/*
 *  Copyright (c) 2013 Andrew Duggan <aduggan@synaptics.com>
 *  Copyright (c) 2013 Synaptics Incorporated
 *  Copyright (c) 2014 Benjamin Tissoires <benjamin.tissoires@gmail.com>
 *  Copyright (c) 2014 Red Hat, Inc
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/kernel.h>
#include <linux/hid.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include "hid-ids.h"

#define RMI_MOUSE_REPORT_ID             0x01 /* Mouse emulation Report */
#define RMI_WRITE_REPORT_ID             0x09 /* Output Report */
#define RMI_READ_ADDR_REPORT_ID         0x0a /* Output Report */
#define RMI_READ_DATA_REPORT_ID         0x0b /* Input Report */
#define RMI_ATTN_REPORT_ID              0x0c /* Input Report */
#define RMI_SET_RMI_MODE_REPORT_ID      0x0f /* Feature Report */

/* flags */
#define RMI_READ_REQUEST_PENDING        BIT(0)
#define RMI_READ_DATA_PENDING           BIT(1)
#define RMI_STARTED                     BIT(2)

enum rmi_mode_type {
        RMI_MODE_OFF                    = 0,
        RMI_MODE_ATTN_REPORTS           = 1,
        RMI_MODE_NO_PACKED_ATTN_REPORTS = 2,
};

struct rmi_function {
        unsigned page;                  /* page of the function */
        u16 query_base_addr;            /* base address for queries */
        u16 command_base_addr;          /* base address for commands */
        u16 control_base_addr;          /* base address for controls */
        u16 data_base_addr;             /* base address for datas */
        unsigned int interrupt_base;    /* cross-function interrupt number
                                         * (uniq in the device)*/
        unsigned int interrupt_count;   /* number of interrupts */
        unsigned int report_size;       /* size of a report */
        unsigned long irq_mask;         /* mask of the interrupts
                                         * (to be applied against ATTN IRQ) */
};

/**
 * struct rmi_data - stores information for hid communication
 *
 * @page_mutex: Locks current page to avoid changing pages in unexpected ways.
 * @page: Keeps track of the current virtual page
 *
 * @wait: Used for waiting for read data
 *
 * @writeReport: output buffer when writing RMI registers
 * @readReport: input buffer when reading RMI registers
 *
 * @input_report_size: size of an input report (advertised by HID)
 * @output_report_size: size of an output report (advertised by HID)
 *
 * @flags: flags for the current device (started, reading, etc...)
 *
 * @f11: placeholder of internal RMI function F11 description
 * @f30: placeholder of internal RMI function F30 description
 *
 * @max_fingers: maximum finger count reported by the device
 * @max_x: maximum x value reported by the device
 * @max_y: maximum y value reported by the device
 *
 * @gpio_led_count: count of GPIOs + LEDs reported by F30
 * @button_count: actual physical buttons count
 * @button_mask: button mask used to decode GPIO ATTN reports
 * @button_state_mask: pull state of the buttons
 *
 * @input: pointer to the kernel input device
 *
 * @reset_work: worker which will be called in case of a mouse report
 * @hdev: pointer to the struct hid_device
 */
struct rmi_data {
        struct mutex page_mutex;
        int page;

        wait_queue_head_t wait;

        u8 *writeReport;
        u8 *readReport;

        int input_report_size;
        int output_report_size;

        unsigned long flags;

        struct rmi_function f11;
        struct rmi_function f30;

        unsigned int max_fingers;
        unsigned int max_x;
        unsigned int max_y;
        unsigned int x_size_mm;
        unsigned int y_size_mm;

        unsigned int gpio_led_count;
        unsigned int button_count;
        unsigned long button_mask;
        unsigned long button_state_mask;

        struct input_dev *input;

        struct work_struct reset_work;
        struct hid_device *hdev;
};

#define RMI_PAGE(addr) (((addr) >> 8) & 0xff)

static int rmi_write_report(struct hid_device *hdev, u8 *report, int len);

