1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * UART Link Layer for S3FWRN82 NCI based Driver
4 *
5 * Copyright (C) 2015 Samsung Electronics
6 * Robert Baldyga <r.baldyga@samsung.com>
7 * Copyright (C) 2020 Samsung Electronics
8 * Bongsu Jeon <bongsu.jeon@samsung.com>
9 */
10
11 #include <linux/device.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/nfc.h>
15 #include <linux/netdevice.h>
16 #include <linux/of.h>
17 #include <linux/serdev.h>
18 #include <linux/gpio.h>
19 #include <linux/of_gpio.h>
20
21 #include "phy_common.h"
22
23 #define S3FWRN82_NCI_HEADER 3
24 #define S3FWRN82_NCI_IDX 2
25 #define NCI_SKB_BUFF_LEN 258
26
27 struct s3fwrn82_uart_phy {
28 struct phy_common common;
29 struct serdev_device *ser_dev;
30 struct sk_buff *recv_skb;
31 };
32
s3fwrn82_uart_write(void * phy_id,struct sk_buff * out)33 static int s3fwrn82_uart_write(void *phy_id, struct sk_buff *out)
34 {
35 struct s3fwrn82_uart_phy *phy = phy_id;
36 int err;
37
38 err = serdev_device_write(phy->ser_dev,
39 out->data, out->len,
40 MAX_SCHEDULE_TIMEOUT);
41 if (err < 0)
42 return err;
43
44 return 0;
45 }
46
47 static const struct s3fwrn5_phy_ops uart_phy_ops = {
48 .set_wake = s3fwrn5_phy_set_wake,
49 .set_mode = s3fwrn5_phy_set_mode,
50 .get_mode = s3fwrn5_phy_get_mode,
51 .write = s3fwrn82_uart_write,
52 };
53
s3fwrn82_uart_read(struct serdev_device * serdev,const u8 * data,size_t count)54 static size_t s3fwrn82_uart_read(struct serdev_device *serdev,
55 const u8 *data, size_t count)
56 {
57 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
58 size_t i;
59
60 for (i = 0; i < count; i++) {
61 skb_put_u8(phy->recv_skb, *data++);
62
63 if (phy->recv_skb->len < S3FWRN82_NCI_HEADER)
64 continue;
65
66 if ((phy->recv_skb->len - S3FWRN82_NCI_HEADER)
67 < phy->recv_skb->data[S3FWRN82_NCI_IDX])
68 continue;
69
70 s3fwrn5_recv_frame(phy->common.ndev, phy->recv_skb,
71 phy->common.mode);
72 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);
73 if (!phy->recv_skb)
74 return 0;
75 }
76
77 return i;
78 }
79
80 static const struct serdev_device_ops s3fwrn82_serdev_ops = {
81 .receive_buf = s3fwrn82_uart_read,
82 .write_wakeup = serdev_device_write_wakeup,
83 };
84
85 static const struct of_device_id s3fwrn82_uart_of_match[] = {
86 { .compatible = "samsung,s3fwrn82", },
87 {},
88 };
89 MODULE_DEVICE_TABLE(of, s3fwrn82_uart_of_match);
90
s3fwrn82_uart_parse_dt(struct serdev_device * serdev)91 static int s3fwrn82_uart_parse_dt(struct serdev_device *serdev)
92 {
93 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
94 struct device_node *np = serdev->dev.of_node;
95
96 if (!np)
97 return -ENODEV;
98
99 phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0);
100 if (!gpio_is_valid(phy->common.gpio_en))
101 return -ENODEV;
102
103 phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
104 if (!gpio_is_valid(phy->common.gpio_fw_wake))
105 return -ENODEV;
106
107 return 0;
108 }
109
s3fwrn82_uart_probe(struct serdev_device * serdev)110 static int s3fwrn82_uart_probe(struct serdev_device *serdev)
111 {
112 struct s3fwrn82_uart_phy *phy;
113 int ret = -ENOMEM;
114
115 phy = devm_kzalloc(&serdev->dev, sizeof(*phy), GFP_KERNEL);
116 if (!phy)
117 goto err_exit;
118
119 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);
120 if (!phy->recv_skb)
121 goto err_exit;
122
123 mutex_init(&phy->common.mutex);
124 phy->common.mode = S3FWRN5_MODE_COLD;
125
126 phy->ser_dev = serdev;
127 serdev_device_set_drvdata(serdev, phy);
128 serdev_device_set_client_ops(serdev, &s3fwrn82_serdev_ops);
129 ret = serdev_device_open(serdev);
130 if (ret) {
131 dev_err(&serdev->dev, "Unable to open device\n");
132 goto err_skb;
133 }
134
135 ret = serdev_device_set_baudrate(serdev, 115200);
136 if (ret != 115200) {
137 ret = -EINVAL;
138 goto err_serdev;
139 }
140
141 serdev_device_set_flow_control(serdev, false);
142
143 ret = s3fwrn82_uart_parse_dt(serdev);
144 if (ret < 0)
145 goto err_serdev;
146
147 ret = devm_gpio_request_one(&phy->ser_dev->dev, phy->common.gpio_en,
148 GPIOF_OUT_INIT_HIGH, "s3fwrn82_en");
149 if (ret < 0)
150 goto err_serdev;
151
152 ret = devm_gpio_request_one(&phy->ser_dev->dev,
153 phy->common.gpio_fw_wake,
154 GPIOF_OUT_INIT_LOW, "s3fwrn82_fw_wake");
155 if (ret < 0)
156 goto err_serdev;
157
158 ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->ser_dev->dev,
159 &uart_phy_ops);
160 if (ret < 0)
161 goto err_serdev;
162
163 return ret;
164
165 err_serdev:
166 serdev_device_close(serdev);
167 err_skb:
168 kfree_skb(phy->recv_skb);
169 err_exit:
170 return ret;
171 }
172
s3fwrn82_uart_remove(struct serdev_device * serdev)173 static void s3fwrn82_uart_remove(struct serdev_device *serdev)
174 {
175 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
176
177 s3fwrn5_remove(phy->common.ndev);
178 serdev_device_close(serdev);
179 kfree_skb(phy->recv_skb);
180 }
181
182 static struct serdev_device_driver s3fwrn82_uart_driver = {
183 .probe = s3fwrn82_uart_probe,
184 .remove = s3fwrn82_uart_remove,
185 .driver = {
186 .name = "s3fwrn82_uart",
187 .of_match_table = s3fwrn82_uart_of_match,
188 },
189 };
190
191 module_serdev_device_driver(s3fwrn82_uart_driver);
192
193 MODULE_LICENSE("GPL");
194 MODULE_DESCRIPTION("UART driver for Samsung NFC");
195 MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");
196