xref: /openbmc/linux/drivers/nfc/nxp-nci/i2c.c (revision 5b394b2d) 
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/module.h>
33 #include <linux/nfc.h>
34 #include <linux/gpio/consumer.h>
35 #include <linux/of_gpio.h>
36 #include <linux/of_irq.h>
37 #include <linux/platform_data/nxp-nci.h>
38 #include <asm/unaligned.h>
39 
40 #include <net/nfc/nfc.h>
41 
42 #include "nxp-nci.h"
43 
44 #define NXP_NCI_I2C_DRIVER_NAME	"nxp-nci_i2c"
45 
46 #define NXP_NCI_I2C_MAX_PAYLOAD	32
47 
48 struct nxp_nci_i2c_phy {
49 	struct i2c_client *i2c_dev;
50 	struct nci_dev *ndev;
51 
52 	unsigned int gpio_en;
53 	unsigned int gpio_fw;
54 
55 	int hard_fault; /*
56 			 * < 0 if hardware error occurred (e.g. i2c err)
57 			 * and prevents normal operation.
58 			 */
59 };
60 
61 static int nxp_nci_i2c_set_mode(void *phy_id,
62 				    enum nxp_nci_mode mode)
63 {
64 	struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
65 
66 	gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
67 	gpio_set_value(phy->gpio_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
68 	usleep_range(10000, 15000);
69 
70 	if (mode == NXP_NCI_MODE_COLD)
71 		phy->hard_fault = 0;
72 
73 	return 0;
74 }
75 
76 static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
77 {
78 	int r;
79 	struct nxp_nci_i2c_phy *phy = phy_id;
80 	struct i2c_client *client = phy->i2c_dev;
81 
82 	if (phy->hard_fault != 0)
83 		return phy->hard_fault;
84 
85 	r = i2c_master_send(client, skb->data, skb->len);
86 	if (r < 0) {
87 		/* Retry, chip was in standby */
88 		msleep(110);
89 		r = i2c_master_send(client, skb->data, skb->len);
90 	}
91 
92 	if (r < 0) {
93 		nfc_err(&client->dev, "Error %d on I2C send\n", r);
94 	} else if (r != skb->len) {
95 		nfc_err(&client->dev,
96 			"Invalid length sent: %u (expected %u)\n",
97 			r, skb->len);
98 		r = -EREMOTEIO;
99 	} else {
100 		/* Success but return 0 and not number of bytes */
101 		r = 0;
102 	}
103 
104 	return r;
105 }
106 
107 static const struct nxp_nci_phy_ops i2c_phy_ops = {
108 	.set_mode = nxp_nci_i2c_set_mode,
109 	.write = nxp_nci_i2c_write,
110 };
111 
112 static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
113 			       struct sk_buff **skb)
114 {
115 	struct i2c_client *client = phy->i2c_dev;
116 	u16 header;
117 	size_t frame_len;
118 	int r;
119 
120 	r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
121 	if (r < 0) {
122 		goto fw_read_exit;
123 	} else if (r != NXP_NCI_FW_HDR_LEN) {
124 		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
125 		r = -EBADMSG;
126 		goto fw_read_exit;
127 	}
128 
129 	frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) +
130 		    NXP_NCI_FW_CRC_LEN;
131 
132 	*skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
133 	if (*skb == NULL) {
134 		r = -ENOMEM;
135 		goto fw_read_exit;
136 	}
137 
138 	skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN);
139 
140 	r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
141 	if (r != frame_len) {
142 		nfc_err(&client->dev,
143 			"Invalid frame length: %u (expected %zu)\n",
144 			r, frame_len);
145 		r = -EBADMSG;
146 		goto fw_read_exit_free_skb;
147 	}
148 
149 	return 0;
150 
151 fw_read_exit_free_skb:
152 	kfree_skb(*skb);
153 fw_read_exit:
154 	return r;
155 }
156 
157 static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
158 				struct sk_buff **skb)
159 {
160 	struct nci_ctrl_hdr header; /* May actually be a data header */
161 	struct i2c_client *client = phy->i2c_dev;
162 	int r;
163 
164 	r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
