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: Clément 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
32 struct 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
nxp_nci_i2c_set_mode(void * phy_id,enum nxp_nci_mode mode)45 static 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
nxp_nci_i2c_write(void * phy_id,struct sk_buff * skb)60 static 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
91 static 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
nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy * phy,struct sk_buff ** skb)96 static 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 u16 header;
101 size_t frame_len;
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 != frame_len) {
126 nfc_err(&client->dev,
127 "Invalid frame length: %u (expected %zu)\n",
128 r, frame_len);
129 r = -EBADMSG;
130 goto fw_read_exit_free_skb;
131 }
132
133 return 0;
134
135 fw_read_exit_free_skb:
136 kfree_skb(*skb);
137 fw_read_exit:
138 return r;
139 }
140
nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy * phy,struct sk_buff ** skb)141 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
142 struct sk_buff **skb)
143 {
144 struct nci_ctrl_hdr header; /* May actually be a data header */
145 struct i2c_client *client = phy->i2c_dev;
146 int r;
147
148 r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
149 if (r < 0) {
150 goto nci_read_exit;
151 } else if (r != NCI_CTRL_HDR_SIZE) {
152 nfc_err(&client->dev, "Incorrect header length: %u\n", r);
153 r = -EBADMSG;
154 goto nci_read_exit;
155 }
156
157 *skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
158 if (*skb == NULL) {
159 r = -ENOMEM;
160 goto nci_read_exit;
161 }
162
163 skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
164
165 r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
166 if (r != header.plen) {
167 nfc_err(&client->dev,
168 "Invalid frame payload length: %u (expected %u)\n",
169 r, header.plen);
170 r = -EBADMSG;
171 goto nci_read_exit_free_skb;
172 }
173
174 return 0;
175
176 nci_read_exit_free_skb:
177 kfree_skb(*skb);
178 nci_read_exit:
179 return r;
180 }
181
nxp_nci_i2c_irq_thread_fn(int irq,void * phy_id)182 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
183 {
184 struct nxp_nci_i2c_phy *phy = phy_id;
185 struct i2c_client *client;
186 struct nxp_nci_info *info;
187
188 struct sk_buff *skb = NULL;
189 int r = 0;
190
191 if (!phy || !phy->ndev)
192 goto exit_irq_none;
193
194 client = phy->i2c_dev;
195
196 if (!client || irq != client->irq)
197 goto exit_irq_none;
198
199 info = nci_get_drvdata(phy->ndev);
200
201 if (!info)
202 goto exit_irq_none;
203
204 mutex_lock(&info->info_lock);
205
206 if (phy->hard_fault != 0)
207 goto exit_irq_handled;
208
209 switch (info->mode) {
210 case NXP_NCI_MODE_NCI:
211 r = nxp_nci_i2c_nci_read(phy, &skb);
212 break;
213 case NXP_NCI_MODE_FW:
214 r = nxp_nci_i2c_fw_read(phy, &skb);
215 break;
216 case NXP_NCI_MODE_COLD:
217 r = -EREMOTEIO;
218 break;
219 }
220
221 if (r == -EREMOTEIO) {
222 phy->hard_fault = r;
223 if (info->mode == NXP_NCI_MODE_FW)
224 nxp_nci_fw_recv_frame(phy->ndev, NULL);
225 }
226 if (r < 0) {
227 nfc_err(&client->dev, "Read failed with error %d\n", r);
228 goto exit_irq_handled;
229 }
230
231 switch (info->mode) {
232 case NXP_NCI_MODE_NCI:
233 nci_recv_frame(phy->ndev, skb);
234 break;
235 case NXP_NCI_MODE_FW:
236 nxp_nci_fw_recv_frame(phy->ndev, skb);
237 break;
238 case NXP_NCI_MODE_COLD:
239 break;
240 }
241
242 exit_irq_handled:
243 mutex_unlock(&info->info_lock);
244 return IRQ_HANDLED;
245 exit_irq_none:
246 WARN_ON_ONCE(1);
247 return IRQ_NONE;
248 }
249
250 static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
251 static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
252
253 static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
254 { "enable-gpios", &enable_gpios, 1 },
255 { "firmware-gpios", &firmware_gpios, 1 },
256 { }
257 };
258
nxp_nci_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)259 static int nxp_nci_i2c_probe(struct i2c_client *client,
260 const struct i2c_device_id *id)
261 {
262 struct device *dev = &client->dev;
263 struct nxp_nci_i2c_phy *phy;
264 int r;
265
266 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
267 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
268 return -ENODEV;
269 }
270
271 phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
272 GFP_KERNEL);
273 if (!phy)
274 return -ENOMEM;
275
276 phy->i2c_dev = client;
277 i2c_set_clientdata(client, phy);
278
279 r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios);
280 if (r)
281 dev_dbg(dev, "Unable to add GPIO mapping table\n");
282
283 phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
284 if (IS_ERR(phy->gpiod_en)) {
285 nfc_err(dev, "Failed to get EN gpio\n");
286 return PTR_ERR(phy->gpiod_en);
287 }
288
289 phy->gpiod_fw = devm_gpiod_get(dev, "firmware", GPIOD_OUT_LOW);
290 if (IS_ERR(phy->gpiod_fw)) {
291 nfc_err(dev, "Failed to get FW gpio\n");
292 return PTR_ERR(phy->gpiod_fw);
293 }
294
295 r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
296 NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
297 if (r < 0)
298 return r;
299
300 r = request_threaded_irq(client->irq, NULL,
301 nxp_nci_i2c_irq_thread_fn,
302 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
303 NXP_NCI_I2C_DRIVER_NAME, phy);
304 if (r < 0)
305 nfc_err(&client->dev, "Unable to register IRQ handler\n");
306
307 return r;
308 }
309
nxp_nci_i2c_remove(struct i2c_client * client)310 static int nxp_nci_i2c_remove(struct i2c_client *client)
311 {
312 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
313
314 nxp_nci_remove(phy->ndev);
315 free_irq(client->irq, phy);
316
317 return 0;
318 }
319
320 static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
321 {"nxp-nci_i2c", 0},
322 {}
323 };
324 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
325
326 static const struct of_device_id of_nxp_nci_i2c_match[] = {
327 { .compatible = "nxp,nxp-nci-i2c", },
328 {}
329 };
330 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
331
332 #ifdef CONFIG_ACPI
333 static const struct acpi_device_id acpi_id[] = {
334 { "NXP1001" },
335 { "NXP7471" },
336 { }
337 };
338 MODULE_DEVICE_TABLE(acpi, acpi_id);
339 #endif
340
341 static struct i2c_driver nxp_nci_i2c_driver = {
342 .driver = {
343 .name = NXP_NCI_I2C_DRIVER_NAME,
344 .acpi_match_table = ACPI_PTR(acpi_id),
345 .of_match_table = of_nxp_nci_i2c_match,
346 },
347 .probe = nxp_nci_i2c_probe,
348 .id_table = nxp_nci_i2c_id_table,
349 .remove = nxp_nci_i2c_remove,
350 };
351
352 module_i2c_driver(nxp_nci_i2c_driver);
353
354 MODULE_LICENSE("GPL");
355 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
356 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
357 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
358
