1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Marvell NFC-over-I2C driver: I2C interface related functions
4 *
5 * Copyright (C) 2015, Marvell International Ltd.
6 */
7
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <linux/i2c.h>
11 #include <linux/nfc.h>
12 #include <linux/delay.h>
13 #include <linux/of_irq.h>
14 #include <net/nfc/nci.h>
15 #include <net/nfc/nci_core.h>
16 #include "nfcmrvl.h"
17
18 struct nfcmrvl_i2c_drv_data {
19 unsigned long flags;
20 struct device *dev;
21 struct i2c_client *i2c;
22 struct nfcmrvl_private *priv;
23 };
24
nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data * drv_data,struct sk_buff ** skb)25 static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
26 struct sk_buff **skb)
27 {
28 int ret;
29 struct nci_ctrl_hdr nci_hdr;
30
31 /* Read NCI header to know the payload size */
32 ret = i2c_master_recv(drv_data->i2c, (u8 *)&nci_hdr, NCI_CTRL_HDR_SIZE);
33 if (ret != NCI_CTRL_HDR_SIZE) {
34 nfc_err(&drv_data->i2c->dev, "cannot read NCI header\n");
35 return -EBADMSG;
36 }
37
38 *skb = nci_skb_alloc(drv_data->priv->ndev,
39 nci_hdr.plen + NCI_CTRL_HDR_SIZE, GFP_KERNEL);
40 if (!*skb)
41 return -ENOMEM;
42
43 /* Copy NCI header into the SKB */
44 skb_put_data(*skb, &nci_hdr, NCI_CTRL_HDR_SIZE);
45
46 if (nci_hdr.plen) {
47 /* Read the NCI payload */
48 ret = i2c_master_recv(drv_data->i2c,
49 skb_put(*skb, nci_hdr.plen),
50 nci_hdr.plen);
51
52 if (ret != nci_hdr.plen) {
53 nfc_err(&drv_data->i2c->dev,
54 "Invalid frame payload length: %u (expected %u)\n",
55 ret, nci_hdr.plen);
56 kfree_skb(*skb);
57 return -EBADMSG;
58 }
59 }
60
61 return 0;
62 }
63
nfcmrvl_i2c_int_irq_thread_fn(int irq,void * drv_data_ptr)64 static irqreturn_t nfcmrvl_i2c_int_irq_thread_fn(int irq, void *drv_data_ptr)
65 {
66 struct nfcmrvl_i2c_drv_data *drv_data = drv_data_ptr;
67 struct sk_buff *skb = NULL;
68 int ret;
69
70 if (!drv_data->priv)
71 return IRQ_HANDLED;
72
73 if (test_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags))
74 return IRQ_HANDLED;
75
76 ret = nfcmrvl_i2c_read(drv_data, &skb);
77
78 switch (ret) {
79 case -EREMOTEIO:
80 set_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags);
81 break;
82 case -ENOMEM:
83 case -EBADMSG:
84 nfc_err(&drv_data->i2c->dev, "read failed %d\n", ret);
85 break;
86 default:
87 if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
88 nfc_err(&drv_data->i2c->dev, "corrupted RX packet\n");
89 break;
90 }
91 return IRQ_HANDLED;
92 }
93
nfcmrvl_i2c_nci_open(struct nfcmrvl_private * priv)94 static int nfcmrvl_i2c_nci_open(struct nfcmrvl_private *priv)
95 {
96 struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
97
98 if (!drv_data)
99 return -ENODEV;
100
101 return 0;
102 }
103
nfcmrvl_i2c_nci_close(struct nfcmrvl_private * priv)104 static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
105 {
106 return 0;
107 }
108
nfcmrvl_i2c_nci_send(struct nfcmrvl_private * priv,struct sk_buff * skb)109 static int nfcmrvl_i2c_nci_send(struct nfcmrvl_private *priv,
110 struct sk_buff *skb)
111 {
112 struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
113 int ret;
114
115 if (test_bit(NFCMRVL_PHY_ERROR, &priv->flags)) {
116 kfree_skb(skb);
117 return -EREMOTEIO;
118 }
119
120 ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
121
122 /* Retry if chip was in standby */
123 if (ret == -EREMOTEIO) {
124 nfc_info(drv_data->dev, "chip may sleep, retry\n");
125 usleep_range(6000, 10000);
126 ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
127 }
128
129 if (ret >= 0) {
130 if (ret != skb->len) {
131 nfc_err(drv_data->dev,
132 "Invalid length sent: %u (expected %u)\n",
133 ret, skb->len);
134 ret = -EREMOTEIO;
135 } else
136 ret = 0;
137 }
138
139 if (ret) {