/**
 * rmi_set_page - Set RMI page
 * @hdev: The pointer to the hid_device struct
 * @page: The new page address.
 *
 * RMI devices have 16-bit addressing, but some of the physical
 * implementations (like SMBus) only have 8-bit addressing. So RMI implements
 * a page address at 0xff of every page so we can reliable page addresses
 * every 256 registers.
 *
 * The page_mutex lock must be held when this function is entered.
 *
 * Returns zero on success, non-zero on failure.
 */
static int rmi_set_page(struct hid_device *hdev, u8 page)
{
        struct rmi_data *data = hid_get_drvdata(hdev);
        int retval;

        data->writeReport[0] = RMI_WRITE_REPORT_ID;
        data->writeReport[1] = 1;
        data->writeReport[2] = 0xFF;
        data->writeReport[4] = page;

        retval = rmi_write_report(hdev, data->writeReport,
                        data->output_report_size);
        if (retval != data->output_report_size) {
                dev_err(&hdev->dev,
                        "%s: set page failed: %d.", __func__, retval);
                return retval;
        }

        data->page = page;
        return 0;
}

static int rmi_set_mode(struct hid_device *hdev, u8 mode)
{
        int ret;
        u8 txbuf[2] = {RMI_SET_RMI_MODE_REPORT_ID, mode};

        ret = hid_hw_raw_request(hdev, RMI_SET_RMI_MODE_REPORT_ID, txbuf,
                        sizeof(txbuf), HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
        if (ret < 0) {
                dev_err(&hdev->dev, "unable to set rmi mode to %d (%d)\n", mode,
                        ret);
                return ret;
        }

        return 0;
}

static int rmi_write_report(struct hid_device *hdev, u8 *report, int len)
{
        int ret;

        ret = hid_hw_output_report(hdev, (void *)report, len);
        if (ret < 0) {
                dev_err(&hdev->dev, "failed to write hid report (%d)\n", ret);
                return ret;
        }

        return ret;
}

static int rmi_read_block(struct hid_device *hdev, u16 addr, void *buf,
                const int len)
{
        struct rmi_data *data = hid_get_drvdata(hdev);
        int ret;
        int bytes_read;
        int bytes_needed;
        int retries;
        int read_input_count;

        mutex_lock(&data->page_mutex);

        if (RMI_PAGE(addr) != data->page) {
                ret = rmi_set_page(hdev, RMI_PAGE(addr));
                if (ret < 0)
                        goto exit;
        }

        for (retries = 5; retries > 0; retries--) {
                data->writeReport[0] = RMI_READ_ADDR_REPORT_ID;
                data->writeReport[1] = 0; /* old 1 byte read count */
                data->writeReport[2] = addr & 0xFF;
                data->writeReport[3] = (addr >> 8) & 0xFF;
                data->writeReport[4] = len  & 0xFF;
                data->writeReport[5] = (len >> 8) & 0xFF;

                set_bit(RMI_READ_REQUEST_PENDING, &data->flags);

                ret = rmi_write_report(hdev, data->writeReport,
                                                data->output_report_size);
                if (ret != data->output_report_size) {
                        clear_bit(RMI_READ_REQUEST_PENDING, &data->flags);
                        dev_err(&hdev->dev,
                                "failed to write request output report (%d)\n",
                                ret);
                        goto exit;
                }

                bytes_read = 0;
                bytes_needed = len;
                while (bytes_read < len) {
                        if (!wait_event_timeout(data->wait,
                                test_bit(RMI_READ_DATA_PENDING, &data->flags),
                                        msecs_to_jiffies(1000))) {
                                hid_warn(hdev, "%s: timeout elapsed\n",
                                         __func__);
                                ret = -EAGAIN;
                                break;
                        }

                        read_input_count = data->readReport[1];
                        memcpy(buf + bytes_read, &data->readReport[2],
                                read_input_count < bytes_needed ?
                                        read_input_count : bytes_needed);

