drivers/nfc/nfcmrvl/i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Marvell NFC-over-I2C driver: I2C interface related functions
   4  *
   5  * Copyright (C) 2015, Marvell International Ltd.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/i2c.h>
  11 #include <linux/nfc.h>
  12 #include <linux/delay.h>
  13 #include <linux/of_irq.h>
  14 #include <net/nfc/nci.h>
  15 #include <net/nfc/nci_core.h>
  16 #include "nfcmrvl.h"
  17
  18 struct nfcmrvl_i2c_drv_data {
  19         unsigned long flags;
  20         struct device *dev;
  21         struct i2c_client *i2c;
  22         struct nfcmrvl_private *priv;
  23 };
  24
  25 static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
  26                             struct sk_buff **skb)
  27 {
  28         int ret;
  29         struct nci_ctrl_hdr nci_hdr;
  30
  31         /* Read NCI header to know the payload size */
  32         ret = i2c_master_recv(drv_data->i2c, (u8 *)&nci_hdr, NCI_CTRL_HDR_SIZE);
  33         if (ret != NCI_CTRL_HDR_SIZE) {
  34                 nfc_err(&drv_data->i2c->dev, "cannot read NCI header\n");
  35                 return -EBADMSG;
  36         }
  37
  38         *skb = nci_skb_alloc(drv_data->priv->ndev,
  39                              nci_hdr.plen + NCI_CTRL_HDR_SIZE, GFP_KERNEL);
  40         if (!*skb)
  41                 return -ENOMEM;
  42
  43         /* Copy NCI header into the SKB */
  44         skb_put_data(*skb, &nci_hdr, NCI_CTRL_HDR_SIZE);
  45
  46         if (nci_hdr.plen) {
  47                 /* Read the NCI payload */
  48                 ret = i2c_master_recv(drv_data->i2c,
  49                                       skb_put(*skb, nci_hdr.plen),
  50                                       nci_hdr.plen);
  51
  52                 if (ret != nci_hdr.plen) {
  53                         nfc_err(&drv_data->i2c->dev,
  54                                 "Invalid frame payload length: %u (expected %u)\n",
  55                                 ret, nci_hdr.plen);
  56                         kfree_skb(*skb);
  57                         return -EBADMSG;
  58                 }
  59         }
  60
  61         return 0;
  62 }
  63
  64 static irqreturn_t nfcmrvl_i2c_int_irq_thread_fn(int irq, void *drv_data_ptr)
  65 {
  66         struct nfcmrvl_i2c_drv_data *drv_data = drv_data_ptr;
  67         struct sk_buff *skb = NULL;
  68         int ret;
  69
  70         if (!drv_data->priv)
  71                 return IRQ_HANDLED;
  72
  73         if (test_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags))
  74                 return IRQ_HANDLED;
  75
  76         ret = nfcmrvl_i2c_read(drv_data, &skb);
  77
  78         switch (ret) {
  79         case -EREMOTEIO:
  80                 set_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags);
  81                 break;
  82         case -ENOMEM:
  83         case -EBADMSG:
  84                 nfc_err(&drv_data->i2c->dev, "read failed %d\n", ret);
  85                 break;
  86         default:
  87                 if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
  88                         nfc_err(&drv_data->i2c->dev, "corrupted RX packet\n");
  89                 break;
  90         }
  91         return IRQ_HANDLED;
  92 }
  93
  94 static int nfcmrvl_i2c_nci_open(struct nfcmrvl_private *priv)
  95 {
  96         struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
  97
  98         if (!drv_data)
  99                 return -ENODEV;
 100
 101         return 0;
 102 }
 103
 104 static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
 105 {
 106         return 0;
 107 }
 108
 109 static int nfcmrvl_i2c_nci_send(struct nfcmrvl_private *priv,
 110                                 struct sk_buff *skb)
 111 {
 112         struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
 113         int ret;
 114
 115         if (test_bit(NFCMRVL_PHY_ERROR, &priv->flags)) {
 116                 kfree_skb(skb);
 117                 return -EREMOTEIO;
 118         }
 119
 120         ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
 121
 122         /* Retry if chip was in standby */
 123         if (ret == -EREMOTEIO) {
 124                 nfc_info(drv_data->dev, "chip may sleep, retry\n");
 125                 usleep_range(6000, 10000);
 126                 ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
 127         }
 128
 129         if (ret >= 0) {
 130                 if (ret != skb->len) {
 131                         nfc_err(drv_data->dev,
 132                                 "Invalid length sent: %u (expected %u)\n",
 133                                 ret, skb->len);
 134                         ret = -EREMOTEIO;
 135                 } else
