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                 return -EREMOTEIO;
 117
 118         ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
 119
 120         /* Retry if chip was in standby */
 121         if (ret == -EREMOTEIO) {
 122                 nfc_info(drv_data->dev, "chip may sleep, retry\n");
 123                 usleep_range(6000, 10000);
 124                 ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
 125         }
 126
 127         if (ret >= 0) {
 128                 if (ret != skb->len) {
 129                         nfc_err(drv_data->dev,
 130                                 "Invalid length sent: %u (expected %u)\n",
 131                                 ret, skb->len);
 132                         ret = -EREMOTEIO;
 133                 } else
 134                         ret = 0;
 135                 kfree_skb(skb);
 136         }
 137
 138         return ret;
 139 }
 140
 141 static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
 142                                           const void *param)
 143 {
 144 }
 145
 146 static const struct nfcmrvl_if_ops i2c_ops = {
 147         .nci_open = nfcmrvl_i2c_nci_open,
 148         .nci_close = nfcmrvl_i2c_nci_close,
 149         .nci_send = nfcmrvl_i2c_nci_send,
 150         .nci_update_config = nfcmrvl_i2c_nci_update_config,
 151 };
 152
 153 static int nfcmrvl_i2c_parse_dt(struct device_node *node,
 154                                 struct nfcmrvl_platform_data *pdata)
 155 {
 156         int ret;
 157
 158         ret = nfcmrvl_parse_dt(node, pdata);
 159         if (ret < 0) {
 160                 pr_err("Failed to get generic entries\n");
 161                 return ret;
 162         }
 163
 164         if (of_find_property(node, "i2c-int-falling", NULL))
 165                 pdata->irq_polarity = IRQF_TRIGGER_FALLING;
 166         else
 167                 pdata->irq_polarity = IRQF_TRIGGER_RISING;
 168
 169         ret = irq_of_parse_and_map(node, 0);
 170         if (ret < 0) {
 171                 pr_err("Unable to get irq, error: %d\n", ret);
 172                 return ret;
 173         }
 174         pdata->irq = ret;
 175
 176         return 0;
 177 }
 178
 179 static int nfcmrvl_i2c_probe(struct i2c_client *client,
 180                              const struct i2c_device_id *id)
 181 {
 182         const struct nfcmrvl_platform_data *pdata;
 183         struct nfcmrvl_i2c_drv_data *drv_data;
 184         struct nfcmrvl_platform_data config;
 185         int ret;
 186
 187         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 188                 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 189                 return -ENODEV;
 190         }
 191
 192         drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
 193         if (!drv_data)
 194                 return -ENOMEM;
 195
 196         drv_data->i2c = client;
 197         drv_data->dev = &client->dev;
 198         drv_data->priv = NULL;
 199
 200         i2c_set_clientdata(client, drv_data);
 201
 202         pdata = client->dev.platform_data;
 203
 204         if (!pdata && client->dev.of_node)
 205                 if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
 206                         pdata = &config;
 207
 208         if (!pdata)
 209                 return -EINVAL;
 210
 211         /* Request the read IRQ */
 212         ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
 213                                         NULL, nfcmrvl_i2c_int_irq_thread_fn,
 214                                         pdata->irq_polarity | IRQF_ONESHOT,
 215                                         "nfcmrvl_i2c_int", drv_data);
 216         if (ret < 0) {
 217                 nfc_err(&drv_data->i2c->dev,
 218                         "Unable to register IRQ handler\n");
 219                 return ret;
 220         }
 221
 222         drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
 223                                                   drv_data, &i2c_ops,
 224                                                   &drv_data->i2c->dev, pdata);
 225
 226         if (IS_ERR(drv_data->priv))
 227                 return PTR_ERR(drv_data->priv);
 228
 229         drv_data->priv->support_fw_dnld = true;
 230
 231         return 0;
 232 }
 233
 234 static int nfcmrvl_i2c_remove(struct i2c_client *client)
 235 {
 236         struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
 237
 238         nfcmrvl_nci_unregister_dev(drv_data->priv);
 239
 240         return 0;
 241 }
 242
 243
 244 static const struct of_device_id of_nfcmrvl_i2c_match[] __maybe_unused = {
 245         { .compatible = "marvell,nfc-i2c", },
 246         {},
 247 };
 248 MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
 249
 250 static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
 251         { "nfcmrvl_i2c", 0 },
 252         {}
 253 };
 254 MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
 255
 256 static struct i2c_driver nfcmrvl_i2c_driver = {
 257         .probe = nfcmrvl_i2c_probe,
 258         .id_table = nfcmrvl_i2c_id_table,
 259         .remove = nfcmrvl_i2c_remove,
 260         .driver = {
 261                 .name           = "nfcmrvl_i2c",
 262                 .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
 263         },
 264 };
 265
 266 module_i2c_driver(nfcmrvl_i2c_driver);
 267
 268 MODULE_AUTHOR("Marvell International Ltd.");
 269 MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
 270 MODULE_LICENSE("GPL v2");