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: Clément 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 <asm/unaligned.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
49 struct 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
nxp_nci_i2c_set_mode(void * phy_id,enum nxp_nci_mode mode)63 static 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
nxp_nci_i2c_write(void * phy_id,struct sk_buff * skb)78 static 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
109 static 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
nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy * phy,struct sk_buff ** skb)114 static 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
153 fw_read_exit_free_skb:
154 kfree_skb(*skb);
155 fw_read_exit:
156 return r;
157 }
158
nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy * phy,struct sk_buff ** skb)159 static 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
195 nci_read_exit_free_skb:
196 kfree_skb(*skb);
197 nci_read_exit:
198 return r;
199 }
200
nxp_nci_i2c_irq_thread_fn(int irq,void * phy_id)201 static 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 if (info->mode == NXP_NCI_MODE_FW)
243 nxp_nci_fw_recv_frame(phy->ndev, NULL);
244 }
245 if (r < 0) {
246 nfc_err(&client->dev, "Read failed with error %d\n", r);
247 goto exit_irq_handled;
248 }
249
250 switch (info->mode) {
251 case NXP_NCI_MODE_NCI:
252 nci_recv_frame(phy->ndev, skb);
253 break;
254 case NXP_NCI_MODE_FW:
255 nxp_nci_fw_recv_frame(phy->ndev, skb);
256 break;
257 case NXP_NCI_MODE_COLD:
258 break;
259 }
260
261 exit_irq_handled:
262 mutex_unlock(&info->info_lock);
263 return IRQ_HANDLED;
264 exit_irq_none:
265 WARN_ON_ONCE(1);
266 return IRQ_NONE;
267 }
268
269 #ifdef CONFIG_OF
270
nxp_nci_i2c_parse_devtree(struct i2c_client * client)271 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
272 {
273 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
274 struct device_node *pp;
275 int r;
276
277 pp = client->dev.of_node;
278 if (!pp)
279 return -ENODEV;
280
281 r = of_get_named_gpio(pp, "enable-gpios", 0);
282 if (r == -EPROBE_DEFER)
283 r = of_get_named_gpio(pp, "enable-gpios", 0);
284 if (r < 0) {
285 nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);
286 return r;
287 }
288 phy->gpio_en = r;
289
290 r = of_get_named_gpio(pp, "firmware-gpios", 0);
291 if (r == -EPROBE_DEFER)
292 r = of_get_named_gpio(pp, "firmware-gpios", 0);
293 if (r < 0) {
294 nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);
295 return r;
296 }
297 phy->gpio_fw = r;
298
299 r = irq_of_parse_and_map(pp, 0);
300 if (r < 0) {
301 nfc_err(&client->dev, "Unable to get irq, error: %d\n", r);
302 return r;
303 }
304 client->irq = r;
305
306 return 0;
307 }
308
309 #else
310
nxp_nci_i2c_parse_devtree(struct i2c_client * client)311 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
312 {
313 return -ENODEV;
314 }
315
316 #endif
317
nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy * phy)318 static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy)
319 {
320 struct i2c_client *client = phy->i2c_dev;
321 struct gpio_desc *gpiod_en, *gpiod_fw, *gpiod_irq;
322
323 gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW);
324 gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW);
325 gpiod_irq = devm_gpiod_get_index(&client->dev, NULL, 0, GPIOD_IN);
326
327 if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw) || IS_ERR(gpiod_irq)) {
328 nfc_err(&client->dev, "No GPIOs\n");
329 return -EINVAL;
330 }
331
332 client->irq = gpiod_to_irq(gpiod_irq);
333 if (client->irq < 0) {