 136                         ret = 0;
 137         }
 138
 139         if (ret) {
 140                 kfree_skb(skb);
 141                 return ret;
 142         }
 143
 144         consume_skb(skb);
 145         return 0;
 146 }
 147
 148 static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
 149                                           const void *param)
 150 {
 151 }
 152
 153 static const struct nfcmrvl_if_ops i2c_ops = {
 154         .nci_open = nfcmrvl_i2c_nci_open,
 155         .nci_close = nfcmrvl_i2c_nci_close,
 156         .nci_send = nfcmrvl_i2c_nci_send,
 157         .nci_update_config = nfcmrvl_i2c_nci_update_config,
 158 };
 159
 160 static int nfcmrvl_i2c_parse_dt(struct device_node *node,
 161                                 struct nfcmrvl_platform_data *pdata)
 162 {
 163         int ret;
 164
 165         ret = nfcmrvl_parse_dt(node, pdata);
 166         if (ret < 0) {
 167                 pr_err("Failed to get generic entries\n");
 168                 return ret;
 169         }
 170
 171         if (of_property_read_bool(node, "i2c-int-falling"))
 172                 pdata->irq_polarity = IRQF_TRIGGER_FALLING;
 173         else
 174                 pdata->irq_polarity = IRQF_TRIGGER_RISING;
 175
 176         ret = irq_of_parse_and_map(node, 0);
 177         if (!ret) {
 178                 pr_err("Unable to get irq\n");
 179                 return -EINVAL;
 180         }
 181         pdata->irq = ret;
 182
 183         return 0;
 184 }
 185
 186 static int nfcmrvl_i2c_probe(struct i2c_client *client)
 187 {
 188         const struct nfcmrvl_platform_data *pdata;
 189         struct nfcmrvl_i2c_drv_data *drv_data;
 190         struct nfcmrvl_platform_data config;
 191         int ret;
 192
 193         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 194                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 195                 return -ENODEV;
 196         }
 197
 198         drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
 199         if (!drv_data)
 200                 return -ENOMEM;
 201
 202         drv_data->i2c = client;
 203         drv_data->dev = &client->dev;
 204         drv_data->priv = NULL;
 205
 206         i2c_set_clientdata(client, drv_data);
 207
 208         pdata = client->dev.platform_data;
 209
 210         if (!pdata && client->dev.of_node)
 211                 if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
 212                         pdata = &config;
 213
 214         if (!pdata)
 215                 return -EINVAL;
 216
 217         /* Request the read IRQ */
 218         ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
 219                                         NULL, nfcmrvl_i2c_int_irq_thread_fn,
 220                                         pdata->irq_polarity | IRQF_ONESHOT,
 221                                         "nfcmrvl_i2c_int", drv_data);
 222         if (ret < 0) {
 223                 nfc_err(&drv_data->i2c->dev,
 224                         "Unable to register IRQ handler\n");
 225                 return ret;
 226         }
 227
 228         drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
 229                                                   drv_data, &i2c_ops,
 230                                                   &drv_data->i2c->dev, pdata);
 231
 232         if (IS_ERR(drv_data->priv))
 233                 return PTR_ERR(drv_data->priv);
 234
 235         drv_data->priv->support_fw_dnld = true;
 236
 237         return 0;
 238 }
 239
 240 static void nfcmrvl_i2c_remove(struct i2c_client *client)
 241 {
 242         struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
 243
 244         nfcmrvl_nci_unregister_dev(drv_data->priv);
 245 }
 246
 247
 248 static const struct of_device_id of_nfcmrvl_i2c_match[] __maybe_unused = {
 249         { .compatible = "marvell,nfc-i2c", },
 250         {},
 251 };
 252 MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
 253
 254 static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
 255         { "nfcmrvl_i2c" },
 256         {}
 257 };
 258 MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
 259
 260 static struct i2c_driver nfcmrvl_i2c_driver = {
 261         .probe = nfcmrvl_i2c_probe,
 262         .id_table = nfcmrvl_i2c_id_table,
 263         .remove = nfcmrvl_i2c_remove,
 264         .driver = {
 265                 .name           = "nfcmrvl_i2c",
 266                 .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
 267         },
 268 };
 269
 270 module_i2c_driver(nfcmrvl_i2c_driver);
 271
 272 MODULE_AUTHOR("Marvell International Ltd.");
 273 MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
 274 MODULE_LICENSE("GPL v2");