1/*
  2 * Driver for NXP PN533 NFC Chip - I2C transport layer
  3 *
  4 * Copyright (C) 2011 Instituto Nokia de Tecnologia
  5 * Copyright (C) 2012-2013 Tieto Poland
  6 * Copyright (C) 2016 HALE electronic
  7 *
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 *
 14 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 17 * GNU General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License
 20 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 21 */
 22
 23#include <linux/device.h>
 24#include <linux/kernel.h>
 25#include <linux/module.h>
 26#include <linux/slab.h>
 27#include <linux/i2c.h>
 28#include <linux/nfc.h>
 29#include <linux/netdevice.h>
 30#include <linux/interrupt.h>
 31#include <net/nfc/nfc.h>
 32#include "pn533.h"
 33
 34#define VERSION "0.1"
 35
 36#define PN533_I2C_DRIVER_NAME "pn533_i2c"
 37
 38struct pn533_i2c_phy {
 39	struct i2c_client *i2c_dev;
 40	struct pn533 *priv;
 41
 42	bool aborted;
 43
 44	int hard_fault;		/*
 45				 * < 0 if hardware error occurred (e.g. i2c err)
 46				 * and prevents normal operation.
 47				 */
 48};
 49
 50static int pn533_i2c_send_ack(struct pn533 *dev, gfp_t flags)
 51{
 52	struct pn533_i2c_phy *phy = dev->phy;
 53	struct i2c_client *client = phy->i2c_dev;
 54	u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
 55	/* spec 6.2.1.3:  Preamble, SoPC (2), ACK Code (2), Postamble */
 56	int rc;
 57
 58	rc = i2c_master_send(client, ack, 6);
 59
 60	return rc;
 61}
 62
 63static int pn533_i2c_send_frame(struct pn533 *dev,
 64				struct sk_buff *out)
 65{
 66	struct pn533_i2c_phy *phy = dev->phy;
 67	struct i2c_client *client = phy->i2c_dev;
 68	int rc;
 69
 70	if (phy->hard_fault != 0)
 71		return phy->hard_fault;
 72
 73	if (phy->priv == NULL)
 74		phy->priv = dev;
 75
 76	phy->aborted = false;
 77
 78	print_hex_dump_debug("PN533_i2c TX: ", DUMP_PREFIX_NONE, 16, 1,
 79			     out->data, out->len, false);
 80
 81	rc = i2c_master_send(client, out->data, out->len);
 82
 83	if (rc == -EREMOTEIO) { /* Retry, chip was in power down */
 84		usleep_range(6000, 10000);
 85		rc = i2c_master_send(client, out->data, out->len);
 86	}
 87
 88	if (rc >= 0) {
 89		if (rc != out->len)
 90			rc = -EREMOTEIO;
 91		else
 92			rc = 0;
 93	}
 94
 95	return rc;
 96}
 97
 98static void pn533_i2c_abort_cmd(struct pn533 *dev, gfp_t flags)
 99{
100	struct pn533_i2c_phy *phy = dev->phy;
101
102	phy->aborted = true;
103
104	/* An ack will cancel the last issued command */
105	pn533_i2c_send_ack(dev, flags);
106
107	/* schedule cmd_complete_work to finish current command execution */
108	pn533_recv_frame(phy->priv, NULL, -ENOENT);
109}
110
111static int pn533_i2c_read(struct pn533_i2c_phy *phy, struct sk_buff **skb)
112{
113	struct i2c_client *client = phy->i2c_dev;
114	int len = PN533_EXT_FRAME_HEADER_LEN +
115		  PN533_STD_FRAME_MAX_PAYLOAD_LEN +
116		  PN533_STD_FRAME_TAIL_LEN + 1;
117	int r;
118
119	*skb = alloc_skb(len, GFP_KERNEL);
120	if (*skb == NULL)
121		return -ENOMEM;
122
123	r = i2c_master_recv(client, skb_put(*skb, len), len);
124	if (r != len) {
125		nfc_err(&client->dev, "cannot read. r=%d len=%d\n", r, len);
126		kfree_skb(*skb);
127		return -EREMOTEIO;
128	}
129
130	if (!((*skb)->data[0] & 0x01)) {
131		nfc_err(&client->dev, "READY flag not set");
132		kfree_skb(*skb);
133		return -EBUSY;
134	}
135
136	/* remove READY byte */
137	skb_pull(*skb, 1);
138	/* trim to frame size */
139	skb_trim(*skb, phy->priv->ops->rx_frame_size((*skb)->data));
140
141	return 0;