                        bytes_read += read_input_count;
                        bytes_needed -= read_input_count;
                        clear_bit(RMI_READ_DATA_PENDING, &data->flags);
                }

                if (ret >= 0) {
                        ret = 0;
                        break;
                }
        }

exit:
        clear_bit(RMI_READ_REQUEST_PENDING, &data->flags);
        mutex_unlock(&data->page_mutex);
        return ret;
}

static inline int rmi_read(struct hid_device *hdev, u16 addr, void *buf)
{
        return rmi_read_block(hdev, addr, buf, 1);
}

static void rmi_f11_process_touch(struct rmi_data *hdata, int slot,
                u8 finger_state, u8 *touch_data)
{
        int x, y, wx, wy;
        int wide, major, minor;
        int z;

        input_mt_slot(hdata->input, slot);
        input_mt_report_slot_state(hdata->input, MT_TOOL_FINGER,
                        finger_state == 0x01);
        if (finger_state == 0x01) {
                x = (touch_data[0] << 4) | (touch_data[2] & 0x0F);
                y = (touch_data[1] << 4) | (touch_data[2] >> 4);
                wx = touch_data[3] & 0x0F;
                wy = touch_data[3] >> 4;
                wide = (wx > wy);
                major = max(wx, wy);
                minor = min(wx, wy);
                z = touch_data[4];

                /* y is inverted */
                y = hdata->max_y - y;

                input_event(hdata->input, EV_ABS, ABS_MT_POSITION_X, x);
                input_event(hdata->input, EV_ABS, ABS_MT_POSITION_Y, y);
                input_event(hdata->input, EV_ABS, ABS_MT_ORIENTATION, wide);
                input_event(hdata->input, EV_ABS, ABS_MT_PRESSURE, z);
                input_event(hdata->input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
                input_event(hdata->input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
        }
}

static void rmi_reset_work(struct work_struct *work)
{
        struct rmi_data *hdata = container_of(work, struct rmi_data,
                                                reset_work);

        /* switch the device to RMI if we receive a generic mouse report */
        rmi_set_mode(hdata->hdev, RMI_MODE_ATTN_REPORTS);
}

static inline int rmi_schedule_reset(struct hid_device *hdev)
{
        struct rmi_data *hdata = hid_get_drvdata(hdev);
        return schedule_work(&hdata->reset_work);
}

static int rmi_f11_input_event(struct hid_device *hdev, u8 irq, u8 *data,
                int size)
{
        struct rmi_data *hdata = hid_get_drvdata(hdev);
        int offset;
        int i;

        if (!(irq & hdata->f11.irq_mask) || size <= 0)
                return 0;

        offset = (hdata->max_fingers >> 2) + 1;
        for (i = 0; i < hdata->max_fingers; i++) {
                int fs_byte_position = i >> 2;
                int fs_bit_position = (i & 0x3) << 1;
                int finger_state = (data[fs_byte_position] >> fs_bit_position) &
                                        0x03;
                int position = offset + 5 * i;

                if (position + 5 > size) {
                        /* partial report, go on with what we received */
                        printk_once(KERN_WARNING
                                "%s %s: Detected incomplete finger report. Finger reports may occasionally get dropped on this platform.\n",
                                 dev_driver_string(&hdev->dev),
                                 dev_name(&hdev->dev));
                        hid_dbg(hdev, "Incomplete finger report\n");
                        break;
                }

                rmi_f11_process_touch(hdata, i, finger_state, &data[position]);
        }
        input_mt_sync_frame(hdata->input);
        input_sync(hdata->input);
        return hdata->f11.report_size;
}

static int rmi_f30_input_event(struct hid_device *hdev, u8 irq, u8 *data,
                int size)
{
        struct rmi_data *hdata = hid_get_drvdata(hdev);
        int i;
        int button = 0;
        bool value;

        if (!(irq & hdata->f30.irq_mask))
                return 0;

        if (size < (int)hdata->f30.report_size) {
                hid_warn(hdev, "Click Button pressed, but the click data is missing\n");
                return 0;
        }

        for (i = 0; i < hdata->gpio_led_count; i++) {
                if (test_bit(i, &hdata->button_mask)) {
                        value = (data[i / 8] >> (i & 0x07)) & BIT(0);
                        if (test_bit(i, &hdata->button_state_mask))
                                value = !value;
                        input_event(hdata->input, EV_KEY, BTN_LEFT + button++,
                                        value);
                }
        }
        return hdata->f30.report_size;
}

