1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * I2C Link Layer for Samsung S3FWRN5 NCI based Driver
4 *
5 * Copyright (C) 2015 Samsung Electrnoics
6 * Robert Baldyga <r.baldyga@samsung.com>
7 */
8
9 #include <linux/i2c.h>
10 #include <linux/gpio.h>
11 #include <linux/delay.h>
12 #include <linux/of_gpio.h>
13 #include <linux/of_irq.h>
14 #include <linux/module.h>
15
16 #include <net/nfc/nfc.h>
17
18 #include "s3fwrn5.h"
19
20 #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"
21
22 #define S3FWRN5_I2C_MAX_PAYLOAD 32
23 #define S3FWRN5_EN_WAIT_TIME 150
24
25 struct s3fwrn5_i2c_phy {
26 struct i2c_client *i2c_dev;
27 struct nci_dev *ndev;
28
29 int gpio_en;
30 int gpio_fw_wake;
31
32 struct mutex mutex;
33
34 enum s3fwrn5_mode mode;
35 unsigned int irq_skip:1;
36 };
37
s3fwrn5_i2c_set_wake(void * phy_id,bool wake)38 static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
39 {
40 struct s3fwrn5_i2c_phy *phy = phy_id;
41
42 mutex_lock(&phy->mutex);
43 gpio_set_value(phy->gpio_fw_wake, wake);
44 msleep(S3FWRN5_EN_WAIT_TIME/2);
45 mutex_unlock(&phy->mutex);
46 }
47
s3fwrn5_i2c_set_mode(void * phy_id,enum s3fwrn5_mode mode)48 static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
49 {
50 struct s3fwrn5_i2c_phy *phy = phy_id;
51
52 mutex_lock(&phy->mutex);
53
54 if (phy->mode == mode)
55 goto out;
56
57 phy->mode = mode;
58
59 gpio_set_value(phy->gpio_en, 1);
60 gpio_set_value(phy->gpio_fw_wake, 0);
61 if (mode == S3FWRN5_MODE_FW)
62 gpio_set_value(phy->gpio_fw_wake, 1);
63
64 if (mode != S3FWRN5_MODE_COLD) {
65 msleep(S3FWRN5_EN_WAIT_TIME);
66 gpio_set_value(phy->gpio_en, 0);
67 msleep(S3FWRN5_EN_WAIT_TIME/2);
68 }
69
70 phy->irq_skip = true;
71
72 out:
73 mutex_unlock(&phy->mutex);
74 }
75
s3fwrn5_i2c_get_mode(void * phy_id)76 static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
77 {
78 struct s3fwrn5_i2c_phy *phy = phy_id;
79 enum s3fwrn5_mode mode;
80
81 mutex_lock(&phy->mutex);
82
83 mode = phy->mode;
84
85 mutex_unlock(&phy->mutex);
86
87 return mode;
88 }
89
s3fwrn5_i2c_write(void * phy_id,struct sk_buff * skb)90 static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
91 {
92 struct s3fwrn5_i2c_phy *phy = phy_id;
93 int ret;
94
95 mutex_lock(&phy->mutex);
96
97 phy->irq_skip = false;
98
99 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
100 if (ret == -EREMOTEIO) {
101 /* Retry, chip was in standby */
102 usleep_range(110000, 120000);
103 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
104 }
105
106 mutex_unlock(&phy->mutex);
107
108 if (ret < 0)
109 return ret;
110
111 if (ret != skb->len)
112 return -EREMOTEIO;
113
114 return 0;
115 }
116
117 static const struct s3fwrn5_phy_ops i2c_phy_ops = {
118 .set_wake = s3fwrn5_i2c_set_wake,
119 .set_mode = s3fwrn5_i2c_set_mode,
120 .get_mode = s3fwrn5_i2c_get_mode,
121 .write = s3fwrn5_i2c_write,
122 };
123
s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy * phy)124 static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
125 {
126 struct sk_buff *skb;
127 size_t hdr_size;
128 size_t data_len;
129 char hdr[4];
130 int ret;
131
132 hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
133 NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
134 ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
135 if (ret < 0)
136 return ret;
137
138 if (ret < hdr_size)
139 return -EBADMSG;
140
141 data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
142 ((struct nci_ctrl_hdr *)hdr)->plen :
143 ((struct s3fwrn5_fw_header *)hdr)->len;
144
145 skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
146 if (!skb)
147 return -ENOMEM;
148
149 skb_put_data(skb, hdr, hdr_size);
150
151 if (data_len == 0)
152 goto out;
153
154 ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
155 if (ret != data_len) {
156 kfree_skb(skb);
157 return -EBADMSG;
