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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
42 gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_OFF);
43 usleep_range(1000, 4000);
44 gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_ON);
45 usleep_range(10000, 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
70 len = skb->len;
71 *(u8 *)skb_push(skb, 1) = len & 0xff;
72 *(u8 *)skb_push(skb, 1) = len >> 8;
73
74
75 for (i = 0; i < len + 2; i++)
76 lrc ^= skb->data[i];
77
78 skb_put_u8(skb, 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, 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, skb->data, skb->len);
100 if (r == -EREMOTEIO) {
101 usleep_range(1000, 4000);
102 r = i2c_master_send(client, skb->data, 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
139 for (k = 0; k < 2; k++) {
140
141 len = phy->next_read_size;
142
143 r = i2c_master_recv(client, tmp, 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
151 for (lrc = i = 0; i < r; i++)
152 lrc ^= tmp[i];
153
154
155
156
157
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
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(len, GFP_KERNEL);
173 if (*skb == NULL) {
174 r = -ENOMEM;
175 goto flush;
176 }
177
178 skb_put_data(*skb, tmp, len);
179 fdp_nci_i2c_dump_skb(&client->dev, "fdp_rd", *skb);
180
181 fdp_nci_i2c_remove_len_lrc(*skb);
182 }
183 }
184
185 return 0;
186
187flush:
188
189 if (i2c_master_recv(client, tmp, 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);
207
208 if (r == -EREMOTEIO)
209 return IRQ_HANDLED;
210 else if (r == -ENOMEM || r == -EBADMSG)
211 return IRQ_HANDLED;
212
213 if (skb != NULL)
214 nci_recv_frame(phy->ndev, skb);
215
216 return IRQ_HANDLED;
217}
218
219static void fdp_nci_i2c_read_device_properties(struct device *dev,
220 u8 *clock_type, u32 *clock_freq,
221 u8 **fw_vsc_cfg)
222{
223 int r;
224 u8 len;
225
226 r = device_property_read_u8(dev, FDP_DP_CLOCK_TYPE_NAME, clock_type);
227 if (r) {
228 dev_dbg(dev, "Using default clock type");
229 *clock_type = 0;
230 }
231
232 r = device_property_read_u32(dev, FDP_DP_CLOCK_FREQ_NAME, clock_freq);
233 if (r) {
234 dev_dbg(dev, "Using default clock frequency\n");
235 *clock_freq = 26000;
236 }
237
238 if (device_property_present(dev, FDP_DP_FW_VSC_CFG_NAME)) {
239 r = device_property_read_u8(dev, FDP_DP_FW_VSC_CFG_NAME,
240 &len);
241
242 if (r || len <= 0)
243 goto vsc_read_err;
244
245
246 len++;
247
248 *fw_vsc_cfg = devm_kmalloc_array(dev,
249 len, sizeof(**fw_vsc_cfg),
250 GFP_KERNEL);
251
252 r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME,
253 *fw_vsc_cfg, len);
254
255 if (r) {
256 devm_kfree(dev, *fw_vsc_cfg);
257 goto vsc_read_err;
258 }
259 } else {
260vsc_read_err:
261 dev_dbg(dev, "FW vendor specific commands not present\n");
262 *fw_vsc_cfg = NULL;
263 }
264
265 dev_dbg(dev, "Clock type: %d, clock frequency: %d, VSC: %s",
266 *clock_type, *clock_freq, *fw_vsc_cfg != NULL ? "yes" : "no");
267}
268
269static const struct acpi_gpio_params power_gpios = { 0, 0, false };
270
271static const struct acpi_gpio_mapping acpi_fdp_gpios[] = {
272 { "power-gpios", &power_gpios, 1 },
273 {},
274};
275
276static int fdp_nci_i2c_probe(struct i2c_client *client)
277{
278 struct fdp_i2c_phy *phy;
279 struct device *dev = &client->dev;
280 u8 *fw_vsc_cfg;
281 u8 clock_type;
282 u32 clock_freq;
283 int r = 0;
284
285 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
286 nfc_err(dev, "No I2C_FUNC_I2C support\n");
287 return -ENODEV;
288 }
289
290
291 if (client->irq <= 0) {
292 nfc_err(dev, "IRQ not present\n");
293 return -ENODEV;
294 }
295
296 phy = devm_kzalloc(dev, sizeof(struct fdp_i2c_phy), GFP_KERNEL);
297 if (!phy)
298 return -ENOMEM;
299
300 phy->i2c_dev = client;
301 phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
302 i2c_set_clientdata(client, phy);
303
304 r = devm_request_threaded_irq(dev, client->irq,
305 NULL, fdp_nci_i2c_irq_thread_fn,
306 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
307 FDP_I2C_DRIVER_NAME, phy);
308
309 if (r < 0) {
310 nfc_err(&client->dev, "Unable to register IRQ handler\n");
311 return r;
312 }
313
314 r = devm_acpi_dev_add_driver_gpios(dev, acpi_fdp_gpios);
315 if (r)
316 dev_dbg(dev, "Unable to add GPIO mapping table\n");
317
318
319 phy->power_gpio = devm_gpiod_get(dev, "power", GPIOD_OUT_LOW);
320 if (IS_ERR(phy->power_gpio)) {
321 nfc_err(dev, "Power GPIO request failed\n");
322 return PTR_ERR(phy->power_gpio);
323 }
324
325
326 fdp_nci_i2c_read_device_properties(dev, &clock_type, &clock_freq,
327 &fw_vsc_cfg);
328
329
330 r = fdp_nci_probe(phy, &i2c_phy_ops, &phy->ndev,
331 FDP_FRAME_HEADROOM, FDP_FRAME_TAILROOM,
332 clock_type, clock_freq, fw_vsc_cfg);
333 if (r < 0) {
334 nfc_err(dev, "NCI probing error\n");
335 return r;
336 }
337
338 dev_dbg(dev, "I2C driver loaded\n");
339 return 0;
340}
341
342static int fdp_nci_i2c_remove(struct i2c_client *client)
343{
344 struct fdp_i2c_phy *phy = i2c_get_clientdata(client);
345
346 fdp_nci_remove(phy->ndev);
347 fdp_nci_i2c_disable(phy);
348
349 return 0;
350}
351
352static const struct acpi_device_id fdp_nci_i2c_acpi_match[] = {
353 {"INT339A", 0},
354 {}
355};
356MODULE_DEVICE_TABLE(acpi, fdp_nci_i2c_acpi_match);
357
358static struct i2c_driver fdp_nci_i2c_driver = {
359 .driver = {
360 .name = FDP_I2C_DRIVER_NAME,
361 .acpi_match_table = fdp_nci_i2c_acpi_match,
362 },
363 .probe_new = fdp_nci_i2c_probe,
364 .remove = fdp_nci_i2c_remove,
365};
366module_i2c_driver(fdp_nci_i2c_driver);
367
368MODULE_LICENSE("GPL");
369MODULE_DESCRIPTION("I2C driver for Intel Fields Peak NFC controller");
370MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");
371
