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a06347c0 RD |
1 | /* ------------------------------------------------------------------------- |
2 | * Copyright (C) 2014-2016, Intel Corporation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
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 | */ | |
15 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/acpi.h> | |
18 | #include <linux/i2c.h> | |
19 | #include <linux/interrupt.h> | |
20 | #include <linux/nfc.h> | |
21 | #include <linux/delay.h> | |
22 | #include <linux/gpio/consumer.h> | |
23 | #include <net/nfc/nfc.h> | |
24 | #include <net/nfc/nci_core.h> | |
25 | ||
26 | #include "fdp.h" | |
27 | ||
28 | #define FDP_I2C_DRIVER_NAME "fdp_nci_i2c" | |
29 | ||
30 | #define FDP_DP_POWER_GPIO_NAME "power" | |
31 | #define FDP_DP_CLOCK_TYPE_NAME "clock-type" | |
32 | #define FDP_DP_CLOCK_FREQ_NAME "clock-freq" | |
33 | #define FDP_DP_FW_VSC_CFG_NAME "fw-vsc-cfg" | |
34 | ||
35 | #define FDP_FRAME_HEADROOM 2 | |
36 | #define FDP_FRAME_TAILROOM 1 | |
37 | ||
38 | #define FDP_NCI_I2C_MIN_PAYLOAD 5 | |
39 | #define FDP_NCI_I2C_MAX_PAYLOAD 261 | |
40 | ||
41 | #define FDP_POWER_OFF 0 | |
42 | #define FDP_POWER_ON 1 | |
43 | ||
44 | #define fdp_nci_i2c_dump_skb(dev, prefix, skb) \ | |
45 | print_hex_dump(KERN_DEBUG, prefix": ", DUMP_PREFIX_OFFSET, \ | |
46 | 16, 1, (skb)->data, (skb)->len, 0) | |
47 | ||
48 | static void fdp_nci_i2c_reset(struct fdp_i2c_phy *phy) | |
49 | { | |
50 | /* Reset RST/WakeUP for at least 100 micro-second */ | |
51 | gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_OFF); | |
52 | usleep_range(1000, 4000); | |
53 | gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_ON); | |
54 | usleep_range(10000, 14000); | |
55 | } | |
56 | ||
57 | static int fdp_nci_i2c_enable(void *phy_id) | |
58 | { | |
59 | struct fdp_i2c_phy *phy = phy_id; | |
60 | ||
61 | dev_dbg(&phy->i2c_dev->dev, "%s\n", __func__); | |
62 | fdp_nci_i2c_reset(phy); | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | static void fdp_nci_i2c_disable(void *phy_id) | |
68 | { | |
69 | struct fdp_i2c_phy *phy = phy_id; | |
70 | ||
71 | dev_dbg(&phy->i2c_dev->dev, "%s\n", __func__); | |
72 | fdp_nci_i2c_reset(phy); | |
73 | } | |
74 | ||
75 | static void fdp_nci_i2c_add_len_lrc(struct sk_buff *skb) | |
76 | { | |
77 | u8 lrc = 0; | |
78 | u16 len, i; | |
79 | ||
80 | /* Add length header */ | |
81 | len = skb->len; | |
82 | *skb_push(skb, 1) = len & 0xff; | |
83 | *skb_push(skb, 1) = len >> 8; | |
84 | ||
85 | /* Compute and add lrc */ | |
86 | for (i = 0; i < len + 2; i++) | |
87 | lrc ^= skb->data[i]; | |
88 | ||
89 | *skb_put(skb, 1) = lrc; | |
90 | } | |
91 | ||
92 | static void fdp_nci_i2c_remove_len_lrc(struct sk_buff *skb) | |
93 | { | |
94 | skb_pull(skb, FDP_FRAME_HEADROOM); | |
95 | skb_trim(skb, skb->len - FDP_FRAME_TAILROOM); | |
96 | } | |
97 | ||
98 | static int fdp_nci_i2c_write(void *phy_id, struct sk_buff *skb) | |
99 | { | |
100 | struct fdp_i2c_phy *phy = phy_id; | |
