@@ -25,3 +25,13 @@ config NFC_PN533_I2C
If you choose to build a module, it'll be called pn533_i2c.
Say N if unsure.
+
+config NFC_PN532_UART
+ tristate "NFC PN532 device support (UART)"
+ select NFC_PN533
+ ---help---
+ This module adds support for the NXP pn532 UART interface.
+ Select this if your platform is using the UART bus.
+
+ If you choose to build a module, it'll be called pn532_uart.
+ Say N if unsure.
@@ -3,7 +3,9 @@
#
pn533_usb-objs = usb.o
pn533_i2c-objs = i2c.o
+pn532_uart-objs = uart.o
obj-$(CONFIG_NFC_PN533) += pn533.o
obj-$(CONFIG_NFC_PN533_USB) += pn533_usb.o
obj-$(CONFIG_NFC_PN533_I2C) += pn533_i2c.o
+obj-$(CONFIG_NFC_PN532_UART) += pn532_uart.o
@@ -55,6 +55,11 @@
/* Preamble (1), SoPC (2), ACK Code (2), Postamble (1) */
#define PN533_STD_FRAME_ACK_SIZE 6
+/*
+ * Preamble (1), SoPC (2), Packet Length (1), Packet Length Checksum (1),
+ * Specific Application Level Error Code (1) , Postamble (1)
+ */
+#define PN533_STD_ERROR_FRAME_SIZE 8
#define PN533_STD_FRAME_CHECKSUM(f) (f->data[f->datalen])
#define PN533_STD_FRAME_POSTAMBLE(f) (f->data[f->datalen + 1])
/* Half start code (3), LEN (4) should be 0xffff for extended frame */
@@ -96,6 +101,9 @@
#define PN533_CMD_MI_MASK 0x40
#define PN533_CMD_RET_SUCCESS 0x00
+#define PN533_FRAME_DATALEN_ACK 0x00
+#define PN533_FRAME_DATALEN_ERROR 0x01
+#define PN533_FRAME_DATALEN_EXTENDED 0xFF
enum pn533_protocol_type {
PN533_PROTO_REQ_ACK_RESP = 0,
new file mode 100644
@@ -0,0 +1,399 @@
+/*
+ * Driver for NXP PN532 NFC Chip - UART transport layer
+ *
+ * Copyright (C) 2018 Lemonage Software GmbH
+ * Author: Lars Poeschel <poeschel@lemonage.de>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/nfc.h>
+#include <linux/netdevice.h>
+#include <net/nfc/nfc.h>
+#include "pn533.h"
+
+#define VERSION "0.1"
+
+#define PN532_I2C_DRIVER_NAME "pn532_uart"
+
+#define PN532_MAGIC 0x162f
+#define PN532_UART_SKB_BUFF_LEN (PN533_CMD_DATAEXCH_DATA_MAXLEN * 2)
+
+struct pn532_uart_phy {
+ int magic;
+ struct tty_struct *tty;
+ struct sk_buff *recv_skb;
+ struct pn533 *priv;
+ int send_wakeup;
+ struct timer_list cmd_timeout;
+ struct sk_buff *cur_out_buf;
+ struct workqueue_struct *wq_open_tty;
+ struct work_struct open_tty_work;
+ struct completion init_done;
+};
+
+static int pn532_uart_send_frame(struct pn533 *dev,
+ struct sk_buff *out)
+{
+ static const u8 wakeup[] = {
+ 0x55, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+ /* wakeup sequence and dummy bytes for waiting time */
+ struct pn532_uart_phy *pn532 = dev->phy;
+ struct tty_struct *tty = pn532->tty;
+ int count;
+
+ if (pn532->priv == NULL)
+ pn532->priv = dev;
+
+ print_hex_dump_debug("PN532_uart TX: ", DUMP_PREFIX_NONE, 16, 1,
+ out->data, out->len, false);
+
+ pn532->cur_out_buf = out;
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ if (pn532->send_wakeup)
+ count = tty->ops->write(tty, wakeup, sizeof(wakeup));
+
+ count = tty->ops->write(tty, out->data, out->len);
