// SPDX-License-Identifier: GPL-2.0-only
/*
 * I2C link layer for the NXP NCI driver
 *
 * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
 * Copyright (C) 2012-2015  Intel Corporation. All rights reserved.
 *
 * Authors: Clément Perrochaud <clement.perrochaud@nxp.com>
 * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>
 *
 * Derived from PN544 device driver:
 * Copyright (C) 2012  Intel Corporation. All rights reserved.
 */

#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/nfc.h>
#include <linux/gpio/consumer.h>
#include <linux/unaligned.h>

#include <net/nfc/nfc.h>

#include "nxp-nci.h"

#define NXP_NCI_I2C_DRIVER_NAME "nxp-nci_i2c"

#define NXP_NCI_I2C_MAX_PAYLOAD 32

struct nxp_nci_i2c_phy {
        struct i2c_client *i2c_dev;
        struct nci_dev *ndev;

        struct gpio_desc *gpiod_en;
        struct gpio_desc *gpiod_fw;

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

static int nxp_nci_i2c_set_mode(void *phy_id,
                                    enum nxp_nci_mode mode)
{
        struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;

        gpiod_set_value_cansleep(phy->gpiod_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
        gpiod_set_value_cansleep(phy->gpiod_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
        usleep_range(10000, 15000);

        if (mode == NXP_NCI_MODE_COLD)
                phy->hard_fault = 0;

        return 0;
}

static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
{
        int r;
        struct nxp_nci_i2c_phy *phy = phy_id;
        struct i2c_client *client = phy->i2c_dev;

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

        r = i2c_master_send(client, skb->data, skb->len);
        if (r < 0) {
                /* Retry, chip was in standby */
                msleep(110);
                r = i2c_master_send(client, skb->data, skb->len);
        }

        if (r < 0) {
                nfc_err(&client->dev, "Error %d on I2C send\n", r);
        } else if (r != skb->len) {
                nfc_err(&client->dev,
                        "Invalid length sent: %u (expected %u)\n",
                        r, skb->len);
                r = -EREMOTEIO;
        } else {
                /* Success but return 0 and not number of bytes */
                r = 0;
        }

        return r;
}

static const struct nxp_nci_phy_ops i2c_phy_ops = {
        .set_mode = nxp_nci_i2c_set_mode,
        .write = nxp_nci_i2c_write,
};

static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
                               struct sk_buff **skb)
{
        struct i2c_client *client = phy->i2c_dev;
        size_t frame_len;
        __be16 header;
        int r;

        r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
        if (r < 0) {
                goto fw_read_exit;
        } else if (r != NXP_NCI_FW_HDR_LEN) {
                nfc_err(&client->dev, "Incorrect header length: %u\n", r);
                r = -EBADMSG;
                goto fw_read_exit;
        }

        frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) +
                    NXP_NCI_FW_CRC_LEN;

        *skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
        if (*skb == NULL) {
                r = -ENOMEM;
                goto fw_read_exit;
        }

        skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN);

        r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
        if (r < 0) {
                goto fw_read_exit_free_skb;
        } else if (r != frame_len) {
                nfc_err(&client->dev,
                        "Invalid frame length: %u (expected %zu)\n",
                        r, frame_len);
                r = -EBADMSG;
                goto fw_read_exit_free_skb;
        }

        return 0;

fw_read_exit_free_skb:
        kfree_skb(*skb);
fw_read_exit:
        return r;
}

static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
                                struct sk_buff **skb)
{
        struct nci_ctrl_hdr header; /* May actually be a data header */
        struct i2c_client *client = phy->i2c_dev;
        int r;

        r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
        if (r < 0) {
                goto nci_read_exit;
        } else if (r != NCI_CTRL_HDR_SIZE) {
                nfc_err(&client->dev, "Incorrect header length: %u\n", r);
                r = -EBADMSG;
                goto nci_read_exit;
        }