101 | struct i2c_client *client = phy->i2c_dev; | |
102 | int r; | |
103 | ||
104 | if (phy->hard_fault != 0) | |
105 | return phy->hard_fault; | |
106 | ||
107 | fdp_nci_i2c_add_len_lrc(skb); | |
108 | fdp_nci_i2c_dump_skb(&client->dev, "fdp_wr", skb); | |
109 | ||
110 | r = i2c_master_send(client, skb->data, skb->len); | |
111 | if (r == -EREMOTEIO) { /* Retry, chip was in standby */ | |
112 | usleep_range(1000, 4000); | |
113 | r = i2c_master_send(client, skb->data, skb->len); | |
114 | } | |
115 | ||
116 | if (r < 0 || r != skb->len) | |
117 | dev_dbg(&client->dev, "%s: error err=%d len=%d\n", | |
118 | __func__, r, skb->len); | |
119 | ||
120 | if (r >= 0) { | |
121 | if (r != skb->len) { | |
122 | phy->hard_fault = r; | |
123 | r = -EREMOTEIO; | |
124 | } else { | |
125 | r = 0; | |
126 | } | |
127 | } | |
128 | ||
129 | fdp_nci_i2c_remove_len_lrc(skb); | |
130 | ||
131 | return r; | |
132 | } | |
133 | ||
134 | static struct nfc_phy_ops i2c_phy_ops = { | |
135 | .write = fdp_nci_i2c_write, | |
136 | .enable = fdp_nci_i2c_enable, | |
137 | .disable = fdp_nci_i2c_disable, | |
138 | }; | |
139 | ||
140 | static int fdp_nci_i2c_read(struct fdp_i2c_phy *phy, struct sk_buff **skb) | |
141 | { | |
142 | int r, len; | |
143 | u8 tmp[FDP_NCI_I2C_MAX_PAYLOAD], lrc, k; | |
144 | u16 i; | |
145 | struct i2c_client *client = phy->i2c_dev; | |
146 | ||
147 | *skb = NULL; | |
148 | ||
149 | /* Read the length packet and the data packet */ | |
150 | for (k = 0; k < 2; k++) { | |
151 | ||
152 | len = phy->next_read_size; | |
153 | ||
154 | r = i2c_master_recv(client, tmp, len); | |
155 | if (r != len) { | |
156 | dev_dbg(&client->dev, "%s: i2c recv err: %d\n", | |
157 | __func__, r); | |
158 | goto flush; | |
159 | } | |
160 | ||
161 | /* Check packet integruty */ | |
162 | for (lrc = i = 0; i < r; i++) | |
163 | lrc ^= tmp[i]; | |
164 | ||
165 | /* | |
166 | * LRC check failed. This may due to transmission error or | |
167 | * desynchronization between driver and FDP. Drop the paquet | |
168 | * and force resynchronization | |
169 | */ | |
170 | if (lrc) { | |
171 | dev_dbg(&client->dev, "%s: corrupted packet\n", | |
172 | __func__); | |
173 | phy->next_read_size = 5; | |
174 | goto flush; | |
175 | } | |
176 | ||
177 | /* Packet that contains a length */ | |
178 | if (tmp[0] == 0 && tmp[1] == 0) { | |
179 | phy->next_read_size = (tmp[2] << 8) + tmp[3] + 3; | |
180 | } else { | |
181 | phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD; | |
182 | ||
183 | *skb = alloc_skb(len, GFP_KERNEL); | |
184 | if (*skb == NULL) { | |
185 | r = -ENOMEM; | |
186 | goto flush; | |
187 | } | |
188 | ||
189 | memcpy(skb_put(*skb, len), tmp, len); | |
190 | fdp_nci_i2c_dump_skb(&client->dev, "fdp_rd", *skb); | |
191 | ||
192 | fdp_nci_i2c_remove_len_lrc(*skb); | |
193 | } | |
194 | } | |
195 | ||
196 | return 0; | |
197 | ||
198 | flush: | |
199 | /* Flush the remaining data */ | |
200 | if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0) | |