+ if (PN533_FRAME_CMD(((struct pn533_std_frame *)out->data)) ==
+ PN533_CMD_SAM_CONFIGURATION)
+ pn532->send_wakeup = 0;
+
+ mod_timer(&pn532->cmd_timeout, HZ / 40 + jiffies);
+ return 0;
+}
+
+static int pn532_uart_send_ack(struct pn533 *dev, gfp_t flags)
+{
+ struct pn532_uart_phy *phy = dev->phy;
+ static const u8 ack[PN533_STD_FRAME_ACK_SIZE] = {
+ 0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
+ /* spec 7.1.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */
+ int rc;
+
+ set_bit(TTY_DO_WRITE_WAKEUP, &phy->tty->flags);
+ rc = phy->tty->ops->write(phy->tty, ack, sizeof(ack));
+
+ return 0;
+}
+
+static void pn532_uart_abort_cmd(struct pn533 *dev, gfp_t flags)
+{
+ /* An ack will cancel the last issued command */
+ pn532_uart_send_ack(dev, flags);
+
+ /* schedule cmd_complete_work to finish current command execution */
+ pn533_recv_frame(dev, NULL, -ENOENT);
+}
+
+static struct pn533_phy_ops uart_phy_ops = {
+ .send_frame = pn532_uart_send_frame,
+ .send_ack = pn532_uart_send_ack,
+ .abort_cmd = pn532_uart_abort_cmd,
+};
+
+static void pn532_cmd_timeout(struct timer_list *t)
+{
+ struct pn532_uart_phy *dev = from_timer(dev, t, cmd_timeout);
+
+ pn532_uart_send_frame(dev->priv, dev->cur_out_buf);
+}
+
+static void pn532_finalize_setup(struct work_struct *work)
+{
+ struct pn532_uart_phy *pn532 =
+ container_of(work, struct pn532_uart_phy, open_tty_work);
+ int err;
+
+ err = pn533_finalize_setup(pn532->priv);
+ if (err) {
+ complete_all(&pn532->init_done);
+ return;
+ }
+
+ pn532->magic = PN532_MAGIC;
+ complete_all(&pn532->init_done);
+}
+
+static int pn532_open(struct tty_struct *tty)
+{
+ struct pn532_uart_phy *pn532;
+ struct pn533 *priv;
+ int err;
+
+ if (tty->ops->write == NULL)
+ return -EOPNOTSUPP;
+
+ pn532 = tty->disc_data;
+ err = -EEXIST;
+ /* First make sure we're not already connected. */
+ if (pn532 && pn532->magic == PN532_MAGIC)
+ goto err_exit;
+
+ err = -ENOMEM;
+ pn532 = kzalloc(sizeof(*pn532), GFP_KERNEL);
+ if (pn532 == NULL)
+ goto err_exit;
+
+ pn532->recv_skb = alloc_skb(PN532_UART_SKB_BUFF_LEN, GFP_KERNEL);
+ if (pn532->recv_skb == NULL)
+ goto err_free;
+
+ pn532->tty = tty;
+ INIT_WORK(&pn532->open_tty_work, pn532_finalize_setup);
+ pn532->wq_open_tty = alloc_workqueue("pn532_uart_finalize_setup", 0, 0);
+ if (pn532->wq_open_tty == NULL)
+ goto err_skb;
+
+ priv = pn533_register_device(PN533_DEVICE_PN532,
+ PN533_NO_TYPE_B_PROTOCOLS,
+ PN533_PROTO_REQ_ACK_RESP,
+ pn532, &uart_phy_ops, NULL,
+ pn532->tty->dev,
+ tty->dev);
+
+ if (IS_ERR(priv)) {
+ err = PTR_ERR(priv);
+ goto err_wq;
+ }
+
+ pn532->priv = priv;
+ tty->disc_data = pn532;
+ init_completion(&pn532->init_done);
+
+ /* Done. We have linked the TTY line to a channel. */
+ pn532->tty->receive_room = 262 * 2;
+ pn532->send_wakeup = 1;
+ timer_setup(&pn532->cmd_timeout, pn532_cmd_timeout, 0);
+ queue_work(pn532->wq_open_tty, &pn532->open_tty_work);
