2 * SPI Link Layer for ST NCI 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/spi/spi.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 <net/nfc/nci.h>
29 #include <linux/platform_data/st-nci.h>
33 #define DRIVER_DESC "NCI NFC driver for ST_NCI"
36 #define ST_NCI_FRAME_HEADROOM 1
37 #define ST_NCI_FRAME_TAILROOM 0
39 #define ST_NCI_SPI_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
40 #define ST_NCI_SPI_MAX_SIZE 250 /* req 4.2.1 */
42 #define ST_NCI_SPI_DRIVER_NAME "st_nci_spi"
44 static struct spi_device_id st_nci_spi_id_table[] = {
45 {ST_NCI_SPI_DRIVER_NAME, 0},
48 MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table);
50 struct st_nci_spi_phy {
51 struct spi_device *spi_dev;
52 struct llt_ndlc *ndlc;
56 unsigned int gpio_reset;
57 unsigned int irq_polarity;
59 struct st_nci_se_status se_status;
62 static int st_nci_spi_enable(void *phy_id)
64 struct st_nci_spi_phy *phy = phy_id;
66 gpio_set_value(phy->gpio_reset, 0);
67 usleep_range(10000, 15000);
68 gpio_set_value(phy->gpio_reset, 1);
69 usleep_range(80000, 85000);
71 if (phy->ndlc->powered == 0 && phy->irq_active == 0) {
72 enable_irq(phy->spi_dev->irq);
73 phy->irq_active = true;
79 static void st_nci_spi_disable(void *phy_id)
81 struct st_nci_spi_phy *phy = phy_id;
83 disable_irq_nosync(phy->spi_dev->irq);
84 phy->irq_active = false;
88 * Writing a frame must not return the number of written bytes.
89 * It must return either zero for success, or <0 for error.
90 * In addition, it must not alter the skb
92 static int st_nci_spi_write(void *phy_id, struct sk_buff *skb)
95 struct st_nci_spi_phy *phy = phy_id;
96 struct spi_device *dev = phy->spi_dev;
97 struct sk_buff *skb_rx;
98 u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE +
99 ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM];
100 struct spi_transfer spi_xfer = {
106 if (phy->ndlc->hard_fault != 0)
107 return phy->ndlc->hard_fault;
109 r = spi_sync_transfer(dev, &spi_xfer, 1);
111 * We may have received some valuable data on miso line.
112 * Send them back in the ndlc state machine.
115 skb_rx = alloc_skb(skb->len, GFP_KERNEL);
121 skb_put(skb_rx, skb->len);
122 memcpy(skb_rx->data, buf, skb->len);
123 ndlc_recv(phy->ndlc, skb_rx);
131 * Reads an ndlc frame and returns it in a newly allocated sk_buff.
133 * 0 : if received frame is complete
134 * -EREMOTEIO : i2c read error (fatal)
135 * -EBADMSG : frame was incorrect and discarded
136 * -ENOMEM : cannot allocate skb, frame dropped
138 static int st_nci_spi_read(struct st_nci_spi_phy *phy,
139 struct sk_buff **skb)
143 u8 buf[ST_NCI_SPI_MAX_SIZE];
144 struct spi_device *dev = phy->spi_dev;
145 struct spi_transfer spi_xfer = {
147 .len = ST_NCI_SPI_MIN_SIZE,
150 r = spi_sync_transfer(dev, &spi_xfer, 1);
154 len = be16_to_cpu(*(__be16 *) (buf + 2));
155 if (len > ST_NCI_SPI_MAX_SIZE) {
156 nfc_err(&dev->dev, "invalid frame len\n");
157 phy->ndlc->hard_fault = 1;
161 *skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL);
165 skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE);
166 skb_put(*skb, ST_NCI_SPI_MIN_SIZE);
167 memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE);
173 r = spi_sync_transfer(dev, &spi_xfer, 1);
180 memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len);
186 * Reads an ndlc frame from the chip.
188 * On ST21NFCB, IRQ goes in idle state when read starts.
