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/consumer.h>
23 #include <linux/acpi.h>
24 #include <linux/interrupt.h>
25 #include <linux/delay.h>
26 #include <linux/nfc.h>
31 #define DRIVER_DESC "NCI NFC driver for ST_NCI"
34 #define ST_NCI_FRAME_HEADROOM 1
35 #define ST_NCI_FRAME_TAILROOM 0
37 #define ST_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
38 #define ST_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */
40 #define ST_NCI_DRIVER_NAME "st_nci"
41 #define ST_NCI_I2C_DRIVER_NAME "st_nci_i2c"
43 struct st_nci_i2c_phy {
44 struct i2c_client *i2c_dev;
45 struct llt_ndlc *ndlc;
49 struct gpio_desc *gpiod_reset;
51 struct st_nci_se_status se_status;
54 static int st_nci_i2c_enable(void *phy_id)
56 struct st_nci_i2c_phy *phy = phy_id;
58 gpiod_set_value(phy->gpiod_reset, 0);
59 usleep_range(10000, 15000);
60 gpiod_set_value(phy->gpiod_reset, 1);
61 usleep_range(80000, 85000);
63 if (phy->ndlc->powered == 0 && phy->irq_active == 0) {
64 enable_irq(phy->i2c_dev->irq);
65 phy->irq_active = true;
71 static void st_nci_i2c_disable(void *phy_id)
73 struct st_nci_i2c_phy *phy = phy_id;
75 disable_irq_nosync(phy->i2c_dev->irq);
76 phy->irq_active = false;
80 * Writing a frame must not return the number of written bytes.
81 * It must return either zero for success, or <0 for error.
82 * In addition, it must not alter the skb
84 static int st_nci_i2c_write(void *phy_id, struct sk_buff *skb)
87 struct st_nci_i2c_phy *phy = phy_id;
88 struct i2c_client *client = phy->i2c_dev;
90 if (phy->ndlc->hard_fault != 0)
91 return phy->ndlc->hard_fault;
93 r = i2c_master_send(client, skb->data, skb->len);
94 if (r < 0) { /* Retry, chip was in standby */
95 usleep_range(1000, 4000);
96 r = i2c_master_send(client, skb->data, skb->len);
110 * Reads an ndlc frame and returns it in a newly allocated sk_buff.
112 * 0 : if received frame is complete
113 * -EREMOTEIO : i2c read error (fatal)
114 * -EBADMSG : frame was incorrect and discarded
115 * -ENOMEM : cannot allocate skb, frame dropped
117 static int st_nci_i2c_read(struct st_nci_i2c_phy *phy,
118 struct sk_buff **skb)
122 u8 buf[ST_NCI_I2C_MAX_SIZE];
123 struct i2c_client *client = phy->i2c_dev;
125 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
126 if (r < 0) { /* Retry, chip was in standby */
127 usleep_range(1000, 4000);
128 r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
131 if (r != ST_NCI_I2C_MIN_SIZE)
134 len = be16_to_cpu(*(__be16 *) (buf + 2));
135 if (len > ST_NCI_I2C_MAX_SIZE) {
136 nfc_err(&client->dev, "invalid frame len\n");
140 *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
144 skb_reserve(*skb, ST_NCI_I2C_MIN_SIZE);
145 skb_put(*skb, ST_NCI_I2C_MIN_SIZE);
146 memcpy((*skb)->data, buf, ST_NCI_I2C_MIN_SIZE);
151 r = i2c_master_recv(client, buf, len);
158 memcpy((*skb)->data + ST_NCI_I2C_MIN_SIZE, buf, len);
164 * Reads an ndlc frame from the chip.
166 * On ST_NCI, IRQ goes in idle state when read starts.
