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