drivers/nfc/nfcmrvl/i2c.c

   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
  32 struct nfcmrvl_i2c_drv_data {
  33         unsigned long flags;
  34         struct device *dev;
  35         struct i2c_client *i2c;
  36         struct nfcmrvl_private *priv;
  37 };
  38
  39 static 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
  83 static 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
 113 static 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
 123 static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
 124 {
 125         return 0;
 126 }
 127
 128 static 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         }
 155
 156         if (ret) {
 157                 kfree_skb(skb);
 158                 return ret;
 159         }
 160
 161         consume_skb(skb);
 162         return 0;
 163 }
 164
 165 static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
 166                                           const void *param)
 167 {
 168 }
 169
 170 static struct nfcmrvl_if_ops i2c_ops = {
 171         .nci_open = nfcmrvl_i2c_nci_open,
 172         .nci_close = nfcmrvl_i2c_nci_close,
 173         .nci_send = nfcmrvl_i2c_nci_send,
 174         .nci_update_config = nfcmrvl_i2c_nci_update_config,
 175 };
 176
 177 static int nfcmrvl_i2c_parse_dt(struct device_node *node,
 178                                 struct nfcmrvl_platform_data *pdata)
 179 {
 180         int ret;
 181
 182         ret = nfcmrvl_parse_dt(node, pdata);
 183         if (ret < 0) {
 184                 pr_err("Failed to get generic entries\n");
 185                 return ret;
 186         }
 187
 188         if (of_find_property(node, "i2c-int-falling", NULL))
 189                 pdata->irq_polarity = IRQF_TRIGGER_FALLING;
 190         else
 191                 pdata->irq_polarity = IRQF_TRIGGER_RISING;
 192
 193         ret = irq_of_parse_and_map(node, 0);
 194         if (!ret) {
 195                 pr_err("Unable to get irq\n");
 196                 return -EINVAL;
 197         }
 198         pdata->irq = ret;
 199
 200         return 0;
 201 }
 202
 203 static int nfcmrvl_i2c_probe(struct i2c_client *client,
 204                              const struct i2c_device_id *id)
 205 {
 206         struct nfcmrvl_i2c_drv_data *drv_data;
 207         struct nfcmrvl_platform_data *pdata;
 208         struct nfcmrvl_platform_data config;
 209         int ret;
 210
 211         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 212                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 213                 return -ENODEV;
 214         }
 215
 216         drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
 217         if (!drv_data)
 218                 return -ENOMEM;
 219
 220         drv_data->i2c = client;
 221         drv_data->dev = &client->dev;
 222         drv_data->priv = NULL;
 223
 224         i2c_set_clientdata(client, drv_data);
 225
 226         pdata = client->dev.platform_data;
 227
 228         if (!pdata && client->dev.of_node)
 229                 if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
 230                         pdata = &config;
 231
 232         if (!pdata)
 233                 return -EINVAL;
 234
 235         /* Request the read IRQ */
 236         ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
 237                                         NULL, nfcmrvl_i2c_int_irq_thread_fn,
 238                                         pdata->irq_polarity | IRQF_ONESHOT,
 239                                         "nfcmrvl_i2c_int", drv_data);
 240         if (ret < 0) {
 241                 nfc_err(&drv_data->i2c->dev,
 242                         "Unable to register IRQ handler\n");
 243                 return ret;
 244         }
 245
 246         drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
 247                                                   drv_data, &i2c_ops,
 248                                                   &drv_data->i2c->dev, pdata);
 249
 250         if (IS_ERR(drv_data->priv))
 251                 return PTR_ERR(drv_data->priv);
 252
 253         drv_data->priv->support_fw_dnld = true;
 254
 255         return 0;
 256 }
 257
 258 static int nfcmrvl_i2c_remove(struct i2c_client *client)
 259 {
 260         struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
 261
 262         nfcmrvl_nci_unregister_dev(drv_data->priv);
 263
 264         return 0;
 265 }
 266
 267
 268 static const struct of_device_id of_nfcmrvl_i2c_match[] = {
 269         { .compatible = "marvell,nfc-i2c", },
 270         {},
 271 };
 272 MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
 273
 274 static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
 275         { "nfcmrvl_i2c", 0 },
 276         {}
 277 };
 278 MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
 279
 280 static struct i2c_driver nfcmrvl_i2c_driver = {
 281         .probe = nfcmrvl_i2c_probe,
 282         .id_table = nfcmrvl_i2c_id_table,
 283         .remove = nfcmrvl_i2c_remove,
 284         .driver = {
 285                 .name           = "nfcmrvl_i2c",
 286                 .owner          = THIS_MODULE,
 287                 .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
 288         },
 289 };
 290
 291 module_i2c_driver(nfcmrvl_i2c_driver);
 292
 293 MODULE_AUTHOR("Marvell International Ltd.");
 294 MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
 295 MODULE_LICENSE("GPL v2");