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