        *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
        if (*skb == NULL) {
                r = -ENOMEM;
                goto nci_read_exit;
        }

        skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);

        if (!header.plen)
                return 0;

        r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
        if (r < 0) {
                goto nci_read_exit_free_skb;
        } else if (r != header.plen) {
                nfc_err(&client->dev,
                        "Invalid frame payload length: %u (expected %u)\n",
                        r, header.plen);
                r = -EBADMSG;
                goto nci_read_exit_free_skb;
        }

        return 0;

nci_read_exit_free_skb:
        kfree_skb(*skb);
nci_read_exit:
        return r;
}

static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
{
        struct nxp_nci_i2c_phy *phy = phy_id;
        struct i2c_client *client;
        struct nxp_nci_info *info;

        struct sk_buff *skb = NULL;
        int r = 0;

        if (!phy || !phy->ndev)
                goto exit_irq_none;

        client = phy->i2c_dev;

        if (!client || irq != client->irq)
                goto exit_irq_none;

        info = nci_get_drvdata(phy->ndev);

        if (!info)
                goto exit_irq_none;

        mutex_lock(&info->info_lock);

        if (phy->hard_fault != 0)
                goto exit_irq_handled;

        switch (info->mode) {
        case NXP_NCI_MODE_NCI:
                r = nxp_nci_i2c_nci_read(phy, &skb);
                break;
        case NXP_NCI_MODE_FW:
                r = nxp_nci_i2c_fw_read(phy, &skb);
                break;
        case NXP_NCI_MODE_COLD:
                r = -EREMOTEIO;
                break;
        }

        if (r == -EREMOTEIO) {
                phy->hard_fault = r;
                if (info->mode == NXP_NCI_MODE_FW)
                        nxp_nci_fw_recv_frame(phy->ndev, NULL);
        }
        if (r < 0) {
                nfc_err(&client->dev, "Read failed with error %d\n", r);
                goto exit_irq_handled;
        }

        switch (info->mode) {
        case NXP_NCI_MODE_NCI:
                nci_recv_frame(phy->ndev, skb);
                break;
        case NXP_NCI_MODE_FW:
                nxp_nci_fw_recv_frame(phy->ndev, skb);
                break;
        case NXP_NCI_MODE_COLD:
                break;
        }

exit_irq_handled:
        mutex_unlock(&info->info_lock);
        return IRQ_HANDLED;
exit_irq_none:
        WARN_ON_ONCE(1);
        return IRQ_NONE;
}

static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
static const struct acpi_gpio_params enable_gpios = { 2, 0, false };

static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
        { "enable-gpios", &enable_gpios, 1 },
        { "firmware-gpios", &firmware_gpios, 1 },
        { }
};

static int nxp_nci_i2c_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct nxp_nci_i2c_phy *phy;
        int r;

        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 nxp_nci_i2c_phy),
                           GFP_KERNEL);
        if (!phy)
                return -ENOMEM;

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

        r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios);
        if (r)
                dev_dbg(dev, "Unable to add GPIO mapping table\n");

        phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(phy->gpiod_en)) {
                nfc_err(dev, "Failed to get EN gpio\n");
                return PTR_ERR(phy->gpiod_en);
        }

        phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW);
        if (IS_ERR(phy->gpiod_fw)) {
                nfc_err(dev, "Failed to get FW gpio\n");
                return PTR_ERR(phy->gpiod_fw);
        }

        r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
                          NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
        if (r < 0)
                return r;

        r = request_threaded_irq(client->irq, NULL,
                                 nxp_nci_i2c_irq_thread_fn,
                                 IRQF_ONESHOT,
                                 NXP_NCI_I2C_DRIVER_NAME, phy);
        if (r < 0)
                nfc_err(&client->dev, "Unable to register IRQ handler\n");

        return r;
}

static void nxp_nci_i2c_remove(struct i2c_client *client)
{
        struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);

        nxp_nci_remove(phy->ndev);
        free_irq(client->irq, phy);
}

static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
        { "nxp-nci_i2c" },
        {}
};
MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);

static const struct of_device_id of_nxp_nci_i2c_match[] = {
        { .compatible = "nxp,nxp-nci-i2c", },
        {}
};
MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id acpi_id[] = {
        { "NXP1001" },
        { "NXP1002" },
        { "NXP7471" },
        { }
};
MODULE_DEVICE_TABLE(acpi, acpi_id);
#endif

static struct i2c_driver nxp_nci_i2c_driver = {
        .driver = {
                   .name = NXP_NCI_I2C_DRIVER_NAME,
                   .acpi_match_table = ACPI_PTR(acpi_id),
                   .of_match_table = of_nxp_nci_i2c_match,
                  },
        .probe = nxp_nci_i2c_probe,
        .id_table = nxp_nci_i2c_id_table,
        .remove = nxp_nci_i2c_remove,
};

module_i2c_driver(nxp_nci_i2c_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");