static int rmi_input_event(struct hid_device *hdev, u8 *data, int size)
{
        struct rmi_data *hdata = hid_get_drvdata(hdev);
        unsigned long irq_mask = 0;
        unsigned index = 2;

        if (!(test_bit(RMI_STARTED, &hdata->flags)))
                return 0;

        irq_mask |= hdata->f11.irq_mask;
        irq_mask |= hdata->f30.irq_mask;

        if (data[1] & ~irq_mask)
                hid_dbg(hdev, "unknown intr source:%02lx %s:%d\n",
                        data[1] & ~irq_mask, __FILE__, __LINE__);

        if (hdata->f11.interrupt_base < hdata->f30.interrupt_base) {
                index += rmi_f11_input_event(hdev, data[1], &data[index],
                                size - index);
                index += rmi_f30_input_event(hdev, data[1], &data[index],
                                size - index);
        } else {
                index += rmi_f30_input_event(hdev, data[1], &data[index],
                                size - index);
                index += rmi_f11_input_event(hdev, data[1], &data[index],
                                size - index);
        }

        return 1;
}

static int rmi_read_data_event(struct hid_device *hdev, u8 *data, int size)
{
        struct rmi_data *hdata = hid_get_drvdata(hdev);

        if (!test_bit(RMI_READ_REQUEST_PENDING, &hdata->flags)) {
                hid_dbg(hdev, "no read request pending\n");
                return 0;
        }

        memcpy(hdata->readReport, data, size < hdata->input_report_size ?
                        size : hdata->input_report_size);
        set_bit(RMI_READ_DATA_PENDING, &hdata->flags);
        wake_up(&hdata->wait);

        return 1;
}

static int rmi_check_sanity(struct hid_device *hdev, u8 *data, int size)
{
        int valid_size = size;
        /*
         * On the Dell XPS 13 9333, the bus sometimes get confused and fills
         * the report with a sentinel value "ff". Synaptics told us that such
         * behavior does not comes from the touchpad itself, so we filter out
         * such reports here.
         */

        while ((data[valid_size - 1] == 0xff) && valid_size > 0)
                valid_size--;

        return valid_size;
}

static int rmi_raw_event(struct hid_device *hdev,
                struct hid_report *report, u8 *data, int size)
{
        size = rmi_check_sanity(hdev, data, size);
        if (size < 2)
                return 0;

        switch (data[0]) {
        case RMI_READ_DATA_REPORT_ID:
                return rmi_read_data_event(hdev, data, size);
        case RMI_ATTN_REPORT_ID:
                return rmi_input_event(hdev, data, size);
        case RMI_MOUSE_REPORT_ID:
                rmi_schedule_reset(hdev);
                break;
        }

        return 0;
}

#ifdef CONFIG_PM
static int rmi_post_reset(struct hid_device *hdev)
{
        return rmi_set_mode(hdev, RMI_MODE_ATTN_REPORTS);
}

static int rmi_post_resume(struct hid_device *hdev)
{
        return rmi_set_mode(hdev, RMI_MODE_ATTN_REPORTS);
}
#endif /* CONFIG_PM */

#define RMI4_MAX_PAGE 0xff
#define RMI4_PAGE_SIZE 0x0100

#define PDT_START_SCAN_LOCATION 0x00e9
#define PDT_END_SCAN_LOCATION   0x0005
#define RMI4_END_OF_PDT(id) ((id) == 0x00 || (id) == 0xff)

struct pdt_entry {
        u8 query_base_addr:8;
        u8 command_base_addr:8;
        u8 control_base_addr:8;
        u8 data_base_addr:8;
        u8 interrupt_source_count:3;
        u8 bits3and4:2;
        u8 function_version:2;
        u8 bit7:1;
        u8 function_number:8;
} __attribute__((__packed__));

static inline unsigned long rmi_gen_mask(unsigned irq_base, unsigned irq_count)
{
        return GENMASK(irq_count + irq_base - 1, irq_base);
}

static void rmi_register_function(struct rmi_data *data,
        struct pdt_entry *pdt_entry, int page, unsigned interrupt_count)
{
        struct rmi_function *f = NULL;
        u16 page_base = page << 8;