+ /* TTY layer expects 0 on success */
+ return 0;
+
+err_wq:
+ destroy_workqueue(pn532->wq_open_tty);
+err_skb:
+ kfree_skb(pn532->recv_skb);
+err_free:
+ kfree(pn532);
+err_exit:
+ /* Count references from TTY module */
+ return err;
+}
+
+static void pn532_close(struct tty_struct *tty)
+{
+ struct pn532_uart_phy *pn532 = (struct pn532_uart_phy *) tty->disc_data;
+
+ /* First make sure we're connected. */
+ if (!pn532 || pn532->magic != PN532_MAGIC || pn532->tty != tty)
+ return;
+
+ flush_workqueue(pn532->wq_open_tty);
+ destroy_workqueue(pn532->wq_open_tty);
+ pn533_unregister_device(pn532->priv);
+
+ kfree_skb(pn532->recv_skb);
+ kfree(pn532);
+}
+
+static int pn532_hangup(struct tty_struct *tty)
+{
+ pn532_close(tty);
+ return 0;
+}
+
+/* Perform I/O control on an active PN532 line discipline channel. */
+static int pn532_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct pn532_uart_phy *pn532 = (struct pn532_uart_phy *) tty->disc_data;
+ unsigned int tmp;
+
+ wait_for_completion(&pn532->init_done);
+ flush_workqueue(pn532->wq_open_tty);
+ /* First make sure we're connected. */
+ if (!pn532 || pn532->magic != PN532_MAGIC)
+ return -EINVAL;
+
+ switch (cmd) {
+ case SIOCGIFNAME:
+ if (!pn532->priv->nfc_dev) {
+ dev_err(tty->dev, "The device was not (successfully) connected before.\n");
+ return -EINVAL;
+ }
+ tmp = strlen(nfc_device_name(pn532->priv->nfc_dev)) + 1;
+ if (copy_to_user((void __user *)arg,
+ nfc_device_name(pn532->priv->nfc_dev), tmp))
+ return -EFAULT;
+
+ return 0;
+
+ case SIOCSIFHWADDR:
+ return -EINVAL;
+
+ default:
+ return tty_mode_ioctl(tty, file, cmd, arg);
+ }
+}
+
+/*
+ * scans the buffer if it contains a pn532 frame. It is not checked if the
+ * frame is really valid. This is later done with pn533_rx_frame_is_valid.
+ * This is useful for malformed or errornous transmitted frames. Adjusts the
+ * bufferposition where the frame starts, since pn533_recv_frame expects a
+ * well formed frame.
+ */
+static int pn532_uart_rx_is_frame(struct sk_buff *skb, struct tty_struct *tty)
+{
+ int i;
+ u16 frame_len;
+ struct pn533_std_frame *std;
+ struct pn533_ext_frame *ext;
+
+ for (i = 0; i + PN533_STD_FRAME_ACK_SIZE <= skb->len; i++) {
+ std = (struct pn533_std_frame *)&skb->data[i];
+ /* search start code */
+ if (std->start_frame != cpu_to_be16(PN533_STD_FRAME_SOF))
+ continue;
+
+ /* frame type */
+ switch (std->datalen) {
+ case PN533_FRAME_DATALEN_ACK:
+ dev_dbg(tty->dev, "ack frame");
+ if (std->datalen_checksum == 0xff) {
+ skb_pull(skb, i);
+ return 1;
+ }
+
+ break;
+ case PN533_FRAME_DATALEN_ERROR:
+ dev_dbg(tty->dev, "error frame");
+ if ((std->datalen_checksum == 0xff) &&
+ (skb->len >=
+ PN533_STD_ERROR_FRAME_SIZE)) {
+ skb_pull(skb, i);
+ return 1;
+ }
+
+ break;
+ case PN533_FRAME_DATALEN_EXTENDED:
+ dev_dbg(tty->dev, "extended frame");
+ ext = (struct pn533_ext_frame *)&skb->data[i];
+ frame_len = ext->datalen;
