linux/drivers/nfc/nfcmrvl/i2c.c
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   1/**
   2 * Marvell NFC-over-I2C driver: I2C interface related functions
   3 *
   4 * Copyright (C) 2015, Marvell International Ltd.
   5 *
   6 * This software file (the "File") is distributed by Marvell International
   7 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
   8 * (the "License").  You may use, redistribute and/or modify this File in
   9 * accordance with the terms and conditions of the License, a copy of which
  10 * is available on the worldwide web at
  11 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
  12 *
  13 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
  14 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
  15 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
  16 * this warranty disclaimer.
  17 **/
  18
  19#include <linux/module.h>
  20#include <linux/interrupt.h>
  21#include <linux/i2c.h>
  22#include <linux/pm_runtime.h>
  23#include <linux/nfc.h>
  24#include <linux/gpio.h>
  25#include <linux/delay.h>
  26#include <linux/of_irq.h>
  27#include <linux/of_gpio.h>
  28#include <net/nfc/nci.h>
  29#include <net/nfc/nci_core.h>
  30#include "nfcmrvl.h"
  31
  32struct nfcmrvl_i2c_drv_data {
  33        unsigned long flags;
  34        struct device *dev;
  35        struct i2c_client *i2c;
  36        struct nfcmrvl_private *priv;
  37};
  38
  39static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
  40                            struct sk_buff **skb)
  41{
  42        int ret;
  43        struct nci_ctrl_hdr nci_hdr;
  44
  45        /* Read NCI header to know the payload size */
  46        ret = i2c_master_recv(drv_data->i2c, (u8 *)&nci_hdr, NCI_CTRL_HDR_SIZE);
  47        if (ret != NCI_CTRL_HDR_SIZE) {
  48                nfc_err(&drv_data->i2c->dev, "cannot read NCI header\n");
  49                return -EBADMSG;
  50        }
  51
  52        if (nci_hdr.plen > NCI_MAX_PAYLOAD_SIZE) {
  53                nfc_err(&drv_data->i2c->dev, "invalid packet payload size\n");
  54                return -EBADMSG;
  55        }
  56
  57        *skb = nci_skb_alloc(drv_data->priv->ndev,
  58                             nci_hdr.plen + NCI_CTRL_HDR_SIZE, GFP_KERNEL);
  59        if (!*skb)
  60                return -ENOMEM;
  61
  62        /* Copy NCI header into the SKB */
  63        skb_put_data(*skb, &nci_hdr, NCI_CTRL_HDR_SIZE);
  64
  65        if (nci_hdr.plen) {
  66                /* Read the NCI payload */
  67                ret = i2c_master_recv(drv_data->i2c,
  68                                      skb_put(*skb, nci_hdr.plen),
  69                                      nci_hdr.plen);
  70
  71                if (ret != nci_hdr.plen) {
  72                        nfc_err(&drv_data->i2c->dev,
  73                                "Invalid frame payload length: %u (expected %u)\n",
  74                                ret, nci_hdr.plen);
  75                        kfree_skb(*skb);
  76                        return -EBADMSG;
  77                }
  78        }
  79
  80        return 0;
  81}
  82
  83static irqreturn_t nfcmrvl_i2c_int_irq_thread_fn(int irq, void *drv_data_ptr)
  84{
  85        struct nfcmrvl_i2c_drv_data *drv_data = drv_data_ptr;
  86        struct sk_buff *skb = NULL;
  87        int ret;
  88
  89        if (!drv_data->priv)
  90                return IRQ_HANDLED;
  91
  92        if (test_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags))
  93                return IRQ_HANDLED;
  94
  95        ret = nfcmrvl_i2c_read(drv_data, &skb);
  96
  97        switch (ret) {
  98        case -EREMOTEIO:
  99                set_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags);
 100                break;
 101        case -ENOMEM:
 102        case -EBADMSG:
 103                nfc_err(&drv_data->i2c->dev, "read failed %d\n", ret);
 104                break;
 105        default:
 106                if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
 107                        nfc_err(&drv_data->i2c->dev, "corrupted RX packet\n");
 108                break;
 109        }
 110        return IRQ_HANDLED;
 111}
 112
 113static int nfcmrvl_i2c_nci_open(struct nfcmrvl_private *priv)
 114{
 115        struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
 116
 117        if (!drv_data)
 118                return -ENODEV;
 119
 120        return 0;
 121}
 122
 123static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
 124{
 125        return 0;
 126}
 127
 128static int nfcmrvl_i2c_nci_send(struct nfcmrvl_private *priv,
 129                                struct sk_buff *skb)
 130{
 131        struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
 132        int ret;
 133
 134        if (test_bit(NFCMRVL_PHY_ERROR, &priv->flags))
 135                return -EREMOTEIO;
 136
 137        ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
 138
 139        /* Retry if chip was in standby */
 140        if (ret == -EREMOTEIO) {
 141                nfc_info(drv_data->dev, "chip may sleep, retry\n");
