1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -------------------------------------------------------------------------
3 * Copyright (C) 2014-2016, Intel Corporation
4 *
5 * -------------------------------------------------------------------------
6 */
7
8#include <linux/module.h>
9#include <linux/acpi.h>
10#include <linux/i2c.h>
11#include <linux/interrupt.h>
12#include <linux/nfc.h>
13#include <linux/delay.h>
14#include <linux/gpio/consumer.h>
15#include <net/nfc/nfc.h>
16#include <net/nfc/nci_core.h>
17
18#include "fdp.h"
19
20#define FDP_I2C_DRIVER_NAME "fdp_nci_i2c"
21
22#define FDP_DP_CLOCK_TYPE_NAME "clock-type"
23#define FDP_DP_CLOCK_FREQ_NAME "clock-freq"
24#define FDP_DP_FW_VSC_CFG_NAME "fw-vsc-cfg"
25
26#define FDP_FRAME_HEADROOM 2
27#define FDP_FRAME_TAILROOM 1
28
29#define FDP_NCI_I2C_MIN_PAYLOAD 5
30#define FDP_NCI_I2C_MAX_PAYLOAD 261
31
32#define FDP_POWER_OFF 0
33#define FDP_POWER_ON 1
34
35#define fdp_nci_i2c_dump_skb(dev, prefix, skb) \
36 print_hex_dump(KERN_DEBUG, prefix": ", DUMP_PREFIX_OFFSET, \
37 16, 1, (skb)->data, (skb)->len, 0)
38
39static void fdp_nci_i2c_reset(const struct fdp_i2c_phy *phy)
40{
41 /* Reset RST/WakeUP for at least 100 micro-second */
42 gpiod_set_value_cansleep(desc: phy->power_gpio, FDP_POWER_OFF);
43 usleep_range(min: 1000, max: 4000);
44 gpiod_set_value_cansleep(desc: phy->power_gpio, FDP_POWER_ON);
45 usleep_range(min: 10000, max: 14000);
46}
47
48static int fdp_nci_i2c_enable(void *phy_id)
49{
50 const struct fdp_i2c_phy *phy = phy_id;
51
52 fdp_nci_i2c_reset(phy);
53
54 return 0;
55}
56
57static void fdp_nci_i2c_disable(void *phy_id)
58{
59 const struct fdp_i2c_phy *phy = phy_id;
60
61 fdp_nci_i2c_reset(phy);
62}
63
64static void fdp_nci_i2c_add_len_lrc(struct sk_buff *skb)
65{
66 u8 lrc = 0;
67 u16 len, i;
68
69 /* Add length header */
70 len = skb->len;
71 *(u8 *)skb_push(skb, len: 1) = len & 0xff;
72 *(u8 *)skb_push(skb, len: 1) = len >> 8;
73
74 /* Compute and add lrc */
75 for (i = 0; i < len + 2; i++)
76 lrc ^= skb->data[i];
77
78 skb_put_u8(skb, val: lrc);
79}
80
81static void fdp_nci_i2c_remove_len_lrc(struct sk_buff *skb)
82{
83 skb_pull(skb, FDP_FRAME_HEADROOM);
84 skb_trim(skb, len: skb->len - FDP_FRAME_TAILROOM);
85}
86
87static int fdp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
88{
89 struct fdp_i2c_phy *phy = phy_id;
90 struct i2c_client *client = phy->i2c_dev;
91 int r;
92
93 if (phy->hard_fault != 0)
94 return phy->hard_fault;
95
96 fdp_nci_i2c_add_len_lrc(skb);
97 fdp_nci_i2c_dump_skb(&client->dev, "fdp_wr", skb);
98
99 r = i2c_master_send(client, buf: skb->data, count: skb->len);
100 if (r == -EREMOTEIO) { /* Retry, chip was in standby */
101 usleep_range(min: 1000, max: 4000);
102 r = i2c_master_send(client, buf: skb->data, count: skb->len);
103 }
104
105 if (r < 0 || r != skb->len)
106 dev_dbg(&client->dev, "%s: error err=%d len=%d\n",
107 __func__, r, skb->len);
108
109 if (r >= 0) {
110 if (r != skb->len) {
111 phy->hard_fault = r;
112 r = -EREMOTEIO;
113 } else {
114 r = 0;
115 }
116 }
117
118 fdp_nci_i2c_remove_len_lrc(skb);
119
120 return r;
121}
122
123static const struct nfc_phy_ops i2c_phy_ops = {
124 .write = fdp_nci_i2c_write,
125 .enable = fdp_nci_i2c_enable,
126 .disable = fdp_nci_i2c_disable,
