1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Driver for NXP PN533 NFC Chip - I2C transport layer
4 *
5 * Copyright (C) 2011 Instituto Nokia de Tecnologia
6 * Copyright (C) 2012-2013 Tieto Poland
7 * Copyright (C) 2016 HALE electronic
8 */
9
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/i2c.h>
15 #include <linux/nfc.h>
16 #include <linux/netdevice.h>
17 #include <linux/interrupt.h>
18 #include <net/nfc/nfc.h>
19 #include "pn533.h"
20
21 #define VERSION "0.1"
22
23 #define PN533_I2C_DRIVER_NAME "pn533_i2c"
24
25 struct pn533_i2c_phy {
26 struct i2c_client *i2c_dev;
27 struct pn533 *priv;
28
29 bool aborted;
30
31 int hard_fault; /*
32 * < 0 if hardware error occurred (e.g. i2c err)
33 * and prevents normal operation.
34 */
35 };
36
pn533_i2c_send_ack(struct pn533 * dev,gfp_t flags)37 static int pn533_i2c_send_ack(struct pn533 *dev, gfp_t flags)
38 {
39 struct pn533_i2c_phy *phy = dev->phy;
40 struct i2c_client *client = phy->i2c_dev;
41 static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
42 /* spec 6.2.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */
43
44 return i2c_master_send(client, ack, 6);
45 }
46
pn533_i2c_send_frame(struct pn533 * dev,struct sk_buff * out)47 static int pn533_i2c_send_frame(struct pn533 *dev,
48 struct sk_buff *out)
49 {
50 struct pn533_i2c_phy *phy = dev->phy;
51 struct i2c_client *client = phy->i2c_dev;
52 int rc;
53
54 if (phy->hard_fault != 0)
55 return phy->hard_fault;
56
57 if (phy->priv == NULL)
58 phy->priv = dev;
59
60 phy->aborted = false;
61
62 print_hex_dump_debug("PN533_i2c TX: ", DUMP_PREFIX_NONE, 16, 1,
63 out->data, out->len, false);
64
65 rc = i2c_master_send(client, out->data, out->len);
66
67 if (rc == -EREMOTEIO) { /* Retry, chip was in power down */
68 usleep_range(6000, 10000);
69 rc = i2c_master_send(client, out->data, out->len);
70 }
71
72 if (rc >= 0) {
73 if (rc != out->len)
74 rc = -EREMOTEIO;
75 else
76 rc = 0;
77 }
78
79 return rc;
80 }
81
pn533_i2c_abort_cmd(struct pn533 * dev,gfp_t flags)82 static void pn533_i2c_abort_cmd(struct pn533 *dev, gfp_t flags)
83 {
84 struct pn533_i2c_phy *phy = dev->phy;
85
86 phy->aborted = true;
87
88 /* An ack will cancel the last issued command */
89 pn533_i2c_send_ack(dev, flags);
90
91 /* schedule cmd_complete_work to finish current command execution */
92 pn533_recv_frame(phy->priv, NULL, -ENOENT);
93 }
94
pn533_i2c_read(struct pn533_i2c_phy * phy,struct sk_buff ** skb)95 static int pn533_i2c_read(struct pn533_i2c_phy *phy, struct sk_buff **skb)
96 {
97 struct i2c_client *client = phy->i2c_dev;
98 int len = PN533_EXT_FRAME_HEADER_LEN +
99 PN533_STD_FRAME_MAX_PAYLOAD_LEN +
100 PN533_STD_FRAME_TAIL_LEN + 1;
101 int r;
102
103 *skb = alloc_skb(len, GFP_KERNEL);
104 if (*skb == NULL)
105 return -ENOMEM;
106
107 r = i2c_master_recv(client, skb_put(*skb, len), len);
108 if (r != len) {
109 nfc_err(&client->dev, "cannot read. r=%d len=%d\n", r, len);
110 kfree_skb(*skb);
111 return -EREMOTEIO;
112 }
113
114 if (!((*skb)->data[0] & 0x01)) {
115 nfc_err(&client->dev, "READY flag not set");
116 kfree_skb(*skb);
117 return -EBUSY;
118 }
119
120 /* remove READY byte */
121 skb_pull(*skb, 1);
122 /* trim to frame size */
123 skb_trim(*skb, phy->priv->ops->rx_frame_size((*skb)->data));
124
125 return 0;
126 }
127
pn533_i2c_irq_thread_fn(int irq,void * data)128 static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
129 {
130 struct pn533_i2c_phy *phy = data;
131 struct i2c_client *client;
132 struct sk_buff *skb = NULL;
133 int r;
134
135 if (!phy || irq != phy->i2c_dev->irq) {
136 WARN_ON_ONCE(1);
