_free;

        error = cs40l50_effect_gpio_mapping_set(work_data, effect);
        if (error)
                goto err_free;

        if (effect->type == CS40L50_WVFRM_BANK_OWT)
                error = cs40l50_upload_owt(work_data);
err_free:
        if (is_new) {
                if (error)
                        kfree(effect);
                else
                        list_add(&effect->list, &vib->effect_head);
        }
err_pm:
        pm_runtime_put_autosuspend(vib->dev);
err_exit:
        work_data->error = error;
}

static int cs40l50_add(struct input_dev *dev, struct ff_effect *effect,
                       struct ff_effect *old)
{
        struct ff_periodic_effect *periodic = &effect->u.periodic;
        struct cs40l50_vibra *vib = input_get_drvdata(dev);
        struct cs40l50_work work_data;

        if (effect->type != FF_PERIODIC || periodic->waveform != FF_CUSTOM) {
                dev_err(vib->dev, "Type (%#X) or waveform (%#X) unsupported\n",
                        effect->type, periodic->waveform);
                return -EINVAL;
        }

        work_data.custom_data = memdup_array_user(effect->u.periodic.custom_data,
                                                  effect->u.periodic.custom_len,
                                                  sizeof(s16));
        if (IS_ERR(work_data.custom_data))
                return PTR_ERR(work_data.custom_data);

        work_data.custom_len = effect->u.periodic.custom_len;
        work_data.vib = vib;
        work_data.effect = effect;
        INIT_WORK_ONSTACK(&work_data.work, cs40l50_add_worker);

        /* Push to the workqueue to serialize with playbacks */
        queue_work(vib->vib_wq, &work_data.work);
        flush_work(&work_data.work);
        destroy_work_on_stack(&work_data.work);

        kfree(work_data.custom_data);

        return work_data.error;
}

static void cs40l50_start_worker(struct work_struct *work)
{
        struct cs40l50_work *work_data = container_of(work, struct cs40l50_work, work);
        struct cs40l50_vibra *vib = work_data->vib;
        struct cs40l50_effect *start_effect;

        if (pm_runtime_resume_and_get(vib->dev) < 0)
                goto err_free;

        start_effect = cs40l50_find_effect(work_data->effect->id, &vib->effect_head);
        if (start_effect) {
                while (--work_data->count >= 0) {
                        vib->dsp.write(vib->dev, vib->regmap, start_effect->index);
                        usleep_range(work_data->effect->replay.length,
                                     work_data->effect->replay.length + 100);
                }
        } else {
                dev_err(vib->dev, "Effect to play not found\n");
        }

        pm_runtime_put_autosuspend(vib->dev);
err_free:
        kfree(work_data);
}

static void cs40l50_stop_worker(struct work_struct *work)
{
        struct cs40l50_work *work_data = container_of(work, struct cs40l50_work, work);
        struct cs40l50_vibra *vib = work_data->vib;

        if (pm_runtime_resume_and_get(vib->dev) < 0)
                return;

        vib->dsp.write(vib->dev, vib->regmap, vib->dsp.stop_cmd);

        pm_runtime_put_autosuspend(vib->dev);

        kfree(work_data);
}

static int cs40l50_playback(struct input_dev *dev, int effect_id, int val)
{
        struct cs40l50_vibra *vib = input_get_drvdata(dev);
        struct cs40l50_work *work_data;

        work_data = kzalloc_obj(*work_data, GFP_ATOMIC);
        if (!work_data)
                return -ENOMEM;

        work_data->vib = vib;

        if (val > 0) {
                work_data->effect = &dev->ff->effects[effect_id];
                work_data->count = val;
                INIT_WORK(&work_data->work, cs40l50_start_worker);
        } else {
                /* Stop the amplifier as device drives only one effect */
                INIT_WORK(&work_data->work, cs40l50_stop_worker);
        }

        queue_work(vib->vib_wq, &work_data->work);

        return 0;
}

static void cs40l50_erase_worker(struct work_struct *work)
{
        struct cs40l50_work *work_data = container_of(work, struct cs40l50_work, work);
        struct cs40l50_effect *erase_effect, *owt_effect;
        struct cs40l50_vibra *vib = work_data->vib;
        int error;

        error = pm_runtime_resume_and_get(vib->dev);
        if (error)
                goto err_exit;

