// SPDX-License-Identifier: GPL-2.0
/*
 * EZ-USB specific functions used by some of the USB to Serial drivers.
 *
 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/firmware.h>
#include <linux/ihex.h>
#include <linux/usb/ezusb.h>

struct ezusb_fx_type {
        /* EZ-USB Control and Status Register.  Bit 0 controls 8051 reset */
        unsigned short cpucs_reg;
        unsigned short max_internal_adress;
};

static const struct ezusb_fx_type ezusb_fx1 = {
        .cpucs_reg = 0x7F92,
        .max_internal_adress = 0x1B3F,
};

/* Commands for writing to memory */
#define WRITE_INT_RAM 0xA0
#define WRITE_EXT_RAM 0xA3

static int ezusb_writememory(struct usb_device *dev, int address,
                                unsigned char *data, int length, __u8 request)
{
        if (!dev)
                return -ENODEV;

        return usb_control_msg_send(dev, 0, request,
                                 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                 address, 0, data, length, 3000, GFP_KERNEL);
}

static int ezusb_set_reset(struct usb_device *dev, unsigned short cpucs_reg,
                           unsigned char reset_bit)
{
        int response = ezusb_writememory(dev, cpucs_reg, &reset_bit, 1, WRITE_INT_RAM);
        if (response < 0)
                dev_err(&dev->dev, "%s-%d failed: %d\n",
                                                __func__, reset_bit, response);
        return response;
}

int ezusb_fx1_set_reset(struct usb_device *dev, unsigned char reset_bit)
{
        return ezusb_set_reset(dev, ezusb_fx1.cpucs_reg, reset_bit);
}
EXPORT_SYMBOL_GPL(ezusb_fx1_set_reset);

static int ezusb_ihex_firmware_download(struct usb_device *dev,
                                        struct ezusb_fx_type fx,
                                        const char *firmware_path)
{
        int ret = -ENOENT;
        const struct firmware *firmware = NULL;
        const struct ihex_binrec *record;

        if (request_ihex_firmware(&firmware, firmware_path,
                                  &dev->dev)) {
                dev_err(&dev->dev,
                        "%s - request \"%s\" failed\n",
                        __func__, firmware_path);
                goto out;
        }

        ret = ezusb_set_reset(dev, fx.cpucs_reg, 0);
        if (ret < 0)
                goto out;

        record = (const struct ihex_binrec *)firmware->data;
        for (; record; record = ihex_next_binrec(record)) {
                if (be32_to_cpu(record->addr) > fx.max_internal_adress) {
                        ret = ezusb_writememory(dev, be32_to_cpu(record->addr),
                                                (unsigned char *)record->data,
                                                be16_to_cpu(record->len), WRITE_EXT_RAM);
                        if (ret < 0) {
                                dev_err(&dev->dev, "%s - ezusb_writememory "
                                        "failed writing internal memory "
                                        "(%d %04X %p %d)\n", __func__, ret,
                                        be32_to_cpu(record->addr), record->data,
                                        be16_to_cpu(record->len));
                                goto out;
                        }
                }
        }

        ret = ezusb_set_reset(dev, fx.cpucs_reg, 1);
        if (ret < 0)
                goto out;
        record = (const struct ihex_binrec *)firmware->data;
        for (; record; record = ihex_next_binrec(record)) {
                if (be32_to_cpu(record->addr) <= fx.max_internal_adress) {
                        ret = ezusb_writememory(dev, be32_to_cpu(record->addr),
                                                (unsigned char *)record->data,
                                                be16_to_cpu(record->len), WRITE_INT_RAM);
                        if (ret < 0) {
                                dev_err(&dev->dev, "%s - ezusb_writememory "
                                        "failed writing external memory "
                                        "(%d %04X %p %d)\n", __func__, ret,
                                        be32_to_cpu(record->addr), record->data,
                                        be16_to_cpu(record->len));
                                goto out;
                        }
                }
        }
        ret = ezusb_set_reset(dev, fx.cpucs_reg, 0);
out:
        release_firmware(firmware);
        return ret;
}

int ezusb_fx1_ihex_firmware_download(struct usb_device *dev,
                                     const char *firmware_path)
{
        return ezusb_ihex_firmware_download(dev, ezusb_fx1, firmware_path);
}
EXPORT_SYMBOL_GPL(ezusb_fx1_ihex_firmware_download);

#if 0
/*
 * Once someone one needs these fx2 functions, uncomment them
 * and add them to ezusb.h and all should be good.
 */
static struct ezusb_fx_type ezusb_fx2 = {
        .cpucs_reg = 0xE600,
        .max_internal_adress = 0x3FFF,
};

int ezusb_fx2_set_reset(struct usb_device *dev, unsigned char reset_bit)
{
        return ezusb_set_reset(dev, ezusb_fx2.cpucs_reg, reset_bit);
}
EXPORT_SYMBOL_GPL(ezusb_fx2_set_reset);

int ezusb_fx2_ihex_firmware_download(struct usb_device *dev,
                                     const char *firmware_path)
{
        return ezusb_ihex_firmware_download(dev, ezusb_fx2, firmware_path);
}
EXPORT_SYMBOL_GPL(ezusb_fx2_ihex_firmware_download);
#endif

MODULE_DESCRIPTION("EZUSB device support");
MODULE_LICENSE("GPL");