142}
143
144static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
145{
146	struct pn533_i2c_phy *phy = data;
147	struct i2c_client *client;
148	struct sk_buff *skb = NULL;
149	int r;
150
151	if (!phy || irq != phy->i2c_dev->irq) {
152		WARN_ON_ONCE(1);
153		return IRQ_NONE;
154	}
155
156	client = phy->i2c_dev;
157	dev_dbg(&client->dev, "IRQ\n");
158
159	if (phy->hard_fault != 0)
160		return IRQ_HANDLED;
161
162	r = pn533_i2c_read(phy, &skb);
163	if (r == -EREMOTEIO) {
164		phy->hard_fault = r;
165
166		pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
167
168		return IRQ_HANDLED;
169	} else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
170		return IRQ_HANDLED;
171	}
172
173	if (!phy->aborted)
174		pn533_recv_frame(phy->priv, skb, 0);
175
176	return IRQ_HANDLED;
177}
178
179static struct pn533_phy_ops i2c_phy_ops = {
180	.send_frame = pn533_i2c_send_frame,
181	.send_ack = pn533_i2c_send_ack,
182	.abort_cmd = pn533_i2c_abort_cmd,
183};
184
185
186static int pn533_i2c_probe(struct i2c_client *client,
187			       const struct i2c_device_id *id)
188{
189	struct pn533_i2c_phy *phy;
190	struct pn533 *priv;
191	int r = 0;
192
193	dev_dbg(&client->dev, "%s\n", __func__);
194	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
195
196	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
197		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
198		return -ENODEV;
199	}
200
201	phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
202			   GFP_KERNEL);
203	if (!phy)
204		return -ENOMEM;
205
206	phy->i2c_dev = client;
207	i2c_set_clientdata(client, phy);
208
209	r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
210				 IRQF_TRIGGER_FALLING |
211				 IRQF_SHARED | IRQF_ONESHOT,
212				 PN533_I2C_DRIVER_NAME, phy);
213
214	if (r < 0)
215		nfc_err(&client->dev, "Unable to register IRQ handler\n");
216
217	priv = pn533_register_device(PN533_DEVICE_PN532,
218				     PN533_NO_TYPE_B_PROTOCOLS,
219				     PN533_PROTO_REQ_ACK_RESP,
220				     phy, &i2c_phy_ops, NULL,
221				     &phy->i2c_dev->dev,
222				     &client->dev);
223
224	if (IS_ERR(priv)) {
225		r = PTR_ERR(priv);
226		goto err_register;
227	}
228
229	phy->priv = priv;
230
231	return 0;
232
233err_register:
234	free_irq(client->irq, phy);
235
236	return r;
237}
238
239static int pn533_i2c_remove(struct i2c_client *client)
240{
241	struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
242
243	dev_dbg(&client->dev, "%s\n", __func__);
244
245	pn533_unregister_device(phy->priv);
246
247	free_irq(client->irq, phy);
248
249	return 0;
250}
251
252static const struct of_device_id of_pn533_i2c_match[] = {
253	{ .compatible = "nxp,pn533-i2c", },
254	{ .compatible = "nxp,pn532-i2c", },
255	{},
256};
257MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
258
259static struct i2c_device_id pn533_i2c_id_table[] = {
260	{ PN533_I2C_DRIVER_NAME, 0 },
261	{}
262};
263MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
264
265static struct i2c_driver pn533_i2c_driver = {
266	.driver = {
267		   .name = PN533_I2C_DRIVER_NAME,
268		   .owner = THIS_MODULE,
269		   .of_match_table = of_match_ptr(of_pn533_i2c_match),
270		  },
271	.probe = pn533_i2c_probe,
272	.id_table = pn533_i2c_id_table,
273	.remove = pn533_i2c_remove,
274};
275
276module_i2c_driver(pn533_i2c_driver);
277
278MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
279MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
280MODULE_VERSION(VERSION);
281MODULE_LICENSE("GPL");