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;
53 unsigned int gpio_reset;
54 unsigned int irq_polarity;
57 #define I2C_DUMP_SKB(info, skb) \
59 pr_debug("%s:\n", info); \
60 print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \
61 16, 1, (skb)->data, (skb)->len, 0); \
64 static int st_nci_i2c_enable(void *phy_id)
66 struct st_nci_i2c_phy *phy = phy_id;
68 gpio_set_value(phy->gpio_reset, 0);
69 usleep_range(10000, 15000);
70 gpio_set_value(phy->gpio_reset, 1);
71 usleep_range(80000, 85000);
73 if (phy->ndlc->powered == 0)
74 enable_irq(phy->i2c_dev->irq);
79 static void st_nci_i2c_disable(void *phy_id)
81 struct st_nci_i2c_phy *phy = phy_id;
83 disable_irq_nosync(phy->i2c_dev->irq);
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 I2C_DUMP_SKB("st_nci_i2c_write", skb);
99 if (phy->ndlc->hard_fault != 0)
100 return phy->ndlc->hard_fault;
102 r = i2c_master_send(client, skb->data, skb->len);
103 if (r < 0) { /* Retry, chip was in standby */
104 usleep_range(1000, 4000);
105 r = i2c_master_send(client, skb->data, skb->len);
119 * Reads an ndlc frame and returns it in a newly allocated sk_buff.
121 * 0 : if received frame is complete
122 * -EREMOTEIO : i2c read error (fatal)
123 * -EBADMSG : frame was incorrect and discarded
124 * -ENOMEM : cannot allocate skb, frame dropped
126 static int st_nci_i2c_read(struct st_nci_i2c_phy *phy,
127 struct sk_buff **skb)
131 u8 buf[ST_NCI_I2C_MAX_SIZE];
132 struct i2c_client *client = phy->i2c_dev;
134 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
135 if (r < 0) { /* Retry, chip was in standby */
136 usleep_range(1000, 4000);
137 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
140 if (r != ST_NCI_I2C_MIN_SIZE)
143 len = be16_to_cpu(*(__be16 *) (buf + 2));
144 if (len > ST_NCI_I2C_MAX_SIZE) {
145 nfc_err(&client->dev, "invalid frame len\n");
149 *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
153 skb_reserve(*skb, ST_NCI_I2C_MIN_SIZE);
154 skb_put(*skb, ST_NCI_I2C_MIN_SIZE);
155 memcpy((*skb)->data, buf, ST_NCI_I2C_MIN_SIZE);
160 r = i2c_master_recv(client, buf, len);
167 memcpy((*skb)->data + ST_NCI_I2C_MIN_SIZE, buf, len);
169 I2C_DUMP_SKB("i2c frame read", *skb);
175 * Reads an ndlc frame from the chip.
177 * On ST_NCI, IRQ goes in idle state when read starts.
179 static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
181 struct st_nci_i2c_phy *phy = phy_id;
182 struct i2c_client *client;
183 struct sk_buff *skb = NULL;
186 if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) {
191 client = phy->i2c_dev;
192 dev_dbg(&client->dev, "IRQ\n");
194 if (phy->ndlc->hard_fault)
197 if (!phy->ndlc->powered) {
198 st_nci_i2c_disable(phy);
202 r = st_nci_i2c_read(phy, &skb);
203 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
206 ndlc_recv(phy->ndlc, skb);
211 static struct nfc_phy_ops i2c_phy_ops = {
212 .write = st_nci_i2c_write,
213 .enable = st_nci_i2c_enable,
214 .disable = st_nci_i2c_disable,
218 static int st_nci_i2c_of_request_resources(struct i2c_client *client)
220 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
221 struct device_node *pp;
225 pp = client->dev.of_node;
229 /* Get GPIO from device tree */
230 gpio = of_get_named_gpio(pp, "reset-gpios", 0);
232 nfc_err(&client->dev,
233 "Failed to retrieve reset-gpios from device tree\n");
237 /* GPIO request and configuration */
238 r = devm_gpio_request_one(&client->dev, gpio,
239 GPIOF_OUT_INIT_HIGH, "clf_reset");
241 nfc_err(&client->dev, "Failed to request reset pin\n");
244 phy->gpio_reset = gpio;
246 phy->irq_polarity = irq_get_trigger_type(client->irq);
251 static int st_nci_i2c_of_request_resources(struct i2c_client *client)
257 static int st_nci_i2c_request_resources(struct i2c_client *client)
259 struct st_nci_nfc_platform_data *pdata;
260 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
263 pdata = client->dev.platform_data;
265 nfc_err(&client->dev, "No platform data\n");
269 /* store for later use */
270 phy->gpio_reset = pdata->gpio_reset;
271 phy->irq_polarity = pdata->irq_polarity;
273 r = devm_gpio_request_one(&client->dev,
274 phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
276 pr_err("%s : reset gpio_request failed\n", __FILE__);
283 static int st_nci_i2c_probe(struct i2c_client *client,
284 const struct i2c_device_id *id)
286 struct st_nci_i2c_phy *phy;
287 struct st_nci_nfc_platform_data *pdata;
290 dev_dbg(&client->dev, "%s\n", __func__);
291 dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
293 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
294 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
298 phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy),
303 phy->i2c_dev = client;
305 i2c_set_clientdata(client, phy);
307 pdata = client->dev.platform_data;
308 if (!pdata && client->dev.of_node) {
309 r = st_nci_i2c_of_request_resources(client);
311 nfc_err(&client->dev, "No platform data\n");
315 r = st_nci_i2c_request_resources(client);
317 nfc_err(&client->dev,
318 "Cannot get platform resources\n");
322 nfc_err(&client->dev,
323 "st_nci platform resources not available\n");
327 r = ndlc_probe(phy, &i2c_phy_ops, &client->dev,
328 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
331 nfc_err(&client->dev, "Unable to register ndlc layer\n");
335 r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
336 st_nci_irq_thread_fn,
337 phy->irq_polarity | IRQF_ONESHOT,
338 ST_NCI_DRIVER_NAME, phy);
340 nfc_err(&client->dev, "Unable to register IRQ handler\n");
345 static int st_nci_i2c_remove(struct i2c_client *client)
347 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
349 dev_dbg(&client->dev, "%s\n", __func__);
351 ndlc_remove(phy->ndlc);
357 static const struct of_device_id of_st_nci_i2c_match[] = {
358 { .compatible = "st,st21nfcb-i2c", },
359 { .compatible = "st,st21nfcb_i2c", },
360 { .compatible = "st,st21nfcc-i2c", },
363 MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match);
366 static struct i2c_driver st_nci_i2c_driver = {
368 .owner = THIS_MODULE,
369 .name = ST_NCI_I2C_DRIVER_NAME,
370 .of_match_table = of_match_ptr(of_st_nci_i2c_match),
372 .probe = st_nci_i2c_probe,
373 .id_table = st_nci_i2c_id_table,
374 .remove = st_nci_i2c_remove,
377 module_i2c_driver(st_nci_i2c_driver);
379 MODULE_LICENSE("GPL");
380 MODULE_DESCRIPTION(DRIVER_DESC);