summaryrefslogtreecommitdiffstats
path: root/drivers/nfc/nfcmrvl/spi.c
blob: 1f4120e3314b2af911bda7f779725d14497eaf90 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/**
 * Marvell NFC-over-SPI driver: SPI interface related functions
 *
 * Copyright (C) 2015, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available on the worldwide web at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 **/

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/pm_runtime.h>
#include <linux/nfc.h>
#include <linux/gpio.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/spi/spi.h>
#include "nfcmrvl.h"

#define SPI_WAIT_HANDSHAKE	1

struct nfcmrvl_spi_drv_data {
	unsigned long flags;
	struct spi_device *spi;
	struct nci_spi *nci_spi;
	struct completion handshake_completion;
	struct nfcmrvl_private *priv;
};

static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr)
{
	struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr;
	struct sk_buff *skb;

	/*
	 * Special case where we are waiting for SPI_INT deassertion to start a
	 * transfer.
	 */
	if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) {
		complete(&drv_data->handshake_completion);
		return IRQ_HANDLED;
	}

	/* Normal case, SPI_INT deasserted by slave to trigger a master read */

	skb = nci_spi_read(drv_data->nci_spi);
	if (!skb) {
		nfc_err(&drv_data->spi->dev, "failed to read spi packet");
		return IRQ_HANDLED;
	}

	if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
		nfc_err(&drv_data->spi->dev, "corrupted RX packet");

	return IRQ_HANDLED;
}

static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
{
	return 0;
}

static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
{
	return 0;
}

static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv,
				struct sk_buff *skb)
{
	struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
	int err;

	/* Reinit completion for slave handshake */
	reinit_completion(&drv_data->handshake_completion);
	set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags);

	/*
	 * Append a dummy byte at the end of SPI frame. This is due to a
	 * specific DMA implementation in the controller
	 */
	skb_put(skb, 1);

	/* Send the SPI packet */
	err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion,
			   skb);
	if (err)
		nfc_err(priv->dev, "spi_send failed %d", err);

	return err;
}

static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv,
					  const void *param)
{
	struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
	const struct nfcmrvl_fw_spi_config *config = param;

	drv_data->nci_spi->xfer_speed_hz = config->clk;
}

static struct nfcmrvl_if_ops spi_ops = {
	.nci_open = nfcmrvl_spi_nci_open,
	.nci_close = nfcmrvl_spi_nci_close,
	.nci_send = nfcmrvl_spi_nci_send,
	.nci_update_config = nfcmrvl_spi_nci_update_config,
};

static int nfcmrvl_spi_parse_dt(struct device_node *node,
				struct nfcmrvl_platform_data *pdata)
{
	int ret;

	ret = nfcmrvl_parse_dt(node, pdata);
	if (ret < 0) {
		pr_err("Failed to get generic entries\n");
		return ret;
	}

	ret = irq_of_parse_and_map(node, 0);
	if (!ret) {
		pr_err("Unable to get irq\n");
		return -EINVAL;
	}
	pdata->irq = ret;

	return 0;
}

static int nfcmrvl_spi_probe(struct spi_device *spi)
{
	struct nfcmrvl_platform_data *pdata;
	struct nfcmrvl_platform_data config;
	struct nfcmrvl_spi_drv_data *drv_data;
	int ret = 0;

	drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL);
	if (!drv_data)
		return -ENOMEM;

	drv_data->spi = spi;
	drv_data->priv = NULL;
	spi_set_drvdata(spi, drv_data);

	pdata = spi->dev.platform_data;

	if (!pdata && spi->dev.of_node)
		if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0)
			pdata = &config;

	if (!pdata)
		return -EINVAL;

	ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq,
					NULL, nfcmrvl_spi_int_irq_thread_fn,
					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
					"nfcmrvl_spi_int", drv_data);
	if (ret < 0) {
		nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler");
		return -ENODEV;
	}

	drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI,
						  drv_data, &spi_ops,
						  &drv_data->spi->dev,
						  pdata);
	if (IS_ERR(drv_data->priv))
		return PTR_ERR(drv_data->priv);

	drv_data->priv->support_fw_dnld = true;

	drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10,
						 drv_data->priv->ndev);

	/* Init completion for slave handshake */
	init_completion(&drv_data->handshake_completion);
	return 0;
}

static int nfcmrvl_spi_remove(struct spi_device *spi)
{
	struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi);

	nfcmrvl_nci_unregister_dev(drv_data->priv);
	return 0;
}

static const struct of_device_id of_nfcmrvl_spi_match[] = {
	{ .compatible = "marvell,nfc-spi", },
	{},
};
MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);

static const struct spi_device_id nfcmrvl_spi_id_table[] = {
	{ "nfcmrvl_spi", 0 },
	{ }
};
MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);

static struct spi_driver nfcmrvl_spi_driver = {
	.probe		= nfcmrvl_spi_probe,
	.remove		= nfcmrvl_spi_remove,
	.id_table	= nfcmrvl_spi_id_table,
	.driver		= {
		.name		= "nfcmrvl_spi",
		.owner		= THIS_MODULE,
		.of_match_table	= of_match_ptr(of_nfcmrvl_spi_match),
	},
};

module_spi_driver(nfcmrvl_spi_driver);

MODULE_AUTHOR("Marvell International Ltd.");
MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
MODULE_LICENSE("GPL v2");