Add tty over I3C target function driver. Signed-off-by: Frank Li <Frank.Li@xxxxxxx> --- drivers/i3c/Kconfig | 3 + drivers/i3c/Makefile | 1 + drivers/i3c/func/Kconfig | 9 + drivers/i3c/func/Makefile | 3 + drivers/i3c/func/tty.c | 475 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 491 insertions(+) create mode 100644 drivers/i3c/func/Kconfig create mode 100644 drivers/i3c/func/Makefile create mode 100644 drivers/i3c/func/tty.c diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig index d59a7eb83d13a..fca808cda87b3 100644 --- a/drivers/i3c/Kconfig +++ b/drivers/i3c/Kconfig @@ -48,3 +48,6 @@ config I3C_TARGET_CONFIGFS the target function and used to bind the function with a target controller. +if I3C_TARGET +source "drivers/i3c/func/Kconfig" +endif # I3C_TARGET diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile index c275aeae8970c..11f026d6876fe 100644 --- a/drivers/i3c/Makefile +++ b/drivers/i3c/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_I3C) += i3c.o obj-$(CONFIG_I3C_TARGET) += target.o obj-$(CONFIG_I3C_TARGET_CONFIGFS) += i3c-cfs.o obj-$(CONFIG_I3C) += master/ +obj-$(CONFIG_I3C_TARGET) += func/ diff --git a/drivers/i3c/func/Kconfig b/drivers/i3c/func/Kconfig new file mode 100644 index 0000000000000..7115129eb7d5a --- /dev/null +++ b/drivers/i3c/func/Kconfig @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0 + +config I3C_TARGET_FUNC_TTY + tristate "I3C target tty driver" + depends on I3C_TARGET + help + I3C Target TTY Function Driver. + + General TTY over I3C target controller function drivers. diff --git a/drivers/i3c/func/Makefile b/drivers/i3c/func/Makefile new file mode 100644 index 0000000000000..16b3b9301496b --- /dev/null +++ b/drivers/i3c/func/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_I3C_TARGET_FUNC_TTY) += tty.o diff --git a/drivers/i3c/func/tty.c b/drivers/i3c/func/tty.c new file mode 100644 index 0000000000000..bad99c08be0ac --- /dev/null +++ b/drivers/i3c/func/tty.c @@ -0,0 +1,475 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 NXP + * Author: Frank Li <Frank.Li@xxxxxxx> + */ + +#include <linux/iopoll.h> +#include <linux/i3c/target.h> +#include <linux/serial_core.h> +#include <linux/slab.h> +#include <linux/tty_flip.h> + +static DEFINE_IDR(i3c_tty_minors); + +static struct tty_driver *i3c_tty_driver; + +#define I3C_TTY_MINORS 8 + +#define I3C_TX_NOEMPTY BIT(0) +#define I3C_TTY_TRANS_SIZE 16 +#define I3C_TTY_IBI_TX BIT(0) + +struct ttyi3c_port { + struct tty_port port; + int minor; + struct i3c_target_func *i3cdev; + struct completion txcomplete; + spinlock_t xlock; + void *buffer; + struct work_struct work; + u16 status; + struct i3c_request *req; +}; + +static void i3c_target_tty_rx_complete(struct i3c_request *req) +{ + struct ttyi3c_port *port = req->context; + + if (req->status == I3C_REQUEST_CANCEL) { + i3c_target_ctrl_free_request(req); + return; + } + + tty_insert_flip_string(&port->port, req->buf, req->actual); + tty_flip_buffer_push(&port->port); + + req->actual = 0; + req->status = 0; + i3c_target_ctrl_queue(req, GFP_KERNEL); +} + +static void i3c_target_tty_tx_complete(struct i3c_request *req) +{ + struct