summaryrefslogtreecommitdiff
path: root/drivers/nfc/s3fwrn5/i2c.c
blob: b4dd7dd47473c03c7b891e86702ec2060e10c11d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
/*
 * I2C Link Layer for Samsung S3FWRN5 NCI based Driver
 *
 * Copyright (C) 2015 Samsung Electrnoics
 * Robert Baldyga <r.baldyga@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2 or later, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/module.h>

#include <net/nfc/nfc.h>

#include "s3fwrn5.h"

#define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"

#define S3FWRN5_I2C_MAX_PAYLOAD 32
#define S3FWRN5_EN_WAIT_TIME 150

struct s3fwrn5_i2c_phy {
	struct i2c_client *i2c_dev;
	struct nci_dev *ndev;

	unsigned int gpio_en;
	unsigned int gpio_fw_wake;

	struct mutex mutex;

	enum s3fwrn5_mode mode;
	unsigned int irq_skip:1;
};

static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
{
	struct s3fwrn5_i2c_phy *phy = phy_id;

	mutex_lock(&phy->mutex);
	gpio_set_value(phy->gpio_fw_wake, wake);
	msleep(S3FWRN5_EN_WAIT_TIME/2);
	mutex_unlock(&phy->mutex);
}

static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
{
	struct s3fwrn5_i2c_phy *phy = phy_id;

	mutex_lock(&phy->mutex);

	if (phy->mode == mode)
		goto out;

	phy->mode = mode;

	gpio_set_value(phy->gpio_en, 1);
	gpio_set_value(phy->gpio_fw_wake, 0);
	if (mode == S3FWRN5_MODE_FW)
		gpio_set_value(phy->gpio_fw_wake, 1);

	if (mode != S3FWRN5_MODE_COLD) {
		msleep(S3FWRN5_EN_WAIT_TIME);
		gpio_set_value(phy->gpio_en, 0);
		msleep(S3FWRN5_EN_WAIT_TIME/2);
	}

	phy->irq_skip = true;

out:
	mutex_unlock(&phy->mutex);
}

static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
{
	struct s3fwrn5_i2c_phy *phy = phy_id;
	enum s3fwrn5_mode mode;

	mutex_lock(&phy->mutex);

	mode = phy->mode;

	mutex_unlock(&phy->mutex);

	return mode;
}

static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
{
	struct s3fwrn5_i2c_phy *phy = phy_id;
	int ret;

	mutex_lock(&phy->mutex);

	phy->irq_skip = false;

	ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
	if (ret == -EREMOTEIO) {
		/* Retry, chip was in standby */
		usleep_range(110000, 120000);
		ret  = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
	}

	mutex_unlock(&phy->mutex);

	if (ret < 0)
		return ret;

	if (ret != skb->len)
		return -EREMOTEIO;

	return 0;
}

static struct s3fwrn5_phy_ops i2c_phy_ops = {
	.set_wake = s3fwrn5_i2c_set_wake,
	.set_mode = s3fwrn5_i2c_set_mode,
	.get_mode = s3fwrn5_i2c_get_mode,
	.write = s3fwrn5_i2c_write,
};

static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
{
	struct sk_buff *skb;
	size_t hdr_size;
	size_t data_len;
	char hdr[4];
	int ret;

	hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
		NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
	ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
	if (ret < 0)
		return ret;

	if (ret < hdr_size)
		return -EBADMSG;

	data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
		((struct nci_ctrl_hdr *)hdr)->plen :
		((struct s3fwrn5_fw_header *)hdr)->len;

	skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
	if (!skb)
		return -ENOMEM;

	memcpy(skb_put(skb, hdr_size), hdr, hdr_size);

	if (data_len == 0)
		goto out;

	ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
	if (ret != data_len) {
		kfree_skb(skb);
		return -EBADMSG;
	}

out:
	return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
}

static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
{
	struct s3fwrn5_i2c_phy *phy = phy_id;
	int ret = 0;

	if (!phy || !phy->ndev) {
		WARN_ON_ONCE(1);
		return IRQ_NONE;
	}

	mutex_lock(&phy->mutex);

	if (phy->irq_skip)
		goto out;

	switch (phy->mode) {
	case S3FWRN5_MODE_NCI:
	case S3FWRN5_MODE_FW:
		ret = s3fwrn5_i2c_read(phy);
		break;
	case S3FWRN5_MODE_COLD:
		ret = -EREMOTEIO;
		break;
	}

out:
	mutex_unlock(&phy->mutex);

	return IRQ_HANDLED;
}

static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
{
	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
	struct device_node *np = client->dev.of_node;

	if (!np)
		return -ENODEV;

	phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
	if (!gpio_is_valid(phy->gpio_en))
		return -ENODEV;

	phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
	if (!gpio_is_valid(phy->gpio_fw_wake))
		return -ENODEV;

	return 0;
}

static int s3fwrn5_i2c_probe(struct i2c_client *client,
				  const struct i2c_device_id *id)
{
	struct s3fwrn5_i2c_phy *phy;
	int ret;

	phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
	if (!phy)
		return -ENOMEM;

	mutex_init(&phy->mutex);
	phy->mode = S3FWRN5_MODE_COLD;
	phy->irq_skip = true;

	phy->i2c_dev = client;
	i2c_set_clientdata(client, phy);

	ret = s3fwrn5_i2c_parse_dt(client);
	if (ret < 0)
		return ret;

	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
		GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
	if (ret < 0)
		return ret;

	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
		GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
	if (ret < 0)
		return ret;

	ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
		S3FWRN5_I2C_MAX_PAYLOAD);
	if (ret < 0)
		return ret;

	ret = request_threaded_irq(phy->i2c_dev->irq, NULL,
		s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
		S3FWRN5_I2C_DRIVER_NAME, phy);
	if (ret)
		s3fwrn5_remove(phy->ndev);

	return ret;
}

static int s3fwrn5_i2c_remove(struct i2c_client *client)
{
	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);

	s3fwrn5_remove(phy->ndev);

	return 0;
}

static struct i2c_device_id s3fwrn5_i2c_id_table[] = {
	{S3FWRN5_I2C_DRIVER_NAME, 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);

static const struct of_device_id of_s3fwrn5_i2c_match[] = {
	{ .compatible = "samsung,s3fwrn5-i2c", },
	{}
};
MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);

static struct i2c_driver s3fwrn5_i2c_driver = {
	.driver = {
		.owner = THIS_MODULE,
		.name = S3FWRN5_I2C_DRIVER_NAME,
		.of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
	},
	.probe = s3fwrn5_i2c_probe,
	.remove = s3fwrn5_i2c_remove,
	.id_table = s3fwrn5_i2c_id_table,
};

module_i2c_driver(s3fwrn5_i2c_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>");