 142                usleep_range(6000, 10000);
 143                ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
 144        }
 145
 146        if (ret >= 0) {
 147                if (ret != skb->len) {
 148                        nfc_err(drv_data->dev,
 149                                "Invalid length sent: %u (expected %u)\n",
 150                                ret, skb->len);
 151                        ret = -EREMOTEIO;
 152                } else
 153                        ret = 0;
 154                kfree_skb(skb);
 155        }
 156
 157        return ret;
 158}
 159
 160static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
 161                                          const void *param)
 162{
 163}
 164
 165static struct nfcmrvl_if_ops i2c_ops = {
 166        .nci_open = nfcmrvl_i2c_nci_open,
 167        .nci_close = nfcmrvl_i2c_nci_close,
 168        .nci_send = nfcmrvl_i2c_nci_send,
 169        .nci_update_config = nfcmrvl_i2c_nci_update_config,
 170};
 171
 172static int nfcmrvl_i2c_parse_dt(struct device_node *node,
 173                                struct nfcmrvl_platform_data *pdata)
 174{
 175        int ret;
 176
 177        ret = nfcmrvl_parse_dt(node, pdata);
 178        if (ret < 0) {
 179                pr_err("Failed to get generic entries\n");
 180                return ret;
 181        }
 182
 183        if (of_find_property(node, "i2c-int-falling", NULL))
 184                pdata->irq_polarity = IRQF_TRIGGER_FALLING;
 185        else
 186                pdata->irq_polarity = IRQF_TRIGGER_RISING;
 187
 188        ret = irq_of_parse_and_map(node, 0);
 189        if (ret < 0) {
 190                pr_err("Unable to get irq, error: %d\n", ret);
 191                return ret;
 192        }
 193        pdata->irq = ret;
 194
 195        return 0;
 196}
 197
 198static int nfcmrvl_i2c_probe(struct i2c_client *client,
 199                             const struct i2c_device_id *id)
 200{
 201        struct nfcmrvl_i2c_drv_data *drv_data;
 202        struct nfcmrvl_platform_data *pdata;
 203        struct nfcmrvl_platform_data config;
 204        int ret;
 205
 206        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 207                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 208                return -ENODEV;
 209        }
 210
 211        drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
 212        if (!drv_data)
 213                return -ENOMEM;
 214
 215        drv_data->i2c = client;
 216        drv_data->dev = &client->dev;
 217        drv_data->priv = NULL;
 218
 219        i2c_set_clientdata(client, drv_data);
 220
 221        pdata = client->dev.platform_data;
 222
 223        if (!pdata && client->dev.of_node)
 224                if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
 225                        pdata = &config;
 226
 227        if (!pdata)
 228                return -EINVAL;
 229
 230        /* Request the read IRQ */
 231        ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
 232                                        NULL, nfcmrvl_i2c_int_irq_thread_fn,
 233                                        pdata->irq_polarity | IRQF_ONESHOT,
 234                                        "nfcmrvl_i2c_int", drv_data);
 235        if (ret < 0) {
 236                nfc_err(&drv_data->i2c->dev,
 237                        "Unable to register IRQ handler\n");
 238                return ret;
 239        }
 240
 241        drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
 242                                                  drv_data, &i2c_ops,
 243                                                  &drv_data->i2c->dev, pdata);
 244
 245        if (IS_ERR(drv_data->priv))
 246                return PTR_ERR(drv_data->priv);
 247
 248        drv_data->priv->support_fw_dnld = true;
 249
 250        return 0;
 251}
 252
 253static int nfcmrvl_i2c_remove(struct i2c_client *client)
 254{
 255        struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
 256
 257        nfcmrvl_nci_unregister_dev(drv_data->priv);
 258
 259        return 0;
 260}
 261
 262
 263static const struct of_device_id of_nfcmrvl_i2c_match[] = {
 264        { .compatible = "marvell,nfc-i2c", },
 265        {},
 266};
 267MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
 268
 269static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
 270        { "nfcmrvl_i2c", 0 },
 271        {}
 272};
 273MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
 274
 275static struct i2c_driver nfcmrvl_i2c_driver = {
 276        .probe = nfcmrvl_i2c_probe,
 277        .id_table = nfcmrvl_i2c_id_table,
 278        .remove = nfcmrvl_i2c_remove,
 279        .driver = {
 280                .name           = "nfcmrvl_i2c",
 281                .owner          = THIS_MODULE,
 282                .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
 283        },
 284};
 285
 286module_i2c_driver(nfcmrvl_i2c_driver);
 287
 288MODULE_AUTHOR("Marvell International Ltd.");
 289MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
 290MODULE_LICENSE("GPL v2");
 291