/*
 * Copyright (c) 2011-2016 Synaptics Incorporated
 * Copyright (c) 2011 Unixphere
 *
 * This driver provides the core support for a single RMI4-based device.
 *
 * The RMI4 specification can be found here (URL split for line length):
 *
 * http://www.synaptics.com/sites/default/files/
 *      511-000136-01-Rev-E-RMI4-Interfacing-Guide.pdf
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/bitmap.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/irq.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <uapi/linux/input.h>
#include <linux/rmi.h>
#include "rmi_bus.h"
#include "rmi_driver.h"

#define HAS_NONSTANDARD_PDT_MASK 0x40
#define RMI4_MAX_PAGE 0xff
#define RMI4_PAGE_SIZE 0x100
#define RMI4_PAGE_MASK 0xFF00

#define RMI_DEVICE_RESET_CMD    0x01
#define DEFAULT_RESET_DELAY_MS  100

void rmi_free_function_list(struct rmi_device *rmi_dev)
{
        struct rmi_function *fn, *tmp;
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);

        rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev, "Freeing function list\n");

        devm_kfree(&rmi_dev->dev, data->irq_memory);
        data->irq_memory = NULL;
        data->irq_status = NULL;
        data->fn_irq_bits = NULL;
        data->current_irq_mask = NULL;
        data->new_irq_mask = NULL;

        data->f01_container = NULL;
        data->f34_container = NULL;

        /* Doing it in the reverse order so F01 will be removed last */
        list_for_each_entry_safe_reverse(fn, tmp,
                                         &data->function_list, node) {
                list_del(&fn->node);
                rmi_unregister_function(fn);
        }
}

static int reset_one_function(struct rmi_function *fn)
{
        struct rmi_function_handler *fh;
        int retval = 0;

        if (!fn || !fn->dev.driver)
                return 0;

        fh = to_rmi_function_handler(fn->dev.driver);
        if (fh->reset) {
                retval = fh->reset(fn);
                if (retval < 0)
                        dev_err(&fn->dev, "Reset failed with code %d.\n",
                                retval);
        }

        return retval;
}

static int configure_one_function(struct rmi_function *fn)
{
        struct rmi_function_handler *fh;
        int retval = 0;

        if (!fn || !fn->dev.driver)
                return 0;

        fh = to_rmi_function_handler(fn->dev.driver);
        if (fh->config) {
                retval = fh->config(fn);
                if (retval < 0)
                        dev_err(&fn->dev, "Config failed with code %d.\n",
                                retval);
        }

        return retval;
}

static int rmi_driver_process_reset_requests(struct rmi_device *rmi_dev)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct rmi_function *entry;
        int retval;

        list_for_each_entry(entry, &data->function_list, node) {
                retval = reset_one_function(entry);
                if (retval < 0)
                        return retval;
        }

        return 0;
}

static int rmi_driver_process_config_requests(struct rmi_device *rmi_dev)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct rmi_function *entry;
        int retval;

        list_for_each_entry(entry, &data->function_list, node) {
                retval = configure_one_function(entry);
                if (retval < 0)
                        return retval;
        }

        return 0;
}

static void process_one_interrupt(struct rmi_driver_data *data,
                                  struct rmi_function *fn)
{
        struct rmi_function_handler *fh;

        if (!fn || !fn->dev.driver)
                return;

        fh = to_rmi_function_handler(fn->dev.driver);
        if (fh->attention) {
                bitmap_and(data->fn_irq_bits, data->irq_status, fn->irq_mask,
                                data->irq_count);
                if (!bitmap_empty(data->fn_irq_bits, data->irq_count))
                        fh->attention(fn, data->fn_irq_bits);
        }
}

static int rmi_process_interrupt_requests(struct rmi_device *rmi_dev)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct device *dev = &rmi_dev->dev;
        struct rmi_function *entry;
        int error;

        if (!data)
                return 0;

        if (!data->attn_data.data) {
                error = rmi_read_block(rmi_dev,
                                data->f01_container->fd.data_base_addr + 1,
                                data->irq_status, data->num_of_irq_regs);
                if (error < 0) {
                        dev_err(dev, "Failed to read irqs, code=%d\n", error);
                        return error;
                }
        }

        mutex_lock(&data->irq_mutex);
        bitmap_and(data->irq_status, data->irq_status, data->current_irq_mask,
               data->irq_count);
        /*
         * At this point, irq_status has all bits that are set in the
         * interrupt status register and are enabled.
         */
        mutex_unlock(&data->irq_mutex);

