1/*
2 * I2C link layer for the NXP NCI driver
3 *
4 * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
5 * Copyright (C) 2012-2015  Intel Corporation. All rights reserved.
6 *
7 * Authors: Cl��ment Perrochaud <clement.perrochaud@nxp.com>
8 * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>
9 *
10 * Derived from PN544 device driver:
11 * Copyright (C) 2012  Intel Corporation. All rights reserved.
12 *
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms and conditions of the GNU General Public License,
15 * version 2, as published by the Free Software Foundation.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, see <http://www.gnu.org/licenses/>.
24 */
25
26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28#include <linux/acpi.h>
29#include <linux/delay.h>
30#include <linux/i2c.h>
31#include <linux/interrupt.h>
32#include <linux/miscdevice.h>
33#include <linux/module.h>
34#include <linux/nfc.h>
35#include <linux/gpio/consumer.h>
36#include <linux/of_gpio.h>
37#include <linux/of_irq.h>
38#include <linux/platform_data/nxp-nci.h>
39#include <linux/unaligned/access_ok.h>
40
41#include <net/nfc/nfc.h>
42
43#include "nxp-nci.h"
44
45#define NXP_NCI_I2C_DRIVER_NAME	"nxp-nci_i2c"
46
47#define NXP_NCI_I2C_MAX_PAYLOAD	32
48
49struct nxp_nci_i2c_phy {
50	struct i2c_client *i2c_dev;
51	struct nci_dev *ndev;
52
53	unsigned int gpio_en;
54	unsigned int gpio_fw;
55	unsigned int gpio_irq;
56
57	int hard_fault; /*
58			 * < 0 if hardware error occurred (e.g. i2c err)
59			 * and prevents normal operation.
60			 */
61};
62
63static int nxp_nci_i2c_set_mode(void *phy_id,
64				    enum nxp_nci_mode mode)
65{
66	struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
67
68	gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
69	gpio_set_value(phy->gpio_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
70	usleep_range(10000, 15000);
71
72	if (mode == NXP_NCI_MODE_COLD)
73		phy->hard_fault = 0;
74
75	return 0;
76}
77
78static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
79{
80	int r;
81	struct nxp_nci_i2c_phy *phy = phy_id;
82	struct i2c_client *client = phy->i2c_dev;
83
84	if (phy->hard_fault != 0)
85		return phy->hard_fault;
86
87	r = i2c_master_send(client, skb->data, skb->len);
88	if (r == -EREMOTEIO) {
89		/* Retry, chip was in standby */
90		usleep_range(110000, 120000);
91		r = i2c_master_send(client, skb->data, skb->len);
92	}
93
94	if (r < 0) {
95		nfc_err(&client->dev, "Error %d on I2C send\n", r);
96	} else if (r != skb->len) {
97		nfc_err(&client->dev,
98			"Invalid length sent: %u (expected %u)\n",
99			r, skb->len);
100		r = -EREMOTEIO;
101	} else {
102		/* Success but return 0 and not number of bytes */
103		r = 0;
104	}
105
106	return r;
107}
108
109static const struct nxp_nci_phy_ops i2c_phy_ops = {
110	.set_mode = nxp_nci_i2c_set_mode,
111	.write = nxp_nci_i2c_write,
112};
113
114static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
115			       struct sk_buff **skb)
116{
117	struct i2c_client *client = phy->i2c_dev;
118	u16 header;
119	size_t frame_len;
120	int r;
121
122	r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
123	if (r < 0) {
124		goto fw_read_exit;
125	} else if (r != NXP_NCI_FW_HDR_LEN) {
126		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
127		r = -EBADMSG;
128		goto fw_read_exit;
129	}
130
131	frame_len = (get_unaligned_be16(&header) & NXP_NCI_FW_FRAME_LEN_MASK) +
132		    NXP_NCI_FW_CRC_LEN;
133
134	*skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
135	if (*skb == NULL) {
136		r = -ENOMEM;
137		goto fw_read_exit;
138	}
139
140	memcpy(skb_put(*skb, NXP_NCI_FW_HDR_LEN), &header, NXP_NCI_FW_HDR_LEN);
141
142	r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
143	if (r != frame_len) {
144		nfc_err(&client->dev,
145			"Invalid frame length: %u (expected %zu)\n",
146			r, frame_len);
147		r = -EBADMSG;
148		goto fw_read_exit_free_skb;
149	}
150
151	return 0;
152
