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 sk_buff *skb = NULL;
132 int r;
133
134 if (!phy || irq != phy->i2c_dev->irq) {
135 WARN_ON_ONCE(1);
136 return IRQ_NONE;
137 }
138
139 if (phy->hard_fault != 0)
140 return IRQ_HANDLED;
141
142 r = pn533_i2c_read(phy, &skb);
143 if (r == -EREMOTEIO) {
144 phy->hard_fault = r;
145
146 pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
147
148 return IRQ_HANDLED;
149 } else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
150 return IRQ_HANDLED;
151 }
152
153 if (!phy->aborted)
154 pn533_recv_frame(phy->priv, skb, 0);
155
156 return IRQ_HANDLED;
157 }
158
159 static const struct pn533_phy_ops i2c_phy_ops = {
160 .send_frame = pn533_i2c_send_frame,
161 .send_ack = pn533_i2c_send_ack,
162 .abort_cmd = pn533_i2c_abort_cmd,
163 };
164
165
pn533_i2c_probe(struct i2c_client * client)166 static int pn533_i2c_probe(struct i2c_client *client)
167 {
168 struct pn533_i2c_phy *phy;
169 struct pn533 *priv;
170 int r = 0;
171
172 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
173 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
174 return -ENODEV;
175 }
176
177 phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
178 GFP_KERNEL);
179 if (!phy)
180 return -ENOMEM;
181
182 phy->i2c_dev = client;
183 i2c_set_clientdata(client, phy);
184
185 priv = pn53x_common_init(PN533_DEVICE_PN532,
186 PN533_PROTO_REQ_ACK_RESP,
187 phy, &i2c_phy_ops, NULL,
188 &phy->i2c_dev->dev);
189
190 if (IS_ERR(priv))
191 return PTR_ERR(priv);
192
193 phy->priv = priv;
194 r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
195 if (r)
196 goto nfc_alloc_err;
197
198 r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
199 IRQF_TRIGGER_FALLING |
200 IRQF_SHARED | IRQF_ONESHOT,
201 PN533_I2C_DRIVER_NAME, phy);
202 if (r < 0) {
203 nfc_err(&client->dev, "Unable to register IRQ handler\n");
204 goto irq_rqst_err;
205 }
206
207 r = pn533_finalize_setup(priv);
208 if (r)
209 goto fn_setup_err;
210
211 r = nfc_register_device(priv->nfc_dev);
212 if (r)
213 goto fn_setup_err;
214
215 return r;
216
217 fn_setup_err:
218 free_irq(client->irq, phy);
219
220 irq_rqst_err:
221 nfc_free_device(priv->nfc_dev);
222
223 nfc_alloc_err:
224 pn53x_common_clean(phy->priv);
225
226 return r;
227 }
228
pn533_i2c_remove(struct i2c_client * client)229 static void pn533_i2c_remove(struct i2c_client *client)
230 {
231 struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
232
233 free_irq(client->irq, phy);
234
235 pn53x_unregister_nfc(phy->priv);
236 pn53x_common_clean(phy->priv);
237 }
238
239 static const struct of_device_id of_pn533_i2c_match[] __maybe_unused = {
240 { .compatible = "nxp,pn532", },
241 /*
242 * NOTE: The use of the compatibles with the trailing "...-i2c" is
243 * deprecated and will be removed.
244 */
245 { .compatible = "nxp,pn533-i2c", },
246 { .compatible = "nxp,pn532-i2c", },
247 {},
248 };
249 MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
250
251 static const struct i2c_device_id pn533_i2c_id_table[] = {
252 { PN533_I2C_DRIVER_NAME },
253 {}
254 };
255 MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
256
257 static struct i2c_driver pn533_i2c_driver = {
258 .driver = {
259 .name = PN533_I2C_DRIVER_NAME,
260 .of_match_table = of_match_ptr(of_pn533_i2c_match),
261 },
262 .probe = pn533_i2c_probe,
263 .id_table = pn533_i2c_id_table,
264 .remove = pn533_i2c_remove,
265 };
266
267 module_i2c_driver(pn533_i2c_driver);
268
269 MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
270 MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
271 MODULE_VERSION(VERSION);
272 MODULE_LICENSE("GPL");
273