1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * I2C link layer for the NXP NCI driver
4 *
5 * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
6 * Copyright (C) 2012-2015  Intel Corporation. All rights reserved.
7 *
8 * Authors: Cl��ment Perrochaud <clement.perrochaud@nxp.com>
9 * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>
10 *
11 * Derived from PN544 device driver:
12 * Copyright (C) 2012  Intel Corporation. All rights reserved.
13 */
14
15#include <linux/acpi.h>
16#include <linux/delay.h>
17#include <linux/i2c.h>
18#include <linux/interrupt.h>
19#include <linux/module.h>
20#include <linux/nfc.h>
21#include <linux/gpio/consumer.h>
22#include <asm/unaligned.h>
23
24#include <net/nfc/nfc.h>
25
26#include "nxp-nci.h"
27
28#define NXP_NCI_I2C_DRIVER_NAME	"nxp-nci_i2c"
29
30#define NXP_NCI_I2C_MAX_PAYLOAD	32
31
32struct nxp_nci_i2c_phy {
33	struct i2c_client *i2c_dev;
34	struct nci_dev *ndev;
35
36	struct gpio_desc *gpiod_en;
37	struct gpio_desc *gpiod_fw;
38
39	int hard_fault; /*
40			 * < 0 if hardware error occurred (e.g. i2c err)
41			 * and prevents normal operation.
42			 */
43};
44
45static int nxp_nci_i2c_set_mode(void *phy_id,
46				    enum nxp_nci_mode mode)
47{
48	struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
49
50	gpiod_set_value(phy->gpiod_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
51	gpiod_set_value(phy->gpiod_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
52	usleep_range(10000, 15000);
53
54	if (mode == NXP_NCI_MODE_COLD)
55		phy->hard_fault = 0;
56
57	return 0;
58}
59
60static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
61{
62	int r;
63	struct nxp_nci_i2c_phy *phy = phy_id;
64	struct i2c_client *client = phy->i2c_dev;
65
66	if (phy->hard_fault != 0)
67		return phy->hard_fault;
68
69	r = i2c_master_send(client, skb->data, skb->len);
70	if (r < 0) {
71		/* Retry, chip was in standby */
72		msleep(110);
73		r = i2c_master_send(client, skb->data, skb->len);
74	}
75
76	if (r < 0) {
77		nfc_err(&client->dev, "Error %d on I2C send\n", r);
78	} else if (r != skb->len) {
79		nfc_err(&client->dev,
80			"Invalid length sent: %u (expected %u)\n",
81			r, skb->len);
82		r = -EREMOTEIO;
83	} else {
84		/* Success but return 0 and not number of bytes */
85		r = 0;
86	}
87
88	return r;
89}
90
91static const struct nxp_nci_phy_ops i2c_phy_ops = {
92	.set_mode = nxp_nci_i2c_set_mode,
93	.write = nxp_nci_i2c_write,
94};
95
96static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
97			       struct sk_buff **skb)
98{
99	struct i2c_client *client = phy->i2c_dev;
100	size_t frame_len;
101	__be16 header;
102	int r;
103
104	r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
105	if (r < 0) {
106		goto fw_read_exit;
107	} else if (r != NXP_NCI_FW_HDR_LEN) {
108		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
109		r = -EBADMSG;
110		goto fw_read_exit;
111	}
112
113	frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) +
114		    NXP_NCI_FW_CRC_LEN;
115
116	*skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
117	if (*skb == NULL) {
118		r = -ENOMEM;
119		goto fw_read_exit;
120	}
121
122	skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN);
123
124	r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
125	if (r < 0) {
126		goto fw_read_exit_free_skb;
127	} else if (r != frame_len) {
128		nfc_err(&client->dev,
129			"Invalid frame length: %u (expected %zu)\n",
130			r, frame_len);
131		r = -EBADMSG;
132		goto fw_read_exit_free_skb;
133	}
134
135	return 0;
136
137fw_read_exit_free_skb:
138	kfree_skb(*skb);
139fw_read_exit:
140	return r;
141}
142
143static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
144				struct sk_buff **skb)
145{
146	struct nci_ctrl_hdr header; /* May actually be a data header */
147	struct i2c_client *client = phy->i2c_dev;
148	int r;
149
150	r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
151	if (r < 0) {
152		goto nci_read_exit;
153	} else if (r != NCI_CTRL_HDR_SIZE) {
154		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
155		r = -EBADMSG;
156		goto nci_read_exit;
157	}
158
159	*skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
160	if (*skb == NULL) {
161		r = -ENOMEM;
162		goto nci_read_exit;
163	}
164
165	skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
166
167	if (!header.plen)
168		return 0;
169
170	r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
171	if (r < 0) {
172		goto nci_read_exit_free_skb;
173	} else if (r != header.plen) {
174		nfc_err(&client->dev,
175			"Invalid frame payload length: %u (expected %u)\n",
176			r, header.plen);
177		r = -EBADMSG;
178		goto nci_read_exit_free_skb;
179	}
180
181	return 0;