        /*
         * It would be nice to be able to use irq_chip to handle these
         * nested IRQs.  Unfortunately, most of the current customers for
         * this driver are using older kernels (3.0.x) that don't support
         * the features required for that.  Once they've shifted to more
         * recent kernels (say, 3.3 and higher), this should be switched to
         * use irq_chip.
         */
        list_for_each_entry(entry, &data->function_list, node)
                process_one_interrupt(data, entry);

        if (data->input)
                input_sync(data->input);

        return 0;
}

void rmi_set_attn_data(struct rmi_device *rmi_dev, unsigned long irq_status,
                       void *data, size_t size)
{
        struct rmi_driver_data *drvdata = dev_get_drvdata(&rmi_dev->dev);
        struct rmi4_attn_data attn_data;
        void *fifo_data;

        if (!drvdata->enabled)
                return;

        fifo_data = kmemdup(data, size, GFP_ATOMIC);
        if (!fifo_data)
                return;

        attn_data.irq_status = irq_status;
        attn_data.size = size;
        attn_data.data = fifo_data;

        kfifo_put(&drvdata->attn_fifo, attn_data);
}
EXPORT_SYMBOL_GPL(rmi_set_attn_data);

static irqreturn_t rmi_irq_fn(int irq, void *dev_id)
{
        struct rmi_device *rmi_dev = dev_id;
        struct rmi_driver_data *drvdata = dev_get_drvdata(&rmi_dev->dev);
        struct rmi4_attn_data attn_data = {0};
        int ret, count;

        count = kfifo_get(&drvdata->attn_fifo, &attn_data);
        if (count) {
                *(drvdata->irq_status) = attn_data.irq_status;
                drvdata->attn_data = attn_data;
        }

        ret = rmi_process_interrupt_requests(rmi_dev);
        if (ret)
                rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev,
                        "Failed to process interrupt request: %d\n", ret);

        if (count)
                kfree(attn_data.data);

        if (!kfifo_is_empty(&drvdata->attn_fifo))
                return rmi_irq_fn(irq, dev_id);

        return IRQ_HANDLED;
}

static int rmi_irq_init(struct rmi_device *rmi_dev)
{
        struct rmi_device_platform_data *pdata = rmi_get_platform_data(rmi_dev);
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        int irq_flags = irq_get_trigger_type(pdata->irq);
        int ret;

        if (!irq_flags)
                irq_flags = IRQF_TRIGGER_LOW;

        ret = devm_request_threaded_irq(&rmi_dev->dev, pdata->irq, NULL,
                                        rmi_irq_fn, irq_flags | IRQF_ONESHOT,
                                        dev_driver_string(rmi_dev->xport->dev),
                                        rmi_dev);
        if (ret < 0) {
                dev_err(&rmi_dev->dev, "Failed to register interrupt %d\n",
                        pdata->irq);

                return ret;
        }

        data->enabled = true;

        return 0;
}

struct rmi_function *rmi_find_function(struct rmi_device *rmi_dev, u8 number)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct rmi_function *entry;

        list_for_each_entry(entry, &data->function_list, node) {
                if (entry->fd.function_number == number)
                        return entry;
        }

        return NULL;
}

static int suspend_one_function(struct rmi_function *fn)
{
        struct rmi_function_handler *fh;
        int retval = 0;

        if (!fn || !fn->dev.driver)
                return 0;

        fh = to_rmi_function_handler(fn->dev.driver);
        if (fh->suspend) {
                retval = fh->suspend(fn);
                if (retval < 0)
                        dev_err(&fn->dev, "Suspend failed with code %d.\n",
                                retval);
        }

        return retval;
}

static int rmi_suspend_functions(struct rmi_device *rmi_dev)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct rmi_function *entry;
        int retval;

        list_for_each_entry(entry, &data->function_list, node) {
                retval = suspend_one_function(entry);
                if (retval < 0)
                        return retval;
        }

        return 0;
}

static int resume_one_function(struct rmi_function *fn)
{
        struct rmi_function_handler *fh;
        int retval = 0;

        if (!fn || !fn->dev.driver)
                return 0;

        fh = to_rmi_function_handler(fn->dev.driver);
        if (fh->resume) {
                retval = fh->resume(fn);
                if (retval < 0)
                        dev_err(&fn->dev, "Resume failed with code %d.\n",
                                retval);
        }

        return retval;
}

static int rmi_resume_functions(struct rmi_device *rmi_dev)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct rmi_function *entry;
        int retval;

        list_for_each_entry(entry, &data->function_list, node) {
                retval = resume_one_function(entry);
                if (retval < 0)
                        return retval;
        }

        return 0;
}

int rmi_enable_sensor(struct rmi_device *rmi_dev)
{
        int retval = 0;

        retval = rmi_driver_process_config_requests(rmi_dev);
        if (retval < 0)
                return retval;

        return rmi_process_interrupt_requests(rmi_dev);
}

/**
 * rmi_driver_set_input_params - set input device id and other data.
 *
 * @rmi_dev: Pointer to an RMI device
 * @input: Pointer to input device
 *
 */
static int rmi_driver_set_input_params(struct rmi_device *rmi_dev,
                                struct input_dev *input)
{
        input->name = SYNAPTICS_INPUT_DEVICE_NAME;
        input->id.vendor  = SYNAPTICS_VENDOR_ID;
        input->id.bustype = BUS_RMI;
        return 0;
}

