xref: /openbmc/linux/drivers/nfc/nxp-nci/i2c.c (revision 8b72d2a1)
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