// SPDX-License-Identifier: GPL-2.0-only
/***************************************************************************
 *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
 *                                                                         *
 *   Based on Logitech G13 driver (v0.4)                                   *
 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
 *                                                                         *
 ***************************************************************************/

#include <linux/hid.h>
#include <linux/hid-debug.h>
#include <linux/input.h>
#include "hid-ids.h"

#include <linux/fb.h>
#include <linux/vmalloc.h>

#include <linux/completion.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/string.h>

#include "hid-picolcd.h"


/* Input device
 *
 * The PicoLCD has an IR receiver header, a built-in keypad with 5 keys
 * and header for 4x4 key matrix. The built-in keys are part of the matrix.
 */
static const unsigned short def_keymap[PICOLCD_KEYS] = {
        KEY_RESERVED,   /* none */
        KEY_BACK,       /* col 4 + row 1 */
        KEY_HOMEPAGE,   /* col 3 + row 1 */
        KEY_RESERVED,   /* col 2 + row 1 */
        KEY_RESERVED,   /* col 1 + row 1 */
        KEY_SCROLLUP,   /* col 4 + row 2 */
        KEY_OK,         /* col 3 + row 2 */
        KEY_SCROLLDOWN, /* col 2 + row 2 */
        KEY_RESERVED,   /* col 1 + row 2 */
        KEY_RESERVED,   /* col 4 + row 3 */
        KEY_RESERVED,   /* col 3 + row 3 */
        KEY_RESERVED,   /* col 2 + row 3 */
        KEY_RESERVED,   /* col 1 + row 3 */
        KEY_RESERVED,   /* col 4 + row 4 */
        KEY_RESERVED,   /* col 3 + row 4 */
        KEY_RESERVED,   /* col 2 + row 4 */
        KEY_RESERVED,   /* col 1 + row 4 */
};


/* Find a given report */
struct hid_report *picolcd_report(int id, struct hid_device *hdev, int dir)
{
        struct list_head *feature_report_list = &hdev->report_enum[dir].report_list;
        struct hid_report *report = NULL;

        list_for_each_entry(report, feature_report_list, list) {
                if (report->id == id)
                        return report;
        }
        hid_warn(hdev, "No report with id 0x%x found\n", id);
        return NULL;
}

/* Submit a report and wait for a reply from device - if device fades away
 * or does not respond in time, return NULL */
struct picolcd_pending *picolcd_send_and_wait(struct hid_device *hdev,
                int report_id, const u8 *raw_data, int size)
{
        struct picolcd_data *data = hid_get_drvdata(hdev);
        struct picolcd_pending *work;
        struct hid_report *report = picolcd_out_report(report_id, hdev);
        unsigned long flags;
        int i, j, k;

        if (!report || !data)
                return NULL;
        if (data->status & PICOLCD_FAILED)
                return NULL;
        work = kzalloc_obj(*work);
        if (!work)
                return NULL;

        init_completion(&work->ready);
        work->out_report = report;
        work->in_report  = NULL;
        work->raw_size   = 0;

        mutex_lock(&data->mutex);
        spin_lock_irqsave(&data->lock, flags);
        for (i = k = 0; i < report->maxfield; i++)
                for (j = 0; j < report->field[i]->report_count; j++) {
                        hid_set_field(report->field[i], j, k < size ? raw_data[k] : 0);
                        k++;
                }
        if (data->status & PICOLCD_FAILED) {
                kfree(work);
                work = NULL;
        } else {
                data->pending = work;
                hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
                spin_unlock_irqrestore(&data->lock, flags);
                wait_for_completion_interruptible_timeout(&work->ready, HZ*2);
                spin_lock_irqsave(&data->lock, flags);
                data->pending = NULL;
        }
        spin_unlock_irqrestore(&data->lock, flags);
        mutex_unlock(&data->mutex);
        return work;
}

/*
 * input class device
 */
static int picolcd_raw_keypad(struct picolcd_data *data,
                struct hid_report *report, u8 *raw_data, int size)
{
        /*
         * Keypad event
         * First and second data bytes list currently pressed keys,
         * 0x00 means no key and at most 2 keys may be pressed at same time
         */
        int i, j;

