/**
 * Marvell NFC-over-UART driver
 *
 * Copyright (C) 2015, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available on the worldwide web at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/of_gpio.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include "nfcmrvl.h"

static unsigned int hci_muxed;
static unsigned int flow_control;
static unsigned int break_control;
static unsigned int reset_n_io;

/*
** NFCMRVL NCI OPS
*/

static int nfcmrvl_uart_nci_open(struct nfcmrvl_private *priv)
{
        return 0;
}

static int nfcmrvl_uart_nci_close(struct nfcmrvl_private *priv)
{
        return 0;
}

static int nfcmrvl_uart_nci_send(struct nfcmrvl_private *priv,
                                 struct sk_buff *skb)
{
        struct nci_uart *nu = priv->drv_data;

        return nu->ops.send(nu, skb);
}

static void nfcmrvl_uart_nci_update_config(struct nfcmrvl_private *priv,
                                           const void *param)
{
        struct nci_uart *nu = priv->drv_data;
        const struct nfcmrvl_fw_uart_config *config = param;

        nci_uart_set_config(nu, le32_to_cpu(config->baudrate),
                            config->flow_control);
}

static struct nfcmrvl_if_ops uart_ops = {
        .nci_open = nfcmrvl_uart_nci_open,
        .nci_close = nfcmrvl_uart_nci_close,
        .nci_send = nfcmrvl_uart_nci_send,
        .nci_update_config = nfcmrvl_uart_nci_update_config
};

static int nfcmrvl_uart_parse_dt(struct device_node *node,
                                 struct nfcmrvl_platform_data *pdata)
{
        struct device_node *matched_node;
        int ret;

        matched_node = of_find_compatible_node(node, NULL, "marvell,nfc-uart");
        if (!matched_node) {
                matched_node = of_find_compatible_node(node, NULL,
                                                       "mrvl,nfc-uart");
                if (!matched_node)
                        return -ENODEV;
        }

        ret = nfcmrvl_parse_dt(matched_node, pdata);
        if (ret < 0) {
                pr_err("Failed to get generic entries\n");
                return ret;
        }

        if (of_find_property(matched_node, "flow-control", NULL))
                pdata->flow_control = 1;
        else
                pdata->flow_control = 0;

        if (of_find_property(matched_node, "break-control", NULL))
                pdata->break_control = 1;
        else
                pdata->break_control = 0;

        return 0;
}

/*
** NCI UART OPS
*/

static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
{
        struct nfcmrvl_private *priv;
        struct nfcmrvl_platform_data *pdata = NULL;
        struct nfcmrvl_platform_data config;

        /*
         * Platform data cannot be used here since usually it is already used
         * by low level serial driver. We can try to retrieve serial device
         * and check if DT entries were added.
         */

        if (nu->tty->dev->parent && nu->tty->dev->parent->of_node)
                if (nfcmrvl_uart_parse_dt(nu->tty->dev->parent->of_node,
                                          &config) == 0)
                        pdata = &config;

        if (!pdata) {
                pr_info("No platform data / DT -> fallback to module params\n");
                config.hci_muxed = hci_muxed;
                config.reset_n_io = reset_n_io;
                config.flow_control = flow_control;
                config.break_control = break_control;
                pdata = &config;
        }

        priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops,
                                        nu->tty->dev, pdata);
        if (IS_ERR(priv))
                return PTR_ERR(priv);

        priv->support_fw_dnld = true;

        nu->drv_data = priv;
        nu->ndev = priv->ndev;

        return 0;
}

static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
{
        nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
}

static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
{
        return nfcmrvl_nci_recv_frame((struct nfcmrvl_private *)nu->drv_data,
                                      skb);
}

static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
{
        struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;

        if (priv->ndev->nfc_dev->fw_download_in_progress)
                return;

        /* Remove BREAK to wake up the NFCC */
        if (priv->config.break_control && nu->tty->ops->break_ctl) {
                nu->tty->ops->break_ctl(nu->tty, 0);
                usleep_range(3000, 5000);
        }
}

static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
{
        struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;

        if (priv->ndev->nfc_dev->fw_download_in_progress)
                return;

        /*
        ** To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
        ** up. we set BREAK. Once we will be ready to send again we will remove
        ** it.
        */
        if (priv->config.break_control && nu->tty->ops->break_ctl) {
                nu->tty->ops->break_ctl(nu->tty, -1);
                usleep_range(1000, 3000);
        }
}

static struct nci_uart nfcmrvl_nci_uart = {
        .owner  = THIS_MODULE,
        .name   = "nfcmrvl_uart",
        .driver = NCI_UART_DRIVER_MARVELL,
        .ops    = {
                .open           = nfcmrvl_nci_uart_open,
                .close          = nfcmrvl_nci_uart_close,
                .recv           = nfcmrvl_nci_uart_recv,
                .tx_start       = nfcmrvl_nci_uart_tx_start,
                .tx_done        = nfcmrvl_nci_uart_tx_done,
        }
};

/*
** Module init
*/

static int nfcmrvl_uart_init_module(void)
{
        return nci_uart_register(&nfcmrvl_nci_uart);
}

static void nfcmrvl_uart_exit_module(void)
{
        nci_uart_unregister(&nfcmrvl_nci_uart);
}

module_init(nfcmrvl_uart_init_module);
module_exit(nfcmrvl_uart_exit_module);

MODULE_AUTHOR("Marvell International Ltd.");
MODULE_DESCRIPTION("Marvell NFC-over-UART");
MODULE_LICENSE("GPL v2");

module_param(flow_control, uint, 0);
MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");

module_param(break_control, uint, 0);
MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");

module_param(hci_muxed, uint, 0);
MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");

module_param(reset_n_io, uint, 0);
MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");