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
19 struct 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
nfcmrvl_spi_int_irq_thread_fn(int irq,void * drv_data_ptr)27 static 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, &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(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(drv_data->priv, skb) < 0)
50 nfc_err(&drv_data->spi->dev, "corrupted RX packet");
51
52 return IRQ_HANDLED;
53 }
54
nfcmrvl_spi_nci_open(struct nfcmrvl_private * priv)55 static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
56 {
57 return 0;
58 }
59
nfcmrvl_spi_nci_close(struct nfcmrvl_private * priv)60 static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
61 {
62 return 0;
63 }
64
nfcmrvl_spi_nci_send(struct nfcmrvl_private * priv,struct sk_buff * skb)65 static 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(&drv_data->handshake_completion);
73 set_bit(SPI_WAIT_HANDSHAKE, &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, 1);
80
81 /* Send the SPI packet */
82 err = nci_spi_send(drv_data->nci_spi, &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
nfcmrvl_spi_nci_update_config(struct nfcmrvl_private * priv,const void * param)90 static 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
99 static 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
nfcmrvl_spi_parse_dt(struct device_node * node,struct nfcmrvl_platform_data * pdata)106 static 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, 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
nfcmrvl_spi_probe(struct spi_device * spi)127 static 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(&spi->dev, 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, drv_data);
141
142 pdata = spi->dev.platform_data;
143
144 if (!pdata && spi->dev.of_node)
145 if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0)
146 pdata = &config;
147
148 if (!pdata)
149 return -EINVAL;
150
151 ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq,
152 NULL, nfcmrvl_spi_int_irq_thread_fn,
153 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
154 "nfcmrvl_spi_int", 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(NFCMRVL_PHY_SPI,
161 drv_data, &spi_ops,
162 &drv_data->spi->dev,
163 pdata);
164 if (IS_ERR(drv_data->priv))
165 return PTR_ERR(drv_data->priv);
166
167 drv_data->priv->support_fw_dnld = true;
168
169 drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10,
170 drv_data->priv->ndev);
171
172 /* Init completion for slave handshake */
173 init_completion(&drv_data->handshake_completion);
174 return 0;
175 }
176
nfcmrvl_spi_remove(struct spi_device * spi)177 static 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(drv_data->priv);
182 }
183
184 static const struct of_device_id of_nfcmrvl_spi_match[] __maybe_unused = {
185 { .compatible = "marvell,nfc-spi", },
186 {},
187 };
188 MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);
189
190 static const struct spi_device_id nfcmrvl_spi_id_table[] = {
191 { "nfcmrvl_spi", 0 },
192 { }
193 };
194 MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);
195
196 static 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 .of_match_table = of_match_ptr(of_nfcmrvl_spi_match),
203 },
204 };
205
206 module_spi_driver(nfcmrvl_spi_driver);
207
208 MODULE_AUTHOR("Marvell International Ltd.");
209 MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
210 MODULE_LICENSE("GPL v2");
211