// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for NXP PN533 NFC Chip - I2C transport layer
 *
 * Copyright (C) 2011 Instituto Nokia de Tecnologia
 * Copyright (C) 2012-2013 Tieto Poland
 * Copyright (C) 2016 HALE electronic
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/nfc.h>
#include <linux/netdevice.h>
#include <linux/interrupt.h>
#include <net/nfc/nfc.h>
#include "pn533.h"

#define VERSION "0.1"

#define PN533_I2C_DRIVER_NAME "pn533_i2c"

struct pn533_i2c_phy {
        struct i2c_client *i2c_dev;
        struct pn533 *priv;

        bool aborted;

        int hard_fault;         /*
                                 * < 0 if hardware error occurred (e.g. i2c err)
                                 * and prevents normal operation.
                                 */
};

static int pn533_i2c_send_ack(struct pn533 *dev, gfp_t flags)
{
        struct pn533_i2c_phy *phy = dev->phy;
        struct i2c_client *client = phy->i2c_dev;
        static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
        /* spec 6.2.1.3:  Preamble, SoPC (2), ACK Code (2), Postamble */

        return i2c_master_send(client, ack, 6);
}

static int pn533_i2c_send_frame(struct pn533 *dev,
                                struct sk_buff *out)
{
        struct pn533_i2c_phy *phy = dev->phy;
        struct i2c_client *client = phy->i2c_dev;
        int rc;

        if (phy->hard_fault != 0)
                return phy->hard_fault;

        if (phy->priv == NULL)
                phy->priv = dev;

        phy->aborted = false;

        print_hex_dump_debug("PN533_i2c TX: ", DUMP_PREFIX_NONE, 16, 1,
                             out->data, out->len, false);

        rc = i2c_master_send(client, out->data, out->len);

        if (rc == -EREMOTEIO) { /* Retry, chip was in power down */
                usleep_range(6000, 10000);
                rc = i2c_master_send(client, out->data, out->len);
        }

        if (rc >= 0) {
                if (rc != out->len)
                        rc = -EREMOTEIO;
                else
                        rc = 0;
        }

        return rc;
}

static void pn533_i2c_abort_cmd(struct pn533 *dev, gfp_t flags)
{
        struct pn533_i2c_phy *phy = dev->phy;

        phy->aborted = true;

        /* An ack will cancel the last issued command */
        pn533_i2c_send_ack(dev, flags);

        /* schedule cmd_complete_work to finish current command execution */
        pn533_recv_frame(phy->priv, NULL, -ENOENT);
}

static int pn533_i2c_read(struct pn533_i2c_phy *phy, struct sk_buff **skb)
{
        struct i2c_client *client = phy->i2c_dev;
        int len = PN533_EXT_FRAME_HEADER_LEN +
                  PN533_STD_FRAME_MAX_PAYLOAD_LEN +
                  PN533_STD_FRAME_TAIL_LEN + 1;
        int r;

        *skb = alloc_skb(len, GFP_KERNEL);
        if (*skb == NULL)
                return -ENOMEM;

        r = i2c_master_recv(client, skb_put(*skb, len), len);
        if (r != len) {
                nfc_err(&client->dev, "cannot read. r=%d len=%d\n", r, len);
                kfree_skb(*skb);
                return -EREMOTEIO;
        }

        if (!((*skb)->data[0] & 0x01)) {
                nfc_err(&client->dev, "READY flag not set");
                kfree_skb(*skb);
                return -EBUSY;
        }

        /* remove READY byte */
        skb_pull(*skb, 1);
        /* trim to frame size */
        skb_trim(*skb, phy->priv->ops->rx_frame_size((*skb)->data));

        return 0;
}

static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
{
        struct pn533_i2c_phy *phy = data;
        struct sk_buff *skb = NULL;
        int r;

        if (!phy || irq != phy->i2c_dev->irq) {
                WARN_ON_ONCE(1);
                return IRQ_NONE;
        }

        if (phy->hard_fault != 0)
                return IRQ_HANDLED;

        r = pn533_i2c_read(phy, &skb);
        if (r == -EREMOTEIO) {
                phy->hard_fault = r;

                pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);

                return IRQ_HANDLED;
        } else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
                return IRQ_HANDLED;
        }

        if (!phy->aborted)
                pn533_recv_frame(phy->priv, skb, 0);

        return IRQ_HANDLED;
}

static const struct pn533_phy_ops i2c_phy_ops = {
        .send_frame = pn533_i2c_send_frame,
        .send_ack = pn533_i2c_send_ack,
        .abort_cmd = pn533_i2c_abort_cmd,
};


static int pn533_i2c_probe(struct i2c_client *client)
{
        struct pn533_i2c_phy *phy;
        struct pn533 *priv;
        int r = 0;

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
                return -ENODEV;
        }

        phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
                           GFP_KERNEL);
        if (!phy)
                return -ENOMEM;

        phy->i2c_dev = client;
        i2c_set_clientdata(client, phy);

        priv = pn53x_common_init(PN533_DEVICE_PN532,
                                PN533_PROTO_REQ_ACK_RESP,
                                phy, &i2c_phy_ops, NULL,
                                &phy->i2c_dev->dev);

        if (IS_ERR(priv))
                return PTR_ERR(priv);

        phy->priv = priv;
        r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
        if (r)
                goto nfc_alloc_err;

        r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
                                IRQF_TRIGGER_FALLING |
                                IRQF_SHARED | IRQF_ONESHOT,
                                PN533_I2C_DRIVER_NAME, phy);
        if (r < 0) {
                nfc_err(&client->dev, "Unable to register IRQ handler\n");
                goto irq_rqst_err;
        }

        r = pn533_finalize_setup(priv);
        if (r)
                goto fn_setup_err;

        r = nfc_register_device(priv->nfc_dev);
        if (r)
                goto fn_setup_err;

        return r;

fn_setup_err:
        free_irq(client->irq, phy);

irq_rqst_err:
        nfc_free_device(priv->nfc_dev);

nfc_alloc_err:
        pn53x_common_clean(phy->priv);

        return r;
}

static void pn533_i2c_remove(struct i2c_client *client)
{
        struct pn533_i2c_phy *phy = i2c_get_clientdata(client);

        free_irq(client->irq, phy);

        pn53x_unregister_nfc(phy->priv);
        pn53x_common_clean(phy->priv);
}

static const struct of_device_id of_pn533_i2c_match[] __maybe_unused = {
        { .compatible = "nxp,pn532", },
        /*
         * NOTE: The use of the compatibles with the trailing "...-i2c" is
         * deprecated and will be removed.
         */
        { .compatible = "nxp,pn533-i2c", },
        { .compatible = "nxp,pn532-i2c", },
        {},
};
MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);

static const struct i2c_device_id pn533_i2c_id_table[] = {
        { PN533_I2C_DRIVER_NAME },
        {}
};
MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);

static struct i2c_driver pn533_i2c_driver = {
        .driver = {
                   .name = PN533_I2C_DRIVER_NAME,
                   .of_match_table = of_match_ptr(of_pn533_i2c_match),
                  },
        .probe = pn533_i2c_probe,
        .id_table = pn533_i2c_id_table,
        .remove = pn533_i2c_remove,
};

module_i2c_driver(pn533_i2c_driver);

MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");