2 * I2C Link Layer for ST NCI NFC controller familly based Driver
3 * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved.
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.
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.
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/>.
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/module.h>
21 #include <linux/i2c.h>
22 #include <linux/gpio.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_gpio.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/nfc.h>
28 #include <linux/platform_data/st-nci.h>
32 #define DRIVER_DESC "NCI NFC driver for ST_NCI"
35 #define ST_NCI_FRAME_HEADROOM 1
36 #define ST_NCI_FRAME_TAILROOM 0
38 #define ST_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
39 #define ST_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */
41 #define ST_NCI_I2C_DRIVER_NAME "st_nci_i2c"
43 static struct i2c_device_id st_nci_i2c_id_table[] = {
44 {ST_NCI_DRIVER_NAME, 0},
47 MODULE_DEVICE_TABLE(i2c, st_nci_i2c_id_table);
49 struct st_nci_i2c_phy {
50 struct i2c_client *i2c_dev;
51 struct llt_ndlc *ndlc;
55 unsigned int gpio_reset;
56 unsigned int irq_polarity;
58 struct st_nci_se_status se_status;
61 static int st_nci_i2c_enable(void *phy_id)
63 struct st_nci_i2c_phy *phy = phy_id;
65 gpio_set_value(phy->gpio_reset, 0);
66 usleep_range(10000, 15000);
67 gpio_set_value(phy->gpio_reset, 1);
68 usleep_range(80000, 85000);
70 if (phy->ndlc->powered == 0 && phy->irq_active == 0) {
71 enable_irq(phy->i2c_dev->irq);
72 phy->irq_active = true;
78 static void st_nci_i2c_disable(void *phy_id)
80 struct st_nci_i2c_phy *phy = phy_id;
82 disable_irq_nosync(phy->i2c_dev->irq);
83 phy->irq_active = false;
87 * Writing a frame must not return the number of written bytes.
88 * It must return either zero for success, or <0 for error.
89 * In addition, it must not alter the skb
91 static int st_nci_i2c_write(void *phy_id, struct sk_buff *skb)
94 struct st_nci_i2c_phy *phy = phy_id;
95 struct i2c_client *client = phy->i2c_dev;
97 if (phy->ndlc->hard_fault != 0)
98 return phy->ndlc->hard_fault;
100 r = i2c_master_send(client, skb->data, skb->len);
101 if (r < 0) { /* Retry, chip was in standby */
102 usleep_range(1000, 4000);
103 r = i2c_master_send(client, skb->data, skb->len);
117 * Reads an ndlc frame and returns it in a newly allocated sk_buff.
119 * 0 : if received frame is complete
120 * -EREMOTEIO : i2c read error (fatal)
121 * -EBADMSG : frame was incorrect and discarded
122 * -ENOMEM : cannot allocate skb, frame dropped
124 static int st_nci_i2c_read(struct st_nci_i2c_phy *phy,
125 struct sk_buff **skb)
129 u8 buf[ST_NCI_I2C_MAX_SIZE];
130 struct i2c_client *client = phy->i2c_dev;
132 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
133 if (r < 0) { /* Retry, chip was in standby */
134 usleep_range(1000, 4000);
135 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
138 if (r != ST_NCI_I2C_MIN_SIZE)
141 len = be16_to_cpu(*(__be16 *) (buf + 2));
142 if (len > ST_NCI_I2C_MAX_SIZE) {
143 nfc_err(&client->dev, "invalid frame len\n");
147 *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
151 skb_reserve(*skb, ST_NCI_I2C_MIN_SIZE);
152 skb_put(*skb, ST_NCI_I2C_MIN_SIZE);
153 memcpy((*skb)->data, buf, ST_NCI_I2C_MIN_SIZE);
158 r = i2c_master_recv(client, buf, len);
165 memcpy((*skb)->data + ST_NCI_I2C_MIN_SIZE, buf, len);
171 * Reads an ndlc frame from the chip.
173 * On ST_NCI, IRQ goes in idle state when read starts.
