1/**
2 * Marvell NFC-over-I2C driver: I2C interface related functions
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/interrupt.h>
21#include <linux/i2c.h>
22#include <linux/pm_runtime.h>
23#include <linux/nfc.h>
24#include <linux/gpio.h>
25#include <linux/delay.h>
26#include <linux/of_irq.h>
27#include <linux/of_gpio.h>
28#include <net/nfc/nci.h>
29#include <net/nfc/nci_core.h>
30#include "nfcmrvl.h"
31
32struct nfcmrvl_i2c_drv_data {
33	unsigned long flags;
34	struct device *dev;
35	struct i2c_client *i2c;
36	struct nfcmrvl_private *priv;
37};
38
39static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
40			    struct sk_buff **skb)
41{
42	int ret;
43	struct nci_ctrl_hdr nci_hdr;
44
45	/* Read NCI header to know the payload size */
46	ret = i2c_master_recv(drv_data->i2c, (u8 *)&nci_hdr, NCI_CTRL_HDR_SIZE);
47	if (ret != NCI_CTRL_HDR_SIZE) {
48		nfc_err(&drv_data->i2c->dev, "cannot read NCI header\n");
49		return -EBADMSG;
50	}
51
52	if (nci_hdr.plen > NCI_MAX_PAYLOAD_SIZE) {
53		nfc_err(&drv_data->i2c->dev, "invalid packet payload size\n");
54		return -EBADMSG;
55	}
56
57	*skb = nci_skb_alloc(drv_data->priv->ndev,
58			     nci_hdr.plen + NCI_CTRL_HDR_SIZE, GFP_KERNEL);
59	if (!*skb)
60		return -ENOMEM;
61
62	/* Copy NCI header into the SKB */
63	skb_put_data(*skb, &nci_hdr, NCI_CTRL_HDR_SIZE);
64
65	if (nci_hdr.plen) {
66		/* Read the NCI payload */
67		ret = i2c_master_recv(drv_data->i2c,
68				      skb_put(*skb, nci_hdr.plen),
69				      nci_hdr.plen);
70
71		if (ret != nci_hdr.plen) {
72			nfc_err(&drv_data->i2c->dev,
73				"Invalid frame payload length: %u (expected %u)\n",
74				ret, nci_hdr.plen);
75			kfree_skb(*skb);
76			return -EBADMSG;
77		}
78	}
79
80	return 0;
81}
82
83static irqreturn_t nfcmrvl_i2c_int_irq_thread_fn(int irq, void *drv_data_ptr)
84{
85	struct nfcmrvl_i2c_drv_data *drv_data = drv_data_ptr;
86	struct sk_buff *skb = NULL;
87	int ret;
88
89	if (!drv_data->priv)
90		return IRQ_HANDLED;
91
92	if (test_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags))
93		return IRQ_HANDLED;
94
95	ret = nfcmrvl_i2c_read(drv_data, &skb);
96
97	switch (ret) {
98	case -EREMOTEIO:
99		set_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags);
100		break;
101	case -ENOMEM:
102	case -EBADMSG:
103		nfc_err(&drv_data->i2c->dev, "read failed %d\n", ret);
104		break;
105	default:
106		if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
107			nfc_err(&drv_data->i2c->dev, "corrupted RX packet\n");
108		break;
109	}
110	return IRQ_HANDLED;
111}
112
113static int nfcmrvl_i2c_nci_open(struct nfcmrvl_private *priv)
114{
115	struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
116
117	if (!drv_data)
118		return -ENODEV;
119
120	return 0;
121}
122
123static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
124{
125	return 0;
126}
127
128static int nfcmrvl_i2c_nci_send(struct nfcmrvl_private *priv,
129				struct sk_buff *skb)
130{
131	struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
132	int ret;
133
134	if (test_bit(NFCMRVL_PHY_ERROR, &priv->flags))
135		return -EREMOTEIO;
136
137	ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
138
139	/* Retry if chip was in standby */
140	if (ret == -EREMOTEIO) {
141		nfc_info(drv_data->dev, "chip may sleep, retry\n");
142		usleep_range(6000, 10000);
143		ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
144	}
145
146	if (ret >= 0) {
147		if (ret != skb->len) {
148			nfc_err(drv_data->dev,
149				"Invalid length sent: %u (expected %u)\n",
150				ret, skb->len);
151			ret = -EREMOTEIO;
152		} else
