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