        erase_effect = cs40l50_find_effect(work_data->effect->id, &vib->effect_head);
        if (!erase_effect) {
                dev_err(vib->dev, "Effect to erase not found\n");
                error = -EINVAL;
                goto err_pm;
        }

        if (erase_effect->gpio_reg != CS40L50_GPIO_MAPPING_NONE) {
                error = regmap_write(vib->regmap, erase_effect->gpio_reg,
                                     CS40L50_GPIO_DISABLE);
                if (error)
                        goto err_pm;
        }

        if (erase_effect->type == CS40L50_WVFRM_BANK_OWT) {
                error = vib->dsp.write(vib->dev, vib->regmap,
                                       vib->dsp.delete_owt_cmd |
                                       (erase_effect->index & 0xFF));
                if (error)
                        goto err_pm;

                list_for_each_entry(owt_effect, &vib->effect_head, list)
                        if (owt_effect->type == CS40L50_WVFRM_BANK_OWT &&
                            owt_effect->index > erase_effect->index)
                                owt_effect->index--;
        }

        list_del(&erase_effect->list);
        kfree(erase_effect);
err_pm:
        pm_runtime_put_autosuspend(vib->dev);
err_exit:
        work_data->error = error;
}

static int cs40l50_erase(struct input_dev *dev, int effect_id)
{
        struct cs40l50_vibra *vib = input_get_drvdata(dev);
        struct cs40l50_work work_data;

        work_data.vib = vib;
        work_data.effect = &dev->ff->effects[effect_id];

        INIT_WORK_ONSTACK(&work_data.work, cs40l50_erase_worker);

        /* Push to workqueue to serialize with playbacks */
        queue_work(vib->vib_wq, &work_data.work);
        flush_work(&work_data.work);
        destroy_work_on_stack(&work_data.work);

        return work_data.error;
}

static void cs40l50_remove_wq(void *data)
{
        destroy_workqueue(data);
}

static int cs40l50_vibra_probe(struct platform_device *pdev)
{
        struct cs40l50 *cs40l50 = dev_get_drvdata(pdev->dev.parent);
        struct cs40l50_vibra *vib;
        int error;

        vib = devm_kzalloc(pdev->dev.parent, sizeof(*vib), GFP_KERNEL);
        if (!vib)
                return -ENOMEM;

        vib->dev = cs40l50->dev;
        vib->regmap = cs40l50->regmap;
        vib->dsp = cs40l50_dsp;

        vib->input = devm_input_allocate_device(vib->dev);
        if (!vib->input)
                return -ENOMEM;

        vib->input->id.product = cs40l50->devid;
        vib->input->id.version = cs40l50->revid;
        vib->input->name = "cs40l50_vibra";

        input_set_drvdata(vib->input, vib);
        input_set_capability(vib->input, EV_FF, FF_PERIODIC);
        input_set_capability(vib->input, EV_FF, FF_CUSTOM);

        error = input_ff_create(vib->input, CS40L50_EFFECTS_MAX);
        if (error) {
                dev_err(vib->dev, "Failed to create input device\n");
                return error;
        }

        vib->input->ff->upload = cs40l50_add;
        vib->input->ff->playback = cs40l50_playback;
        vib->input->ff->erase = cs40l50_erase;

        INIT_LIST_HEAD(&vib->effect_head);

        vib->vib_wq = alloc_ordered_workqueue("vib_wq", WQ_HIGHPRI);
        if (!vib->vib_wq)
                return -ENOMEM;

        error = devm_add_action_or_reset(vib->dev, cs40l50_remove_wq, vib->vib_wq);
        if (error)
                return error;

        error = input_register_device(vib->input);
        if (error)
                return error;

        return 0;
}

static const struct platform_device_id cs40l50_vibra_id_match[] = {
        { "cs40l50-vibra", },
        {}
};
MODULE_DEVICE_TABLE(platform, cs40l50_vibra_id_match);

static struct platform_driver cs40l50_vibra_driver = {
        .probe          = cs40l50_vibra_probe,
        .id_table       = cs40l50_vibra_id_match,
        .driver         = {
                .name   = "cs40l50-vibra",
        },
};
module_platform_driver(cs40l50_vibra_driver);

MODULE_DESCRIPTION("CS40L50 Advanced Haptic Driver");
MODULE_AUTHOR("James Ogletree, Cirrus Logic Inc. <james.ogletree@cirrus.com>");
MODULE_LICENSE("GPL");