334 nfc_err(&client->dev, "No IRQ\n");
335 return -EINVAL;
336 }
337
338 phy->gpio_en = desc_to_gpio(gpiod_en);
339 phy->gpio_fw = desc_to_gpio(gpiod_fw);
340 phy->gpio_irq = desc_to_gpio(gpiod_irq);
341
342 return 0;
343 }
344
nxp_nci_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)345 static int nxp_nci_i2c_probe(struct i2c_client *client,
346 const struct i2c_device_id *id)
347 {
348 struct nxp_nci_i2c_phy *phy;
349 struct nxp_nci_nfc_platform_data *pdata;
350 int r;
351
352 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
353 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
354 r = -ENODEV;
355 goto probe_exit;
356 }
357
358 phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
359 GFP_KERNEL);
360 if (!phy) {
361 r = -ENOMEM;
362 goto probe_exit;
363 }
364
365 phy->i2c_dev = client;
366 i2c_set_clientdata(client, phy);
367
368 pdata = client->dev.platform_data;
369
370 if (!pdata && client->dev.of_node) {
371 r = nxp_nci_i2c_parse_devtree(client);
372 if (r < 0) {
373 nfc_err(&client->dev, "Failed to get DT data\n");
374 goto probe_exit;
375 }
376 } else if (pdata) {
377 phy->gpio_en = pdata->gpio_en;
378 phy->gpio_fw = pdata->gpio_fw;
379 client->irq = pdata->irq;
380 } else if (ACPI_HANDLE(&client->dev)) {
381 r = nxp_nci_i2c_acpi_config(phy);
382 if (r < 0)
383 goto probe_exit;
384 goto nci_probe;
385 } else {
386 nfc_err(&client->dev, "No platform data\n");
387 r = -EINVAL;
388 goto probe_exit;
389 }
390
391 r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
392 GPIOF_OUT_INIT_LOW, "nxp_nci_en");
393 if (r < 0)
394 goto probe_exit;
395
396 r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,
397 GPIOF_OUT_INIT_LOW, "nxp_nci_fw");
398 if (r < 0)
399 goto probe_exit;
400
401 nci_probe:
402 r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
403 NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
404 if (r < 0)
405 goto probe_exit;
406
407 r = request_threaded_irq(client->irq, NULL,
408 nxp_nci_i2c_irq_thread_fn,
409 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
410 NXP_NCI_I2C_DRIVER_NAME, phy);
411 if (r < 0)
412 nfc_err(&client->dev, "Unable to register IRQ handler\n");
413
414 probe_exit:
415 return r;
416 }
417
nxp_nci_i2c_remove(struct i2c_client * client)418 static int nxp_nci_i2c_remove(struct i2c_client *client)
419 {
420 struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
421
422 nxp_nci_remove(phy->ndev);
423 free_irq(client->irq, phy);
424
425 return 0;
426 }
427
428 static struct i2c_device_id nxp_nci_i2c_id_table[] = {
429 {"nxp-nci_i2c", 0},
430 {}
431 };
432 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
433
434 static const struct of_device_id of_nxp_nci_i2c_match[] = {
435 { .compatible = "nxp,nxp-nci-i2c", },
436 {},
437 };
438 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
439
440 #ifdef CONFIG_ACPI
441 static struct acpi_device_id acpi_id[] = {
442 { "NXP7471" },
443 { },
444 };
445 MODULE_DEVICE_TABLE(acpi, acpi_id);
446 #endif
447
448 static struct i2c_driver nxp_nci_i2c_driver = {
449 .driver = {
450 .name = NXP_NCI_I2C_DRIVER_NAME,
451 .owner = THIS_MODULE,
452 .acpi_match_table = ACPI_PTR(acpi_id),
453 .of_match_table = of_match_ptr(of_nxp_nci_i2c_match),
454 },
455 .probe = nxp_nci_i2c_probe,
456 .id_table = nxp_nci_i2c_id_table,
457 .remove = nxp_nci_i2c_remove,
458 };
459
460 module_i2c_driver(nxp_nci_i2c_driver);
461
462 MODULE_LICENSE("GPL");
463 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
464 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
465 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
466