158 }
159
160 out:
161 return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
162 }
163
s3fwrn5_i2c_irq_thread_fn(int irq,void * phy_id)164 static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
165 {
166 struct s3fwrn5_i2c_phy *phy = phy_id;
167
168 if (!phy || !phy->ndev) {
169 WARN_ON_ONCE(1);
170 return IRQ_NONE;
171 }
172
173 mutex_lock(&phy->mutex);
174
175 if (phy->irq_skip)
176 goto out;
177
178 switch (phy->mode) {
179 case S3FWRN5_MODE_NCI:
180 case S3FWRN5_MODE_FW:
181 s3fwrn5_i2c_read(phy);
182 break;
183 case S3FWRN5_MODE_COLD:
184 break;
185 }
186
187 out:
188 mutex_unlock(&phy->mutex);
189
190 return IRQ_HANDLED;
191 }
192
s3fwrn5_i2c_parse_dt(struct i2c_client * client)193 static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
194 {
195 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
196 struct device_node *np = client->dev.of_node;
197
198 if (!np)
199 return -ENODEV;
200
201 phy->gpio_en = of_get_named_gpio(np, "en-gpios", 0);
202 if (!gpio_is_valid(phy->gpio_en)) {
203 /* Support also deprecated property */
204 phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
205 if (!gpio_is_valid(phy->gpio_en))
206 return -ENODEV;
207 }
208
209 phy->gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
210 if (!gpio_is_valid(phy->gpio_fw_wake)) {
211 /* Support also deprecated property */
212 phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
213 if (!gpio_is_valid(phy->gpio_fw_wake))
214 return -ENODEV;
215 }
216
217 return 0;
218 }
219
s3fwrn5_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)220 static int s3fwrn5_i2c_probe(struct i2c_client *client,
221 const struct i2c_device_id *id)
222 {
223 struct s3fwrn5_i2c_phy *phy;
224 int ret;
225
226 phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
227 if (!phy)
228 return -ENOMEM;
229
230 mutex_init(&phy->mutex);
231 phy->mode = S3FWRN5_MODE_COLD;
232 phy->irq_skip = true;
233
234 phy->i2c_dev = client;
235 i2c_set_clientdata(client, phy);
236
237 ret = s3fwrn5_i2c_parse_dt(client);
238 if (ret < 0)
239 return ret;
240
241 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
242 GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
243 if (ret < 0)
244 return ret;
245
246 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
247 GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
248 if (ret < 0)
249 return ret;
250
251 ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
252 S3FWRN5_I2C_MAX_PAYLOAD);
253 if (ret < 0)
254 return ret;
255
256 ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
257 s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
258 S3FWRN5_I2C_DRIVER_NAME, phy);
259 if (ret)
260 s3fwrn5_remove(phy->ndev);
261
262 return ret;
263 }
264
s3fwrn5_i2c_remove(struct i2c_client * client)265 static int s3fwrn5_i2c_remove(struct i2c_client *client)
266 {
267 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
268
269 s3fwrn5_remove(phy->ndev);
270
271 return 0;
272 }
273
274 static const struct i2c_device_id s3fwrn5_i2c_id_table[] = {
275 {S3FWRN5_I2C_DRIVER_NAME, 0},
276 {}
277 };
278 MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);
279
280 static const struct of_device_id of_s3fwrn5_i2c_match[] = {
281 { .compatible = "samsung,s3fwrn5-i2c", },
282 {}
283 };
284 MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);
285
286 static struct i2c_driver s3fwrn5_i2c_driver = {
287 .driver = {
288 .name = S3FWRN5_I2C_DRIVER_NAME,
289 .of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
290 },
291 .probe = s3fwrn5_i2c_probe,
292 .remove = s3fwrn5_i2c_remove,
293 .id_table = s3fwrn5_i2c_id_table,
294 };
295
296 module_i2c_driver(s3fwrn5_i2c_driver);
297
298 MODULE_LICENSE("GPL");
299 MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
300 MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>");
301
