1 // SPDX-License-Identifier: GPL-2.0-only
3 * SPI Link Layer for ST NCI based Driver
4 * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved.
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/module.h>
10 #include <linux/spi/spi.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/acpi.h>
13 #include <linux/interrupt.h>
14 #include <linux/delay.h>
15 #include <linux/nfc.h>
17 #include <net/nfc/nci.h>
21 #define DRIVER_DESC "NCI NFC driver for ST_NCI"
24 #define ST_NCI_FRAME_HEADROOM 1
25 #define ST_NCI_FRAME_TAILROOM 0
27 #define ST_NCI_SPI_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
28 #define ST_NCI_SPI_MAX_SIZE 250 /* req 4.2.1 */
30 #define ST_NCI_DRIVER_NAME "st_nci"
31 #define ST_NCI_SPI_DRIVER_NAME "st_nci_spi"
33 struct st_nci_spi_phy {
34 struct spi_device *spi_dev;
35 struct llt_ndlc *ndlc;
39 struct gpio_desc *gpiod_reset;
41 struct st_nci_se_status se_status;
44 static int st_nci_spi_enable(void *phy_id)
46 struct st_nci_spi_phy *phy = phy_id;
48 gpiod_set_value(phy->gpiod_reset, 0);
49 usleep_range(10000, 15000);
50 gpiod_set_value(phy->gpiod_reset, 1);
51 usleep_range(80000, 85000);
53 if (phy->ndlc->powered == 0 && phy->irq_active == 0) {
54 enable_irq(phy->spi_dev->irq);
55 phy->irq_active = true;
61 static void st_nci_spi_disable(void *phy_id)
63 struct st_nci_spi_phy *phy = phy_id;
65 disable_irq_nosync(phy->spi_dev->irq);
66 phy->irq_active = false;
70 * Writing a frame must not return the number of written bytes.
71 * It must return either zero for success, or <0 for error.
72 * In addition, it must not alter the skb
74 static int st_nci_spi_write(void *phy_id, struct sk_buff *skb)
77 struct st_nci_spi_phy *phy = phy_id;
78 struct spi_device *dev = phy->spi_dev;
79 struct sk_buff *skb_rx;
80 u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE +
81 ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM];
82 struct spi_transfer spi_xfer = {
88 if (phy->ndlc->hard_fault != 0)
89 return phy->ndlc->hard_fault;
91 r = spi_sync_transfer(dev, &spi_xfer, 1);
93 * We may have received some valuable data on miso line.
94 * Send them back in the ndlc state machine.
97 skb_rx = alloc_skb(skb->len, GFP_KERNEL);
103 skb_put(skb_rx, skb->len);
104 memcpy(skb_rx->data, buf, skb->len);
105 ndlc_recv(phy->ndlc, skb_rx);
113 * Reads an ndlc frame and returns it in a newly allocated sk_buff.
115 * 0 : if received frame is complete
116 * -EREMOTEIO : i2c read error (fatal)
117 * -EBADMSG : frame was incorrect and discarded
118 * -ENOMEM : cannot allocate skb, frame dropped
120 static int st_nci_spi_read(struct st_nci_spi_phy *phy,
121 struct sk_buff **skb)
125 u8 buf[ST_NCI_SPI_MAX_SIZE];
126 struct spi_device *dev = phy->spi_dev;
127 struct spi_transfer spi_xfer = {
129 .len = ST_NCI_SPI_MIN_SIZE,
132 r = spi_sync_transfer(dev, &spi_xfer, 1);
136 len = be16_to_cpu(*(__be16 *) (buf + 2));
137 if (len > ST_NCI_SPI_MAX_SIZE) {
138 nfc_err(&dev->dev, "invalid frame len\n");
139 phy->ndlc->hard_fault = 1;
143 *skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL);
147 skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE);
148 skb_put(*skb, ST_NCI_SPI_MIN_SIZE);
149 memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE);
155 r = spi_sync_transfer(dev, &spi_xfer, 1);
162 memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len);
168 * Reads an ndlc frame from the chip.
