1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Marvell NFC-over-SPI driver: SPI interface related functions
4 *
5 * Copyright (C) 2015, Marvell International Ltd.
6 */
7
8#include <linux/module.h>
9#include <linux/interrupt.h>
10#include <linux/nfc.h>
11#include <linux/of_irq.h>
12#include <net/nfc/nci.h>
13#include <net/nfc/nci_core.h>
14#include <linux/spi/spi.h>
15#include "nfcmrvl.h"
16
17#define SPI_WAIT_HANDSHAKE 1
18
19struct nfcmrvl_spi_drv_data {
20 unsigned long flags;
21 struct spi_device *spi;
22 struct nci_spi *nci_spi;
23 struct completion handshake_completion;
24 struct nfcmrvl_private *priv;
25};
26
27static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr)
28{
29 struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr;
30 struct sk_buff *skb;
31
32 /*
33 * Special case where we are waiting for SPI_INT deassertion to start a
34 * transfer.
35 */
36 if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, addr: &drv_data->flags)) {
37 complete(&drv_data->handshake_completion);
38 return IRQ_HANDLED;
39 }
40
41 /* Normal case, SPI_INT deasserted by slave to trigger a master read */
42
43 skb = nci_spi_read(nspi: drv_data->nci_spi);
44 if (!skb) {
45 nfc_err(&drv_data->spi->dev, "failed to read spi packet");
46 return IRQ_HANDLED;
47 }
48
49 if (nfcmrvl_nci_recv_frame(priv: drv_data->priv, skb) < 0)
50 nfc_err(&drv_data->spi->dev, "corrupted RX packet");
51
52 return IRQ_HANDLED;
53}
54
55static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
56{
57 return 0;
58}
59
60static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
61{
62 return 0;
63}
64
65static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv,
66 struct sk_buff *skb)
67{
68 struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
69 int err;
70
71 /* Reinit completion for slave handshake */
72 reinit_completion(x: &drv_data->handshake_completion);
73 set_bit(SPI_WAIT_HANDSHAKE, addr: &drv_data->flags);
74
75 /*
76 * Append a dummy byte at the end of SPI frame. This is due to a
77 * specific DMA implementation in the controller
78 */
79 skb_put(skb, len: 1);
80
81 /* Send the SPI packet */
82 err = nci_spi_send(nspi: drv_data->nci_spi, write_handshake_completion: &drv_data->handshake_completion,
83 skb);
84 if (err)
85 nfc_err(priv->dev, "spi_send failed %d", err);
86
87 return err;
88}
89
90static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv,
91 const void *param)
92{
93 struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
94 const struct nfcmrvl_fw_spi_config *config = param;
95
96 drv_data->nci_spi->xfer_speed_hz = config->clk;
97}
98
99static const struct nfcmrvl_if_ops spi_ops = {
100 .nci_open = nfcmrvl_spi_nci_open,
101 .nci_close = nfcmrvl_spi_nci_close,
102 .nci_send = nfcmrvl_spi_nci_send,
103 .nci_update_config = nfcmrvl_spi_nci_update_config,
104};
105
106static int nfcmrvl_spi_parse_dt(struct device_node *node,
107 struct nfcmrvl_platform_data *pdata)
108{
109 int ret;
110
111 ret = nfcmrvl_parse_dt(node, pdata);
112 if (ret < 0) {
113 pr_err("Failed to get generic entries\n");
114 return ret;
115 }
116
117 ret = irq_of_parse_and_map(node, index: 0);
118 if (!ret) {
119 pr_err("Unable to get irq\n");
120 return -EINVAL;
121 }
122 pdata->irq = ret;
123
124 return 0;
125}
126
127static int nfcmrvl_spi_probe(struct spi_device *spi)
128{
129 const struct nfcmrvl_platform_data *pdata;
130 struct nfcmrvl_platform_data config;
131 struct nfcmrvl_spi_drv_data *drv_data;
132 int ret = 0;
133
134 drv_data = devm_kzalloc(dev: &spi->dev, size: sizeof(*drv_data), GFP_KERNEL);
135 if (!drv_data)
136 return -ENOMEM;
137
138 drv_data->spi = spi;
139 drv_data->priv = NULL;
140 spi_set_drvdata(spi, data: drv_data);
141
142 pdata = spi->dev.platform_data;
143
144 if (!pdata && spi->dev.of_node)
145 if (nfcmrvl_spi_parse_dt(node: spi->dev.of_node, pdata: &config) == 0)
146 pdata = &config;
147
148 if (!pdata)
149 return -EINVAL;
150
151 ret = devm_request_threaded_irq(dev: &drv_data->spi->dev, irq: pdata->irq,
152 NULL, thread_fn: nfcmrvl_spi_int_irq_thread_fn,
153 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
154 devname: "nfcmrvl_spi_int", dev_id: drv_data);
155 if (ret < 0) {
156 nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler");
157 return -ENODEV;
158 }
159
160 drv_data->priv = nfcmrvl_nci_register_dev(phy: NFCMRVL_PHY_SPI,
161 drv_data, ops: &spi_ops,
162 dev: &drv_data->spi->dev,
163 pdata);
164 if (IS_ERR(ptr: drv_data->priv))
165 return PTR_ERR(ptr: drv_data->priv);
166
167 drv_data->priv->support_fw_dnld = true;
168
169 drv_data->nci_spi = nci_spi_allocate_spi(spi: drv_data->spi, acknowledge_mode: 0, delay: 10,
170 ndev: drv_data->priv->ndev);
171
172 /* Init completion for slave handshake */
173 init_completion(x: &drv_data->handshake_completion);
174 return 0;
175}
176
177static void nfcmrvl_spi_remove(struct spi_device *spi)
178{
179 struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi);
180
181 nfcmrvl_nci_unregister_dev(priv: drv_data->priv);
182}
183
184static const struct of_device_id of_nfcmrvl_spi_match[] __maybe_unused = {
185 { .compatible = "marvell,nfc-spi", },
186 {},
187};
188MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);
189
190static const struct spi_device_id nfcmrvl_spi_id_table[] = {
191 { "nfcmrvl_spi", 0 },
192 { }
193};
194MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);
195
196static struct spi_driver nfcmrvl_spi_driver = {
197 .probe = nfcmrvl_spi_probe,
198 .remove = nfcmrvl_spi_remove,
199 .id_table = nfcmrvl_spi_id_table,
200 .driver = {
201 .name = "nfcmrvl_spi",
202 .owner = THIS_MODULE,
203 .of_match_table = of_match_ptr(of_nfcmrvl_spi_match),
204 },
205};
206
207module_spi_driver(nfcmrvl_spi_driver);
208
209MODULE_AUTHOR("Marvell International Ltd.");
210MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
211MODULE_LICENSE("GPL v2");
212

source code of linux/drivers/nfc/nfcmrvl/spi.c