ttyi3c_port *sport = req->context; + unsigned long flags; + + if (req->status == I3C_REQUEST_CANCEL) { + i3c_target_ctrl_free_request(req); + return; + } + + spin_lock_irqsave(&sport->xlock, flags); + kfifo_dma_out_finish(&sport->port.xmit_fifo, req->actual); + sport->req = NULL; + + if (kfifo_is_empty(&sport->port.xmit_fifo)) + complete(&sport->txcomplete); + else + queue_work(system_unbound_wq, &sport->work); + + if (kfifo_len(&sport->port.xmit_fifo) < WAKEUP_CHARS) + tty_port_tty_wakeup(&sport->port); + spin_unlock_irqrestore(&sport->xlock, flags); + + i3c_target_ctrl_free_request(req); +} + +static void i3c_target_tty_i3c_work(struct work_struct *work) +{ + struct ttyi3c_port *sport = container_of(work, struct ttyi3c_port, work); + struct i3c_request *req = sport->req; + struct scatterlist sg[1]; + unsigned int nents; + u8 ibi; + + if (kfifo_is_empty(&sport->port.xmit_fifo)) + return; + + if (!req) { + req = i3c_target_ctrl_alloc_request(sport->i3cdev->ctrl, GFP_KERNEL); + if (!req) + return; + + sg_init_table(sg, ARRAY_SIZE(sg)); + nents = kfifo_dma_out_prepare(&sport->port.xmit_fifo, sg, ARRAY_SIZE(sg), + UART_XMIT_SIZE); + if (!nents) + goto err; + + req->length = sg->length; + req->buf = sg_virt(sg); + + req->complete = i3c_target_tty_tx_complete; + req->context = sport; + req->tx = true; + + if (i3c_target_ctrl_queue(req, GFP_KERNEL)) + goto err; + + sport->req = req; + } + + ibi = I3C_TTY_IBI_TX; + i3c_target_ctrl_raise_ibi(sport->i3cdev->ctrl, &ibi, 1); + + return; + +err: + i3c_target_ctrl_free_request(req); +} + +static int i3c_port_activate(struct tty_port *port, struct tty_struct *tty) +{ + struct ttyi3c_port *sport = container_of(port, struct ttyi3c_port, port); + const struct i3c_target_ctrl_features *feature; + struct i3c_target_func *func = sport->i3cdev; + struct i3c_request *req; + int rxfifo_size; + int offset = 0; + int ret; + + feature = i3c_target_ctrl_get_features(func->ctrl); + if (!feature) + return -EINVAL; + + ret = tty_port_alloc_xmit_buf(port); + if (ret) + return ret; + + sport->buffer = (void *)get_zeroed_page(GFP_KERNEL); + if (!sport->buffer) + goto err_alloc_rx_buf; + + rxfifo_size = feature->rx_fifo_sz; + + if (!rxfifo_size) + rxfifo_size = I3C_TTY_TRANS_SIZE; + + do { + req = i3c_target_ctrl_alloc_request(func->ctrl, GFP_KERNEL); + if (!req) + goto err_alloc_req; + + req->buf = (void *) (sport->buffer + offset); + req->length = rxfifo_size; + req->context = sport; + req->complete = i3c_target_tty_rx_complete; + offset += rxfifo_size; + + if (i3c_target_ctrl_queue(req, GFP_KERNEL)) + goto err_alloc_req; + } while (req && (offset + rxfifo_size) < UART_XMIT_SIZE); + + reinit_completion(&sport->txcomplete); + + return 0; + +err_alloc_req: + i3c_target_ctrl_cancel_all_reqs(func->ctrl, false); + free_page((unsigned long)sport->buffer); +err_alloc_rx_buf: + tty_port_free_xmit_buf(port); + return -ENOMEM; +} + +static void i3c_port_shutdown(struct tty_port *port) +{ + struct ttyi3c_port *sport = + container_of(port, struct