170 * On ST21NFCB, IRQ goes in idle state when read starts.
172 static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
174 struct st_nci_spi_phy *phy = phy_id;
175 struct spi_device *dev;
176 struct sk_buff *skb = NULL;
179 if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) {
185 dev_dbg(&dev->dev, "IRQ\n");
187 if (phy->ndlc->hard_fault)
190 if (!phy->ndlc->powered) {
191 st_nci_spi_disable(phy);
195 r = st_nci_spi_read(phy, &skb);
196 if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
199 ndlc_recv(phy->ndlc, skb);
204 static struct nfc_phy_ops spi_phy_ops = {
205 .write = st_nci_spi_write,
206 .enable = st_nci_spi_enable,
207 .disable = st_nci_spi_disable,
210 static const struct acpi_gpio_params reset_gpios = { 1, 0, false };
212 static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = {
213 { "reset-gpios", &reset_gpios, 1 },
217 static int st_nci_spi_probe(struct spi_device *dev)
219 struct st_nci_spi_phy *phy;
222 dev_dbg(&dev->dev, "%s\n", __func__);
223 dev_dbg(&dev->dev, "IRQ: %d\n", dev->irq);
225 /* Check SPI platform functionnalities */
227 pr_debug("%s: dev is NULL. Device is not accessible.\n",
232 phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy),
239 spi_set_drvdata(dev, phy);
241 r = devm_acpi_dev_add_driver_gpios(&dev->dev, acpi_st_nci_gpios);
243 dev_dbg(&dev->dev, "Unable to add GPIO mapping table\n");
246 phy->gpiod_reset = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH);
247 if (IS_ERR(phy->gpiod_reset)) {
248 nfc_err(&dev->dev, "Unable to get RESET GPIO\n");
249 return PTR_ERR(phy->gpiod_reset);
252 phy->se_status.is_ese_present =
253 device_property_read_bool(&dev->dev, "ese-present");
254 phy->se_status.is_uicc_present =
255 device_property_read_bool(&dev->dev, "uicc-present");
257 r = ndlc_probe(phy, &spi_phy_ops, &dev->dev,
258 ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
259 &phy->ndlc, &phy->se_status);
261 nfc_err(&dev->dev, "Unable to register ndlc layer\n");
265 phy->irq_active = true;
266 r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL,
267 st_nci_irq_thread_fn,
269 ST_NCI_SPI_DRIVER_NAME, phy);
271 nfc_err(&dev->dev, "Unable to register IRQ handler\n");
276 static int st_nci_spi_remove(struct spi_device *dev)
278 struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
280 dev_dbg(&dev->dev, "%s\n", __func__);
282 ndlc_remove(phy->ndlc);
287 static struct spi_device_id st_nci_spi_id_table[] = {
288 {ST_NCI_SPI_DRIVER_NAME, 0},
291 MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table);
293 static const struct acpi_device_id st_nci_spi_acpi_match[] = {
297 MODULE_DEVICE_TABLE(acpi, st_nci_spi_acpi_match);
299 static const struct of_device_id of_st_nci_spi_match[] = {
300 { .compatible = "st,st21nfcb-spi", },
303 MODULE_DEVICE_TABLE(of, of_st_nci_spi_match);
305 static struct spi_driver st_nci_spi_driver = {
307 .name = ST_NCI_SPI_DRIVER_NAME,
308 .of_match_table = of_match_ptr(of_st_nci_spi_match),
309 .acpi_match_table = ACPI_PTR(st_nci_spi_acpi_match),
311 .probe = st_nci_spi_probe,
312 .id_table = st_nci_spi_id_table,
313 .remove = st_nci_spi_remove,
315 module_spi_driver(st_nci_spi_driver);
317 MODULE_LICENSE("GPL");
318 MODULE_DESCRIPTION(DRIVER_DESC);