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
25struct 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
37static 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
47static 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
82static 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
95static 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
128static 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
159static 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
166static 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
217fn_setup_err:
218	free_irq(client->irq, phy);
219
220irq_rqst_err:
221	nfc_free_device(priv->nfc_dev);
222
223nfc_alloc_err:
224	pn53x_common_clean(phy->priv);
225
226	return r;
227}
228
229static 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
239static 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};
249MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
250
251static const struct i2c_device_id pn533_i2c_id_table[] = {
252	{ PN533_I2C_DRIVER_NAME, 0 },
253	{}
254};
255MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
256
257static 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
267module_i2c_driver(pn533_i2c_driver);
268
269MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
270MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
271MODULE_VERSION(VERSION);
272MODULE_LICENSE("GPL");
273