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 
15 static unsigned int hci_muxed;
16 static unsigned int flow_control;
17 static unsigned int break_control;
18 static int reset_n_io = -EINVAL;
19 
20 /*
21  * NFCMRVL NCI OPS
22  */
23 
nfcmrvl_uart_nci_open(struct nfcmrvl_private * priv)24 static int nfcmrvl_uart_nci_open(struct nfcmrvl_private *priv)
25 {
26 	return 0;
27 }
28 
nfcmrvl_uart_nci_close(struct nfcmrvl_private * priv)29 static int nfcmrvl_uart_nci_close(struct nfcmrvl_private *priv)
30 {
31 	return 0;
32 }
33 
nfcmrvl_uart_nci_send(struct nfcmrvl_private * priv,struct sk_buff * skb)34 static 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 
nfcmrvl_uart_nci_update_config(struct nfcmrvl_private * priv,const void * param)42 static 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 
52 static 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 
nfcmrvl_uart_parse_dt(struct device_node * node,struct nfcmrvl_platform_data * pdata)59 static 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 	if (of_find_property(matched_node, "flow-control", NULL))
80 		pdata->flow_control = 1;
81 	else
82 		pdata->flow_control = 0;
83 
84 	if (of_find_property(matched_node, "break-control", NULL))
85 		pdata->break_control = 1;
86 	else
87 		pdata->break_control = 0;
88 
89 	of_node_put(matched_node);
90 
91 	return 0;
92 }
93 
94 /*
95  * NCI UART OPS
96  */
97 
nfcmrvl_nci_uart_open(struct nci_uart * nu)98 static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
99 {
100 	struct nfcmrvl_private *priv;
101 	struct nfcmrvl_platform_data config;
102 	const struct nfcmrvl_platform_data *pdata = NULL;
103 	struct device *dev = nu->tty->dev;
104 
105 	/*
106 	 * Platform data cannot be used here since usually it is already used
107 	 * by low level serial driver. We can try to retrieve serial device
108 	 * and check if DT entries were added.
109 	 */
110 
111 	if (dev && dev->parent && dev->parent->of_node)
112 		if (nfcmrvl_uart_parse_dt(dev->parent->of_node, &config) == 0)
113 			pdata = &config;
114 
115 	if (!pdata) {
116 		pr_info("No platform data / DT -> fallback to module params\n");
117 		config.hci_muxed = hci_muxed;
118 		config.reset_n_io = reset_n_io;
119 		config.flow_control = flow_control;
120 		config.break_control = break_control;
121 		pdata = &config;
122 	}
123 
124 	priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops,
125 					dev, pdata);
126 	if (IS_ERR(priv))
127 		return PTR_ERR(priv);
128 
129 	priv->support_fw_dnld = true;
130 
131 	nu->drv_data = priv;
132 	nu->ndev = priv->ndev;
133 
134 	return 0;
135 }
136 
nfcmrvl_nci_uart_close(struct nci_uart * nu)137 static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
138 {
139 	nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
140 }
141 
nfcmrvl_nci_uart_recv(struct nci_uart * nu,struct sk_buff * skb)142 static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
143 {
144 	return nfcmrvl_nci_recv_frame((struct nfcmrvl_private *)nu->drv_data,
145 				      skb);
146 }
147 
nfcmrvl_nci_uart_tx_start(struct nci_uart * nu)148 static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
149 {
150 	struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
151 
152 	if (priv->ndev->nfc_dev->fw_download_in_progress)
153 		return;
154 
155 	/* Remove BREAK to wake up the NFCC */
156 	if (priv->config.break_control && nu->tty->ops->break_ctl) {
157 		nu->tty->ops->break_ctl(nu->tty, 0);
158 		usleep_range(3000, 5000);
159 	}
160 }
161 
nfcmrvl_nci_uart_tx_done(struct nci_uart * nu)162 static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
163 {
164 	struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
165 
166 	if (priv->ndev->nfc_dev->fw_download_in_progress)
167 		return;
168 
169 	/*
170 	 * To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
171 	 * up. we set BREAK. Once we will be ready to send again we will remove
172 	 * it.
173 	 */
174 	if (priv->config.break_control && nu->tty->ops->break_ctl) {
175 		nu->tty->ops->break_ctl(nu->tty, -1);
176 		usleep_range(1000, 3000);
177 	}
178 }
179 
180 static struct nci_uart nfcmrvl_nci_uart = {
181 	.owner  = THIS_MODULE,
182 	.name   = "nfcmrvl_uart",
183 	.driver = NCI_UART_DRIVER_MARVELL,
184 	.ops	= {
185 		.open		= nfcmrvl_nci_uart_open,
186 		.close		= nfcmrvl_nci_uart_close,
187 		.recv		= nfcmrvl_nci_uart_recv,
188 		.tx_start	= nfcmrvl_nci_uart_tx_start,
189 		.tx_done	= nfcmrvl_nci_uart_tx_done,
190 	}
191 };
192 module_driver(nfcmrvl_nci_uart, nci_uart_register, nci_uart_unregister);
193 
194 MODULE_AUTHOR("Marvell International Ltd.");
195 MODULE_DESCRIPTION("Marvell NFC-over-UART");
196 MODULE_LICENSE("GPL v2");
197 
198 module_param(flow_control, uint, 0);
199 MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
200 
201 module_param(break_control, uint, 0);
202 MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
203 
204 module_param(hci_muxed, uint, 0);
205 MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
206 
207 module_param(reset_n_io, int, 0);
208 MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");
209