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