static void rmi_driver_set_input_name(struct rmi_device *rmi_dev,
                                struct input_dev *input)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        const char *device_name = rmi_f01_get_product_ID(data->f01_container);
        char *name;

        name = devm_kasprintf(&rmi_dev->dev, GFP_KERNEL,
                              "Synaptics %s", device_name);
        if (!name)
                return;

        input->name = name;
}

static int rmi_driver_set_irq_bits(struct rmi_device *rmi_dev,
                                   unsigned long *mask)
{
        int error = 0;
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct device *dev = &rmi_dev->dev;

        mutex_lock(&data->irq_mutex);
        bitmap_or(data->new_irq_mask,
                  data->current_irq_mask, mask, data->irq_count);

        error = rmi_write_block(rmi_dev,
                        data->f01_container->fd.control_base_addr + 1,
                        data->new_irq_mask, data->num_of_irq_regs);
        if (error < 0) {
                dev_err(dev, "%s: Failed to change enabled interrupts!",
                                                        __func__);
                goto error_unlock;
        }
        bitmap_copy(data->current_irq_mask, data->new_irq_mask,
                    data->num_of_irq_regs);

error_unlock:
        mutex_unlock(&data->irq_mutex);
        return error;
}

static int rmi_driver_clear_irq_bits(struct rmi_device *rmi_dev,
                                     unsigned long *mask)
{
        int error = 0;
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct device *dev = &rmi_dev->dev;

        mutex_lock(&data->irq_mutex);
        bitmap_andnot(data->new_irq_mask,
                  data->current_irq_mask, mask, data->irq_count);

        error = rmi_write_block(rmi_dev,
                        data->f01_container->fd.control_base_addr + 1,
                        data->new_irq_mask, data->num_of_irq_regs);
        if (error < 0) {
                dev_err(dev, "%s: Failed to change enabled interrupts!",
                                                        __func__);
                goto error_unlock;
        }
        bitmap_copy(data->current_irq_mask, data->new_irq_mask,
                    data->num_of_irq_regs);

error_unlock:
        mutex_unlock(&data->irq_mutex);
        return error;
}

static int rmi_driver_reset_handler(struct rmi_device *rmi_dev)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        int error;

        /*
         * Can get called before the driver is fully ready to deal with
         * this situation.
         */
        if (!data || !data->f01_container) {
                dev_warn(&rmi_dev->dev,
                         "Not ready to handle reset yet!\n");
                return 0;
        }

        error = rmi_read_block(rmi_dev,
                               data->f01_container->fd.control_base_addr + 1,
                               data->current_irq_mask, data->num_of_irq_regs);
        if (error < 0) {
                dev_err(&rmi_dev->dev, "%s: Failed to read current IRQ mask.\n",
                        __func__);
                return error;
        }

        error = rmi_driver_process_reset_requests(rmi_dev);
        if (error < 0)
                return error;

        error = rmi_driver_process_config_requests(rmi_dev);
        if (error < 0)
                return error;

        return 0;
}

static int rmi_read_pdt_entry(struct rmi_device *rmi_dev,
                              struct pdt_entry *entry, u16 pdt_address)
{
        u8 buf[RMI_PDT_ENTRY_SIZE];
        int error;

        error = rmi_read_block(rmi_dev, pdt_address, buf, RMI_PDT_ENTRY_SIZE);
        if (error) {
                dev_err(&rmi_dev->dev, "Read PDT entry at %#06x failed, code: %d.\n",
                                pdt_address, error);
                return error;
        }

        entry->page_start = pdt_address & RMI4_PAGE_MASK;
        entry->query_base_addr = buf[0];
        entry->command_base_addr = buf[1];
        entry->control_base_addr = buf[2];
        entry->data_base_addr = buf[3];
        entry->interrupt_source_count = buf[4] & RMI_PDT_INT_SOURCE_COUNT_MASK;
        entry->function_version = (buf[4] & RMI_PDT_FUNCTION_VERSION_MASK) >> 5;
        entry->function_number = buf[5];

        return 0;
}

static void rmi_driver_copy_pdt_to_fd(const struct pdt_entry *pdt,
                                      struct rmi_function_descriptor *fd)
{
        fd->query_base_addr = pdt->query_base_addr + pdt->page_start;
        fd->command_base_addr = pdt->command_base_addr + pdt->page_start;
        fd->control_base_addr = pdt->control_base_addr + pdt->page_start;
        fd->data_base_addr = pdt->data_base_addr + pdt->page_start;
        fd->function_number = pdt->function_number;
        fd->interrupt_source_count = pdt->interrupt_source_count;
        fd->function_version = pdt->function_version;
}