        switch (pdt_entry->function_number) {
        case 0x11:
                f = &data->f11;
                break;
        case 0x30:
                f = &data->f30;
                break;
        }

        if (f) {
                f->page = page;
                f->query_base_addr = page_base | pdt_entry->query_base_addr;
                f->command_base_addr = page_base | pdt_entry->command_base_addr;
                f->control_base_addr = page_base | pdt_entry->control_base_addr;
                f->data_base_addr = page_base | pdt_entry->data_base_addr;
                f->interrupt_base = interrupt_count;
                f->interrupt_count = pdt_entry->interrupt_source_count;
                f->irq_mask = rmi_gen_mask(f->interrupt_base,
                                                f->interrupt_count);
        }
}

static int rmi_scan_pdt(struct hid_device *hdev)
{
        struct rmi_data *data = hid_get_drvdata(hdev);
        struct pdt_entry entry;
        int page;
        bool page_has_function;
        int i;
        int retval;
        int interrupt = 0;
        u16 page_start, pdt_start , pdt_end;

        hid_info(hdev, "Scanning PDT...\n");

        for (page = 0; (page <= RMI4_MAX_PAGE); page++) {
                page_start = RMI4_PAGE_SIZE * page;
                pdt_start = page_start + PDT_START_SCAN_LOCATION;
                pdt_end = page_start + PDT_END_SCAN_LOCATION;

                page_has_function = false;
                for (i = pdt_start; i >= pdt_end; i -= sizeof(entry)) {
                        retval = rmi_read_block(hdev, i, &entry, sizeof(entry));
                        if (retval) {
                                hid_err(hdev,
                                        "Read of PDT entry at %#06x failed.\n",
                                        i);
                                goto error_exit;
                        }

                        if (RMI4_END_OF_PDT(entry.function_number))
                                break;

                        page_has_function = true;

                        hid_info(hdev, "Found F%02X on page %#04x\n",
                                        entry.function_number, page);

                        rmi_register_function(data, &entry, page, interrupt);
                        interrupt += entry.interrupt_source_count;
                }

                if (!page_has_function)
                        break;
        }

        hid_info(hdev, "%s: Done with PDT scan.\n", __func__);
        retval = 0;

error_exit:
        return retval;
}

static int rmi_populate_f11(struct hid_device *hdev)
{
        struct rmi_data *data = hid_get_drvdata(hdev);
        u8 buf[20];
        int ret;
        bool has_query9;
        bool has_query10 = false;
        bool has_query11;
        bool has_query12;
        bool has_query27;
        bool has_query28;
        bool has_query36 = false;
        bool has_physical_props;
        bool has_gestures;
        bool has_rel;
        bool has_data40 = false;
        unsigned x_size, y_size;
        u16 query_offset;

        if (!data->f11.query_base_addr) {
                hid_err(hdev, "No 2D sensor found, giving up.\n");
                return -ENODEV;
        }

        /* query 0 contains some useful information */
        ret = rmi_read(hdev, data->f11.query_base_addr, buf);
        if (ret) {
                hid_err(hdev, "can not get query 0: %d.\n", ret);
                return ret;
        }
        has_query9 = !!(buf[0] & BIT(3));
        has_query11 = !!(buf[0] & BIT(4));
        has_query12 = !!(buf[0] & BIT(5));
        has_query27 = !!(buf[0] & BIT(6));
        has_query28 = !!(buf[0] & BIT(7));

        /* query 1 to get the max number of fingers */
        ret = rmi_read(hdev, data->f11.query_base_addr + 1, buf);
        if (ret) {
                hid_err(hdev, "can not get NumberOfFingers: %d.\n", ret);
                return ret;
        }
        data->max_fingers = (buf[0] & 0x07) + 1;
        if (data->max_fingers > 5)
                data->max_fingers = 10;

        data->f11.report_size = data->max_fingers * 5 +
                                DIV_ROUND_UP(data->max_fingers, 4);

        if (!(buf[0] & BIT(4))) {
                hid_err(hdev, "No absolute events, giving up.\n");
                return -ENODEV;
        }

        has_rel = !!(buf[0] & BIT(3));
        has_gestures = !!(buf[0] & BIT(5));

