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6
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include <linux/module.h>
10#include <linux/spi/spi.h>
11#include <linux/gpio/consumer.h>
12#include <linux/acpi.h>
13#include <linux/interrupt.h>
14#include <linux/delay.h>
15#include <linux/nfc.h>
16#include <linux/of.h>
17#include <net/nfc/nci.h>
18
19#include "st-nci.h"
20
21#define DRIVER_DESC "NCI NFC driver for ST_NCI"
22
23
24#define ST_NCI_FRAME_HEADROOM 1
25#define ST_NCI_FRAME_TAILROOM 0
26
27#define ST_NCI_SPI_MIN_SIZE 4
28#define ST_NCI_SPI_MAX_SIZE 250
29
30#define ST_NCI_DRIVER_NAME "st_nci"
31#define ST_NCI_SPI_DRIVER_NAME "st_nci_spi"
32
33struct st_nci_spi_phy {
34 struct spi_device *spi_dev;
35 struct llt_ndlc *ndlc;
36
37 bool irq_active;
38
39 struct gpio_desc *gpiod_reset;
40
41 struct st_nci_se_status se_status;
42};
43
44static int st_nci_spi_enable(void *phy_id)
45{
46 struct st_nci_spi_phy *phy = phy_id;
47
48 gpiod_set_value(phy->gpiod_reset, 0);
49 usleep_range(10000, 15000);
50 gpiod_set_value(phy->gpiod_reset, 1);
51 usleep_range(80000, 85000);
52
53 if (phy->ndlc->powered == 0 && phy->irq_active == 0) {
54 enable_irq(phy->spi_dev->irq);
55 phy->irq_active = true;
56 }
57
58 return 0;
59}
60
61static void st_nci_spi_disable(void *phy_id)
62{
63 struct st_nci_spi_phy *phy = phy_id;
64
65 disable_irq_nosync(phy->spi_dev->irq);
66 phy->irq_active = false;
67}
68
69
70
71
72
73
74static int st_nci_spi_write(void *phy_id, struct sk_buff *skb)
75{
76 int r;
77 struct st_nci_spi_phy *phy = phy_id;
78 struct spi_device *dev = phy->spi_dev;
79 struct sk_buff *skb_rx;
80 u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE +
81 ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM];
82 struct spi_transfer spi_xfer = {
83 .tx_buf = skb->data,
84 .rx_buf = buf,
85 .len = skb->len,
86 };
87
88 if (phy->ndlc->hard_fault != 0)
89 return phy->ndlc->hard_fault;
90
91 r = spi_sync_transfer(dev, &spi_xfer, 1);
92
93
94
95
96 if (!r) {
97 skb_rx = alloc_skb(skb->len, GFP_KERNEL);
98 if (!skb_rx)
99 return -ENOMEM;
100
101 skb_put(skb_rx, skb->len);
102 memcpy(skb_rx->data, buf, skb->len);
103 ndlc_recv(phy->ndlc, skb_rx);
104 }
105
106 return r;
107}
108
109
110
111
112
113
114
115
116
117static int st_nci_spi_read(struct st_nci_spi_phy *phy,
118 struct sk_buff **skb)
119{
120 int r;
121 u8 len;
122 u8 buf[ST_NCI_SPI_MAX_SIZE];
123 struct spi_device *dev = phy->spi_dev;
124 struct spi_transfer spi_xfer = {
125 .rx_buf = buf,
126 .len = ST_NCI_SPI_MIN_SIZE,
127 };
128
129 r = spi_sync_transfer(dev, &spi_xfer, 1);
130 if (r < 0)
131 return -EREMOTEIO;
132
133 len = be16_to_cpu(*(__be16 *) (buf + 2));
134 if (len > ST_NCI_SPI_MAX_SIZE) {
135 nfc_err(&dev->dev, "invalid frame len\n");
136 phy->ndlc->hard_fault = 1;
137 return -EBADMSG;
138 }
139
140 *skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL);
141 if (*skb == NULL)
142 return -ENOMEM;
143
144 skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE);
145 skb_put(*skb, ST_NCI_SPI_MIN_SIZE);
146 memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE);
147
148 if (!len)
149 return 0;
150
151 spi_xfer.len = len;
152 r = spi_sync_transfer(dev, &spi_xfer, 1);
153 if (r < 0) {
154 kfree_skb(*skb);
155 return -EREMOTEIO;
156 }
157
158 skb_put(*skb, len);
159 memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len);
160
161 return 0;
162}
163
164
165
166
167
168
169static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
170{
171 struct st_nci_spi_phy *phy = phy_id;
172 struct spi_device *dev;