153fw_read_exit_free_skb:
154	kfree_skb(*skb);
155fw_read_exit:
156	return r;
157}
158
159static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
160				struct sk_buff **skb)
161{
162	struct nci_ctrl_hdr header; /* May actually be a data header */
163	struct i2c_client *client = phy->i2c_dev;
164	int r;
165
166	r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
167	if (r < 0) {
168		goto nci_read_exit;
169	} else if (r != NCI_CTRL_HDR_SIZE) {
170		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
171		r = -EBADMSG;
172		goto nci_read_exit;
173	}
174
175	*skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
176	if (*skb == NULL) {
177		r = -ENOMEM;
178		goto nci_read_exit;
179	}
180
181	memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), (void *) &header,
182	       NCI_CTRL_HDR_SIZE);
183
184	r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
185	if (r != header.plen) {
186		nfc_err(&client->dev,
187			"Invalid frame payload length: %u (expected %u)\n",
188			r, header.plen);
189		r = -EBADMSG;
190		goto nci_read_exit_free_skb;
191	}
192
193	return 0;
194
195nci_read_exit_free_skb:
196	kfree_skb(*skb);
197nci_read_exit:
198	return r;
199}
200
201static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
202{
203	struct nxp_nci_i2c_phy *phy = phy_id;
204	struct i2c_client *client;
205	struct nxp_nci_info *info;
206
207	struct sk_buff *skb = NULL;
208	int r = 0;
209
210	if (!phy || !phy->ndev)
211		goto exit_irq_none;
212
213	client = phy->i2c_dev;
214
215	if (!client || irq != client->irq)
216		goto exit_irq_none;
217
218	info = nci_get_drvdata(phy->ndev);
219
220	if (!info)
221		goto exit_irq_none;
222
223	mutex_lock(&info->info_lock);
224
225	if (phy->hard_fault != 0)
226		goto exit_irq_handled;
227
228	switch (info->mode) {
229	case NXP_NCI_MODE_NCI:
230		r = nxp_nci_i2c_nci_read(phy, &skb);
231		break;
232	case NXP_NCI_MODE_FW:
233		r = nxp_nci_i2c_fw_read(phy, &skb);
234		break;
235	case NXP_NCI_MODE_COLD:
236		r = -EREMOTEIO;
237		break;
238	}
239
240	if (r == -EREMOTEIO) {
241		phy->hard_fault = r;
242		skb = NULL;
243	} else if (r < 0) {
244		nfc_err(&client->dev, "Read failed with error %d\n", r);
245		goto exit_irq_handled;
246	}
247
248	switch (info->mode) {
249	case NXP_NCI_MODE_NCI:
250		nci_recv_frame(phy->ndev, skb);
251		break;
252	case NXP_NCI_MODE_FW:
253		nxp_nci_fw_recv_frame(phy->ndev, skb);
254		break;
255	case NXP_NCI_MODE_COLD:
256		break;
257	}
258
259exit_irq_handled:
260	mutex_unlock(&info->info_lock);
261	return IRQ_HANDLED;
262exit_irq_none:
263	WARN_ON_ONCE(1);
264	return IRQ_NONE;
265}
266
267#ifdef CONFIG_OF
268
269static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
270{
271	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
272	struct device_node *pp;
273	int r;
274
275	pp = client->dev.of_node;
276	if (!pp)
277		return -ENODEV;
278
279	r = of_get_named_gpio(pp, "enable-gpios", 0);
280	if (r == -EPROBE_DEFER)
281		r = of_get_named_gpio(pp, "enable-gpios", 0);
282	if (r < 0) {
283		nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);
284		return r;
285	}
286	phy->gpio_en = r;
287
288	r = of_get_named_gpio(pp, "firmware-gpios", 0);
289	if (r == -EPROBE_DEFER)
290		r = of_get_named_gpio(pp, "firmware-gpios", 0);
291	if (r < 0) {
292		nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);
293		return r;
294	}
295	phy->gpio_fw = r;
296
297	r = irq_of_parse_and_map(pp, 0);
298	if (r < 0) {
299		nfc_err(&client->dev, "Unable to get irq, error: %d\n", r);
300		return r;
301	}
302	client->irq = r;
303
304	return 0;
305}
306
307#else
308
309static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
310{
311	return -ENODEV;
312}
313
314#endif
315
316static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy)
317{
318	struct i2c_client *client = phy->i2c_dev;
319	struct gpio_desc *gpiod_en, *gpiod_fw, *gpiod_irq;
320
321	gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW);