#define RMI_SCAN_CONTINUE       0
#define RMI_SCAN_DONE           1

static int rmi_scan_pdt_page(struct rmi_device *rmi_dev,
                             int page,
                             int *empty_pages,
                             void *ctx,
                             int (*callback)(struct rmi_device *rmi_dev,
                                             void *ctx,
                                             const struct pdt_entry *entry))
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct pdt_entry pdt_entry;
        u16 page_start = RMI4_PAGE_SIZE * page;
        u16 pdt_start = page_start + PDT_START_SCAN_LOCATION;
        u16 pdt_end = page_start + PDT_END_SCAN_LOCATION;
        u16 addr;
        int error;
        int retval;

        for (addr = pdt_start; addr >= pdt_end; addr -= RMI_PDT_ENTRY_SIZE) {
                error = rmi_read_pdt_entry(rmi_dev, &pdt_entry, addr);
                if (error)
                        return error;

                if (RMI4_END_OF_PDT(pdt_entry.function_number))
                        break;

                retval = callback(rmi_dev, ctx, &pdt_entry);
                if (retval != RMI_SCAN_CONTINUE)
                        return retval;
        }

        /*
         * Count number of empty PDT pages. If a gap of two pages
         * or more is found, stop scanning.
         */
        if (addr == pdt_start)
                ++*empty_pages;
        else
                *empty_pages = 0;

        return (data->bootloader_mode || *empty_pages >= 2) ?
                                        RMI_SCAN_DONE : RMI_SCAN_CONTINUE;
}

int rmi_scan_pdt(struct rmi_device *rmi_dev, void *ctx,
                 int (*callback)(struct rmi_device *rmi_dev,
                 void *ctx, const struct pdt_entry *entry))
{
        int page;
        int empty_pages = 0;
        int retval = RMI_SCAN_DONE;

        for (page = 0; page <= RMI4_MAX_PAGE; page++) {
                retval = rmi_scan_pdt_page(rmi_dev, page, &empty_pages,
                                           ctx, callback);
                if (retval != RMI_SCAN_CONTINUE)
                        break;
        }

        return retval < 0 ? retval : 0;
}

int rmi_read_register_desc(struct rmi_device *d, u16 addr,
                                struct rmi_register_descriptor *rdesc)
{
        int ret;
        u8 size_presence_reg;
        u8 buf[35];
        int presense_offset = 1;
        u8 *struct_buf;
        int reg;
        int offset = 0;
        int map_offset = 0;
        int i;
        int b;

        /*
         * The first register of the register descriptor is the size of
         * the register descriptor's presense register.
         */
        ret = rmi_read(d, addr, &size_presence_reg);
        if (ret)
                return ret;
        ++addr;

        if (size_presence_reg < 0 || size_presence_reg > 35)
                return -EIO;

        memset(buf, 0, sizeof(buf));

        /*
         * The presence register contains the size of the register structure
         * and a bitmap which identified which packet registers are present
         * for this particular register type (ie query, control, or data).
         */
        ret = rmi_read_block(d, addr, buf, size_presence_reg);
        if (ret)
                return ret;
        ++addr;

        if (buf[0] == 0) {
                presense_offset = 3;
                rdesc->struct_size = buf[1] | (buf[2] << 8);
        } else {
                rdesc->struct_size = buf[0];
        }

        for (i = presense_offset; i < size_presence_reg; i++) {
                for (b = 0; b < 8; b++) {
                        if (buf[i] & (0x1 << b))
                                bitmap_set(rdesc->presense_map, map_offset, 1);
                        ++map_offset;
                }
        }

        rdesc->num_registers = bitmap_weight(rdesc->presense_map,
                                                RMI_REG_DESC_PRESENSE_BITS);

        rdesc->registers = devm_kzalloc(&d->dev, rdesc->num_registers *
                                sizeof(struct rmi_register_desc_item),
                                GFP_KERNEL);
        if (!rdesc->registers)
                return -ENOMEM;

        /*
         * Allocate a temporary buffer to hold the register structure.
         * I'm not using devm_kzalloc here since it will not be retained
         * after exiting this function
         */
        struct_buf = kzalloc(rdesc->struct_size, GFP_KERNEL);
        if (!struct_buf)
                return -ENOMEM;

        /*
         * The register structure contains information about every packet
         * register of this type. This includes the size of the packet
         * register and a bitmap of all subpackets contained in the packet
         * register.
         */
        ret = rmi_read_block(d, addr, struct_buf, rdesc->struct_size);
        if (ret)
                goto free_struct_buff;

        reg = find_first_bit(rdesc->presense_map, RMI_REG_DESC_PRESENSE_BITS);
        for (i = 0; i < rdesc->num_registers; i++) {
                struct rmi_register_desc_item *item = &rdesc->registers[i];
                int reg_size = struct_buf[offset];