        /*
         * At least 4 queries are guaranteed to be present in F11
         * +1 for query 5 which is present since absolute events are
         * reported and +1 for query 12.
         */
        query_offset = 6;

        if (has_rel)
                ++query_offset; /* query 6 is present */

        if (has_gestures) {
                /* query 8 to find out if query 10 exists */
                ret = rmi_read(hdev,
                        data->f11.query_base_addr + query_offset + 1, buf);
                if (ret) {
                        hid_err(hdev, "can not read gesture information: %d.\n",
                                ret);
                        return ret;
                }
                has_query10 = !!(buf[0] & BIT(2));

                query_offset += 2; /* query 7 and 8 are present */
        }

        if (has_query9)
                ++query_offset;

        if (has_query10)
                ++query_offset;

        if (has_query11)
                ++query_offset;

        /* query 12 to know if the physical properties are reported */
        if (has_query12) {
                ret = rmi_read(hdev, data->f11.query_base_addr
                                + query_offset, buf);
                if (ret) {
                        hid_err(hdev, "can not get query 12: %d.\n", ret);
                        return ret;
                }
                has_physical_props = !!(buf[0] & BIT(5));

                if (has_physical_props) {
                        query_offset += 1;
                        ret = rmi_read_block(hdev,
                                        data->f11.query_base_addr
                                                + query_offset, buf, 4);
                        if (ret) {
                                hid_err(hdev, "can not read query 15-18: %d.\n",
                                        ret);
                                return ret;
                        }

                        x_size = buf[0] | (buf[1] << 8);
                        y_size = buf[2] | (buf[3] << 8);

                        data->x_size_mm = DIV_ROUND_CLOSEST(x_size, 10);
                        data->y_size_mm = DIV_ROUND_CLOSEST(y_size, 10);

                        hid_info(hdev, "%s: size in mm: %d x %d\n",
                                 __func__, data->x_size_mm, data->y_size_mm);

                        /*
                         * query 15 - 18 contain the size of the sensor
                         * and query 19 - 26 contain bezel dimensions
                         */
                        query_offset += 12;
                }
        }

        if (has_query27)
                ++query_offset;

        if (has_query28) {
                ret = rmi_read(hdev, data->f11.query_base_addr
                                + query_offset, buf);
                if (ret) {
                        hid_err(hdev, "can not get query 28: %d.\n", ret);
                        return ret;
                }

                has_query36 = !!(buf[0] & BIT(6));
        }

        if (has_query36) {
                query_offset += 2;
                ret = rmi_read(hdev, data->f11.query_base_addr
                                + query_offset, buf);
                if (ret) {
                        hid_err(hdev, "can not get query 36: %d.\n", ret);
                        return ret;
                }

                has_data40 = !!(buf[0] & BIT(5));
        }


        if (has_data40)
                data->f11.report_size += data->max_fingers * 2;

        /*
         * retrieve the ctrl registers
         * the ctrl register has a size of 20 but a fw bug split it into 16 + 4,
         * and there is no way to know if the first 20 bytes are here or not.
         * We use only the first 10 bytes, so get only them.
         */
        ret = rmi_read_block(hdev, data->f11.control_base_addr, buf, 10);
        if (ret) {
                hid_err(hdev, "can not read ctrl block of size 10: %d.\n", ret);
                return ret;
        }

        data->max_x = buf[6] | (buf[7] << 8);
        data->max_y = buf[8] | (buf[9] << 8);

        return 0;
}

static int rmi_populate_f30(struct hid_device *hdev)
{
        struct rmi_data *data = hid_get_drvdata(hdev);
        u8 buf[20];
        int ret;
        bool has_gpio, has_led;
        unsigned bytes_per_ctrl;
        u8 ctrl2_addr;
        int ctrl2_3_length;
        int i;

        /* function F30 is for physical buttons */
        if (!data->f30.query_base_addr) {
                hid_err(hdev, "No GPIO/LEDs found, giving up.\n");
                return -ENODEV;
        }

        ret = rmi_read_block(hdev, data->f30.query_base_addr, buf, 2);
        if (ret) {
                hid_err(hdev, "can not get F30 query registers: %d.\n", ret);
                return ret;
        }

        has_gpio = !!(buf[0] & BIT(3));
        has_led = !!(buf[0] & BIT(2));
        data->gpio_led_count = buf[1] & 0x1f;