153			ret = 0;
154	}
155
156	if (ret) {
157		kfree_skb(skb);
158		return ret;
159	}
160
161	consume_skb(skb);
162	return 0;
163}
164
165static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
166					  const void *param)
167{
168}
169
170static struct nfcmrvl_if_ops i2c_ops = {
171	.nci_open = nfcmrvl_i2c_nci_open,
172	.nci_close = nfcmrvl_i2c_nci_close,
173	.nci_send = nfcmrvl_i2c_nci_send,
174	.nci_update_config = nfcmrvl_i2c_nci_update_config,
175};
176
177static int nfcmrvl_i2c_parse_dt(struct device_node *node,
178				struct nfcmrvl_platform_data *pdata)
179{
180	int ret;
181
182	ret = nfcmrvl_parse_dt(node, pdata);
183	if (ret < 0) {
184		pr_err("Failed to get generic entries\n");
185		return ret;
186	}
187
188	if (of_find_property(node, "i2c-int-falling", NULL))
189		pdata->irq_polarity = IRQF_TRIGGER_FALLING;
190	else
191		pdata->irq_polarity = IRQF_TRIGGER_RISING;
192
193	ret = irq_of_parse_and_map(node, 0);
194	if (!ret) {
195		pr_err("Unable to get irq\n");
196		return -EINVAL;
197	}
198	pdata->irq = ret;
199
200	return 0;
201}
202
203static int nfcmrvl_i2c_probe(struct i2c_client *client,
204			     const struct i2c_device_id *id)
205{
206	struct nfcmrvl_i2c_drv_data *drv_data;
207	struct nfcmrvl_platform_data *pdata;
208	struct nfcmrvl_platform_data config;
209	int ret;
210
211	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
212		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
213		return -ENODEV;
214	}
215
216	drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
217	if (!drv_data)
218		return -ENOMEM;
219
220	drv_data->i2c = client;
221	drv_data->dev = &client->dev;
222	drv_data->priv = NULL;
223
224	i2c_set_clientdata(client, drv_data);
225
226	pdata = client->dev.platform_data;
227
228	if (!pdata && client->dev.of_node)
229		if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
230			pdata = &config;
231
232	if (!pdata)
233		return -EINVAL;
234
235	/* Request the read IRQ */
236	ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
237					NULL, nfcmrvl_i2c_int_irq_thread_fn,
238					pdata->irq_polarity | IRQF_ONESHOT,
239					"nfcmrvl_i2c_int", drv_data);
240	if (ret < 0) {
241		nfc_err(&drv_data->i2c->dev,
242			"Unable to register IRQ handler\n");
243		return ret;
244	}
245
246	drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
247						  drv_data, &i2c_ops,
248						  &drv_data->i2c->dev, pdata);
249
250	if (IS_ERR(drv_data->priv))
251		return PTR_ERR(drv_data->priv);
252
253	drv_data->priv->support_fw_dnld = true;
254
255	return 0;
256}
257
258static int nfcmrvl_i2c_remove(struct i2c_client *client)
259{
260	struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
261
262	nfcmrvl_nci_unregister_dev(drv_data->priv);
263
264	return 0;
265}
266
267
268static const struct of_device_id of_nfcmrvl_i2c_match[] = {
269	{ .compatible = "marvell,nfc-i2c", },
270	{},
271};
272MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
273
274static const struct i2c_device_id nfcmrvl_i2c_id_table[] = {
275	{ "nfcmrvl_i2c", 0 },
276	{}
277};
278MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
279
280static struct i2c_driver nfcmrvl_i2c_driver = {
281	.probe = nfcmrvl_i2c_probe,
282	.id_table = nfcmrvl_i2c_id_table,
283	.remove = nfcmrvl_i2c_remove,
284	.driver = {
285		.name		= "nfcmrvl_i2c",
286		.of_match_table	= of_match_ptr(of_nfcmrvl_i2c_match),
287	},
288};
289
290module_i2c_driver(nfcmrvl_i2c_driver);
291
292MODULE_AUTHOR("Marvell International Ltd.");
293MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
294MODULE_LICENSE("GPL v2");
295