175 static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
177 struct st_nci_i2c_phy *phy = phy_id;
178 struct i2c_client *client;
179 struct sk_buff *skb = NULL;
182 if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) {
187 client = phy->i2c_dev;
188 dev_dbg(&client->dev, "IRQ\n");
190 if (phy->ndlc->hard_fault)
193 if (!phy->ndlc->powered) {
194 st_nci_i2c_disable(phy);
198 r = st_nci_i2c_read(phy, &skb);
199 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
202 ndlc_recv(phy->ndlc, skb);
207 static struct nfc_phy_ops i2c_phy_ops = {
208 .write = st_nci_i2c_write,
209 .enable = st_nci_i2c_enable,
210 .disable = st_nci_i2c_disable,
214 static int st_nci_i2c_of_request_resources(struct i2c_client *client)
216 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
217 struct device_node *pp;
221 pp = client->dev.of_node;
225 /* Get GPIO from device tree */
226 gpio = of_get_named_gpio(pp, "reset-gpios", 0);
228 nfc_err(&client->dev,
229 "Failed to retrieve reset-gpios from device tree\n");
233 /* GPIO request and configuration */
234 r = devm_gpio_request_one(&client->dev, gpio,
235 GPIOF_OUT_INIT_HIGH, "clf_reset");
237 nfc_err(&client->dev, "Failed to request reset pin\n");
240 phy->gpio_reset = gpio;
242 phy->irq_polarity = irq_get_trigger_type(client->irq);
244 phy->se_status.is_ese_present =
245 of_property_read_bool(pp, "ese-present");
246 phy->se_status.is_uicc_present =
247 of_property_read_bool(pp, "uicc-present");
252 static int st_nci_i2c_of_request_resources(struct i2c_client *client)
258 static int st_nci_i2c_request_resources(struct i2c_client *client)
260 struct st_nci_nfc_platform_data *pdata;
261 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
264 pdata = client->dev.platform_data;
266 nfc_err(&client->dev, "No platform data\n");
270 /* store for later use */
271 phy->gpio_reset = pdata->gpio_reset;
272 phy->irq_polarity = pdata->irq_polarity;
274 r = devm_gpio_request_one(&client->dev,
275 phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
277 pr_err("%s : reset gpio_request failed\n", __FILE__);
281 phy->se_status.is_ese_present = pdata->is_ese_present;
282 phy->se_status.is_uicc_present = pdata->is_uicc_present;
287 static int st_nci_i2c_probe(struct i2c_client *client,
288 const struct i2c_device_id *id)
290 struct st_nci_i2c_phy *phy;
291 struct st_nci_nfc_platform_data *pdata;
294 dev_dbg(&client->dev, "%s\n", __func__);
295 dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
297 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
298 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
302 phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy),
307 phy->i2c_dev = client;
309 i2c_set_clientdata(client, phy);
311 pdata = client->dev.platform_data;
312 if (!pdata && client->dev.of_node) {
313 r = st_nci_i2c_of_request_resources(client);
315 nfc_err(&client->dev, "No platform data\n");
319 r = st_nci_i2c_request_resources(client);
321 nfc_err(&client->dev,
322 "Cannot get platform resources\n");
326 nfc_err(&client->dev,
327 "st_nci platform resources not available\n");
331 r = ndlc_probe(phy, &i2c_phy_ops, &client->dev,
332 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
333 &phy->ndlc, &phy->se_status);
335 nfc_err(&client->dev, "Unable to register ndlc layer\n");
339 phy->irq_active = true;
340 r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
341 st_nci_irq_thread_fn,
342 phy->irq_polarity | IRQF_ONESHOT,
343 ST_NCI_DRIVER_NAME, phy);
345 nfc_err(&client->dev, "Unable to register IRQ handler\n");
350 static int st_nci_i2c_remove(struct i2c_client *client)
352 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
354 dev_dbg(&client->dev, "%s\n", __func__);
356 ndlc_remove(phy->ndlc);
362 static const struct of_device_id of_st_nci_i2c_match[] = {
363 { .compatible = "st,st21nfcb-i2c", },
364 { .compatible = "st,st21nfcb_i2c", },
365 { .compatible = "st,st21nfcc-i2c", },
368 MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match);
371 static struct i2c_driver st_nci_i2c_driver = {
373 .owner = THIS_MODULE,
374 .name = ST_NCI_I2C_DRIVER_NAME,
375 .of_match_table = of_match_ptr(of_st_nci_i2c_match),
377 .probe = st_nci_i2c_probe,
378 .id_table = st_nci_i2c_id_table,
379 .remove = st_nci_i2c_remove,
382 module_i2c_driver(st_nci_i2c_driver);
384 MODULE_LICENSE("GPL");
385 MODULE_DESCRIPTION(DRIVER_DESC);