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2bc4d4f8 CR |
1 | /* |
2 | * SPI Link Layer for ST NCI based Driver | |
3 | * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/spi/spi.h> | |
60cd6d89 | 22 | #include <linux/gpio/consumer.h> |
60cd6d89 | 23 | #include <linux/acpi.h> |
2bc4d4f8 CR |
24 | #include <linux/interrupt.h> |
25 | #include <linux/delay.h> | |
26 | #include <linux/nfc.h> | |
a89e68f1 | 27 | #include <linux/of.h> |
a1269dd1 | 28 | #include <net/nfc/nci.h> |
2bc4d4f8 | 29 | |
e67e7e59 | 30 | #include "st-nci.h" |
2bc4d4f8 CR |
31 | |
32 | #define DRIVER_DESC "NCI NFC driver for ST_NCI" | |
33 | ||
34 | /* ndlc header */ | |
35 | #define ST_NCI_FRAME_HEADROOM 1 | |
ba2c231c | 36 | #define ST_NCI_FRAME_TAILROOM 0 |
2bc4d4f8 CR |
37 | |
38 | #define ST_NCI_SPI_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */ | |
39 | #define ST_NCI_SPI_MAX_SIZE 250 /* req 4.2.1 */ | |
40 | ||
61a04101 | 41 | #define ST_NCI_DRIVER_NAME "st_nci" |
2bc4d4f8 CR |
42 | #define ST_NCI_SPI_DRIVER_NAME "st_nci_spi" |
43 | ||
2bc4d4f8 CR |
44 | struct st_nci_spi_phy { |
45 | struct spi_device *spi_dev; | |
46 | struct llt_ndlc *ndlc; | |
47 | ||
bb2496c3 CR |
48 | bool irq_active; |
49 | ||
a89e68f1 | 50 | struct gpio_desc *gpiod_reset; |
3648dc6d CR |
51 | |
52 | struct st_nci_se_status se_status; | |
2bc4d4f8 CR |
53 | }; |
54 | ||
2bc4d4f8 CR |
55 | static int st_nci_spi_enable(void *phy_id) |
56 | { | |
57 | struct st_nci_spi_phy *phy = phy_id; | |
58 | ||
a89e68f1 | 59 | gpiod_set_value(phy->gpiod_reset, 0); |
2bc4d4f8 | 60 | usleep_range(10000, 15000); |
a89e68f1 | 61 | gpiod_set_value(phy->gpiod_reset, 1); |
2bc4d4f8 CR |
62 | usleep_range(80000, 85000); |
63 | ||
bb2496c3 | 64 | if (phy->ndlc->powered == 0 && phy->irq_active == 0) { |
2bc4d4f8 | 65 | enable_irq(phy->spi_dev->irq); |
bb2496c3 CR |
66 | phy->irq_active = true; |
67 | } | |
2bc4d4f8 CR |
68 | |
69 | return 0; | |
70 | } | |
71 | ||
72 | static void st_nci_spi_disable(void *phy_id) | |
73 | { | |
74 | struct st_nci_spi_phy *phy = phy_id; | |
75 | ||
76 | disable_irq_nosync(phy->spi_dev->irq); | |
bb2496c3 | 77 | phy->irq_active = false; |
2bc4d4f8 CR |
78 | } |
79 | ||
80 | /* | |
81 | * Writing a frame must not return the number of written bytes. | |
82 | * It must return either zero for success, or <0 for error. | |
83 | * In addition, it must not alter the skb | |
84 | */ | |
85 | static int st_nci_spi_write(void *phy_id, struct sk_buff *skb) | |
86 | { | |
87 | int r; | |
88 | struct st_nci_spi_phy *phy = phy_id; | |
89 | struct spi_device *dev = phy->spi_dev; | |
90 | struct sk_buff *skb_rx; | |
a1269dd1 CR |
91 | u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE + |
92 | ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM]; | |
2bc4d4f8 CR |
93 | struct spi_transfer spi_xfer = { |
94 | .tx_buf = skb->data, | |
95 | .rx_buf = buf, | |
96 | .len = skb->len, | |
97 | }; | |
98 | ||
2bc4d4f8 CR |
99 | if (phy->ndlc->hard_fault != 0) |
100 | return phy->ndlc->hard_fault; | |
101 | ||
102 | r = spi_sync_transfer(dev, &spi_xfer, 1); | |
103 | /* | |
104 | * We may have received some valuable data on miso line. | |
105 | * Send them back in the ndlc state machine. | |
106 | */ | |
107 | if (!r) { | |
108 | skb_rx = alloc_skb(skb->len, GFP_KERNEL); | |
109 | if (!skb_rx) { | |
110 | r = -ENOMEM; | |
111 | goto exit; | |
112 | } | |
113 | ||
114 | skb_put(skb_rx, skb->len); | |
115 | memcpy(skb_rx->data, buf, skb->len); | |
116 | ndlc_recv(phy->ndlc, skb_rx); | |
