1/**
2 * Marvell NFC-over-SPI driver: SPI 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/pm_runtime.h>
22#include <linux/nfc.h>
23#include <linux/gpio.h>
24#include <linux/of_irq.h>
25#include <linux/of_gpio.h>
26#include <net/nfc/nci.h>
27#include <net/nfc/nci_core.h>
28#include <linux/spi/spi.h>
29#include <linux/gpio.h>
30#include "nfcmrvl.h"
31
32#define SPI_WAIT_HANDSHAKE	1
33
34struct nfcmrvl_spi_drv_data {
35	unsigned long flags;
36	struct spi_device *spi;
37	struct nci_spi *nci_spi;
38	struct completion handshake_completion;
39	struct nfcmrvl_private *priv;
40};
41
42static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr)
43{
44	struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr;
45	struct sk_buff *skb;
46
47	/*
48	 * Special case where we are waiting for SPI_INT deassertion to start a
49	 * transfer.
50	 */
51	if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) {
52		complete(&drv_data->handshake_completion);
53		return IRQ_HANDLED;
54	}
55
56	/* Normal case, SPI_INT deasserted by slave to trigger a master read */
57
58	skb = nci_spi_read(drv_data->nci_spi);
59	if (!skb) {
60		nfc_err(&drv_data->spi->dev, "failed to read spi packet");
61		return IRQ_HANDLED;
62	}
63
64	if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
65		nfc_err(&drv_data->spi->dev, "corrupted RX packet");
66
67	return IRQ_HANDLED;
68}
69
70static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
71{
72	return 0;
73}
74
75static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
76{
77	return 0;
78}
79
80static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv,
81				struct sk_buff *skb)
82{
83	struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
84	int err;
85
86	/* Reinit completion for slave handshake */
87	reinit_completion(&drv_data->handshake_completion);
88	set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags);
89
90	/*
91	 * Append a dummy byte at the end of SPI frame. This is due to a
92	 * specific DMA implementation in the controller
93	 */
94	skb_put(skb, 1);
95
96	/* Send the SPI packet */
97	err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion,
98			   skb);
99	if (err != 0) {
100		nfc_err(priv->dev, "spi_send failed %d", err);
101		kfree_skb(skb);
102	}
103	return err;
104}
105
106static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv,
107					  const void *param)
108{
109	struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
110	const struct nfcmrvl_fw_spi_config *config = param;
111
112	drv_data->nci_spi->xfer_speed_hz = config->clk;
113}
114
115static struct nfcmrvl_if_ops spi_ops = {
116	.nci_open = nfcmrvl_spi_nci_open,
117	.nci_close = nfcmrvl_spi_nci_close,
118	.nci_send = nfcmrvl_spi_nci_send,
119	.nci_update_config = nfcmrvl_spi_nci_update_config,
120};
121
122static int nfcmrvl_spi_parse_dt(struct device_node *node,
123				struct nfcmrvl_platform_data *pdata)
124{
125	int ret;
126
127	ret = nfcmrvl_parse_dt(node, pdata);
128	if (ret < 0) {
129		pr_err("Failed to get generic entries\n");
130		return ret;
131	}
132
133	ret = irq_of_parse_and_map(node, 0);
134	if (ret < 0) {
135		pr_err("Unable to get irq, error: %d\n", ret);
136		return ret;
137	}
138	pdata->irq = ret;
139
140	return 0;
141}
142
143static int nfcmrvl_spi_probe(struct spi_device *spi)
144{
145	struct nfcmrvl_platform_data *pdata;
146	struct nfcmrvl_platform_data config;
147	struct nfcmrvl_spi_drv_data *drv_data;
148	int ret = 0;
149
150	drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL);
151	if (!drv_data)
152		return -ENOMEM;
153
154	drv_data->spi = spi;
155	drv_data->priv = NULL;
156	spi_set_drvdata(spi, drv_data);
157
158	pdata = spi->dev.platform_data;
159
160	if (!pdata && spi->dev.of_node)
161		if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0)
162			pdata = &config;
163
164	if (!pdata)
165		return -EINVAL;
166
167	ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq,
168					NULL, nfcmrvl_spi_int_irq_thread_fn,
169					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
170					"nfcmrvl_spi_int", drv_data);
171	if (ret < 0) {
172		nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler");
173		return -ENODEV;
174	}
175
176	drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI,
177						  drv_data, &spi_ops,
178						  &drv_data->spi->dev,
179						  pdata);
180	if (IS_ERR(drv_data->priv))
181		return PTR_ERR(drv_data->priv);
182
183	drv_data->priv->support_fw_dnld = true;
184
185	drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10,
186						 drv_data->priv->ndev);
187
188	/* Init completion for slave handshake */
189	init_completion(&drv_data->handshake_completion);
190	return 0;
191}
192
193static int nfcmrvl_spi_remove(struct spi_device *spi)
194{
195	struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi);
196
197	nfcmrvl_nci_unregister_dev(drv_data->priv);
198	return 0;
199}
200
201static const struct of_device_id of_nfcmrvl_spi_match[] = {
202	{ .compatible = "marvell,nfc-spi", },
203	{},
204};
205MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);
206
207static const struct spi_device_id nfcmrvl_spi_id_table[] = {
208	{ "nfcmrvl_spi", 0 },
209	{ }
210};
211MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);
212
213static struct spi_driver nfcmrvl_spi_driver = {
214	.probe		= nfcmrvl_spi_probe,
215	.remove		= nfcmrvl_spi_remove,
216	.id_table	= nfcmrvl_spi_id_table,
217	.driver		= {
218		.name		= "nfcmrvl_spi",
219		.owner		= THIS_MODULE,
220		.of_match_table	= of_match_ptr(of_nfcmrvl_spi_match),
221	},
222};
223
224module_spi_driver(nfcmrvl_spi_driver);
225
226MODULE_AUTHOR("Marvell International Ltd.");
227MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
228MODULE_LICENSE("GPL v2");
229