1/**
2 * Marvell NFC-over-UART driver
3 *
4 * Copyright (C) 2015, Marvell International Ltd.
5 *
6 * This software file (the "File") is distributed by Marvell International
7 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
8 * (the "License").  You may use, redistribute and/or modify this File in
9 * accordance with the terms and conditions of the License, a copy of which
10 * is available on the worldwide web at
11 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
12 *
13 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
14 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
15 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
16 * this warranty disclaimer.
17 */
18
19#include <linux/module.h>
20#include <linux/delay.h>
21#include <linux/of_gpio.h>
22#include <net/nfc/nci.h>
23#include <net/nfc/nci_core.h>
24#include "nfcmrvl.h"
25
26static unsigned int hci_muxed;
27static unsigned int flow_control;
28static unsigned int break_control;
29static unsigned int reset_n_io;
30
31/*
32** NFCMRVL NCI OPS
33*/
34
35static int nfcmrvl_uart_nci_open(struct nfcmrvl_private *priv)
36{
37	return 0;
38}
39
40static int nfcmrvl_uart_nci_close(struct nfcmrvl_private *priv)
41{
42	return 0;
43}
44
45static int nfcmrvl_uart_nci_send(struct nfcmrvl_private *priv,
46				 struct sk_buff *skb)
47{
48	struct nci_uart *nu = priv->drv_data;
49
50	return nu->ops.send(nu, skb);
51}
52
53static void nfcmrvl_uart_nci_update_config(struct nfcmrvl_private *priv,
54					   const void *param)
55{
56	struct nci_uart *nu = priv->drv_data;
57	const struct nfcmrvl_fw_uart_config *config = param;
58
59	nci_uart_set_config(nu, le32_to_cpu(config->baudrate),
60			    config->flow_control);
61}
62
63static struct nfcmrvl_if_ops uart_ops = {
64	.nci_open = nfcmrvl_uart_nci_open,
65	.nci_close = nfcmrvl_uart_nci_close,
66	.nci_send = nfcmrvl_uart_nci_send,
67	.nci_update_config = nfcmrvl_uart_nci_update_config
68};
69
70static int nfcmrvl_uart_parse_dt(struct device_node *node,
71				 struct nfcmrvl_platform_data *pdata)
72{
73	struct device_node *matched_node;
74	int ret;
75
76	matched_node = of_find_compatible_node(node, NULL, "marvell,nfc-uart");
77	if (!matched_node) {
78		matched_node = of_find_compatible_node(node, NULL,
79						       "mrvl,nfc-uart");
80		if (!matched_node)
81			return -ENODEV;
82	}
83
84	ret = nfcmrvl_parse_dt(matched_node, pdata);
85	if (ret < 0) {
86		pr_err("Failed to get generic entries\n");
87		return ret;
88	}
89
90	if (of_find_property(matched_node, "flow-control", NULL))
91		pdata->flow_control = 1;
92	else
93		pdata->flow_control = 0;
94
95	if (of_find_property(matched_node, "break-control", NULL))
96		pdata->break_control = 1;
97	else
98		pdata->break_control = 0;
99
100	return 0;
101}
102
103/*
104** NCI UART OPS
105*/
106
107static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
108{
109	struct nfcmrvl_private *priv;
110	struct nfcmrvl_platform_data *pdata = NULL;
111	struct nfcmrvl_platform_data config;
112
113	/*
114	 * Platform data cannot be used here since usually it is already used
115	 * by low level serial driver. We can try to retrieve serial device
116	 * and check if DT entries were added.
117	 */
118
119	if (nu->tty->dev->parent && nu->tty->dev->parent->of_node)
120		if (nfcmrvl_uart_parse_dt(nu->tty->dev->parent->of_node,
121					  &config) == 0)
122			pdata = &config;
123
124	if (!pdata) {
125		pr_info("No platform data / DT -> fallback to module params\n");
126		config.hci_muxed = hci_muxed;
127		config.reset_n_io = reset_n_io;
128		config.flow_control = flow_control;
129		config.break_control = break_control;
130		pdata = &config;
131	}
132
133	priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops,
134					nu->tty->dev, pdata);
135	if (IS_ERR(priv))
136		return PTR_ERR(priv);
137
138	priv->support_fw_dnld = true;
139
140	nu->drv_data = priv;
141	nu->ndev = priv->ndev;
142
143	return 0;
144}
145
146static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
147{
148	nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
149}
150
151static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
152{
153	return nfcmrvl_nci_recv_frame((struct nfcmrvl_private *)nu->drv_data,
154				      skb);
155}
156
157static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
158{
159	struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
160
161	if (priv->ndev->nfc_dev->fw_download_in_progress)
162		return;
163
164	/* Remove BREAK to wake up the NFCC */
165	if (priv->config.break_control && nu->tty->ops->break_ctl) {
166		nu->tty->ops->break_ctl(nu->tty, 0);
167		usleep_range(3000, 5000);
168	}
169}
170
171static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
172{
173	struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
174
175	if (priv->ndev->nfc_dev->fw_download_in_progress)
176		return;
177
178	/*
179	** To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
180	** up. we set BREAK. Once we will be ready to send again we will remove
181	** it.
182	*/
183	if (priv->config.break_control && nu->tty->ops->break_ctl) {
184		nu->tty->ops->break_ctl(nu->tty, -1);
185		usleep_range(1000, 3000);
186	}
187}
188
189static struct nci_uart nfcmrvl_nci_uart = {
190	.owner  = THIS_MODULE,
191	.name   = "nfcmrvl_uart",
192	.driver = NCI_UART_DRIVER_MARVELL,
193	.ops	= {
194		.open		= nfcmrvl_nci_uart_open,
195		.close		= nfcmrvl_nci_uart_close,
196		.recv		= nfcmrvl_nci_uart_recv,
197		.tx_start	= nfcmrvl_nci_uart_tx_start,
198		.tx_done	= nfcmrvl_nci_uart_tx_done,
199	}
200};
201
202/*
203** Module init
204*/
205
206static int nfcmrvl_uart_init_module(void)
207{
208	return nci_uart_register(&nfcmrvl_nci_uart);
209}
210
211static void nfcmrvl_uart_exit_module(void)
212{
213	nci_uart_unregister(&nfcmrvl_nci_uart);
214}
215
216module_init(nfcmrvl_uart_init_module);
217module_exit(nfcmrvl_uart_exit_module);
218
219MODULE_AUTHOR("Marvell International Ltd.");
220MODULE_DESCRIPTION("Marvell NFC-over-UART");
221MODULE_LICENSE("GPL v2");
222
223module_param(flow_control, uint, 0);
224MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
225
226module_param(break_control, uint, 0);
227MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
228
229module_param(hci_muxed, uint, 0);
230MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
231
232module_param(reset_n_io, uint, 0);
233MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");
234