140 kfree_skb(skb);
141 return ret;
142 }
143
144 consume_skb(skb);
145 return 0;
146 }
147
nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private * priv,const void * param)148 static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
149 const void *param)
150 {
151 }
152
153 static const struct nfcmrvl_if_ops i2c_ops = {
154 .nci_open = nfcmrvl_i2c_nci_open,
155 .nci_close = nfcmrvl_i2c_nci_close,
156 .nci_send = nfcmrvl_i2c_nci_send,
157 .nci_update_config = nfcmrvl_i2c_nci_update_config,
158 };
159
nfcmrvl_i2c_parse_dt(struct device_node * node,struct nfcmrvl_platform_data * pdata)160 static int nfcmrvl_i2c_parse_dt(struct device_node *node,
161 struct nfcmrvl_platform_data *pdata)
162 {
163 int ret;
164
165 ret = nfcmrvl_parse_dt(node, pdata);
166 if (ret < 0) {
167 pr_err("Failed to get generic entries\n");
168 return ret;
169 }
170
171 if (of_property_read_bool(node, "i2c-int-falling"))
172 pdata->irq_polarity = IRQF_TRIGGER_FALLING;
173 else
174 pdata->irq_polarity = IRQF_TRIGGER_RISING;
175
176 ret = irq_of_parse_and_map(node, 0);
177 if (!ret) {
178 pr_err("Unable to get irq\n");
179 return -EINVAL;
180 }
181 pdata->irq = ret;
182
183 return 0;
184 }
185
nfcmrvl_i2c_probe(struct i2c_client * client)186 static int nfcmrvl_i2c_probe(struct i2c_client *client)
187 {
188 const struct nfcmrvl_platform_data *pdata;
189 struct nfcmrvl_i2c_drv_data *drv_data;
190 struct nfcmrvl_platform_data config;
191 int ret;
192
193 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
194 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
195 return -ENODEV;
196 }
197
198 drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
199 if (!drv_data)
200 return -ENOMEM;
201
202 drv_data->i2c = client;
203 drv_data->dev = &client->dev;
204 drv_data->priv = NULL;
205
206 i2c_set_clientdata(client, drv_data);
207
208 pdata = client->dev.platform_data;
209
210 if (!pdata && client->dev.of_node)
211 if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
212 pdata = &config;
213
214 if (!pdata)
215 return -EINVAL;
216
217 /* Request the read IRQ */
218 ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
219 NULL, nfcmrvl_i2c_int_irq_thread_fn,
220 pdata->irq_polarity | IRQF_ONESHOT,
221 "nfcmrvl_i2c_int", drv_data);
222 if (ret < 0) {
223 nfc_err(&drv_data->i2c->dev,
224 "Unable to register IRQ handler\n");
225 return ret;
226 }
227
228 drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
229 drv_data, &i2c_ops,
230 &drv_data->i2c->dev, pdata);
231
232 if (IS_ERR(drv_data->priv))
233 return PTR_ERR(drv_data->priv);
234
235 drv_data->priv->support_fw_dnld = true;
236
237 return 0;
238 }
239
nfcmrvl_i2c_remove(struct i2c_client * client)240 static void nfcmrvl_i2c_remove(struct i2c_client *client)
241 {
242 struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
243
244 nfcmrvl_nci_unregister_dev(drv_data->priv);
245 }
246
247
248 static const struct of_device_id of_nfcmrvl_i2c_match[] __maybe_unused = {
249 { .compatible = "marvell,nfc-i2c", },
250 {},
251 };
252 MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
253
254 static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
255 { "nfcmrvl_i2c", 0 },
256 {}
257 };
258 MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
259
260 static struct i2c_driver nfcmrvl_i2c_driver = {
261 .probe = nfcmrvl_i2c_probe,
262 .id_table = nfcmrvl_i2c_id_table,
263 .remove = nfcmrvl_i2c_remove,
264 .driver = {
265 .name = "nfcmrvl_i2c",
266 .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
267 },
268 };
269
270 module_i2c_driver(nfcmrvl_i2c_driver);
271
272 MODULE_AUTHOR("Marvell International Ltd.");
273 MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
274 MODULE_LICENSE("GPL v2");
275
