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 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
137 fw_read_exit_free_skb:
138 kfree_skb(*skb);
139 fw_read_exit:
140 return r;
141 }
142
nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy * phy,struct sk_buff ** skb)143 static 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
183 nci_read_exit_free_skb:
184 kfree_skb(*skb);
185 nci_read_exit:
186 return r;
187 }
188
nxp_nci_i2c_irq_thread_fn(int irq,void * phy_id)189 static 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
249 exit_irq_handled:
250 mutex_unlock(&info->info_lock);
251 return IRQ_HANDLED;
252 exit_irq_none:
253 WARN_ON_ONCE(1);
254 return IRQ_NONE;
255 }
256
257 static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
258 static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
259
260 static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
261 { "enable-gpios", &enable_gpios, 1 },
262 { "firmware-gpios", &firmware_gpios, 1 },
263 { }
264 };
265
nxp_nci_i2c_probe(struct i2c_client * client)266 static 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
nxp_nci_i2c_remove(struct i2c_client * client)316 static 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
324 static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
325 {"nxp-nci_i2c", 0},
326 {}
327 };
328 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
329
330 static const struct of_device_id of_nxp_nci_i2c_match[] = {
331 { .compatible = "nxp,nxp-nci-i2c", },
332 {}
333 };
334 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
335
336 #ifdef CONFIG_ACPI
337 static const struct acpi_device_id acpi_id[] = {
338 { "NXP1001" },
339 { "NXP1002" },
340 { "NXP7471" },
341 { }
342 };
343 MODULE_DEVICE_TABLE(acpi, acpi_id);
344 #endif
345
346 static 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
357 module_i2c_driver(nxp_nci_i2c_driver);
358
359 MODULE_LICENSE("GPL");
360 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
361 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
362 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
363