                ++offset;
                if (reg_size == 0) {
                        reg_size = struct_buf[offset] |
                                        (struct_buf[offset + 1] << 8);
                        offset += 2;
                }

                if (reg_size == 0) {
                        reg_size = struct_buf[offset] |
                                        (struct_buf[offset + 1] << 8) |
                                        (struct_buf[offset + 2] << 16) |
                                        (struct_buf[offset + 3] << 24);
                        offset += 4;
                }

                item->reg = reg;
                item->reg_size = reg_size;

                map_offset = 0;

                do {
                        for (b = 0; b < 7; b++) {
                                if (struct_buf[offset] & (0x1 << b))
                                        bitmap_set(item->subpacket_map,
                                                map_offset, 1);
                                ++map_offset;
                        }
                } while (struct_buf[offset++] & 0x80);

                item->num_subpackets = bitmap_weight(item->subpacket_map,
                                                RMI_REG_DESC_SUBPACKET_BITS);

                rmi_dbg(RMI_DEBUG_CORE, &d->dev,
                        "%s: reg: %d reg size: %ld subpackets: %d\n", __func__,
                        item->reg, item->reg_size, item->num_subpackets);

                reg = find_next_bit(rdesc->presense_map,
                                RMI_REG_DESC_PRESENSE_BITS, reg + 1);
        }

free_struct_buff:
        kfree(struct_buf);
        return ret;
}

const struct rmi_register_desc_item *rmi_get_register_desc_item(
                                struct rmi_register_descriptor *rdesc, u16 reg)
{
        const struct rmi_register_desc_item *item;
        int i;

        for (i = 0; i < rdesc->num_registers; i++) {
                item = &rdesc->registers[i];
                if (item->reg == reg)
                        return item;
        }

        return NULL;
}

size_t rmi_register_desc_calc_size(struct rmi_register_descriptor *rdesc)
{
        const struct rmi_register_desc_item *item;
        int i;
        size_t size = 0;

        for (i = 0; i < rdesc->num_registers; i++) {
                item = &rdesc->registers[i];
                size += item->reg_size;
        }
        return size;
}

/* Compute the register offset relative to the base address */
int rmi_register_desc_calc_reg_offset(
                struct rmi_register_descriptor *rdesc, u16 reg)
{
        const struct rmi_register_desc_item *item;
        int offset = 0;
        int i;

        for (i = 0; i < rdesc->num_registers; i++) {
                item = &rdesc->registers[i];
                if (item->reg == reg)
                        return offset;
                ++offset;
        }
        return -1;
}

bool rmi_register_desc_has_subpacket(const struct rmi_register_desc_item *item,
        u8 subpacket)
{
        return find_next_bit(item->subpacket_map, RMI_REG_DESC_PRESENSE_BITS,
                                subpacket) == subpacket;
}

static int rmi_check_bootloader_mode(struct rmi_device *rmi_dev,
                                     const struct pdt_entry *pdt)
{
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        int ret;
        u8 status;

        if (pdt->function_number == 0x34 && pdt->function_version > 1) {
                ret = rmi_read(rmi_dev, pdt->data_base_addr, &status);
                if (ret) {
                        dev_err(&rmi_dev->dev,
                                "Failed to read F34 status: %d.\n", ret);
                        return ret;
                }

                if (status & BIT(7))
                        data->bootloader_mode = true;
        } else if (pdt->function_number == 0x01) {
                ret = rmi_read(rmi_dev, pdt->data_base_addr, &status);
                if (ret) {
                        dev_err(&rmi_dev->dev,
                                "Failed to read F01 status: %d.\n", ret);
                        return ret;
                }

                if (status & BIT(6))
                        data->bootloader_mode = true;
        }

        return 0;
}

static int rmi_count_irqs(struct rmi_device *rmi_dev,
                         void *ctx, const struct pdt_entry *pdt)
{
        int *irq_count = ctx;
        int ret;

        *irq_count += pdt->interrupt_source_count;

        ret = rmi_check_bootloader_mode(rmi_dev, pdt);
        if (ret < 0)
                return ret;

        return RMI_SCAN_CONTINUE;
}

int rmi_initial_reset(struct rmi_device *rmi_dev, void *ctx,
                      const struct pdt_entry *pdt)
{
        int error;

        if (pdt->function_number == 0x01) {
                u16 cmd_addr = pdt->page_start + pdt->command_base_addr;
                u8 cmd_buf = RMI_DEVICE_RESET_CMD;
                const struct rmi_device_platform_data *pdata =
                                rmi_get_platform_data(rmi_dev);

                if (rmi_dev->xport->ops->reset) {
                        error = rmi_dev->xport->ops->reset(rmi_dev->xport,
                                                                cmd_addr);
                        if (error)
                                return error;