168 static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
170 struct st_nci_i2c_phy *phy = phy_id;
171 struct i2c_client *client;
172 struct sk_buff *skb = NULL;
175 if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) {
180 client = phy->i2c_dev;
181 dev_dbg(&client->dev, "IRQ\n");
183 if (phy->ndlc->hard_fault)
186 if (!phy->ndlc->powered) {
187 st_nci_i2c_disable(phy);
191 r = st_nci_i2c_read(phy, &skb);
192 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
195 ndlc_recv(phy->ndlc, skb);
200 static struct nfc_phy_ops i2c_phy_ops = {
201 .write = st_nci_i2c_write,
202 .enable = st_nci_i2c_enable,
203 .disable = st_nci_i2c_disable,
206 static const struct acpi_gpio_params reset_gpios = { 1, 0, false };
208 static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = {
209 { "reset-gpios", &reset_gpios, 1 },
213 static int st_nci_i2c_acpi_request_resources(struct i2c_client *client)
215 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
216 struct device *dev = &client->dev;
219 r = devm_acpi_dev_add_driver_gpios(dev, acpi_st_nci_gpios);
223 /* Get RESET GPIO from ACPI */
224 phy->gpiod_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
225 if (IS_ERR(phy->gpiod_reset)) {
226 nfc_err(dev, "Unable to get RESET GPIO\n");
233 static int st_nci_i2c_of_request_resources(struct i2c_client *client)
235 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
236 struct device *dev = &client->dev;
238 /* Get GPIO from device tree */
239 phy->gpiod_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
240 if (IS_ERR(phy->gpiod_reset)) {
241 nfc_err(dev, "Unable to get RESET GPIO\n");
242 return PTR_ERR(phy->gpiod_reset);
248 static int st_nci_i2c_probe(struct i2c_client *client,
249 const struct i2c_device_id *id)
251 struct device *dev = &client->dev;
252 struct st_nci_i2c_phy *phy;
255 dev_dbg(&client->dev, "%s\n", __func__);
256 dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
258 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
259 nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
263 phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy),
268 phy->i2c_dev = client;
270 i2c_set_clientdata(client, phy);
272 if (client->dev.of_node) {
273 r = st_nci_i2c_of_request_resources(client);
275 nfc_err(&client->dev, "No platform data\n");
278 } else if (ACPI_HANDLE(&client->dev)) {
279 r = st_nci_i2c_acpi_request_resources(client);
281 nfc_err(&client->dev, "Cannot get ACPI data\n");
285 nfc_err(&client->dev,
286 "st_nci platform resources not available\n");
290 phy->se_status.is_ese_present =
291 device_property_read_bool(dev, "ese-present");
292 phy->se_status.is_uicc_present =
293 device_property_read_bool(dev, "uicc-present");
295 r = ndlc_probe(phy, &i2c_phy_ops, &client->dev,
296 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
297 &phy->ndlc, &phy->se_status);
299 nfc_err(&client->dev, "Unable to register ndlc layer\n");
303 phy->irq_active = true;
304 r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
305 st_nci_irq_thread_fn,
307 ST_NCI_DRIVER_NAME, phy);
309 nfc_err(&client->dev, "Unable to register IRQ handler\n");
314 static int st_nci_i2c_remove(struct i2c_client *client)
316 struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
318 dev_dbg(&client->dev, "%s\n", __func__);
320 ndlc_remove(phy->ndlc);
325 static struct i2c_device_id st_nci_i2c_id_table[] = {
326 {ST_NCI_DRIVER_NAME, 0},
329 MODULE_DEVICE_TABLE(i2c, st_nci_i2c_id_table);
331 static const struct acpi_device_id st_nci_i2c_acpi_match[] = {
336 MODULE_DEVICE_TABLE(acpi, st_nci_i2c_acpi_match);
338 static const struct of_device_id of_st_nci_i2c_match[] = {
339 { .compatible = "st,st21nfcb-i2c", },
340 { .compatible = "st,st21nfcb_i2c", },
341 { .compatible = "st,st21nfcc-i2c", },
344 MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match);
346 static struct i2c_driver st_nci_i2c_driver = {
348 .name = ST_NCI_I2C_DRIVER_NAME,
349 .of_match_table = of_match_ptr(of_st_nci_i2c_match),
350 .acpi_match_table = ACPI_PTR(st_nci_i2c_acpi_match),
352 .probe = st_nci_i2c_probe,
353 .id_table = st_nci_i2c_id_table,
354 .remove = st_nci_i2c_remove,
356 module_i2c_driver(st_nci_i2c_driver);
358 MODULE_LICENSE("GPL");
359 MODULE_DESCRIPTION(DRIVER_DESC);