137 return IRQ_NONE;
138 }
139
140 client = phy->i2c_dev;
141 dev_dbg(&client->dev, "IRQ\n");
142
143 if (phy->hard_fault != 0)
144 return IRQ_HANDLED;
145
146 r = pn533_i2c_read(phy, &skb);
147 if (r == -EREMOTEIO) {
148 phy->hard_fault = r;
149
150 pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
151
152 return IRQ_HANDLED;
153 } else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
154 return IRQ_HANDLED;
155 }
156
157 if (!phy->aborted)
158 pn533_recv_frame(phy->priv, skb, 0);
159
160 return IRQ_HANDLED;
161 }
162
163 static struct pn533_phy_ops i2c_phy_ops = {
164 .send_frame = pn533_i2c_send_frame,
165 .send_ack = pn533_i2c_send_ack,
166 .abort_cmd = pn533_i2c_abort_cmd,
167 };
168
169
pn533_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)170 static int pn533_i2c_probe(struct i2c_client *client,
171 const struct i2c_device_id *id)
172 {
173 struct pn533_i2c_phy *phy;
174 struct pn533 *priv;
175 int r = 0;
176
177 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
178 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
179 return -ENODEV;
180 }
181
182 phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
183 GFP_KERNEL);
184 if (!phy)
185 return -ENOMEM;
186
187 phy->i2c_dev = client;
188 i2c_set_clientdata(client, phy);
189
190 priv = pn53x_common_init(PN533_DEVICE_PN532,
191 PN533_PROTO_REQ_ACK_RESP,
192 phy, &i2c_phy_ops, NULL,
193 &phy->i2c_dev->dev);
194
195 if (IS_ERR(priv))
196 return PTR_ERR(priv);
197
198 phy->priv = priv;
199 r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
200 if (r)
201 goto nfc_alloc_err;
202
203 r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
204 IRQF_TRIGGER_FALLING |
205 IRQF_SHARED | IRQF_ONESHOT,
206 PN533_I2C_DRIVER_NAME, phy);
207 if (r < 0) {
208 nfc_err(&client->dev, "Unable to register IRQ handler\n");
209 goto irq_rqst_err;
210 }
211
212 r = pn533_finalize_setup(priv);
213 if (r)
214 goto fn_setup_err;
215
216 r = nfc_register_device(priv->nfc_dev);
217 if (r)
218 goto fn_setup_err;
219
220 return r;
221
222 fn_setup_err:
223 free_irq(client->irq, phy);
224
225 irq_rqst_err:
226 nfc_free_device(priv->nfc_dev);
227
228 nfc_alloc_err:
229 pn53x_common_clean(phy->priv);
230
231 return r;
232 }
233
pn533_i2c_remove(struct i2c_client * client)234 static int pn533_i2c_remove(struct i2c_client *client)
235 {
236 struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
237
238 free_irq(client->irq, phy);
239
240 pn53x_unregister_nfc(phy->priv);
241 pn53x_common_clean(phy->priv);
242
243 return 0;
244 }
245
246 static const struct of_device_id of_pn533_i2c_match[] __maybe_unused = {
247 { .compatible = "nxp,pn532", },
248 /*
249 * NOTE: The use of the compatibles with the trailing "...-i2c" is
250 * deprecated and will be removed.
251 */
252 { .compatible = "nxp,pn533-i2c", },
253 { .compatible = "nxp,pn532-i2c", },
254 {},
255 };
256 MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
257
258 static const struct i2c_device_id pn533_i2c_id_table[] = {
259 { PN533_I2C_DRIVER_NAME, 0 },
260 {}
261 };
262 MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
263
264 static struct i2c_driver pn533_i2c_driver = {
265 .driver = {
266 .name = PN533_I2C_DRIVER_NAME,
267 .of_match_table = of_match_ptr(of_pn533_i2c_match),
268 },
269 .probe = pn533_i2c_probe,
270 .id_table = pn533_i2c_id_table,
271 .remove = pn533_i2c_remove,
272 };
273
274 module_i2c_driver(pn533_i2c_driver);
275
276 MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
277 MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
278 MODULE_VERSION(VERSION);
279 MODULE_LICENSE("GPL");
280