127};
128
129static int fdp_nci_i2c_read(struct fdp_i2c_phy *phy, struct sk_buff **skb)
130{
131 int r, len;
132 u8 tmp[FDP_NCI_I2C_MAX_PAYLOAD], lrc, k;
133 u16 i;
134 struct i2c_client *client = phy->i2c_dev;
135
136 *skb = NULL;
137
138 /* Read the length packet and the data packet */
139 for (k = 0; k < 2; k++) {
140
141 len = phy->next_read_size;
142
143 r = i2c_master_recv(client, buf: tmp, count: len);
144 if (r != len) {
145 dev_dbg(&client->dev, "%s: i2c recv err: %d\n",
146 __func__, r);
147 goto flush;
148 }
149
150 /* Check packet integruty */
151 for (lrc = i = 0; i < r; i++)
152 lrc ^= tmp[i];
153
154 /*
155 * LRC check failed. This may due to transmission error or
156 * desynchronization between driver and FDP. Drop the packet
157 * and force resynchronization
158 */
159 if (lrc) {
160 dev_dbg(&client->dev, "%s: corrupted packet\n",
161 __func__);
162 phy->next_read_size = 5;
163 goto flush;
164 }
165
166 /* Packet that contains a length */
167 if (tmp[0] == 0 && tmp[1] == 0) {
168 phy->next_read_size = (tmp[2] << 8) + tmp[3] + 3;
169 } else {
170 phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
171
172 *skb = alloc_skb(size: len, GFP_KERNEL);
173 if (*skb == NULL) {
174 r = -ENOMEM;
175 goto flush;
176 }
177
178 skb_put_data(skb: *skb, data: tmp, len);
179 fdp_nci_i2c_dump_skb(&client->dev, "fdp_rd", *skb);
180
181 fdp_nci_i2c_remove_len_lrc(skb: *skb);
182 }
183 }
184
185 return 0;
186
187flush:
188 /* Flush the remaining data */
189 if (i2c_master_recv(client, buf: tmp, count: sizeof(tmp)) < 0)
190 r = -EREMOTEIO;
191
192 return r;
193}
194
195static irqreturn_t fdp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
196{
197 struct fdp_i2c_phy *phy = phy_id;
198 struct sk_buff *skb;
199 int r;
200
201 if (!phy || irq != phy->i2c_dev->irq) {
202 WARN_ON_ONCE(1);
203 return IRQ_NONE;
204 }
205
206 r = fdp_nci_i2c_read(phy, skb: &skb);
207
208 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
209 return IRQ_HANDLED;
210
211 if (skb != NULL)
212 nci_recv_frame(ndev: phy->ndev, skb);
213
214 return IRQ_HANDLED;
215}
216
217static void fdp_nci_i2c_read_device_properties(struct device *dev,
218 u8 *clock_type, u32 *clock_freq,
219 u8 **fw_vsc_cfg)
220{
221 int r;
222 u8 len;
223
224 r = device_property_read_u8(dev, FDP_DP_CLOCK_TYPE_NAME, val: clock_type);
225 if (r) {
226 dev_dbg(dev, "Using default clock type");
227 *clock_type = 0;
228 }
229
230 r = device_property_read_u32(dev, FDP_DP_CLOCK_FREQ_NAME, val: clock_freq);
231 if (r) {
232 dev_dbg(dev, "Using default clock frequency\n");
233 *clock_freq = 26000;
234 }
235
236 if (device_property_present(dev, FDP_DP_FW_VSC_CFG_NAME)) {
237 r = device_property_read_u8(dev, FDP_DP_FW_VSC_CFG_NAME,
238 val: &len);
239
240 if (r || len <= 0)
241 goto vsc_read_err;
242
243 /* Add 1 to the length to inclue the length byte itself */
244 len++;
245
246 *fw_vsc_cfg = devm_kmalloc_array(dev,
247 n: len, size: sizeof(**fw_vsc_cfg),
248 GFP_KERNEL);
249
250 if (!*fw_vsc_cfg)
251 goto alloc_err;
252
253 r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME,
254 val: *fw_vsc_cfg, nval: len);
255
256 if (r) {
257 devm_kfree(dev, p: *fw_vsc_cfg);
258 goto vsc_read_err;
259 }
260 } else {
261vsc_read_err:
262 dev_dbg(dev, "FW vendor specific commands not present\n");
263 *fw_vsc_cfg = NULL;
264 }
265
266alloc_err:
267 dev_dbg(dev, "Clock type: %d, clock frequency: %d, VSC: %s",
268 *clock_type, *clock_freq, *fw_vsc_cfg != NULL ? "yes" : "no");
269}
270
271static const struct acpi_gpio_params power_gpios = { 0, 0, false };
272
273static const struct acpi_gpio_mapping acpi_fdp_gpios[] = {
274 { "power-gpios", &power_gpios, 1 },
275 {},
276};
277
278static int fdp_nci_i2c_probe(struct i2c_client *client)
279{
280 struct fdp_i2c_phy *phy;
281 struct device *dev = &client->dev;
282 u8 *fw_vsc_cfg;
283 u8 clock_type;
284 u32 clock_freq;
285 int r = 0;
286
287 if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_I2C)) {
288 nfc_err(dev, "No I2C_FUNC_I2C support\n");
289 return -ENODEV;
290 }
291
292 /* Checking if we have an irq */
293 if (client->irq <= 0) {
294 nfc_err(dev, "IRQ not present\n");
295 return -ENODEV;
296 }
297
298 phy = devm_kzalloc(dev, size: sizeof(struct fdp_i2c_phy), GFP_KERNEL);
299 if (!phy)
300 return -ENOMEM;
301
302 phy->i2c_dev = client;
303 phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
304 i2c_set_clientdata(client, data: phy);
305
306 r = devm_request_threaded_irq(dev, irq: client->irq,
307 NULL, thread_fn: fdp_nci_i2c_irq_thread_fn,
308 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
309 FDP_I2C_DRIVER_NAME, dev_id: phy);
310
311 if (r < 0) {
312 nfc_err(&client->dev, "Unable to register IRQ handler\n");
313 return r;
314 }
315
316 r = devm_acpi_dev_add_driver_gpios(dev, gpios: acpi_fdp_gpios);
317 if (r)
318 dev_dbg(dev, "Unable to add GPIO mapping table\n");
319
320 /* Requesting the power gpio */
321 phy->power_gpio = devm_gpiod_get(dev, con_id: "power", flags: GPIOD_OUT_LOW);
322 if (IS_ERR(ptr: phy->power_gpio)) {
323 nfc_err(dev, "Power GPIO request failed\n");
324 return PTR_ERR(ptr: phy->power_gpio);
325 }
326
327 /* read device properties to get the clock and production settings */
328 fdp_nci_i2c_read_device_properties(dev, clock_type: &clock_type, clock_freq: &clock_freq,
329 fw_vsc_cfg: &fw_vsc_cfg);
330
331 /* Call the NFC specific probe function */
332 r = fdp_nci_probe(phy, phy_ops: &i2c_phy_ops, ndev: &phy->ndev,
333 FDP_FRAME_HEADROOM, FDP_FRAME_TAILROOM,
334 clock_type, clock_freq, fw_vsc_cfg);
335 if (r < 0) {
336 nfc_err(dev, "NCI probing error\n");
337 return r;
338 }
339
340 return 0;
341}
342
343static void fdp_nci_i2c_remove(struct i2c_client *client)
344{
345 struct fdp_i2c_phy *phy = i2c_get_clientdata(client);
346
347 fdp_nci_remove(ndev: phy->ndev);
348 fdp_nci_i2c_disable(phy_id: phy);
349}
350
351static const struct acpi_device_id fdp_nci_i2c_acpi_match[] = {
352 {"INT339A", 0},
353 {}
354};
355MODULE_DEVICE_TABLE(acpi, fdp_nci_i2c_acpi_match);
356
357static struct i2c_driver fdp_nci_i2c_driver = {
358 .driver = {
359 .name = FDP_I2C_DRIVER_NAME,
360 .acpi_match_table = fdp_nci_i2c_acpi_match,
361 },
362 .probe = fdp_nci_i2c_probe,
363 .remove = fdp_nci_i2c_remove,
364};
365module_i2c_driver(fdp_nci_i2c_driver);
366
367MODULE_LICENSE("GPL");
368MODULE_DESCRIPTION("I2C driver for Intel Fields Peak NFC controller");
369MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");
370

source code of linux/drivers/nfc/fdp/i2c.c