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 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
nfcmrvl_nci_uart_open(struct nci_uart * nu)91 static 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
nfcmrvl_nci_uart_close(struct nci_uart * nu)130 static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
131 {
132 nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
133 }
134
nfcmrvl_nci_uart_recv(struct nci_uart * nu,struct sk_buff * skb)135 static 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
nfcmrvl_nci_uart_tx_start(struct nci_uart * nu)141 static 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
nfcmrvl_nci_uart_tx_done(struct nci_uart * nu)155 static 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
173 static 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 };
185 module_driver(nfcmrvl_nci_uart, nci_uart_register, nci_uart_unregister);
186
187 MODULE_AUTHOR("Marvell International Ltd.");
188 MODULE_DESCRIPTION("Marvell NFC-over-UART");
189 MODULE_LICENSE("GPL v2");
190
191 module_param(flow_control, uint, 0);
192 MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
193
194 module_param(break_control, uint, 0);
195 MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
196
197 module_param(hci_muxed, uint, 0);
198 MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
199
200 module_param(reset_n_io, int, 0);
201 MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");
202