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 < 0) {
133 pr_err("Unable to get irq, error: %d\n", ret);
134 return ret;
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