// SPDX-License-Identifier: GPL-2.0-or-later
/* cx25840 firmware functions
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/firmware.h>
#include <media/v4l2-common.h>
#include <media/drv-intf/cx25840.h>

#include "cx25840-core.h"

/*
 * Mike Isely <isely@pobox.com> - The FWSEND parameter controls the
 * size of the firmware chunks sent down the I2C bus to the chip.
 * Previously this had been set to 1024 but unfortunately some I2C
 * implementations can't transfer data in such big gulps.
 * Specifically, the pvrusb2 driver has a hard limit of around 60
 * bytes, due to the encapsulation there of I2C traffic into USB
 * messages.  So we have to significantly reduce this parameter.
 */
#define FWSEND 48

#define FWDEV(x) &((x)->dev)

static char *firmware = "";

module_param(firmware, charp, 0444);

MODULE_PARM_DESC(firmware, "Firmware image to load");

static void start_fw_load(struct i2c_client *client)
{
        /* DL_ADDR_LB=0 DL_ADDR_HB=0 */
        cx25840_write(client, 0x800, 0x00);
        cx25840_write(client, 0x801, 0x00);
        // DL_MAP=3 DL_AUTO_INC=0 DL_ENABLE=1
        cx25840_write(client, 0x803, 0x0b);
        /* AUTO_INC_DIS=1 */
        cx25840_write(client, 0x000, 0x20);
}

static void end_fw_load(struct i2c_client *client)
{
        /* AUTO_INC_DIS=0 */
        cx25840_write(client, 0x000, 0x00);
        /* DL_ENABLE=0 */
        cx25840_write(client, 0x803, 0x03);
}

#define CX2388x_FIRMWARE "v4l-cx23885-avcore-01.fw"
#define CX231xx_FIRMWARE "v4l-cx231xx-avcore-01.fw"
#define CX25840_FIRMWARE "v4l-cx25840.fw"

static const char *get_fw_name(struct i2c_client *client)
{
        struct cx25840_state *state = to_state(i2c_get_clientdata(client));

        if (firmware[0])
                return firmware;
        if (is_cx2388x(state))
                return CX2388x_FIRMWARE;
        if (is_cx231xx(state))
                return CX231xx_FIRMWARE;
        return CX25840_FIRMWARE;
}

static int check_fw_load(struct i2c_client *client, int size)
{
        /* DL_ADDR_HB DL_ADDR_LB */
        int s = cx25840_read(client, 0x801) << 8;
        s |= cx25840_read(client, 0x800);

        if (size != s) {
                v4l_err(client, "firmware %s load failed\n",
                                get_fw_name(client));
                return -EINVAL;
        }

        v4l_info(client, "loaded %s firmware (%d bytes)\n",
                        get_fw_name(client), size);
        return 0;
}

static int fw_write(struct i2c_client *client, const u8 *data, int size)
{
        if (i2c_master_send(client, data, size) < size) {
                v4l_err(client, "firmware load i2c failure\n");
                return -ENOSYS;
        }

        return 0;
}

int cx25840_loadfw(struct i2c_client *client)
{
        struct cx25840_state *state = to_state(i2c_get_clientdata(client));
        const struct firmware *fw = NULL;
        u8 buffer[FWSEND];
        const u8 *ptr;
        const char *fwname = get_fw_name(client);
        int size, retval;
        int max_buf_size = FWSEND;
        u32 gpio_oe = 0, gpio_da = 0;

        if (is_cx2388x(state)) {
                /* Preserve the GPIO OE and output bits */
                gpio_oe = cx25840_read(client, 0x160);
                gpio_da = cx25840_read(client, 0x164);
        }

        /* cx231xx cannot accept more than 16 bytes at a time */
        if (is_cx231xx(state) && max_buf_size > 16)
                max_buf_size = 16;

        if (request_firmware(&fw, fwname, FWDEV(client)) != 0) {
                v4l_err(client, "unable to open firmware %s\n", fwname);
                return -EINVAL;
        }

        start_fw_load(client);

        buffer[0] = 0x08;
        buffer[1] = 0x02;

        size = fw->size;
        ptr = fw->data;
        while (size > 0) {
                int len = min(max_buf_size - 2, size);

                memcpy(buffer + 2, ptr, len);

                retval = fw_write(client, buffer, len + 2);

                if (retval < 0) {
                        release_firmware(fw);
                        return retval;
                }

                size -= len;
                ptr += len;
        }

        end_fw_load(client);

        size = fw->size;
        release_firmware(fw);

        if (is_cx2388x(state)) {
                /* Restore GPIO configuration after f/w load */
                cx25840_write(client, 0x160, gpio_oe);
                cx25840_write(client, 0x164, gpio_da);
        }

        return check_fw_load(client, size);
}

MODULE_FIRMWARE(CX2388x_FIRMWARE);
MODULE_FIRMWARE(CX231xx_FIRMWARE);
MODULE_FIRMWARE(CX25840_FIRMWARE);