+ if (skb->len >= frame_len +
+ sizeof(struct pn533_ext_frame) +
+ 2 /* CKS + Postamble */) {
+ skb_pull(skb, i);
+ return 1;
+ }
+
+ break;
+ default: /* normal information frame */
+ frame_len = std->datalen;
+ if (skb->len >= frame_len +
+ sizeof(struct pn533_std_frame) +
+ 2 /* CKS + Postamble */) {
+ skb_pull(skb, i);
+ return 1;
+ }
+
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static void pn532_receive_buf(struct tty_struct *tty,
+ const unsigned char *cp, char *fp, int count)
+{
+ struct pn532_uart_phy *dev = (struct pn532_uart_phy *)tty->disc_data;
+
+ if (!dev)
+ return;
+
+ del_timer(&dev->cmd_timeout);
+ while (count-- && (skb_end_offset(dev->recv_skb) > 1)) {
+ if (fp && *fp++) {
+ cp++;
+ continue;
+ }
+
+ skb_put_u8(dev->recv_skb, *cp++);
+ if (!pn532_uart_rx_is_frame(dev->recv_skb, tty))
+ continue;
+
+ pn533_recv_frame(dev->priv, dev->recv_skb, 0);
+ dev->recv_skb = alloc_skb(PN532_UART_SKB_BUFF_LEN, GFP_KERNEL);
+ if (dev->recv_skb == NULL)
+ return;
+ }
+}
+
+static void pn532_write_wakeup(struct tty_struct *tty)
+{
+ struct pn532_uart_phy *pn532 = (struct pn532_uart_phy *)tty->disc_data;
+
+ if (!pn532 || pn532->magic != PN532_MAGIC)
+ return;
+
+ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+}
+
+static struct tty_ldisc_ops pn532_ldisc = {
+ .owner = THIS_MODULE,
+ .magic = TTY_LDISC_MAGIC,
+ .name = "pn532",
+ .open = pn532_open,
+ .close = pn532_close,
+ .hangup = pn532_hangup,
+ .ioctl = pn532_ioctl,
+ .receive_buf = pn532_receive_buf,
+ .write_wakeup = pn532_write_wakeup,
+};
+
+static int __init pn532_init(void)
+{
+ int ret;
+
+ ret = tty_register_ldisc(N_PN532, &pn532_ldisc);
+ if (ret)
+ pr_err("pn532: can not register line discipline\n");
+
+ return ret;
+}
+
+static void __exit pn532_exit(void)
+{
+ int ret;
+
+ ret = tty_unregister_ldisc(N_PN532);
+ if (ret)
+ pr_err("pn532: can not unregister ldisc (err %d)\n", ret);
+}
+
+module_init(pn532_init);
+module_exit(pn532_exit);
+
+MODULE_ALIAS_LDISC(N_PN532);
+MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
+MODULE_DESCRIPTION("PN532 UART driver ver " VERSION);
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");
@@ -38,5 +38,6 @@
#define N_NCI 25 /* NFC NCI UART */
#define N_SPEAKUP 26 /* Speakup communication with synths */
#define N_NULL 27 /* Null ldisc used for error handling */
+#define N_PN532 28 /* NXP PN532 NFC chip */
#endif /* _UAPI_LINUX_TTY_H */
This adds the UART phy interface for the pn533 driver. The pn533 driver can be used through UART interface this way. It is implemented as a tty line discipline. Signed-off-by: Lars Poeschel <poeschel@lemonage.de> --- drivers/nfc/pn533/Kconfig | 10 + drivers/nfc/pn533/Makefile | 2 + drivers/nfc/pn533/pn533.h | 8 + drivers/nfc/pn533/uart.c | 399 +++++++++++++++++++++++++++++++++++++ include/uapi/linux/tty.h | 1 + 5 files changed, 420 insertions(+) create mode 100644 drivers/nfc/pn533/uart.c