                        return RMI_SCAN_DONE;
                }

                rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev, "Sending reset\n");
                error = rmi_write_block(rmi_dev, cmd_addr, &cmd_buf, 1);
                if (error) {
                        dev_err(&rmi_dev->dev,
                                "Initial reset failed. Code = %d.\n", error);
                        return error;
                }

                mdelay(pdata->reset_delay_ms ?: DEFAULT_RESET_DELAY_MS);

                return RMI_SCAN_DONE;
        }

        /* F01 should always be on page 0. If we don't find it there, fail. */
        return pdt->page_start == 0 ? RMI_SCAN_CONTINUE : -ENODEV;
}

static int rmi_create_function(struct rmi_device *rmi_dev,
                               void *ctx, const struct pdt_entry *pdt)
{
        struct device *dev = &rmi_dev->dev;
        struct rmi_driver_data *data = dev_get_drvdata(dev);
        int *current_irq_count = ctx;
        struct rmi_function *fn;
        int i;
        int error;

        rmi_dbg(RMI_DEBUG_CORE, dev, "Initializing F%02X.\n",
                        pdt->function_number);

        fn = kzalloc(sizeof(struct rmi_function) +
                        BITS_TO_LONGS(data->irq_count) * sizeof(unsigned long),
                     GFP_KERNEL);
        if (!fn) {
                dev_err(dev, "Failed to allocate memory for F%02X\n",
                        pdt->function_number);
                return -ENOMEM;
        }

        INIT_LIST_HEAD(&fn->node);
        rmi_driver_copy_pdt_to_fd(pdt, &fn->fd);

        fn->rmi_dev = rmi_dev;

        fn->num_of_irqs = pdt->interrupt_source_count;
        fn->irq_pos = *current_irq_count;
        *current_irq_count += fn->num_of_irqs;

        for (i = 0; i < fn->num_of_irqs; i++)
                set_bit(fn->irq_pos + i, fn->irq_mask);

        error = rmi_register_function(fn);
        if (error)
                goto err_put_fn;

        if (pdt->function_number == 0x01)
                data->f01_container = fn;
        else if (pdt->function_number == 0x34)
                data->f34_container = fn;

        list_add_tail(&fn->node, &data->function_list);

        return RMI_SCAN_CONTINUE;

err_put_fn:
        put_device(&fn->dev);
        return error;
}

void rmi_enable_irq(struct rmi_device *rmi_dev, bool clear_wake)
{
        struct rmi_device_platform_data *pdata = rmi_get_platform_data(rmi_dev);
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        int irq = pdata->irq;
        int irq_flags;
        int retval;

        mutex_lock(&data->enabled_mutex);

        if (data->enabled)
                goto out;

        enable_irq(irq);
        data->enabled = true;
        if (clear_wake && device_may_wakeup(rmi_dev->xport->dev)) {
                retval = disable_irq_wake(irq);
                if (retval)
                        dev_warn(&rmi_dev->dev,
                                 "Failed to disable irq for wake: %d\n",
                                 retval);
        }

        /*
         * Call rmi_process_interrupt_requests() after enabling irq,
         * otherwise we may lose interrupt on edge-triggered systems.
         */
        irq_flags = irq_get_trigger_type(pdata->irq);
        if (irq_flags & IRQ_TYPE_EDGE_BOTH)
                rmi_process_interrupt_requests(rmi_dev);

out:
        mutex_unlock(&data->enabled_mutex);
}

void rmi_disable_irq(struct rmi_device *rmi_dev, bool enable_wake)
{
        struct rmi_device_platform_data *pdata = rmi_get_platform_data(rmi_dev);
        struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
        struct rmi4_attn_data attn_data = {0};
        int irq = pdata->irq;
        int retval, count;

        mutex_lock(&data->enabled_mutex);

        if (!data->enabled)
                goto out;

        data->enabled = false;
        disable_irq(irq);
        if (enable_wake && device_may_wakeup(rmi_dev->xport->dev)) {
                retval = enable_irq_wake(irq);
                if (retval)
                        dev_warn(&rmi_dev->dev,
                                 "Failed to enable irq for wake: %d\n",
                                 retval);
        }

        /* make sure the fifo is clean */
        while (!kfifo_is_empty(&data->attn_fifo)) {
                count = kfifo_get(&data->attn_fifo, &attn_data);
                if (count)
                        kfree(attn_data.data);
        }

out:
        mutex_unlock(&data->enabled_mutex);
}

int rmi_driver_suspend(struct rmi_device *rmi_dev, bool enable_wake)
{
        int retval;

        retval = rmi_suspend_functions(rmi_dev);
        if (retval)
                dev_warn(&rmi_dev->dev, "Failed to suspend functions: %d\n",
                        retval);

        rmi_disable_irq(rmi_dev, enable_wake);
        return retval;
}
EXPORT_SYMBOL_GPL(rmi_driver_suspend);

int rmi_driver_resume(struct rmi_device *rmi_dev, bool clear_wake)
{
        int retval;

