1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Marvell NFC-over-UART driver
4 *
5 * Copyright (C) 2015, Marvell International Ltd.
6 */
7
8#include <linux/delay.h>
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/printk.h>
14
15#include <net/nfc/nci.h>
16#include <net/nfc/nci_core.h>
17
18#include "nfcmrvl.h"
19
20static unsigned int hci_muxed;
21static unsigned int flow_control;
22static unsigned int break_control;
23static int reset_n_io = -EINVAL;
24
25/*
26 * NFCMRVL NCI OPS
27 */
28
29static int nfcmrvl_uart_nci_open(struct nfcmrvl_private *priv)
30{
31 return 0;
32}
33
34static int nfcmrvl_uart_nci_close(struct nfcmrvl_private *priv)
35{
36 return 0;
37}
38
39static int nfcmrvl_uart_nci_send(struct nfcmrvl_private *priv,
40 struct sk_buff *skb)
41{
42 struct nci_uart *nu = priv->drv_data;
43
44 return nu->ops.send(nu, skb);
45}
46
47static void nfcmrvl_uart_nci_update_config(struct nfcmrvl_private *priv,
48 const void *param)
49{
50 struct nci_uart *nu = priv->drv_data;
51 const struct nfcmrvl_fw_uart_config *config = param;
52
53 nci_uart_set_config(nu, le32_to_cpu(config->baudrate),
54 flow_ctrl: config->flow_control);
55}
56
57static const struct nfcmrvl_if_ops uart_ops = {
58 .nci_open = nfcmrvl_uart_nci_open,
59 .nci_close = nfcmrvl_uart_nci_close,
60 .nci_send = nfcmrvl_uart_nci_send,
61 .nci_update_config = nfcmrvl_uart_nci_update_config
62};
63
64static int nfcmrvl_uart_parse_dt(struct device_node *node,
65 struct nfcmrvl_platform_data *pdata)
66{
67 struct device_node *matched_node;
68 int ret;
69
70 matched_node = of_get_compatible_child(parent: node, compatible: "marvell,nfc-uart");
71 if (!matched_node) {
72 matched_node = of_get_compatible_child(parent: node, compatible: "mrvl,nfc-uart");
73 if (!matched_node)
74 return -ENODEV;
75 }
76
77 ret = nfcmrvl_parse_dt(node: matched_node, pdata);
78 if (ret < 0) {
79 pr_err("Failed to get generic entries\n");
80 of_node_put(node: matched_node);
81 return ret;
82 }
83
84 pdata->flow_control = of_property_read_bool(np: matched_node, propname: "flow-control");
85 pdata->break_control = of_property_read_bool(np: matched_node, propname: "break-control");
86
87 of_node_put(node: matched_node);
88
89 return 0;
90}
91
92/*
93 * NCI UART OPS
94 */
95
96static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
97{
98 struct nfcmrvl_private *priv;
99 struct nfcmrvl_platform_data config;
100 const struct nfcmrvl_platform_data *pdata = NULL;
101 struct device *dev = nu->tty->dev;
102
103 /*
104 * Platform data cannot be used here since usually it is already used
105 * by low level serial driver. We can try to retrieve serial device
106 * and check if DT entries were added.
107 */
108
109 if (dev && dev->parent && dev->parent->of_node)
110 if (nfcmrvl_uart_parse_dt(node: dev->parent->of_node, pdata: &config) == 0)
111 pdata = &config;
112
113 if (!pdata) {
114 pr_info("No platform data / DT -> fallback to module params\n");
115 config.hci_muxed = hci_muxed;
116 config.reset_n_io = reset_n_io;
117 config.flow_control = flow_control;
118 config.break_control = break_control;
119 pdata = &config;
120 }
121
122 priv = nfcmrvl_nci_register_dev(phy: NFCMRVL_PHY_UART, drv_data: nu, ops: &uart_ops,
123 dev, pdata);
124 if (IS_ERR(ptr: priv))
125 return PTR_ERR(ptr: priv);
126
127 priv->support_fw_dnld = true;
128
129 nu->drv_data = priv;
130 nu->ndev = priv->ndev;
131
132 return 0;
133}
134
135static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
136{
137 nfcmrvl_nci_unregister_dev(priv: (struct nfcmrvl_private *)nu->drv_data);
138}
139
140static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
141{
142 return nfcmrvl_nci_recv_frame(priv: (struct nfcmrvl_private *)nu->drv_data,
143 skb);
144}
145
146static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
147{
148 struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
149
150 if (priv->ndev->nfc_dev->fw_download_in_progress)
151 return;
152
153 /* Remove BREAK to wake up the NFCC */
154 if (priv->config.break_control && nu->tty->ops->break_ctl) {
155 nu->tty->ops->break_ctl(nu->tty, 0);
156 usleep_range(min: 3000, max: 5000);
157 }
158}
159
160static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
161{
162 struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
163
164 if (priv->ndev->nfc_dev->fw_download_in_progress)
165 return;
166
167 /*
168 * To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
169 * up. we set BREAK. Once we will be ready to send again we will remove
170 * it.
171 */
172 if (priv->config.break_control && nu->tty->ops->break_ctl) {
173 nu->tty->ops->break_ctl(nu->tty, -1);
174 usleep_range(min: 1000, max: 3000);
175 }
176}
177
178static struct nci_uart nfcmrvl_nci_uart = {
179 .owner = THIS_MODULE,
180 .name = "nfcmrvl_uart",
181 .driver = NCI_UART_DRIVER_MARVELL,
182 .ops = {
183 .open = nfcmrvl_nci_uart_open,
184 .close = nfcmrvl_nci_uart_close,
185 .recv = nfcmrvl_nci_uart_recv,
186 .tx_start = nfcmrvl_nci_uart_tx_start,
187 .tx_done = nfcmrvl_nci_uart_tx_done,
188 }
189};
190module_driver(nfcmrvl_nci_uart, nci_uart_register, nci_uart_unregister);
191
192MODULE_AUTHOR("Marvell International Ltd.");
193MODULE_DESCRIPTION("Marvell NFC-over-UART");
194MODULE_LICENSE("GPL v2");
195
196module_param(flow_control, uint, 0);
197MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
198
199module_param(break_control, uint, 0);
200MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
201
202module_param(hci_muxed, uint, 0);
203MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
204
205module_param(reset_n_io, int, 0);
206MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");
207

source code of linux/drivers/nfc/nfcmrvl/uart.c