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20#include <linux/i2c.h>
21#include <linux/gpio.h>
22#include <linux/delay.h>
23#include <linux/of_gpio.h>
24#include <linux/of_irq.h>
25#include <linux/module.h>
26
27#include <net/nfc/nfc.h>
28
29#include "s3fwrn5.h"
30
31#define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"
32
33#define S3FWRN5_I2C_MAX_PAYLOAD 32
34#define S3FWRN5_EN_WAIT_TIME 150
35
36struct s3fwrn5_i2c_phy {
37 struct i2c_client *i2c_dev;
38 struct nci_dev *ndev;
39
40 unsigned int gpio_en;
41 unsigned int gpio_fw_wake;
42
43 struct mutex mutex;
44
45 enum s3fwrn5_mode mode;
46 unsigned int irq_skip:1;
47};
48
49static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
50{
51 struct s3fwrn5_i2c_phy *phy = phy_id;
52
53 mutex_lock(&phy->mutex);
54 gpio_set_value(phy->gpio_fw_wake, wake);
55 msleep(S3FWRN5_EN_WAIT_TIME/2);
56 mutex_unlock(&phy->mutex);
57}
58
59static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
60{
61 struct s3fwrn5_i2c_phy *phy = phy_id;
62
63 mutex_lock(&phy->mutex);
64
65 if (phy->mode == mode)
66 goto out;
67
68 phy->mode = mode;
69
70 gpio_set_value(phy->gpio_en, 1);
71 gpio_set_value(phy->gpio_fw_wake, 0);
72 if (mode == S3FWRN5_MODE_FW)
73 gpio_set_value(phy->gpio_fw_wake, 1);
74
75 if (mode != S3FWRN5_MODE_COLD) {
76 msleep(S3FWRN5_EN_WAIT_TIME);
77 gpio_set_value(phy->gpio_en, 0);
78 msleep(S3FWRN5_EN_WAIT_TIME/2);
79 }
80
81 phy->irq_skip = true;
82
83out:
84 mutex_unlock(&phy->mutex);
85}
86
87static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
88{
89 struct s3fwrn5_i2c_phy *phy = phy_id;
90 enum s3fwrn5_mode mode;
91
92 mutex_lock(&phy->mutex);
93
94 mode = phy->mode;
95
96 mutex_unlock(&phy->mutex);
97
98 return mode;
99}
100
101static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
102{
103 struct s3fwrn5_i2c_phy *phy = phy_id;
104 int ret;
105
106 mutex_lock(&phy->mutex);
107
108 phy->irq_skip = false;
109
110 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
111 if (ret == -EREMOTEIO) {
112
113 usleep_range(110000, 120000);
114 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
115 }
116
117 mutex_unlock(&phy->mutex);
118
119 if (ret < 0)
120 return ret;
121
122 if (ret != skb->len)
123 return -EREMOTEIO;
124
125 return 0;
126}
127
128static const struct s3fwrn5_phy_ops i2c_phy_ops = {
129 .set_wake = s3fwrn5_i2c_set_wake,
130 .set_mode = s3fwrn5_i2c_set_mode,
131 .get_mode = s3fwrn5_i2c_get_mode,
132 .write = s3fwrn5_i2c_write,
133};
134
135static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
136{
137 struct sk_buff *skb;
138 size_t hdr_size;
139 size_t data_len;
140 char hdr[4];
141 int ret;
142
143 hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
144 NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
145 ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
146 if (ret < 0)
147 return ret;
148
149 if (ret < hdr_size)
150 return -EBADMSG;
151
152 data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
153 ((struct nci_ctrl_hdr *)hdr)->plen :
154 ((struct s3fwrn5_fw_header *)hdr)->len;
155
156 skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
157 if (!skb)
158 return -ENOMEM;
159
160 skb_put_data(skb, hdr, hdr_size);
161
162 if (data_len == 0)
163 goto out;
164
165 ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
166 if (ret != data_len) {
167 kfree_skb(skb);
168 return -EBADMSG;
169 }
170
171out:
172 return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
173}
174
175static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
176{
177 struct s3fwrn5_i2c_phy *phy = phy_id;
178 int ret = 0;
179
180 if (!phy || !phy->ndev) {
181 WARN_ON_ONCE(1);
182 return IRQ_NONE;
183 }
184
185 mutex_lock(&phy->mutex);
186
187 if (phy->irq_skip)
188 goto out;
189
190 switch (phy->mode) {
191 case S3FWRN5_MODE_NCI:
192 case S3FWRN5_MODE_FW:
193 ret = s3fwrn5_i2c_read(phy);
194 break;
195 case S3FWRN5_MODE_COLD:
196 ret = -EREMOTEIO;
197 break;
198 }
199
200out:
201 mutex_unlock(&phy->mutex);
202
203 return IRQ_HANDLED;
204}
205
206static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
207{
208 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
209 struct device_node *np = client->dev.of_node;
210
211 if (!np)
212 return -ENODEV;
213
214 phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
215 if (!gpio_is_valid(phy->gpio_en))
216 return -ENODEV;
217
218 phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
219 if (!gpio_is_valid(phy->gpio_fw_wake))
220 return -ENODEV;
221
222 return 0;
223}
224
225static int s3fwrn5_i2c_probe(struct i2c_client *client,
226 const struct i2c_device_id *id)
227{
228 struct s3fwrn5_i2c_phy *phy;
229 int ret;
230
231 phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
232 if (!phy)
233 return -ENOMEM;
234
235 mutex_init(&phy->mutex);
236 phy->mode = S3FWRN5_MODE_COLD;
237 phy->irq_skip = true;
238
239 phy->i2c_dev = client;
240 i2c_set_clientdata(client, phy);
241
242 ret = s3fwrn5_i2c_parse_dt(client);
243 if (ret < 0)
244 return ret;
245
246 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
247 GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
248 if (ret < 0)
249 return ret;
250
251 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
252 GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
253 if (ret < 0)
254 return ret;
255
256 ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
257 S3FWRN5_I2C_MAX_PAYLOAD);
258 if (ret < 0)
259 return ret;
260
261 ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
262 s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
263 S3FWRN5_I2C_DRIVER_NAME, phy);
264 if (ret)
265 s3fwrn5_remove(phy->ndev);
266
267 return ret;
268}
269
270static int s3fwrn5_i2c_remove(struct i2c_client *client)
271{
272 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
273
274 s3fwrn5_remove(phy->ndev);
275
276 return 0;
277}
278
279static const struct i2c_device_id s3fwrn5_i2c_id_table[] = {
280 {S3FWRN5_I2C_DRIVER_NAME, 0},
281 {}
282};
283MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);
284
285static const struct of_device_id of_s3fwrn5_i2c_match[] = {
286 { .compatible = "samsung,s3fwrn5-i2c", },
287 {}
288};
289MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);
290
291static struct i2c_driver s3fwrn5_i2c_driver = {
292 .driver = {
293 .owner = THIS_MODULE,
294 .name = S3FWRN5_I2C_DRIVER_NAME,
295 .of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
296 },
297 .probe = s3fwrn5_i2c_probe,
298 .remove = s3fwrn5_i2c_remove,
299 .id_table = s3fwrn5_i2c_id_table,
300};
301
302module_i2c_driver(s3fwrn5_i2c_driver);
303
304MODULE_LICENSE("GPL");
305MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
306MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>");
307