117 | } | |
118 | ||
119 | exit: | |
120 | return r; | |
121 | } | |
122 | ||
123 | /* | |
124 | * Reads an ndlc frame and returns it in a newly allocated sk_buff. | |
125 | * returns: | |
126 | * 0 : if received frame is complete | |
127 | * -EREMOTEIO : i2c read error (fatal) | |
128 | * -EBADMSG : frame was incorrect and discarded | |
129 | * -ENOMEM : cannot allocate skb, frame dropped | |
130 | */ | |
131 | static int st_nci_spi_read(struct st_nci_spi_phy *phy, | |
132 | struct sk_buff **skb) | |
133 | { | |
134 | int r; | |
135 | u8 len; | |
136 | u8 buf[ST_NCI_SPI_MAX_SIZE]; | |
137 | struct spi_device *dev = phy->spi_dev; | |
138 | struct spi_transfer spi_xfer = { | |
139 | .rx_buf = buf, | |
140 | .len = ST_NCI_SPI_MIN_SIZE, | |
141 | }; | |
142 | ||
143 | r = spi_sync_transfer(dev, &spi_xfer, 1); | |
144 | if (r < 0) | |
145 | return -EREMOTEIO; | |
146 | ||
147 | len = be16_to_cpu(*(__be16 *) (buf + 2)); | |
148 | if (len > ST_NCI_SPI_MAX_SIZE) { | |
149 | nfc_err(&dev->dev, "invalid frame len\n"); | |
150 | phy->ndlc->hard_fault = 1; | |
151 | return -EBADMSG; | |
152 | } | |
153 | ||
154 | *skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL); | |
155 | if (*skb == NULL) | |
156 | return -ENOMEM; | |
157 | ||
158 | skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE); | |
159 | skb_put(*skb, ST_NCI_SPI_MIN_SIZE); | |
160 | memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE); | |
161 | ||
162 | if (!len) | |
163 | return 0; | |
164 | ||
165 | spi_xfer.len = len; | |
166 | r = spi_sync_transfer(dev, &spi_xfer, 1); | |
167 | if (r < 0) { | |
168 | kfree_skb(*skb); | |
169 | return -EREMOTEIO; | |
170 | } | |
171 | ||
172 | skb_put(*skb, len); | |
173 | memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len); | |
174 | ||
2bc4d4f8 CR |
175 | return 0; |
176 | } | |
177 | ||
178 | /* | |
179 | * Reads an ndlc frame from the chip. | |
180 | * | |
181 | * On ST21NFCB, IRQ goes in idle state when read starts. | |
182 | */ | |
183 | static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id) | |
184 | { | |
185 | struct st_nci_spi_phy *phy = phy_id; | |
186 | struct spi_device *dev; | |
187 | struct sk_buff *skb = NULL; | |
188 | int r; | |
189 | ||
190 | if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) { | |
191 | WARN_ON_ONCE(1); | |
192 | return IRQ_NONE; | |
193 | } | |
194 | ||
195 | dev = phy->spi_dev; | |
196 | dev_dbg(&dev->dev, "IRQ\n"); | |
197 | ||
198 | if (phy->ndlc->hard_fault) | |
199 | return IRQ_HANDLED; | |
200 | ||
201 | if (!phy->ndlc->powered) { | |
202 | st_nci_spi_disable(phy); | |
203 | return IRQ_HANDLED; | |
204 | } | |
205 | ||
206 | r = st_nci_spi_read(phy, &skb); | |
207 | if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG) | |
208 | return IRQ_HANDLED; | |
209 | ||
210 | ndlc_recv(phy->ndlc, skb); | |
211 | ||
212 | return IRQ_HANDLED; | |
213 | } | |
214 | ||
215 | static struct nfc_phy_ops spi_phy_ops = { | |
216 | .write = st_nci_spi_write, | |
217 | .enable = st_nci_spi_enable, | |
218 | .disable = st_nci_spi_disable, | |
219 | }; | |
220 | ||
85d23e77 AS |
221 | static const struct acpi_gpio_params reset_gpios = { 1, 0, false }; |
222 | ||
223 | static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = { | |
224 | { "reset-gpios", &reset_gpios, 1 }, | |
225 | {}, | |
226 | }; | |
227 | ||
2bc4d4f8 CR |
228 | static int st_nci_spi_probe(struct spi_device *dev) |
229 | { | |
230 | struct st_nci_spi_phy *phy; | |
2bc4d4f8 CR |