173 struct sk_buff *skb = NULL;
174 int r;
175
176 if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) {
177 WARN_ON_ONCE(1);
178 return IRQ_NONE;
179 }
180
181 dev = phy->spi_dev;
182 dev_dbg(&dev->dev, "IRQ\n");
183
184 if (phy->ndlc->hard_fault)
185 return IRQ_HANDLED;
186
187 if (!phy->ndlc->powered) {
188 st_nci_spi_disable(phy);
189 return IRQ_HANDLED;
190 }
191
192 r = st_nci_spi_read(phy, &skb);
193 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
194 return IRQ_HANDLED;
195
196 ndlc_recv(phy->ndlc, skb);
197
198 return IRQ_HANDLED;
199}
200
201static struct nfc_phy_ops spi_phy_ops = {
202 .write = st_nci_spi_write,
203 .enable = st_nci_spi_enable,
204 .disable = st_nci_spi_disable,
205};
206
207static const struct acpi_gpio_params reset_gpios = { 1, 0, false };
208
209static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = {
210 { "reset-gpios", &reset_gpios, 1 },
211 {},
212};
213
214static int st_nci_spi_probe(struct spi_device *dev)
215{
216 struct st_nci_spi_phy *phy;
217 int r;
218
219
220 if (!dev) {
221 pr_debug("%s: dev is NULL. Device is not accessible.\n",
222 __func__);
223 return -ENODEV;
224 }
225
226 phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy),
227 GFP_KERNEL);
228 if (!phy)
229 return -ENOMEM;
230
231 phy->spi_dev = dev;
232
233 spi_set_drvdata(dev, phy);
234
235 r = devm_acpi_dev_add_driver_gpios(&dev->dev, acpi_st_nci_gpios);
236 if (r)
237 dev_dbg(&dev->dev, "Unable to add GPIO mapping table\n");
238
239
240 phy->gpiod_reset = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH);
241 if (IS_ERR(phy->gpiod_reset)) {
242 nfc_err(&dev->dev, "Unable to get RESET GPIO\n");
243 return PTR_ERR(phy->gpiod_reset);
244 }
245
246 phy->se_status.is_ese_present =
247 device_property_read_bool(&dev->dev, "ese-present");
248 phy->se_status.is_uicc_present =
249 device_property_read_bool(&dev->dev, "uicc-present");
250
251 r = ndlc_probe(phy, &spi_phy_ops, &dev->dev,
252 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
253 &phy->ndlc, &phy->se_status);
254 if (r < 0) {
255 nfc_err(&dev->dev, "Unable to register ndlc layer\n");
256 return r;
257 }
258
259 phy->irq_active = true;
260 r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL,
261 st_nci_irq_thread_fn,
262 IRQF_ONESHOT,
263 ST_NCI_SPI_DRIVER_NAME, phy);
264 if (r < 0)
265 nfc_err(&dev->dev, "Unable to register IRQ handler\n");
266
267 return r;
268}
269
270static int st_nci_spi_remove(struct spi_device *dev)
271{
272 struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
273
274 ndlc_remove(phy->ndlc);
275
276 return 0;
277}
278
279static struct spi_device_id st_nci_spi_id_table[] = {
280 {ST_NCI_SPI_DRIVER_NAME, 0},
281 {}
282};
283MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table);
284
285static const struct acpi_device_id st_nci_spi_acpi_match[] __maybe_unused = {
286 {"SMO2101", 0},
287 {}
288};
289MODULE_DEVICE_TABLE(acpi, st_nci_spi_acpi_match);
290
291static const struct of_device_id of_st_nci_spi_match[] __maybe_unused = {
292 { .compatible = "st,st21nfcb-spi", },
293 {}
294};
295MODULE_DEVICE_TABLE(of, of_st_nci_spi_match);
296
297static struct spi_driver st_nci_spi_driver = {
298 .driver = {
299 .name = ST_NCI_SPI_DRIVER_NAME,
300 .of_match_table = of_match_ptr(of_st_nci_spi_match),
301 .acpi_match_table = ACPI_PTR(st_nci_spi_acpi_match),
302 },
303 .probe = st_nci_spi_probe,
304 .id_table = st_nci_spi_id_table,
305 .remove = st_nci_spi_remove,
306};
307module_spi_driver(st_nci_spi_driver);
308
309MODULE_LICENSE("GPL");
310MODULE_DESCRIPTION(DRIVER_DESC);
311