182
183nci_read_exit_free_skb:
184	kfree_skb(*skb);
185nci_read_exit:
186	return r;
187}
188
189static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
190{
191	struct nxp_nci_i2c_phy *phy = phy_id;
192	struct i2c_client *client;
193	struct nxp_nci_info *info;
194
195	struct sk_buff *skb = NULL;
196	int r = 0;
197
198	if (!phy || !phy->ndev)
199		goto exit_irq_none;
200
201	client = phy->i2c_dev;
202
203	if (!client || irq != client->irq)
204		goto exit_irq_none;
205
206	info = nci_get_drvdata(phy->ndev);
207
208	if (!info)
209		goto exit_irq_none;
210
211	mutex_lock(&info->info_lock);
212
213	if (phy->hard_fault != 0)
214		goto exit_irq_handled;
215
216	switch (info->mode) {
217	case NXP_NCI_MODE_NCI:
218		r = nxp_nci_i2c_nci_read(phy, &skb);
219		break;
220	case NXP_NCI_MODE_FW:
221		r = nxp_nci_i2c_fw_read(phy, &skb);
222		break;
223	case NXP_NCI_MODE_COLD:
224		r = -EREMOTEIO;
225		break;
226	}
227
228	if (r == -EREMOTEIO) {
229		phy->hard_fault = r;
230		if (info->mode == NXP_NCI_MODE_FW)
231			nxp_nci_fw_recv_frame(phy->ndev, NULL);
232	}
233	if (r < 0) {
234		nfc_err(&client->dev, "Read failed with error %d\n", r);
235		goto exit_irq_handled;
236	}
237
238	switch (info->mode) {
239	case NXP_NCI_MODE_NCI:
240		nci_recv_frame(phy->ndev, skb);
241		break;
242	case NXP_NCI_MODE_FW:
243		nxp_nci_fw_recv_frame(phy->ndev, skb);
244		break;
245	case NXP_NCI_MODE_COLD:
246		break;
247	}
248
249exit_irq_handled:
250	mutex_unlock(&info->info_lock);
251	return IRQ_HANDLED;
252exit_irq_none:
253	WARN_ON_ONCE(1);
254	return IRQ_NONE;
255}
256
257static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
258static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
259
260static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
261	{ "enable-gpios", &enable_gpios, 1 },
262	{ "firmware-gpios", &firmware_gpios, 1 },
263	{ }
264};
265
266static int nxp_nci_i2c_probe(struct i2c_client *client)
267{
268	struct device *dev = &client->dev;
269	struct nxp_nci_i2c_phy *phy;
270	int r;
271
272	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
273		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
274		return -ENODEV;
275	}
276
277	phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
278			   GFP_KERNEL);
279	if (!phy)
280		return -ENOMEM;
281
282	phy->i2c_dev = client;
283	i2c_set_clientdata(client, phy);
284
285	r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios);
286	if (r)
287		dev_dbg(dev, "Unable to add GPIO mapping table\n");
288
289	phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
290	if (IS_ERR(phy->gpiod_en)) {
291		nfc_err(dev, "Failed to get EN gpio\n");
292		return PTR_ERR(phy->gpiod_en);
293	}
294
295	phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW);
296	if (IS_ERR(phy->gpiod_fw)) {
297		nfc_err(dev, "Failed to get FW gpio\n");
298		return PTR_ERR(phy->gpiod_fw);
299	}
300
301	r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
302			  NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
303	if (r < 0)
304		return r;
305
306	r = request_threaded_irq(client->irq, NULL,
307				 nxp_nci_i2c_irq_thread_fn,
308				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
309				 NXP_NCI_I2C_DRIVER_NAME, phy);
310	if (r < 0)
311		nfc_err(&client->dev, "Unable to register IRQ handler\n");
312
313	return r;
314}
315
316static void nxp_nci_i2c_remove(struct i2c_client *client)
317{
318	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
319
320	nxp_nci_remove(phy->ndev);
321	free_irq(client->irq, phy);
322}
323
324static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
325	{"nxp-nci_i2c", 0},
326	{}
327};
328MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
329
330static const struct of_device_id of_nxp_nci_i2c_match[] = {
331	{ .compatible = "nxp,nxp-nci-i2c", },
332	{}
333};
334MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
335
336#ifdef CONFIG_ACPI
337static const struct acpi_device_id acpi_id[] = {
338	{ "NXP1001" },
339	{ "NXP1002" },
340	{ "NXP7471" },
341	{ }
342};
343MODULE_DEVICE_TABLE(acpi, acpi_id);
344#endif
345
346static struct i2c_driver nxp_nci_i2c_driver = {
347	.driver = {
348		   .name = NXP_NCI_I2C_DRIVER_NAME,
349		   .acpi_match_table = ACPI_PTR(acpi_id),
350		   .of_match_table = of_nxp_nci_i2c_match,
351		  },
352	.probe = nxp_nci_i2c_probe,
353	.id_table = nxp_nci_i2c_id_table,
354	.remove = nxp_nci_i2c_remove,
355};
356
357module_i2c_driver(nxp_nci_i2c_driver);
358
359MODULE_LICENSE("GPL");
360MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
361MODULE_AUTHOR("Cl��ment Perrochaud <clement.perrochaud@nxp.com>");
362MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
363