        /* determine newly pressed keys */
        for (i = 0; i < size; i++) {
                unsigned int key_code;
                if (raw_data[i] == 0)
                        continue;
                for (j = 0; j < sizeof(data->pressed_keys); j++)
                        if (data->pressed_keys[j] == raw_data[i])
                                goto key_already_down;
                for (j = 0; j < sizeof(data->pressed_keys); j++)
                        if (data->pressed_keys[j] == 0) {
                                data->pressed_keys[j] = raw_data[i];
                                break;
                        }
                input_event(data->input_keys, EV_MSC, MSC_SCAN, raw_data[i]);
                if (raw_data[i] < PICOLCD_KEYS)
                        key_code = data->keycode[raw_data[i]];
                else
                        key_code = KEY_UNKNOWN;
                if (key_code != KEY_UNKNOWN) {
                        dbg_hid(PICOLCD_NAME " got key press for %u:%d",
                                        raw_data[i], key_code);
                        input_report_key(data->input_keys, key_code, 1);
                }
                input_sync(data->input_keys);
key_already_down:
                continue;
        }

        /* determine newly released keys */
        for (j = 0; j < sizeof(data->pressed_keys); j++) {
                unsigned int key_code;
                if (data->pressed_keys[j] == 0)
                        continue;
                for (i = 0; i < size; i++)
                        if (data->pressed_keys[j] == raw_data[i])
                                goto key_still_down;
                input_event(data->input_keys, EV_MSC, MSC_SCAN, data->pressed_keys[j]);
                if (data->pressed_keys[j] < PICOLCD_KEYS)
                        key_code = data->keycode[data->pressed_keys[j]];
                else
                        key_code = KEY_UNKNOWN;
                if (key_code != KEY_UNKNOWN) {
                        dbg_hid(PICOLCD_NAME " got key release for %u:%d",
                                        data->pressed_keys[j], key_code);
                        input_report_key(data->input_keys, key_code, 0);
                }
                input_sync(data->input_keys);
                data->pressed_keys[j] = 0;
key_still_down:
                continue;
        }
        return 1;
}

static int picolcd_check_version(struct hid_device *hdev)
{
        struct picolcd_data *data = hid_get_drvdata(hdev);
        struct picolcd_pending *verinfo;
        int ret = 0;

        if (!data)
                return -ENODEV;

        verinfo = picolcd_send_and_wait(hdev, REPORT_VERSION, NULL, 0);
        if (!verinfo) {
                hid_err(hdev, "no version response from PicoLCD\n");
                return -ENODEV;
        }

        if (verinfo->raw_size == 2) {
                data->version[0] = verinfo->raw_data[1];
                data->version[1] = verinfo->raw_data[0];
                if (data->status & PICOLCD_BOOTLOADER) {
                        hid_info(hdev, "PicoLCD, bootloader version %d.%d\n",
                                 verinfo->raw_data[1], verinfo->raw_data[0]);
                } else {
                        hid_info(hdev, "PicoLCD, firmware version %d.%d\n",
                                 verinfo->raw_data[1], verinfo->raw_data[0]);
                }
        } else {
                hid_err(hdev, "confused, got unexpected version response from PicoLCD\n");
                ret = -EINVAL;
        }
        kfree(verinfo);
        return ret;
}

/*
 * Reset our device and wait for answer to VERSION request
 */
int picolcd_reset(struct hid_device *hdev)
{
        struct picolcd_data *data = hid_get_drvdata(hdev);
        struct hid_report *report = picolcd_out_report(REPORT_RESET, hdev);
        unsigned long flags;
        int error;

        if (!data || !report || report->maxfield != 1)
                return -ENODEV;

        spin_lock_irqsave(&data->lock, flags);
        if (hdev->product == USB_DEVICE_ID_PICOLCD_BOOTLOADER)
                data->status |= PICOLCD_BOOTLOADER;

        /* perform the reset */
        hid_set_field(report->field[0], 0, 1);
        if (data->status & PICOLCD_FAILED) {
                spin_unlock_irqrestore(&data->lock, flags);
                return -ENODEV;
        }
        hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&data->lock, flags);

        error = picolcd_check_version(hdev);
        if (error)
                return error;

        picolcd_resume_lcd(data);
        picolcd_resume_backlight(data);
        picolcd_fb_refresh(data);
        picolcd_leds_set(data);
        return 0;
}

