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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 r = -ENOMEM;
100 goto exit;
101 }
102
103 skb_put(skb_rx, skb->len);
104 memcpy(skb_rx->data, buf, skb->len);
105 ndlc_recv(phy->ndlc, skb_rx);
106 }
107
108exit:
109 return r;
110}
111
112
113
114
115
116
117
118
119
120static int st_nci_spi_read(struct st_nci_spi_phy *phy,
121 struct sk_buff **skb)
122{
123 int r;
124 u8 len;
125 u8 buf[ST_NCI_SPI_MAX_SIZE];
126 struct spi_device *dev = phy->spi_dev;
127 struct spi_transfer spi_xfer = {
128 .rx_buf = buf,
129 .len = ST_NCI_SPI_MIN_SIZE,
130 };
131
132 r = spi_sync_transfer(dev, &spi_xfer, 1);
133 if (r < 0)
134 return -EREMOTEIO;
135
136 len = be16_to_cpu(*(__be16 *) (buf + 2));
137 if (len > ST_NCI_SPI_MAX_SIZE) {
138 nfc_err(&dev->dev, "invalid frame len\n");
139 phy->ndlc->hard_fault = 1;
140 return -EBADMSG;
141 }
142
143 *skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL);
144 if (*skb == NULL)
145 return -ENOMEM;
146
147 skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE);
148 skb_put(*skb, ST_NCI_SPI_MIN_SIZE);
149 memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE);
150
151 if (!len)
152 return 0;
153
154 spi_xfer.len = len;
155 r = spi_sync_transfer(dev, &spi_xfer, 1);
156 if (r < 0) {
157 kfree_skb(*skb);
158 return -EREMOTEIO;
159 }
160
161 skb_put(*skb, len);
162 memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len);
163
164 return 0;
165}
166
167
168
169
170
171
172static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
173{
174 struct st_nci_spi_phy *phy = phy_id;
175 struct spi_device *dev;
176 struct sk_buff *skb = NULL;
177 int r;
178
179 if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) {
180 WARN_ON_ONCE(1);
181 return IRQ_NONE;
182 }
183
184 dev = phy->spi_dev;
185 dev_dbg(&dev->dev, "IRQ\n");
186
187 if (phy->ndlc->hard_fault)
188 return IRQ_HANDLED;
189
190 if (!phy->ndlc->powered) {
191 st_nci_spi_disable(phy);
192 return IRQ_HANDLED;
193 }
194
195 r = st_nci_spi_read(phy, &skb);
196 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
197 return IRQ_HANDLED;
198
199 ndlc_recv(phy->ndlc, skb);
200
201 return IRQ_HANDLED;
202}
203
204static struct nfc_phy_ops spi_phy_ops = {
205 .write = st_nci_spi_write,
206 .enable = st_nci_spi_enable,
207 .disable = st_nci_spi_disable,
208};
209
210static const struct acpi_gpio_params reset_gpios = { 1, 0, false };
211
212static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = {
213 { "reset-gpios", &reset_gpios, 1 },
214 {},
215};
216
217static int st_nci_spi_probe(struct spi_device *dev)
218{
219 struct st_nci_spi_phy *phy;
220 int r;
221
222 dev_dbg(&dev->dev, "%s\n", __func__);
223 dev_dbg(&dev->dev, "IRQ: %d\n", dev->irq);
224
225
226 if (!dev) {
227 pr_debug("%s: dev is NULL. Device is not accessible.\n",
228 __func__);
229 return -ENODEV;
230 }
231
232 phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy),
233 GFP_KERNEL);
234 if (!phy)
235 return -ENOMEM;
236
237 phy->spi_dev = dev;
238
239 spi_set_drvdata(dev, phy);
240
241 r = devm_acpi_dev_add_driver_gpios(&dev->dev, acpi_st_nci_gpios);
242 if (r)
243 dev_dbg(&dev->dev, "Unable to add GPIO mapping table\n");
244
245
246 phy->gpiod_reset = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH);
247 if (IS_ERR(phy->gpiod_reset)) {
248 nfc_err(&dev->dev, "Unable to get RESET GPIO\n");
249 return PTR_ERR(phy->gpiod_reset);
250 }
251
252 phy->se_status.is_ese_present =
253 device_property_read_bool(&dev->dev, "ese-present");
254 phy->se_status.is_uicc_present =
255 device_property_read_bool(&dev->dev, "uicc-present");
256
257 r = ndlc_probe(phy, &spi_phy_ops, &dev->dev,
258 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
259 &phy->ndlc, &phy->se_status);
260 if (r < 0) {
261 nfc_err(&dev->dev, "Unable to register ndlc layer\n");
262 return r;
263 }
264
265 phy->irq_active = true;
266 r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL,
267 st_nci_irq_thread_fn,
268 IRQF_ONESHOT,
269 ST_NCI_SPI_DRIVER_NAME, phy);
270 if (r < 0)
271 nfc_err(&dev->dev, "Unable to register IRQ handler\n");
272
273 return r;
274}
275
276static int st_nci_spi_remove(struct spi_device *dev)
277{
278 struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
279
280 dev_dbg(&dev->dev, "%s\n", __func__);
281
282 ndlc_remove(phy->ndlc);
283
284 return 0;
285}
286
287static struct spi_device_id st_nci_spi_id_table[] = {
288 {ST_NCI_SPI_DRIVER_NAME, 0},
289 {}
290};
291MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table);
292
293static const struct acpi_device_id st_nci_spi_acpi_match[] = {
294 {"SMO2101", 0},
295 {}
296};
297MODULE_DEVICE_TABLE(acpi, st_nci_spi_acpi_match);
298
299static const struct of_device_id of_st_nci_spi_match[] = {
300 { .compatible = "st,st21nfcb-spi", },
301 {}
302};
303MODULE_DEVICE_TABLE(of, of_st_nci_spi_match);
304
305static struct spi_driver st_nci_spi_driver = {
306 .driver = {
307 .name = ST_NCI_SPI_DRIVER_NAME,
308 .of_match_table = of_match_ptr(of_st_nci_spi_match),
309 .acpi_match_table = ACPI_PTR(st_nci_spi_acpi_match),
310 },
311 .probe = st_nci_spi_probe,
312 .id_table = st_nci_spi_id_table,
313 .remove = st_nci_spi_remove,
314};
315module_spi_driver(st_nci_spi_driver);
316
317MODULE_LICENSE("GPL");
318MODULE_DESCRIPTION(DRIVER_DESC);
319