        rmi_enable_irq(rmi_dev, clear_wake);

        retval = rmi_resume_functions(rmi_dev);
        if (retval)
                dev_warn(&rmi_dev->dev, "Failed to suspend functions: %d\n",
                        retval);

        return retval;
}
EXPORT_SYMBOL_GPL(rmi_driver_resume);

static int rmi_driver_remove(struct device *dev)
{
        struct rmi_device *rmi_dev = to_rmi_device(dev);

        rmi_disable_irq(rmi_dev, false);

        rmi_f34_remove_sysfs(rmi_dev);
        rmi_free_function_list(rmi_dev);

        return 0;
}

#ifdef CONFIG_OF
static int rmi_driver_of_probe(struct device *dev,
                                struct rmi_device_platform_data *pdata)
{
        int retval;

        retval = rmi_of_property_read_u32(dev, &pdata->reset_delay_ms,
                                        "syna,reset-delay-ms", 1);
        if (retval)
                return retval;

        return 0;
}
#else
static inline int rmi_driver_of_probe(struct device *dev,
                                        struct rmi_device_platform_data *pdata)
{
        return -ENODEV;
}
#endif

int rmi_probe_interrupts(struct rmi_driver_data *data)
{
        struct rmi_device *rmi_dev = data->rmi_dev;
        struct device *dev = &rmi_dev->dev;
        int irq_count;
        size_t size;
        int retval;

        /*
         * We need to count the IRQs and allocate their storage before scanning
         * the PDT and creating the function entries, because adding a new
         * function can trigger events that result in the IRQ related storage
         * being accessed.
         */
        rmi_dbg(RMI_DEBUG_CORE, dev, "%s: Counting IRQs.\n", __func__);
        irq_count = 0;
        data->bootloader_mode = false;

        retval = rmi_scan_pdt(rmi_dev, &irq_count, rmi_count_irqs);
        if (retval < 0) {
                dev_err(dev, "IRQ counting failed with code %d.\n", retval);
                return retval;
        }

        if (data->bootloader_mode)
                dev_warn(dev, "Device in bootloader mode.\n");

        data->irq_count = irq_count;
        data->num_of_irq_regs = (data->irq_count + 7) / 8;

        size = BITS_TO_LONGS(data->irq_count) * sizeof(unsigned long);
        data->irq_memory = devm_kzalloc(dev, size * 4, GFP_KERNEL);
        if (!data->irq_memory) {
                dev_err(dev, "Failed to allocate memory for irq masks.\n");
                return -ENOMEM;
        }

        data->irq_status        = data->irq_memory + size * 0;
        data->fn_irq_bits       = data->irq_memory + size * 1;
        data->current_irq_mask  = data->irq_memory + size * 2;
        data->new_irq_mask      = data->irq_memory + size * 3;

        return retval;
}

int rmi_init_functions(struct rmi_driver_data *data)
{
        struct rmi_device *rmi_dev = data->rmi_dev;
        struct device *dev = &rmi_dev->dev;
        int irq_count;
        int retval;

        irq_count = 0;
        rmi_dbg(RMI_DEBUG_CORE, dev, "%s: Creating functions.\n", __func__);
        retval = rmi_scan_pdt(rmi_dev, &irq_count, rmi_create_function);
        if (retval < 0) {
                dev_err(dev, "Function creation failed with code %d.\n",
                        retval);
                goto err_destroy_functions;
        }

        if (!data->f01_container) {
                dev_err(dev, "Missing F01 container!\n");
                retval = -EINVAL;
                goto err_destroy_functions;
        }

        retval = rmi_read_block(rmi_dev,
                                data->f01_container->fd.control_base_addr + 1,
                                data->current_irq_mask, data->num_of_irq_regs);
        if (retval < 0) {
                dev_err(dev, "%s: Failed to read current IRQ mask.\n",
                        __func__);
                goto err_destroy_functions;
        }

        return 0;

err_destroy_functions:
        rmi_free_function_list(rmi_dev);
        return retval;
}

static int rmi_driver_probe(struct device *dev)
{
        struct rmi_driver *rmi_driver;
        struct rmi_driver_data *data;
        struct rmi_device_platform_data *pdata;
        struct rmi_device *rmi_dev;
        int retval;

        rmi_dbg(RMI_DEBUG_CORE, dev, "%s: Starting probe.\n",
                        __func__);

        if (!rmi_is_physical_device(dev)) {
                rmi_dbg(RMI_DEBUG_CORE, dev, "Not a physical device.\n");
                return -ENODEV;
        }

        rmi_dev = to_rmi_device(dev);
        rmi_driver = to_rmi_driver(dev->driver);
        rmi_dev->driver = rmi_driver;

        pdata = rmi_get_platform_data(rmi_dev);

        if (rmi_dev->xport->dev->of_node) {
                retval = rmi_driver_of_probe(rmi_dev->xport->dev, pdata);
                if (retval)
                        return retval;
        }

        data = devm_kzalloc(dev, sizeof(struct rmi_driver_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        INIT_LIST_HEAD(&data->function_list);
        data->rmi_dev = rmi_dev;
        dev_set_drvdata(&rmi_dev->dev, data);