/*
 * The "operation_mode" sysfs attribute
 */
static ssize_t picolcd_operation_mode_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct picolcd_data *data = dev_get_drvdata(dev);

        if (data->status & PICOLCD_BOOTLOADER)
                return sysfs_emit(buf, "[bootloader] lcd\n");
        else
                return sysfs_emit(buf, "bootloader [lcd]\n");
}

static ssize_t picolcd_operation_mode_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
{
        struct picolcd_data *data = dev_get_drvdata(dev);
        struct hid_report *report = NULL;
        int timeout = data->opmode_delay;
        unsigned long flags;

        if (sysfs_streq(buf, "lcd")) {
                if (data->status & PICOLCD_BOOTLOADER)
                        report = picolcd_out_report(REPORT_EXIT_FLASHER, data->hdev);
        } else if (sysfs_streq(buf, "bootloader")) {
                if (!(data->status & PICOLCD_BOOTLOADER))
                        report = picolcd_out_report(REPORT_EXIT_KEYBOARD, data->hdev);
        } else {
                return -EINVAL;
        }

        if (!report || report->maxfield != 1)
                return -EINVAL;

        spin_lock_irqsave(&data->lock, flags);
        hid_set_field(report->field[0], 0, timeout & 0xff);
        hid_set_field(report->field[0], 1, (timeout >> 8) & 0xff);
        hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&data->lock, flags);
        return count;
}

static DEVICE_ATTR(operation_mode, 0644, picolcd_operation_mode_show,
                picolcd_operation_mode_store);

/*
 * The "operation_mode_delay" sysfs attribute
 */
static ssize_t picolcd_operation_mode_delay_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct picolcd_data *data = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%hu\n", data->opmode_delay);
}

static ssize_t picolcd_operation_mode_delay_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
{
        struct picolcd_data *data = dev_get_drvdata(dev);
        unsigned u;
        if (sscanf(buf, "%u", &u) != 1)
                return -EINVAL;
        if (u > 30000)
                return -EINVAL;
        else
                data->opmode_delay = u;
        return count;
}

static DEVICE_ATTR(operation_mode_delay, 0644, picolcd_operation_mode_delay_show,
                picolcd_operation_mode_delay_store);

/*
 * Handle raw report as sent by device
 */
static int picolcd_raw_event(struct hid_device *hdev,
                struct hid_report *report, u8 *raw_data, int size)
{
        struct picolcd_data *data = hid_get_drvdata(hdev);
        unsigned long flags;

        if (!data)
                return 1;

        if (size > 64) {
                hid_warn(hdev, "invalid size value (%d) for picolcd raw event (%d)\n",
                                size, report->id);
                return 0;
        }

        if (report->id == REPORT_KEY_STATE) {
                if (data->input_keys)
                        picolcd_raw_keypad(data, report, raw_data+1, size-1);
        } else if (report->id == REPORT_IR_DATA) {
                picolcd_raw_cir(data, report, raw_data+1, size-1);
        } else {
                spin_lock_irqsave(&data->lock, flags);
                /*
                 * We let the caller of picolcd_send_and_wait() check if the
                 * report we got is one of the expected ones or not.
                 */
                if (data->pending) {
                        memcpy(data->pending->raw_data, raw_data+1, size-1);
                        data->pending->raw_size  = size-1;
                        data->pending->in_report = report;
                        complete(&data->pending->ready);
                }
                spin_unlock_irqrestore(&data->lock, flags);
        }

        picolcd_debug_raw_event(data, hdev, report, raw_data, size);
        return 1;
}

static int picolcd_suspend(struct hid_device *hdev, pm_message_t message)
{
        if (PMSG_IS_AUTO(message))
                return 0;

        picolcd_suspend_backlight(hid_get_drvdata(hdev));
        dbg_hid(PICOLCD_NAME " device ready for suspend\n");
        return 0;
}

static int picolcd_resume(struct hid_device *hdev)
{
        int ret;
        ret = picolcd_resume_backlight(hid_get_drvdata(hdev));
        if (ret)
                dbg_hid(PICOLCD_NAME " restoring backlight failed: %d\n", ret);
        return 0;
}

static int picolcd_reset_resume(struct hid_device *hdev)
{
        int ret;
        ret = picolcd_reset(hdev);
        if (ret)
                dbg_hid(PICOLCD_NAME " resetting our device failed: %d\n", ret);
        ret = picolcd_fb_reset(hid_get_drvdata(hdev), 0);
        if (ret)
                dbg_hid(PICOLCD_NAME " restoring framebuffer content failed: %d\n", ret);
        ret = picolcd_resume_lcd(hid_get_drvdata(hdev));
        if (ret)
                dbg_hid(PICOLCD_NAME " restoring lcd failed: %d\n", ret);
        ret = picolcd_resume_backlight(hid_get_drvdata(hdev));
        if (ret)
                dbg_hid(PICOLCD_NAME " restoring backlight failed: %d\n", ret);
        picolcd_leds_set(hid_get_drvdata(hdev));
        return 0;
}