201 | r = -EREMOTEIO; | |
202 | ||
203 | return r; | |
204 | } | |
205 | ||
206 | static irqreturn_t fdp_nci_i2c_irq_thread_fn(int irq, void *phy_id) | |
207 | { | |
208 | struct fdp_i2c_phy *phy = phy_id; | |
209 | struct i2c_client *client; | |
210 | struct sk_buff *skb; | |
211 | int r; | |
212 | ||
213 | client = phy->i2c_dev; | |
214 | dev_dbg(&client->dev, "%s\n", __func__); | |
215 | ||
216 | if (!phy || irq != phy->i2c_dev->irq) { | |
217 | WARN_ON_ONCE(1); | |
218 | return IRQ_NONE; | |
219 | } | |
220 | ||
221 | r = fdp_nci_i2c_read(phy, &skb); | |
222 | ||
223 | if (r == -EREMOTEIO) | |
224 | return IRQ_HANDLED; | |
225 | else if (r == -ENOMEM || r == -EBADMSG) | |
226 | return IRQ_HANDLED; | |
227 | ||
228 | if (skb != NULL) | |
229 | fdp_nci_recv_frame(phy->ndev, skb); | |
230 | ||
231 | return IRQ_HANDLED; | |
232 | } | |
233 | ||
234 | static void fdp_nci_i2c_read_device_properties(struct device *dev, | |
235 | u8 *clock_type, u32 *clock_freq, | |
236 | u8 **fw_vsc_cfg) | |
237 | { | |
238 | int r; | |
239 | u8 len; | |
240 | ||
241 | r = device_property_read_u8(dev, FDP_DP_CLOCK_TYPE_NAME, clock_type); | |
242 | if (r) { | |
243 | dev_dbg(dev, "Using default clock type"); | |
244 | *clock_type = 0; | |
245 | } | |
246 | ||
247 | r = device_property_read_u32(dev, FDP_DP_CLOCK_FREQ_NAME, clock_freq); | |
248 | if (r) { | |
249 | dev_dbg(dev, "Using default clock frequency\n"); | |
250 | *clock_freq = 26000; | |
251 | } | |
252 | ||
253 | if (device_property_present(dev, FDP_DP_FW_VSC_CFG_NAME)) { | |
254 | r = device_property_read_u8(dev, FDP_DP_FW_VSC_CFG_NAME, | |
255 | &len); | |
256 | ||
257 | if (r || len <= 0) | |
258 | goto vsc_read_err; | |
259 | ||
260 | /* Add 1 to the length to inclue the length byte itself */ | |
261 | len++; | |
262 | ||
263 | *fw_vsc_cfg = devm_kmalloc(dev, | |
264 | len * sizeof(**fw_vsc_cfg), | |
265 | GFP_KERNEL); | |
266 | ||
267 | r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME, | |
268 | *fw_vsc_cfg, len); | |
269 | ||
270 | if (r) { | |
271 | devm_kfree(dev, fw_vsc_cfg); | |
272 | goto vsc_read_err; | |
273 | } | |
274 | } else { | |
275 | vsc_read_err: | |
276 | dev_dbg(dev, "FW vendor specific commands not present\n"); | |
277 | *fw_vsc_cfg = NULL; | |
278 | } | |
279 | ||
280 | dev_dbg(dev, "Clock type: %d, clock frequency: %d, VSC: %s", | |
281 | *clock_type, *clock_freq, *fw_vsc_cfg != NULL ? "yes" : "no"); | |
282 | } | |
283 | ||
284 | static int fdp_nci_i2c_probe(struct i2c_client *client, | |
285 | const struct i2c_device_id *id) | |
286 | { | |
287 | struct fdp_i2c_phy *phy; | |
288 | struct device *dev = &client->dev; | |
289 | u8 *fw_vsc_cfg; | |
290 | u8 clock_type; | |
291 | u32 clock_freq; | |
292 | int r = 0; | |
293 | ||
294 | dev_dbg(dev, "%s\n", __func__); | |
295 | ||
296 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { | |
297 | nfc_err(dev, "No I2C_FUNC_I2C support\n"); | |
298 | return -ENODEV; | |
299 | } | |
300 | ||
0b0a264d CR |