190 static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
192 struct st_nci_spi_phy *phy = phy_id;
193 struct spi_device *dev;
194 struct sk_buff *skb = NULL;
197 if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) {
203 dev_dbg(&dev->dev, "IRQ\n");
205 if (phy->ndlc->hard_fault)
208 if (!phy->ndlc->powered) {
209 st_nci_spi_disable(phy);
213 r = st_nci_spi_read(phy, &skb);
214 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
217 ndlc_recv(phy->ndlc, skb);
222 static struct nfc_phy_ops spi_phy_ops = {
223 .write = st_nci_spi_write,
224 .enable = st_nci_spi_enable,
225 .disable = st_nci_spi_disable,
229 static int st_nci_spi_of_request_resources(struct spi_device *dev)
231 struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
232 struct device_node *pp;
236 pp = dev->dev.of_node;
240 /* Get GPIO from device tree */
241 gpio = of_get_named_gpio(pp, "reset-gpios", 0);
244 "Failed to retrieve reset-gpios from device tree\n");
248 /* GPIO request and configuration */
249 r = devm_gpio_request_one(&dev->dev, gpio,
250 GPIOF_OUT_INIT_HIGH, "clf_reset");
252 nfc_err(&dev->dev, "Failed to request reset pin\n");
255 phy->gpio_reset = gpio;
257 phy->irq_polarity = irq_get_trigger_type(dev->irq);
259 phy->se_status.is_ese_present =
260 of_property_read_bool(pp, "ese-present");
261 phy->se_status.is_uicc_present =
262 of_property_read_bool(pp, "uicc-present");
267 static int st_nci_spi_of_request_resources(struct spi_device *dev)
273 static int st_nci_spi_request_resources(struct spi_device *dev)
275 struct st_nci_nfc_platform_data *pdata;
276 struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
279 pdata = dev->dev.platform_data;
281 nfc_err(&dev->dev, "No platform data\n");
285 /* store for later use */
286 phy->gpio_reset = pdata->gpio_reset;
287 phy->irq_polarity = pdata->irq_polarity;
289 r = devm_gpio_request_one(&dev->dev,
290 phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
292 pr_err("%s : reset gpio_request failed\n", __FILE__);
296 phy->se_status.is_ese_present = pdata->is_ese_present;
297 phy->se_status.is_uicc_present = pdata->is_uicc_present;
302 static int st_nci_spi_probe(struct spi_device *dev)
304 struct st_nci_spi_phy *phy;
305 struct st_nci_nfc_platform_data *pdata;
308 dev_dbg(&dev->dev, "%s\n", __func__);
309 dev_dbg(&dev->dev, "IRQ: %d\n", dev->irq);
311 /* Check SPI platform functionnalities */
313 pr_debug("%s: dev is NULL. Device is not accessible.\n",
318 phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy),
325 spi_set_drvdata(dev, phy);
327 pdata = dev->dev.platform_data;
328 if (!pdata && dev->dev.of_node) {
329 r = st_nci_spi_of_request_resources(dev);
331 nfc_err(&dev->dev, "No platform data\n");
335 r = st_nci_spi_request_resources(dev);
338 "Cannot get platform resources\n");
343 "st_nci platform resources not available\n");
347 r = ndlc_probe(phy, &spi_phy_ops, &dev->dev,
348 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
349 &phy->ndlc, &phy->se_status);
351 nfc_err(&dev->dev, "Unable to register ndlc layer\n");
355 phy->irq_active = true;
356 r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL,
357 st_nci_irq_thread_fn,
358 phy->irq_polarity | IRQF_ONESHOT,
359 ST_NCI_SPI_DRIVER_NAME, phy);
361 nfc_err(&dev->dev, "Unable to register IRQ handler\n");
366 static int st_nci_spi_remove(struct spi_device *dev)
368 struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
370 dev_dbg(&dev->dev, "%s\n", __func__);
372 ndlc_remove(phy->ndlc);
378 static const struct of_device_id of_st_nci_spi_match[] = {
379 { .compatible = "st,st21nfcb-spi", },
382 MODULE_DEVICE_TABLE(of, of_st_nci_spi_match);
385 static struct spi_driver st_nci_spi_driver = {
387 .name = ST_NCI_SPI_DRIVER_NAME,
388 .of_match_table = of_match_ptr(of_st_nci_spi_match),
390 .probe = st_nci_spi_probe,
391 .id_table = st_nci_spi_id_table,
392 .remove = st_nci_spi_remove,
395 module_spi_driver(st_nci_spi_driver);
397 MODULE_LICENSE("GPL");
398 MODULE_DESCRIPTION(DRIVER_DESC);