/* initialize keypad input device */
static int picolcd_init_keys(struct picolcd_data *data,
                struct hid_report *report)
{
        struct hid_device *hdev = data->hdev;
        struct input_dev *idev;
        int error, i;

        if (!report)
                return -ENODEV;
        if (report->maxfield != 1 || report->field[0]->report_count != 2 ||
                        report->field[0]->report_size != 8) {
                hid_err(hdev, "unsupported KEY_STATE report\n");
                return -EINVAL;
        }

        idev = input_allocate_device();
        if (idev == NULL) {
                hid_err(hdev, "failed to allocate input device\n");
                return -ENOMEM;
        }
        input_set_drvdata(idev, hdev);
        memcpy(data->keycode, def_keymap, sizeof(def_keymap));
        idev->name = hdev->name;
        idev->phys = hdev->phys;
        idev->uniq = hdev->uniq;
        idev->id.bustype = hdev->bus;
        idev->id.vendor  = hdev->vendor;
        idev->id.product = hdev->product;
        idev->id.version = hdev->version;
        idev->dev.parent = &hdev->dev;
        idev->keycode     = &data->keycode;
        idev->keycodemax  = PICOLCD_KEYS;
        idev->keycodesize = sizeof(data->keycode[0]);
        input_set_capability(idev, EV_MSC, MSC_SCAN);
        set_bit(EV_REP, idev->evbit);
        for (i = 0; i < PICOLCD_KEYS; i++)
                input_set_capability(idev, EV_KEY, data->keycode[i]);
        error = input_register_device(idev);
        if (error) {
                hid_err(hdev, "error registering the input device\n");
                input_free_device(idev);
                return error;
        }
        data->input_keys = idev;
        return 0;
}

static void picolcd_exit_keys(struct picolcd_data *data)
{
        struct input_dev *idev = data->input_keys;

        data->input_keys = NULL;
        if (idev)
                input_unregister_device(idev);
}

static int picolcd_probe_lcd(struct hid_device *hdev, struct picolcd_data *data)
{
        int error;

        /* Setup keypad input device */
        error = picolcd_init_keys(data, picolcd_in_report(REPORT_KEY_STATE, hdev));
        if (error)
                goto err;

        /* Setup CIR input device */
        error = picolcd_init_cir(data, picolcd_in_report(REPORT_IR_DATA, hdev));
        if (error)
                goto err;

        /* Setup lcd class device */
        error = picolcd_init_lcd(data, picolcd_out_report(REPORT_CONTRAST, hdev));
        if (error)
                goto err;

        /* Setup backlight class device */
        error = picolcd_init_backlight(data, picolcd_out_report(REPORT_BRIGHTNESS, hdev));
        if (error)
                goto err;

        /* Set up the framebuffer device */
        error = picolcd_init_framebuffer(data);
        if (error)
                goto err;

        /* Setup the LED class devices */
        error = picolcd_init_leds(data, picolcd_out_report(REPORT_LED_STATE, hdev));
        if (error)
                goto err;

        picolcd_init_devfs(data, picolcd_out_report(REPORT_EE_READ, hdev),
                        picolcd_out_report(REPORT_EE_WRITE, hdev),
                        picolcd_out_report(REPORT_READ_MEMORY, hdev),
                        picolcd_out_report(REPORT_WRITE_MEMORY, hdev),
                        picolcd_out_report(REPORT_RESET, hdev));
        return 0;
err:
        picolcd_exit_leds(data);
        picolcd_exit_framebuffer(data);
        picolcd_exit_backlight(data);
        picolcd_exit_lcd(data);
        picolcd_exit_cir(data);
        picolcd_exit_keys(data);
        return error;
}

static int picolcd_probe_bootloader(struct hid_device *hdev, struct picolcd_data *data)
{
        picolcd_init_devfs(data, NULL, NULL,
                        picolcd_out_report(REPORT_BL_READ_MEMORY, hdev),
                        picolcd_out_report(REPORT_BL_WRITE_MEMORY, hdev), NULL);
        return 0;
}

static int picolcd_probe(struct hid_device *hdev,
                     const struct hid_device_id *id)
{
        struct picolcd_data *data;
        int error = -ENOMEM;

        dbg_hid(PICOLCD_NAME " hardware probe...\n");