322	gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW);
323	gpiod_irq = devm_gpiod_get_index(&client->dev, NULL, 0, GPIOD_IN);
324
325	if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw) || IS_ERR(gpiod_irq)) {
326		nfc_err(&client->dev, "No GPIOs\n");
327		return -EINVAL;
328	}
329
330	client->irq = gpiod_to_irq(gpiod_irq);
331	if (client->irq < 0) {
332		nfc_err(&client->dev, "No IRQ\n");
333		return -EINVAL;
334	}
335
336	phy->gpio_en = desc_to_gpio(gpiod_en);
337	phy->gpio_fw = desc_to_gpio(gpiod_fw);
338	phy->gpio_irq = desc_to_gpio(gpiod_irq);
339
340	return 0;
341}
342
343static int nxp_nci_i2c_probe(struct i2c_client *client,
344			    const struct i2c_device_id *id)
345{
346	struct nxp_nci_i2c_phy *phy;
347	struct nxp_nci_nfc_platform_data *pdata;
348	int r;
349
350	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
351		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
352		r = -ENODEV;
353		goto probe_exit;
354	}
355
356	phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
357			   GFP_KERNEL);
358	if (!phy) {
359		r = -ENOMEM;
360		goto probe_exit;
361	}
362
363	phy->i2c_dev = client;
364	i2c_set_clientdata(client, phy);
365
366	pdata = client->dev.platform_data;
367
368	if (!pdata && client->dev.of_node) {
369		r = nxp_nci_i2c_parse_devtree(client);
370		if (r < 0) {
371			nfc_err(&client->dev, "Failed to get DT data\n");
372			goto probe_exit;
373		}
374	} else if (pdata) {
375		phy->gpio_en = pdata->gpio_en;
376		phy->gpio_fw = pdata->gpio_fw;
377		client->irq = pdata->irq;
378	} else if (ACPI_HANDLE(&client->dev)) {
379		r = nxp_nci_i2c_acpi_config(phy);
380		if (r < 0)
381			goto probe_exit;
382		goto nci_probe;
383	} else {
384		nfc_err(&client->dev, "No platform data\n");
385		r = -EINVAL;
386		goto probe_exit;
387	}
388
389	r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
390				  GPIOF_OUT_INIT_LOW, "nxp_nci_en");
391	if (r < 0)
392		goto probe_exit;
393
394	r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,
395				  GPIOF_OUT_INIT_LOW, "nxp_nci_fw");
396	if (r < 0)
397		goto probe_exit;
398
399nci_probe:
400	r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
401			  NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
402	if (r < 0)
403		goto probe_exit;
404
405	r = request_threaded_irq(client->irq, NULL,
406				 nxp_nci_i2c_irq_thread_fn,
407				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
408				 NXP_NCI_I2C_DRIVER_NAME, phy);
409	if (r < 0)
410		nfc_err(&client->dev, "Unable to register IRQ handler\n");
411
412probe_exit:
413	return r;
414}
415
416static int nxp_nci_i2c_remove(struct i2c_client *client)
417{
418	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
419
420	nxp_nci_remove(phy->ndev);
421	free_irq(client->irq, phy);
422
423	return 0;
424}
425
426static struct i2c_device_id nxp_nci_i2c_id_table[] = {
427	{"nxp-nci_i2c", 0},
428	{}
429};
430MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
431
432static const struct of_device_id of_nxp_nci_i2c_match[] = {
433	{ .compatible = "nxp,nxp-nci-i2c", },
434	{},
435};
436MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
437
438#ifdef CONFIG_ACPI
439static struct acpi_device_id acpi_id[] = {
440	{ "NXP7471" },
441	{ },
442};
443MODULE_DEVICE_TABLE(acpi, acpi_id);
444#endif
445
446static struct i2c_driver nxp_nci_i2c_driver = {
447	.driver = {
448		   .name = NXP_NCI_I2C_DRIVER_NAME,
449		   .owner  = THIS_MODULE,
450		   .acpi_match_table = ACPI_PTR(acpi_id),
451		   .of_match_table = of_match_ptr(of_nxp_nci_i2c_match),
452		  },
453	.probe = nxp_nci_i2c_probe,
454	.id_table = nxp_nci_i2c_id_table,
455	.remove = nxp_nci_i2c_remove,
456};
457
458module_i2c_driver(nxp_nci_i2c_driver);
459
460MODULE_LICENSE("GPL");
461MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
462MODULE_AUTHOR("Cl��ment Perrochaud <clement.perrochaud@nxp.com>");
463MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
464