        /* retrieve ctrl 2 & 3 registers */
        bytes_per_ctrl = (data->gpio_led_count + 7) / 8;
        /* Ctrl0 is present only if both has_gpio and has_led are set*/
        ctrl2_addr = (has_gpio && has_led) ? bytes_per_ctrl : 0;
        /* Ctrl1 is always be present */
        ctrl2_addr += bytes_per_ctrl;
        ctrl2_3_length = 2 * bytes_per_ctrl;

        data->f30.report_size = bytes_per_ctrl;

        ret = rmi_read_block(hdev, data->f30.control_base_addr + ctrl2_addr,
                                buf, ctrl2_3_length);
        if (ret) {
                hid_err(hdev, "can not read ctrl 2&3 block of size %d: %d.\n",
                        ctrl2_3_length, ret);
                return ret;
        }

        for (i = 0; i < data->gpio_led_count; i++) {
                int byte_position = i >> 3;
                int bit_position = i & 0x07;
                u8 dir_byte = buf[byte_position];
                u8 data_byte = buf[byte_position + bytes_per_ctrl];
                bool dir = (dir_byte >> bit_position) & BIT(0);
                bool dat = (data_byte >> bit_position) & BIT(0);

                if (dir == 0) {
                        /* input mode */
                        if (dat) {
                                /* actual buttons have pull up resistor */
                                data->button_count++;
                                set_bit(i, &data->button_mask);
                                set_bit(i, &data->button_state_mask);
                        }
                }

        }

        return 0;
}

static int rmi_populate(struct hid_device *hdev)
{
        int ret;

        ret = rmi_scan_pdt(hdev);
        if (ret) {
                hid_err(hdev, "PDT scan failed with code %d.\n", ret);
                return ret;
        }

        ret = rmi_populate_f11(hdev);
        if (ret) {
                hid_err(hdev, "Error while initializing F11 (%d).\n", ret);
                return ret;
        }

        ret = rmi_populate_f30(hdev);
        if (ret)
                hid_warn(hdev, "Error while initializing F30 (%d).\n", ret);

        return 0;
}

static void rmi_input_configured(struct hid_device *hdev, struct hid_input *hi)
{
        struct rmi_data *data = hid_get_drvdata(hdev);
        struct input_dev *input = hi->input;
        int ret;
        int res_x, res_y, i;

        data->input = input;

        hid_dbg(hdev, "Opening low level driver\n");
        ret = hid_hw_open(hdev);
        if (ret)
                return;

        /* Allow incoming hid reports */
        hid_device_io_start(hdev);

        ret = rmi_set_mode(hdev, RMI_MODE_ATTN_REPORTS);
        if (ret < 0) {
                dev_err(&hdev->dev, "failed to set rmi mode\n");
                goto exit;
        }

        ret = rmi_set_page(hdev, 0);
        if (ret < 0) {
                dev_err(&hdev->dev, "failed to set page select to 0.\n");
                goto exit;
        }

        ret = rmi_populate(hdev);
        if (ret)
                goto exit;

        __set_bit(EV_ABS, input->evbit);
        input_set_abs_params(input, ABS_MT_POSITION_X, 1, data->max_x, 0, 0);
        input_set_abs_params(input, ABS_MT_POSITION_Y, 1, data->max_y, 0, 0);

        if (data->x_size_mm && data->y_size_mm) {
                res_x = (data->max_x - 1) / data->x_size_mm;
                res_y = (data->max_y - 1) / data->y_size_mm;

                input_abs_set_res(input, ABS_MT_POSITION_X, res_x);
                input_abs_set_res(input, ABS_MT_POSITION_Y, res_y);
        }

        input_set_abs_params(input, ABS_MT_ORIENTATION, 0, 1, 0, 0);
        input_set_abs_params(input, ABS_MT_PRESSURE, 0, 0xff, 0, 0);
        input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 0x0f, 0, 0);
        input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 0x0f, 0, 0);

