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 unsigned char * data,size_t count)54 static int s3fwrn82_uart_read(struct serdev_device *serdev,
55 const unsigned char *data,
56 size_t count)
57 {
58 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
59 size_t i;
60
61 for (i = 0; i < count; i++) {
62 skb_put_u8(phy->recv_skb, *data++);
63
64 if (phy->recv_skb->len < S3FWRN82_NCI_HEADER)
65 continue;
66
67 if ((phy->recv_skb->len - S3FWRN82_NCI_HEADER)
68 < phy->recv_skb->data[S3FWRN82_NCI_IDX])
69 continue;
70
71 s3fwrn5_recv_frame(phy->common.ndev, phy->recv_skb,
72 phy->common.mode);
73 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);
74 if (!phy->recv_skb)
75 return 0;
76 }
77
78 return i;
79 }
80
81 static const struct serdev_device_ops s3fwrn82_serdev_ops = {
82 .receive_buf = s3fwrn82_uart_read,
83 .write_wakeup = serdev_device_write_wakeup,
84 };
85
86 static const struct of_device_id s3fwrn82_uart_of_match[] = {
87 { .compatible = "samsung,s3fwrn82", },
88 {},
89 };
90 MODULE_DEVICE_TABLE(of, s3fwrn82_uart_of_match);
91
s3fwrn82_uart_parse_dt(struct serdev_device * serdev)92 static int s3fwrn82_uart_parse_dt(struct serdev_device *serdev)
93 {
94 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
95 struct device_node *np = serdev->dev.of_node;
96
97 if (!np)
98 return -ENODEV;
99
100 phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0);
101 if (!gpio_is_valid(phy->common.gpio_en))
102 return -ENODEV;
103
104 phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
105 if (!gpio_is_valid(phy->common.gpio_fw_wake))
106 return -ENODEV;
107
108 return 0;
109 }
110
s3fwrn82_uart_probe(struct serdev_device * serdev)111 static int s3fwrn82_uart_probe(struct serdev_device *serdev)
112 {
113 struct s3fwrn82_uart_phy *phy;
114 int ret = -ENOMEM;
115
116 phy = devm_kzalloc(&serdev->dev, sizeof(*phy), GFP_KERNEL);
117 if (!phy)
118 goto err_exit;
119
120 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);
121 if (!phy->recv_skb)
122 goto err_exit;
123
124 mutex_init(&phy->common.mutex);
125 phy->common.mode = S3FWRN5_MODE_COLD;
126
127 phy->ser_dev = serdev;
128 serdev_device_set_drvdata(serdev, phy);
129 serdev_device_set_client_ops(serdev, &s3fwrn82_serdev_ops);
130 ret = serdev_device_open(serdev);
131 if (ret) {
132 dev_err(&serdev->dev, "Unable to open device\n");
133 goto err_skb;
134 }
135
136 ret = serdev_device_set_baudrate(serdev, 115200);
137 if (ret != 115200) {
138 ret = -EINVAL;
139 goto err_serdev;
140 }
141
142 serdev_device_set_flow_control(serdev, false);
143
144 ret = s3fwrn82_uart_parse_dt(serdev);
145 if (ret < 0)
146 goto err_serdev;
147
148 ret = devm_gpio_request_one(&phy->ser_dev->dev, phy->common.gpio_en,
149 GPIOF_OUT_INIT_HIGH, "s3fwrn82_en");
150 if (ret < 0)
151 goto err_serdev;
152
153 ret = devm_gpio_request_one(&phy->ser_dev->dev,
154 phy->common.gpio_fw_wake,
155 GPIOF_OUT_INIT_LOW, "s3fwrn82_fw_wake");
156 if (ret < 0)
157 goto err_serdev;
158
159 ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->ser_dev->dev,
160 &uart_phy_ops);
161 if (ret < 0)
162 goto err_serdev;
163
164 return ret;
165
166 err_serdev:
167 serdev_device_close(serdev);
168 err_skb:
169 kfree_skb(phy->recv_skb);
170 err_exit:
171 return ret;
172 }
173
s3fwrn82_uart_remove(struct serdev_device * serdev)174 static void s3fwrn82_uart_remove(struct serdev_device *serdev)
175 {
176 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
177
178 s3fwrn5_remove(phy->common.ndev);
179 serdev_device_close(serdev);
180 kfree_skb(phy->recv_skb);
181 }
182
183 static struct serdev_device_driver s3fwrn82_uart_driver = {
184 .probe = s3fwrn82_uart_probe,
185 .remove = s3fwrn82_uart_remove,
186 .driver = {
187 .name = "s3fwrn82_uart",
188 .of_match_table = s3fwrn82_uart_of_match,
189 },
190 };
191
192 module_serdev_device_driver(s3fwrn82_uart_driver);
193
194 MODULE_LICENSE("GPL");
195 MODULE_DESCRIPTION("UART driver for Samsung NFC");
196 MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");
197