231 | int r; |
232 | ||
233 | dev_dbg(&dev->dev, "%s\n", __func__); | |
234 | dev_dbg(&dev->dev, "IRQ: %d\n", dev->irq); | |
235 | ||
236 | /* Check SPI platform functionnalities */ | |
237 | if (!dev) { | |
238 | pr_debug("%s: dev is NULL. Device is not accessible.\n", | |
239 | __func__); | |
240 | return -ENODEV; | |
241 | } | |
242 | ||
243 | phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy), | |
244 | GFP_KERNEL); | |
245 | if (!phy) | |
246 | return -ENOMEM; | |
247 | ||
248 | phy->spi_dev = dev; | |
249 | ||
250 | spi_set_drvdata(dev, phy); | |
251 | ||
c745120e AS |
252 | r = devm_acpi_dev_add_driver_gpios(&dev->dev, acpi_st_nci_gpios); |
253 | if (r) | |
254 | dev_dbg(&dev->dev, "Unable to add GPIO mapping table\n"); | |
255 | ||
256 | /* Get RESET GPIO */ | |
257 | phy->gpiod_reset = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH); | |
258 | if (IS_ERR(phy->gpiod_reset)) { | |
259 | nfc_err(&dev->dev, "Unable to get RESET GPIO\n"); | |
260 | return PTR_ERR(phy->gpiod_reset); | |
2bc4d4f8 CR |
261 | } |
262 | ||
75719b2b AS |
263 | phy->se_status.is_ese_present = |
264 | device_property_read_bool(&dev->dev, "ese-present"); | |
265 | phy->se_status.is_uicc_present = | |
266 | device_property_read_bool(&dev->dev, "uicc-present"); | |
267 | ||
2bc4d4f8 CR |
268 | r = ndlc_probe(phy, &spi_phy_ops, &dev->dev, |
269 | ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM, | |
3648dc6d | 270 | &phy->ndlc, &phy->se_status); |
2bc4d4f8 CR |
271 | if (r < 0) { |
272 | nfc_err(&dev->dev, "Unable to register ndlc layer\n"); | |
273 | return r; | |
274 | } | |
275 | ||
bb2496c3 | 276 | phy->irq_active = true; |
2bc4d4f8 CR |
277 | r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL, |
278 | st_nci_irq_thread_fn, | |
1af9fea6 | 279 | IRQF_ONESHOT, |
2bc4d4f8 CR |
280 | ST_NCI_SPI_DRIVER_NAME, phy); |
281 | if (r < 0) | |
282 | nfc_err(&dev->dev, "Unable to register IRQ handler\n"); | |
283 | ||
284 | return r; | |
285 | } | |
286 | ||
287 | static int st_nci_spi_remove(struct spi_device *dev) | |
288 | { | |
289 | struct st_nci_spi_phy *phy = spi_get_drvdata(dev); | |
290 | ||
291 | dev_dbg(&dev->dev, "%s\n", __func__); | |
292 | ||
293 | ndlc_remove(phy->ndlc); | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
3252897f CR |
298 | static struct spi_device_id st_nci_spi_id_table[] = { |
299 | {ST_NCI_SPI_DRIVER_NAME, 0}, | |
300 | {} | |
301 | }; | |
302 | MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table); | |
303 | ||
60cd6d89 CR |
304 | static const struct acpi_device_id st_nci_spi_acpi_match[] = { |
305 | {"SMO2101", 0}, | |
306 | {} | |
307 | }; | |
308 | MODULE_DEVICE_TABLE(acpi, st_nci_spi_acpi_match); | |
309 | ||
2bc4d4f8 CR |
310 | static const struct of_device_id of_st_nci_spi_match[] = { |
311 | { .compatible = "st,st21nfcb-spi", }, | |
312 | {} | |
313 | }; | |
314 | MODULE_DEVICE_TABLE(of, of_st_nci_spi_match); | |
2bc4d4f8 CR |
315 | |
316 | static struct spi_driver st_nci_spi_driver = { | |
317 | .driver = { | |
2bc4d4f8 CR |
318 | .name = ST_NCI_SPI_DRIVER_NAME, |
319 | .of_match_table = of_match_ptr(of_st_nci_spi_match), | |
60cd6d89 | 320 | .acpi_match_table = ACPI_PTR(st_nci_spi_acpi_match), |
2bc4d4f8 CR |
321 | }, |
322 | .probe = st_nci_spi_probe, | |
323 | .id_table = st_nci_spi_id_table, | |
324 | .remove = st_nci_spi_remove, | |
325 | }; | |
2bc4d4f8 CR |
326 | module_spi_driver(st_nci_spi_driver); |
327 | ||
328 | MODULE_LICENSE("GPL"); | |
329 | MODULE_DESCRIPTION(DRIVER_DESC); |