165 	if (r < 0) {
166 		goto nci_read_exit;
167 	} else if (r != NCI_CTRL_HDR_SIZE) {
168 		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
169 		r = -EBADMSG;
170 		goto nci_read_exit;
171 	}
172 
173 	*skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
174 	if (*skb == NULL) {
175 		r = -ENOMEM;
176 		goto nci_read_exit;
177 	}
178 
179 	skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
180 
181 	r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
182 	if (r != header.plen) {
183 		nfc_err(&client->dev,
184 			"Invalid frame payload length: %u (expected %u)\n",
185 			r, header.plen);
186 		r = -EBADMSG;
187 		goto nci_read_exit_free_skb;
188 	}
189 
190 	return 0;
191 
192 nci_read_exit_free_skb:
193 	kfree_skb(*skb);
194 nci_read_exit:
195 	return r;
196 }
197 
198 static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
199 {
200 	struct nxp_nci_i2c_phy *phy = phy_id;
201 	struct i2c_client *client;
202 	struct nxp_nci_info *info;
203 
204 	struct sk_buff *skb = NULL;
205 	int r = 0;
206 
207 	if (!phy || !phy->ndev)
208 		goto exit_irq_none;
209 
210 	client = phy->i2c_dev;
211 
212 	if (!client || irq != client->irq)
213 		goto exit_irq_none;
214 
215 	info = nci_get_drvdata(phy->ndev);
216 
217 	if (!info)
218 		goto exit_irq_none;
219 
220 	mutex_lock(&info->info_lock);
221 
222 	if (phy->hard_fault != 0)
223 		goto exit_irq_handled;
224 
225 	switch (info->mode) {
226 	case NXP_NCI_MODE_NCI:
227 		r = nxp_nci_i2c_nci_read(phy, &skb);
228 		break;
229 	case NXP_NCI_MODE_FW:
230 		r = nxp_nci_i2c_fw_read(phy, &skb);
231 		break;
232 	case NXP_NCI_MODE_COLD:
233 		r = -EREMOTEIO;
234 		break;
235 	}
236 
237 	if (r == -EREMOTEIO) {
238 		phy->hard_fault = r;
239 		skb = NULL;
240 	} else if (r < 0) {
241 		nfc_err(&client->dev, "Read failed with error %d\n", r);
242 		goto exit_irq_handled;
243 	}
244 
245 	switch (info->mode) {
246 	case NXP_NCI_MODE_NCI:
247 		nci_recv_frame(phy->ndev, skb);
248 		break;
249 	case NXP_NCI_MODE_FW:
250 		nxp_nci_fw_recv_frame(phy->ndev, skb);
251 		break;
252 	case NXP_NCI_MODE_COLD:
253 		break;
254 	}
255 
256 exit_irq_handled:
257 	mutex_unlock(&info->info_lock);
258 	return IRQ_HANDLED;
259 exit_irq_none:
260 	WARN_ON_ONCE(1);
261 	return IRQ_NONE;
262 }
263 
264 static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)
265 {
266 	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
267 	struct device_node *pp;
268 	int r;
269 
270 	pp = client->dev.of_node;
271 	if (!pp)
272 		return -ENODEV;
273 
274 	r = of_get_named_gpio(pp, "enable-gpios", 0);
275 	if (r == -EPROBE_DEFER)
276 		r = of_get_named_gpio(pp, "enable-gpios", 0);
277 	if (r < 0) {
278 		nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);
279 		return r;
280 	}
281 	phy->gpio_en = r;
282 
283 	r = of_get_named_gpio(pp, "firmware-gpios", 0);
284 	if (r == -EPROBE_DEFER)
285 		r = of_get_named_gpio(pp, "firmware-gpios", 0);
286 	if (r < 0) {
287 		nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);
288 		return r;
289 	}
290 	phy->gpio_fw = r;
291 
292 	return 0;
293 }
294 
295 static int nxp_nci_i2c_acpi_config(struct nxp_nci_i2c_phy *phy)
296 {
297 	struct i2c_client *client = phy->i2c_dev;
298 	struct gpio_desc *gpiod_en, *gpiod_fw;
299 
300 	gpiod_en = devm_gpiod_get_index(&client->dev, NULL, 2, GPIOD_OUT_LOW);
301 	gpiod_fw = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_LOW);
302 
303 	if (IS_ERR(gpiod_en) || IS_ERR(gpiod_fw)) {
304 		nfc_err(&client->dev, "No GPIOs\n");