        /*
         * Right before a warm boot, the sensor might be in some unusual state,
         * such as F54 diagnostics, or F34 bootloader mode after a firmware
         * or configuration update.  In order to clear the sensor to a known
         * state and/or apply any updates, we issue a initial reset to clear any
         * previous settings and force it into normal operation.
         *
         * We have to do this before actually building the PDT because
         * the reflash updates (if any) might cause various registers to move
         * around.
         *
         * For a number of reasons, this initial reset may fail to return
         * within the specified time, but we'll still be able to bring up the
         * driver normally after that failure.  This occurs most commonly in
         * a cold boot situation (where then firmware takes longer to come up
         * than from a warm boot) and the reset_delay_ms in the platform data
         * has been set too short to accommodate that.  Since the sensor will
         * eventually come up and be usable, we don't want to just fail here
         * and leave the customer's device unusable.  So we warn them, and
         * continue processing.
         */
        retval = rmi_scan_pdt(rmi_dev, NULL, rmi_initial_reset);
        if (retval < 0)
                dev_warn(dev, "RMI initial reset failed! Continuing in spite of this.\n");

        retval = rmi_read(rmi_dev, PDT_PROPERTIES_LOCATION, &data->pdt_props);
        if (retval < 0) {
                /*
                 * we'll print out a warning and continue since
                 * failure to get the PDT properties is not a cause to fail
                 */
                dev_warn(dev, "Could not read PDT properties from %#06x (code %d). Assuming 0x00.\n",
                         PDT_PROPERTIES_LOCATION, retval);
        }

        mutex_init(&data->irq_mutex);
        mutex_init(&data->enabled_mutex);

        retval = rmi_probe_interrupts(data);
        if (retval)
                goto err;

        if (rmi_dev->xport->input) {
                /*
                 * The transport driver already has an input device.
                 * In some cases it is preferable to reuse the transport
                 * devices input device instead of creating a new one here.
                 * One example is some HID touchpads report "pass-through"
                 * button events are not reported by rmi registers.
                 */
                data->input = rmi_dev->xport->input;
        } else {
                data->input = devm_input_allocate_device(dev);
                if (!data->input) {
                        dev_err(dev, "%s: Failed to allocate input device.\n",
                                __func__);
                        retval = -ENOMEM;
                        goto err;
                }
                rmi_driver_set_input_params(rmi_dev, data->input);
                data->input->phys = devm_kasprintf(dev, GFP_KERNEL,
                                                "%s/input0", dev_name(dev));
        }

        retval = rmi_init_functions(data);
        if (retval)
                goto err;

        retval = rmi_f34_create_sysfs(rmi_dev);
        if (retval)
                goto err;

        if (data->input) {
                rmi_driver_set_input_name(rmi_dev, data->input);
                if (!rmi_dev->xport->input) {
                        if (input_register_device(data->input)) {
                                dev_err(dev, "%s: Failed to register input device.\n",
                                        __func__);
                                goto err_destroy_functions;
                        }
                }
        }

        retval = rmi_irq_init(rmi_dev);
        if (retval < 0)
                goto err_destroy_functions;

        if (data->f01_container->dev.driver) {
                /* Driver already bound, so enable ATTN now. */
                retval = rmi_enable_sensor(rmi_dev);
                if (retval)
                        goto err_disable_irq;
        }

        return 0;

err_disable_irq:
        rmi_disable_irq(rmi_dev, false);
err_destroy_functions:
        rmi_free_function_list(rmi_dev);
err:
        return retval;
}

static struct rmi_driver rmi_physical_driver = {
        .driver = {
                .owner  = THIS_MODULE,
                .name   = "rmi4_physical",
                .bus    = &rmi_bus_type,
                .probe = rmi_driver_probe,
                .remove = rmi_driver_remove,
        },
        .reset_handler = rmi_driver_reset_handler,
        .clear_irq_bits = rmi_driver_clear_irq_bits,
        .set_irq_bits = rmi_driver_set_irq_bits,
        .set_input_params = rmi_driver_set_input_params,
};

bool rmi_is_physical_driver(struct device_driver *drv)
{
        return drv == &rmi_physical_driver.driver;
}

int __init rmi_register_physical_driver(void)
{
        int error;

        error = driver_register(&rmi_physical_driver.driver);
        if (error) {
                pr_err("%s: driver register failed, code=%d.\n", __func__,
                       error);
                return error;
        }

        return 0;
}

void __exit rmi_unregister_physical_driver(void)
{
        driver_unregister(&rmi_physical_driver.driver);
}