301 | /* Checking if we have an irq */ |
302 | if (client->irq <= 0) { | |
303 | nfc_err(dev, "IRQ not present\n"); | |
304 | return -ENODEV; | |
305 | } | |
306 | ||
a06347c0 RD |
307 | phy = devm_kzalloc(dev, sizeof(struct fdp_i2c_phy), |
308 | GFP_KERNEL); | |
309 | if (!phy) | |
310 | return -ENOMEM; | |
311 | ||
312 | phy->i2c_dev = client; | |
313 | phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD; | |
314 | i2c_set_clientdata(client, phy); | |
315 | ||
a06347c0 RD |
316 | r = request_threaded_irq(client->irq, NULL, fdp_nci_i2c_irq_thread_fn, |
317 | IRQF_TRIGGER_RISING | IRQF_ONESHOT, | |
318 | FDP_I2C_DRIVER_NAME, phy); | |
319 | ||
320 | if (r < 0) { | |
321 | nfc_err(&client->dev, "Unable to register IRQ handler\n"); | |
322 | return r; | |
323 | } | |
324 | ||
325 | /* Requesting the power gpio */ | |
326 | phy->power_gpio = devm_gpiod_get(dev, FDP_DP_POWER_GPIO_NAME, | |
327 | GPIOD_OUT_LOW); | |
328 | ||
329 | if (IS_ERR(phy->power_gpio)) { | |
330 | nfc_err(dev, "Power GPIO request failed\n"); | |
331 | return PTR_ERR(phy->power_gpio); | |
332 | } | |
333 | ||
334 | /* read device properties to get the clock and production settings */ | |
335 | fdp_nci_i2c_read_device_properties(dev, &clock_type, &clock_freq, | |
336 | &fw_vsc_cfg); | |
337 | ||
338 | /* Call the NFC specific probe function */ | |
339 | r = fdp_nci_probe(phy, &i2c_phy_ops, &phy->ndev, | |
340 | FDP_FRAME_HEADROOM, FDP_FRAME_TAILROOM, | |
341 | clock_type, clock_freq, fw_vsc_cfg); | |
342 | if (r < 0) { | |
343 | nfc_err(dev, "NCI probing error\n"); | |
344 | return r; | |
345 | } | |
346 | ||
347 | dev_dbg(dev, "I2C driver loaded\n"); | |
348 | return 0; | |
349 | } | |
350 | ||
351 | static int fdp_nci_i2c_remove(struct i2c_client *client) | |
352 | { | |
353 | struct fdp_i2c_phy *phy = i2c_get_clientdata(client); | |
354 | ||
355 | dev_dbg(&client->dev, "%s\n", __func__); | |
356 | ||
357 | fdp_nci_remove(phy->ndev); | |
358 | fdp_nci_i2c_disable(phy); | |
359 | ||
360 | return 0; | |
361 | } | |
362 | ||
363 | static struct i2c_device_id fdp_nci_i2c_id_table[] = { | |
364 | {"int339a", 0}, | |
365 | {} | |
366 | }; | |
367 | MODULE_DEVICE_TABLE(i2c, fdp_nci_i2c_id_table); | |
368 | ||
369 | static const struct acpi_device_id fdp_nci_i2c_acpi_match[] = { | |
370 | {"INT339A", 0}, | |
371 | {} | |
372 | }; | |
373 | MODULE_DEVICE_TABLE(acpi, fdp_nci_i2c_acpi_match); | |
374 | ||
375 | static struct i2c_driver fdp_nci_i2c_driver = { | |
376 | .driver = { | |
377 | .name = FDP_I2C_DRIVER_NAME, | |
378 | .acpi_match_table = ACPI_PTR(fdp_nci_i2c_acpi_match), | |
379 | }, | |
380 | .id_table = fdp_nci_i2c_id_table, | |
381 | .probe = fdp_nci_i2c_probe, | |
382 | .remove = fdp_nci_i2c_remove, | |
383 | }; | |
384 | module_i2c_driver(fdp_nci_i2c_driver); | |
385 | ||
386 | MODULE_LICENSE("GPL"); | |
387 | MODULE_DESCRIPTION("I2C driver for Intel Fields Peak NFC controller"); | |
388 | MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>"); |