305 		return -EINVAL;
306 	}
307 
308 	phy->gpio_en = desc_to_gpio(gpiod_en);
309 	phy->gpio_fw = desc_to_gpio(gpiod_fw);
310 
311 	return 0;
312 }
313 
314 static int nxp_nci_i2c_probe(struct i2c_client *client,
315 			    const struct i2c_device_id *id)
316 {
317 	struct nxp_nci_i2c_phy *phy;
318 	struct nxp_nci_nfc_platform_data *pdata;
319 	int r;
320 
321 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
322 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
323 		r = -ENODEV;
324 		goto probe_exit;
325 	}
326 
327 	phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),
328 			   GFP_KERNEL);
329 	if (!phy) {
330 		r = -ENOMEM;
331 		goto probe_exit;
332 	}
333 
334 	phy->i2c_dev = client;
335 	i2c_set_clientdata(client, phy);
336 
337 	pdata = client->dev.platform_data;
338 
339 	if (!pdata && client->dev.of_node) {
340 		r = nxp_nci_i2c_parse_devtree(client);
341 		if (r < 0) {
342 			nfc_err(&client->dev, "Failed to get DT data\n");
343 			goto probe_exit;
344 		}
345 	} else if (pdata) {
346 		phy->gpio_en = pdata->gpio_en;
347 		phy->gpio_fw = pdata->gpio_fw;
348 	} else if (ACPI_HANDLE(&client->dev)) {
349 		r = nxp_nci_i2c_acpi_config(phy);
350 		if (r < 0)
351 			goto probe_exit;
352 		goto nci_probe;
353 	} else {
354 		nfc_err(&client->dev, "No platform data\n");
355 		r = -EINVAL;
356 		goto probe_exit;
357 	}
358 
359 	r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
360 				  GPIOF_OUT_INIT_LOW, "nxp_nci_en");
361 	if (r < 0)
362 		goto probe_exit;
363 
364 	r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,
365 				  GPIOF_OUT_INIT_LOW, "nxp_nci_fw");
366 	if (r < 0)
367 		goto probe_exit;
368 
369 nci_probe:
370 	r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
371 			  NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
372 	if (r < 0)
373 		goto probe_exit;
374 
375 	r = request_threaded_irq(client->irq, NULL,
376 				 nxp_nci_i2c_irq_thread_fn,
377 				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
378 				 NXP_NCI_I2C_DRIVER_NAME, phy);
379 	if (r < 0)
380 		nfc_err(&client->dev, "Unable to register IRQ handler\n");
381 
382 probe_exit:
383 	return r;
384 }
385 
386 static int nxp_nci_i2c_remove(struct i2c_client *client)
387 {
388 	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
389 
390 	nxp_nci_remove(phy->ndev);
391 	free_irq(client->irq, phy);
392 
393 	return 0;
394 }
395 
396 static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
397 	{"nxp-nci_i2c", 0},
398 	{}
399 };
400 MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
401 
402 static const struct of_device_id of_nxp_nci_i2c_match[] = {
403 	{ .compatible = "nxp,nxp-nci-i2c", },
404 	{},
405 };
406 MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
407 
408 #ifdef CONFIG_ACPI
409 static struct acpi_device_id acpi_id[] = {
410 	{ "NXP7471" },
411 	{ },
412 };
413 MODULE_DEVICE_TABLE(acpi, acpi_id);
414 #endif
415 
416 static struct i2c_driver nxp_nci_i2c_driver = {
417 	.driver = {
418 		   .name = NXP_NCI_I2C_DRIVER_NAME,
419 		   .acpi_match_table = ACPI_PTR(acpi_id),
420 		   .of_match_table = of_match_ptr(of_nxp_nci_i2c_match),
421 		  },
422 	.probe = nxp_nci_i2c_probe,
423 	.id_table = nxp_nci_i2c_id_table,
424 	.remove = nxp_nci_i2c_remove,
425 };
426 
427 module_i2c_driver(nxp_nci_i2c_driver);
428 
429 MODULE_LICENSE("GPL");
430 MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
431 MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
432 MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");
433