        input_mt_init_slots(input, data->max_fingers, INPUT_MT_POINTER);

        if (data->button_count) {
                __set_bit(EV_KEY, input->evbit);
                for (i = 0; i < data->button_count; i++)
                        __set_bit(BTN_LEFT + i, input->keybit);

                if (data->button_count == 1)
                        __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
        }

        set_bit(RMI_STARTED, &data->flags);

exit:
        hid_device_io_stop(hdev);
        hid_hw_close(hdev);
}

static int rmi_input_mapping(struct hid_device *hdev,
                struct hid_input *hi, struct hid_field *field,
                struct hid_usage *usage, unsigned long **bit, int *max)
{
        /* we want to make HID ignore the advertised HID collection */
        return -1;
}

static int rmi_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        struct rmi_data *data = NULL;
        int ret;
        size_t alloc_size;
        struct hid_report *input_report;
        struct hid_report *output_report;

        data = devm_kzalloc(&hdev->dev, sizeof(struct rmi_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        INIT_WORK(&data->reset_work, rmi_reset_work);
        data->hdev = hdev;

        hid_set_drvdata(hdev, data);

        hdev->quirks |= HID_QUIRK_NO_INIT_REPORTS;

        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "parse failed\n");
                return ret;
        }

        input_report = hdev->report_enum[HID_INPUT_REPORT]
                        .report_id_hash[RMI_ATTN_REPORT_ID];
        if (!input_report) {
                hid_err(hdev, "device does not have expected input report\n");
                ret = -ENODEV;
                return ret;
        }

        data->input_report_size = (input_report->size >> 3) + 1 /* report id */;

        output_report = hdev->report_enum[HID_OUTPUT_REPORT]
                        .report_id_hash[RMI_WRITE_REPORT_ID];
        if (!output_report) {
                hid_err(hdev, "device does not have expected output report\n");
                ret = -ENODEV;
                return ret;
        }

        data->output_report_size = (output_report->size >> 3)
                                        + 1 /* report id */;

        alloc_size = data->output_report_size + data->input_report_size;

        data->writeReport = devm_kzalloc(&hdev->dev, alloc_size, GFP_KERNEL);
        if (!data->writeReport) {
                ret = -ENOMEM;
                return ret;
        }

        data->readReport = data->writeReport + data->output_report_size;

        init_waitqueue_head(&data->wait);

        mutex_init(&data->page_mutex);

        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
        if (ret) {
                hid_err(hdev, "hw start failed\n");
                return ret;
        }

        if (!test_bit(RMI_STARTED, &data->flags))
                /*
                 * The device maybe in the bootloader if rmi_input_configured
                 * failed to find F11 in the PDT. Print an error, but don't
                 * return an error from rmi_probe so that hidraw will be
                 * accessible from userspace. That way a userspace tool
                 * can be used to reload working firmware on the touchpad.
                 */
                hid_err(hdev, "Device failed to be properly configured\n");

        return 0;
}

static void rmi_remove(struct hid_device *hdev)

{
        struct rmi_data *hdata = hid_get_drvdata(hdev);

        clear_bit(RMI_STARTED, &hdata->flags);

        hid_hw_stop(hdev);
}

static const struct hid_device_id rmi_id[] = {
        { HID_DEVICE(HID_BUS_ANY, HID_GROUP_RMI, HID_ANY_ID, HID_ANY_ID) },
        { }
};
MODULE_DEVICE_TABLE(hid, rmi_id);

static struct hid_driver rmi_driver = {
        .name = "hid-rmi",
        .id_table               = rmi_id,
        .probe                  = rmi_probe,
        .remove                 = rmi_remove,
        .raw_event              = rmi_raw_event,
        .input_mapping          = rmi_input_mapping,
        .input_configured       = rmi_input_configured,
#ifdef CONFIG_PM
        .resume                 = rmi_post_resume,
        .reset_resume           = rmi_post_reset,
#endif
};

module_hid_driver(rmi_driver);

MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
MODULE_DESCRIPTION("RMI HID driver");
MODULE_LICENSE("GPL");