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