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
nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data * drv_data,struct sk_buff ** skb)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
nfcmrvl_i2c_int_irq_thread_fn(int irq,void * drv_data_ptr)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
nfcmrvl_i2c_nci_open(struct nfcmrvl_private * priv)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
nfcmrvl_i2c_nci_close(struct nfcmrvl_private * priv)104 static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
105 {
106 return 0;
107 }
108
nfcmrvl_i2c_nci_send(struct nfcmrvl_private * priv,struct sk_buff * skb)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
nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private * priv,const void * param)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
nfcmrvl_i2c_parse_dt(struct device_node * node,struct nfcmrvl_platform_data * pdata)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_find_property(node, "i2c-int-falling", NULL))
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
nfcmrvl_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)186 static int nfcmrvl_i2c_probe(struct i2c_client *client,
187 const struct i2c_device_id *id)
188 {
189 const struct nfcmrvl_platform_data *pdata;
190 struct nfcmrvl_i2c_drv_data *drv_data;
191 struct nfcmrvl_platform_data config;
192 int ret;
193
194 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
195 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
196 return -ENODEV;
197 }
198
199 drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
200 if (!drv_data)
201 return -ENOMEM;
202
203 drv_data->i2c = client;
204 drv_data->dev = &client->dev;
205 drv_data->priv = NULL;
206
207 i2c_set_clientdata(client, drv_data);
208
209 pdata = client->dev.platform_data;
210
211 if (!pdata && client->dev.of_node)
212 if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
213 pdata = &config;
214
215 if (!pdata)
216 return -EINVAL;
217
218 /* Request the read IRQ */
219 ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
220 NULL, nfcmrvl_i2c_int_irq_thread_fn,
221 pdata->irq_polarity | IRQF_ONESHOT,
222 "nfcmrvl_i2c_int", drv_data);
223 if (ret < 0) {
224 nfc_err(&drv_data->i2c->dev,
225 "Unable to register IRQ handler\n");
226 return ret;
227 }
228
229 drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
230 drv_data, &i2c_ops,
231 &drv_data->i2c->dev, pdata);
232
233 if (IS_ERR(drv_data->priv))
234 return PTR_ERR(drv_data->priv);
235
236 drv_data->priv->support_fw_dnld = true;
237
238 return 0;
239 }
240
nfcmrvl_i2c_remove(struct i2c_client * client)241 static void nfcmrvl_i2c_remove(struct i2c_client *client)
242 {
243 struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
244
245 nfcmrvl_nci_unregister_dev(drv_data->priv);
246 }
247
248
249 static const struct of_device_id of_nfcmrvl_i2c_match[] __maybe_unused = {
250 { .compatible = "marvell,nfc-i2c", },
251 {},
252 };
253 MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
254
255 static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
256 { "nfcmrvl_i2c", 0 },
257 {}
258 };
259 MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
260
261 static struct i2c_driver nfcmrvl_i2c_driver = {
262 .probe = nfcmrvl_i2c_probe,
263 .id_table = nfcmrvl_i2c_id_table,
264 .remove = nfcmrvl_i2c_remove,
265 .driver = {
266 .name = "nfcmrvl_i2c",
267 .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
268 },
269 };
270
271 module_i2c_driver(nfcmrvl_i2c_driver);
272
273 MODULE_AUTHOR("Marvell International Ltd.");
274 MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
275 MODULE_LICENSE("GPL v2");
276