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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/nfc/pn533/uart.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/nfc/pn533/uart.c')
| -rw-r--r-- | drivers/nfc/pn533/uart.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c new file mode 100644 index 000000000..83c1ccda0 --- /dev/null +++ b/drivers/nfc/pn533/uart.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for NXP PN532 NFC Chip - UART transport layer + * + * Copyright (C) 2018 Lemonage Software GmbH + * Author: Lars Pöschel <poeschel@lemonage.de> + * All rights reserved. + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/nfc.h> +#include <linux/netdevice.h> +#include <linux/of.h> +#include <linux/serdev.h> +#include "pn533.h" + +#define PN532_UART_SKB_BUFF_LEN (PN533_CMD_DATAEXCH_DATA_MAXLEN * 2) + +enum send_wakeup { + PN532_SEND_NO_WAKEUP = 0, + PN532_SEND_WAKEUP, + PN532_SEND_LAST_WAKEUP, +}; + + +struct pn532_uart_phy { + struct serdev_device *serdev; + struct sk_buff *recv_skb; + struct pn533 *priv; + /* + * send_wakeup variable is used to control if we need to send a wakeup + * request to the pn532 chip prior to our actual command. There is a + * little propability of a race condition. We decided to not mutex the + * variable as the worst that could happen is, that we send a wakeup + * to the chip that is already awake. This does not hurt. It is a + * no-op to the chip. + */ + enum send_wakeup send_wakeup; + struct timer_list cmd_timeout; + struct sk_buff *cur_out_buf; +}; + +static int pn532_uart_send_frame(struct pn533 *dev, + struct sk_buff *out) +{ + /* wakeup sequence and dummy bytes for waiting time */ + static const u8 wakeup[] = { + 0x55, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; + struct pn532_uart_phy *pn532 = dev->phy; + int err; + + print_hex_dump_debug("PN532_uart TX: ", DUMP_PREFIX_NONE, 16, 1, + out->data, out->len, false); + + pn532->cur_out_buf = out; + if (pn532->send_wakeup) { + err = serdev_device_write(pn532->serdev, + wakeup, sizeof(wakeup), + MAX_SCHEDULE_TIMEOUT); + if (err < 0) + return err; + } + + if (pn532->send_wakeup == PN532_SEND_LAST_WAKEUP) + pn532->send_wakeup = PN532_SEND_NO_WAKEUP; + + err = serdev_device_write(pn532->serdev, out->data, out->len, + MAX_SCHEDULE_TIMEOUT); + if (err < 0) + return err; + + mod_timer(&pn532->cmd_timeout, HZ / 40 + jiffies); + return 0; +} + +static int pn532_uart_send_ack(struct pn533 *dev, gfp_t flags) +{ + /* spec 7.1.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */ + static const u8 ack[PN533_STD_FRAME_ACK_SIZE] = { + 0x00, 0x00, 0xff, 0x00, 0xff, 0x00}; + struct pn532_uart_phy *pn532 = dev->phy; + int err; + + err = serdev_device_write(pn532->serdev, ack, sizeof(ack), + MAX_SCHEDULE_TIMEOUT); + if (err < 0) + return err; + + 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 int pn532_dev_up(struct pn533 *dev) +{ + struct pn532_uart_phy *pn532 = dev->phy; + int ret = 0; + + ret = serdev_device_open(pn532->serdev); + if (ret) + return ret; + + pn532->send_wakeup = PN532_SEND_LAST_WAKEUP; + return ret; +} + +static int pn532_dev_down(struct pn533 *dev) +{ + struct pn532_uart_phy *pn532 = dev->phy; + + serdev_device_close(pn532->serdev); + pn532->send_wakeup = PN532_SEND_WAKEUP; + + return 0; +} + +static const 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, + .dev_up = pn532_dev_up, + .dev_down = pn532_dev_down, +}; + +static void pn532_cmd_timeout(struct timer_list *t) +{ + struct pn532_uart_phy *dev = timer_container_of(dev, t, cmd_timeout); + + pn532_uart_send_frame(dev->priv, dev->cur_out_buf); +} + +/* + * 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 pn533_std_frame *std; + struct pn533_ext_frame *ext; + u16 frame_len; + int i; + + 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: + if (std->datalen_checksum == 0xff) { + skb_pull(skb, i); + return 1; + } + + break; + case PN533_FRAME_DATALEN_ERROR: + if ((std->datalen_checksum == 0xff) && + (skb->len >= + PN533_STD_ERROR_FRAME_SIZE)) { + skb_pull(skb, i); + return 1; + } + + break; + case PN533_FRAME_DATALEN_EXTENDED: + ext = (struct pn533_ext_frame *)&skb->data[i]; + frame_len = be16_to_cpu(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 size_t pn532_receive_buf(struct serdev_device *serdev, + const u8 *data, size_t count) +{ + struct pn532_uart_phy *dev = serdev_device_get_drvdata(serdev); + size_t i; + + timer_delete(&dev->cmd_timeout); + for (i = 0; i < count; i++) { + if (!dev->recv_skb) { + dev->recv_skb = alloc_skb(PN532_UART_SKB_BUFF_LEN, + GFP_KERNEL); + if (!dev->recv_skb) + return i; + } + + if (unlikely(!skb_tailroom(dev->recv_skb))) + skb_trim(dev->recv_skb, 0); + + skb_put_u8(dev->recv_skb, *data++); + if (!pn532_uart_rx_is_frame(dev->recv_skb)) + continue; + + pn533_recv_frame(dev->priv, dev->recv_skb, 0); + dev->recv_skb = NULL; + } + + return i; +} + +static const struct serdev_device_ops pn532_serdev_ops = { + .receive_buf = pn532_receive_buf, + .write_wakeup = serdev_device_write_wakeup, +}; + +static const struct of_device_id pn532_uart_of_match[] = { + { .compatible = "nxp,pn532" }, + { } +}; +MODULE_DEVICE_TABLE(of, pn532_uart_of_match); + +static int pn532_uart_probe(struct serdev_device *serdev) +{ + struct pn532_uart_phy *pn532; + struct pn533 *priv; + int err; + + err = -ENOMEM; + pn532 = kzalloc_obj(*pn532); + if (!pn532) + goto err_exit; + + pn532->recv_skb = alloc_skb(PN532_UART_SKB_BUFF_LEN, GFP_KERNEL); + if (!pn532->recv_skb) + goto err_free; + + pn532->serdev = serdev; + serdev_device_set_drvdata(serdev, pn532); + serdev_device_set_client_ops(serdev, &pn532_serdev_ops); + err = serdev_device_open(serdev); + if (err) { + dev_err(&serdev->dev, "Unable to open device\n"); + goto err_skb; + } + + err = serdev_device_set_baudrate(serdev, 115200); + if (err != 115200) { + err = -EINVAL; + goto err_serdev; + } + + serdev_device_set_flow_control(serdev, false); + pn532->send_wakeup = PN532_SEND_WAKEUP; + timer_setup(&pn532->cmd_timeout, pn532_cmd_timeout, 0); + priv = pn53x_common_init(PN533_DEVICE_PN532_AUTOPOLL, + PN533_PROTO_REQ_ACK_RESP, + pn532, &uart_phy_ops, NULL, + &pn532->serdev->dev); + if (IS_ERR(priv)) { + err = PTR_ERR(priv); + goto err_serdev; + } + + pn532->priv = priv; + err = pn533_finalize_setup(pn532->priv); + if (err) + goto err_clean; + + serdev_device_close(serdev); + err = pn53x_register_nfc(priv, PN533_NO_TYPE_B_PROTOCOLS, &serdev->dev); + if (err) { + pn53x_common_clean(pn532->priv); + goto err_skb; + } + + return err; + +err_clean: + pn53x_common_clean(pn532->priv); +err_serdev: + serdev_device_close(serdev); +err_skb: + kfree_skb(pn532->recv_skb); +err_free: + kfree(pn532); +err_exit: + return err; +} + +static void pn532_uart_remove(struct serdev_device *serdev) +{ + struct pn532_uart_phy *pn532 = serdev_device_get_drvdata(serdev); + + pn53x_unregister_nfc(pn532->priv); + serdev_device_close(serdev); + pn53x_common_clean(pn532->priv); + timer_shutdown_sync(&pn532->cmd_timeout); + kfree_skb(pn532->recv_skb); + kfree(pn532); +} + +static struct serdev_device_driver pn532_uart_driver = { + .probe = pn532_uart_probe, + .remove = pn532_uart_remove, + .driver = { + .name = "pn532_uart", + .of_match_table = pn532_uart_of_match, + }, +}; + +module_serdev_device_driver(pn532_uart_driver); + +MODULE_AUTHOR("Lars Pöschel <poeschel@lemonage.de>"); +MODULE_DESCRIPTION("PN532 UART driver"); +MODULE_LICENSE("GPL"); |