        /*
         * Let's allocate the picolcd data structure, set some reasonable
         * defaults, and associate it with the device
         */
        data = kzalloc_obj(struct picolcd_data);
        if (data == NULL) {
                hid_err(hdev, "can't allocate space for Minibox PicoLCD device data\n");
                return -ENOMEM;
        }

        spin_lock_init(&data->lock);
        mutex_init(&data->mutex);
        data->hdev = hdev;
        data->opmode_delay = 5000;
        if (hdev->product == USB_DEVICE_ID_PICOLCD_BOOTLOADER)
                data->status |= PICOLCD_BOOTLOADER;
        hid_set_drvdata(hdev, data);

        /* Parse the device reports and start it up */
        error = hid_parse(hdev);
        if (error) {
                hid_err(hdev, "device report parse failed\n");
                goto err_cleanup_data;
        }

        error = hid_hw_start(hdev, 0);
        if (error) {
                hid_err(hdev, "hardware start failed\n");
                goto err_cleanup_data;
        }

        error = hid_hw_open(hdev);
        if (error) {
                hid_err(hdev, "failed to open input interrupt pipe for key and IR events\n");
                goto err_cleanup_hid_hw;
        }

        error = device_create_file(&hdev->dev, &dev_attr_operation_mode_delay);
        if (error) {
                hid_err(hdev, "failed to create sysfs attributes\n");
                goto err_cleanup_hid_ll;
        }

        error = device_create_file(&hdev->dev, &dev_attr_operation_mode);
        if (error) {
                hid_err(hdev, "failed to create sysfs attributes\n");
                goto err_cleanup_sysfs1;
        }

        if (data->status & PICOLCD_BOOTLOADER)
                error = picolcd_probe_bootloader(hdev, data);
        else
                error = picolcd_probe_lcd(hdev, data);
        if (error)
                goto err_cleanup_sysfs2;

        dbg_hid(PICOLCD_NAME " activated and initialized\n");
        return 0;

err_cleanup_sysfs2:
        device_remove_file(&hdev->dev, &dev_attr_operation_mode);
err_cleanup_sysfs1:
        device_remove_file(&hdev->dev, &dev_attr_operation_mode_delay);
err_cleanup_hid_ll:
        hid_hw_close(hdev);
err_cleanup_hid_hw:
        hid_hw_stop(hdev);
err_cleanup_data:
        kfree(data);
        return error;
}

static void picolcd_remove(struct hid_device *hdev)
{
        struct picolcd_data *data = hid_get_drvdata(hdev);
        unsigned long flags;

        dbg_hid(PICOLCD_NAME " hardware remove...\n");
        spin_lock_irqsave(&data->lock, flags);
        data->status |= PICOLCD_FAILED;
        spin_unlock_irqrestore(&data->lock, flags);

        picolcd_exit_devfs(data);
        device_remove_file(&hdev->dev, &dev_attr_operation_mode);
        device_remove_file(&hdev->dev, &dev_attr_operation_mode_delay);
        hid_hw_close(hdev);
        hid_hw_stop(hdev);

        /* Shortcut potential pending reply that will never arrive */
        spin_lock_irqsave(&data->lock, flags);
        if (data->pending)
                complete(&data->pending->ready);
        spin_unlock_irqrestore(&data->lock, flags);

        /* Cleanup LED */
        picolcd_exit_leds(data);
        /* Clean up the framebuffer */
        picolcd_exit_framebuffer(data);
        picolcd_exit_backlight(data);
        picolcd_exit_lcd(data);
        /* Cleanup input */
        picolcd_exit_cir(data);
        picolcd_exit_keys(data);

        mutex_destroy(&data->mutex);
        /* Finally, clean up the picolcd data itself */
        kfree(data);
}

static const struct hid_device_id picolcd_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_PICOLCD) },
        { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_PICOLCD_BOOTLOADER) },
        { }
};
MODULE_DEVICE_TABLE(hid, picolcd_devices);

static struct hid_driver picolcd_driver = {
        .name =          "hid-picolcd",
        .id_table =      picolcd_devices,
        .probe =         picolcd_probe,
        .remove =        picolcd_remove,
        .raw_event =     picolcd_raw_event,
        .suspend =       pm_ptr(picolcd_suspend),
        .resume =        pm_ptr(picolcd_resume),
        .reset_resume =  pm_ptr(picolcd_reset_resume),
};
module_hid_driver(picolcd_driver);

MODULE_DESCRIPTION("Minibox graphics PicoLCD Driver");
MODULE_LICENSE("GPL v2");