ttyi3c_port, port); + + cancel_work_sync(&sport->work); + + i3c_target_ctrl_cancel_all_reqs(sport->i3cdev->ctrl, true); + i3c_target_ctrl_cancel_all_reqs(sport->i3cdev->ctrl, false); + + i3c_target_ctrl_fifo_flush(sport->i3cdev->ctrl, true); + i3c_target_ctrl_fifo_flush(sport->i3cdev->ctrl, false); + + tty_port_free_xmit_buf(port); + free_page((unsigned long)sport->buffer); +} + +static void i3c_port_destruct(struct tty_port *port) +{ + struct ttyi3c_port *sport = + container_of(port, struct ttyi3c_port, port); + + idr_remove(&i3c_tty_minors, sport->minor); +} + +static const struct tty_port_operations i3c_port_ops = { + .shutdown = i3c_port_shutdown, + .activate = i3c_port_activate, + .destruct = i3c_port_destruct, +}; + +static int i3c_target_tty_bind(struct i3c_target_func *func) +{ + struct ttyi3c_port *sport; + struct device *tty_dev; + int minor; + int ret; + + sport = dev_get_drvdata(&func->dev); + + if (i3c_target_ctrl_set_config(func->ctrl, func)) { + dev_err(&func->dev, "failure set i3c config\n"); + return -EINVAL; + } + + spin_lock_init(&sport->xlock); + init_completion(&sport->txcomplete); + + ret = minor = idr_alloc(&i3c_tty_minors, sport, 0, I3C_TTY_MINORS, GFP_KERNEL); + + if (minor < 0) + goto err_idr_alloc; + + tty_port_init(&sport->port); + sport->port.ops = &i3c_port_ops; + + tty_dev = tty_port_register_device(&sport->port, i3c_tty_driver, minor, + &func->dev); + if (IS_ERR(tty_dev)) { + ret = PTR_ERR(tty_dev); + goto err_register_port; + } + + sport->minor = minor; + ret = i3c_target_ctrl_enable(func->ctrl); + if (ret) + goto err_ctrl_enable; + + return 0; + +err_ctrl_enable: + tty_port_unregister_device(&sport->port, i3c_tty_driver, sport->minor); +err_register_port: + idr_remove(&i3c_tty_minors, sport->minor); +err_idr_alloc: + i3c_target_ctrl_cancel_all_reqs(func->ctrl, false); + dev_err(&func->dev, "bind failure\n"); + + return ret; +} + +static void i3c_target_tty_unbind(struct i3c_target_func *func) +{ + struct ttyi3c_port *sport; + + sport = dev_get_drvdata(&func->dev); + + cancel_work_sync(&sport->work); + + i3c_target_ctrl_disable(func->ctrl); + i3c_target_ctrl_cancel_all_reqs(func->ctrl, 0); + i3c_target_ctrl_cancel_all_reqs(func->ctrl, 1); + + tty_port_unregister_device(&sport->port, i3c_tty_driver, sport->minor); + + free_page((unsigned long)sport->buffer); +} + +static struct i3c_target_func_ops i3c_func_ops = { + .bind = i3c_target_tty_bind, + .unbind = i3c_target_tty_unbind, +}; + +static int i3c_tty_probe(struct i3c_target_func *func) +{ + struct device *dev = &func->dev; + struct ttyi3c_port *port; + + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL); + if (!port) + return -ENOMEM; + + port->i3cdev = func; + dev_set_drvdata(&func->dev, port); + + INIT_WORK(&port->work, i3c_target_tty_i3c_work); + + return 0; +} + +static ssize_t i3c_write(struct tty_struct *tty, const unsigned char *buf, size_t count) +{ + struct ttyi3c_port *sport = tty->driver_data; + unsigned long flags; + bool is_empty; + int ret = 0; + + spin_lock_irqsave(&sport->xlock, flags); + ret = kfifo_in(&sport->port.xmit_fifo, buf, count); + is_empty = kfifo_is_empty(&sport->port.xmit_fifo); + i3c_target_ctrl_set_status_format1(sport->i3cdev->ctrl, sport->status | I3C_TX_NOEMPTY); + spin_unlock_irqrestore(&sport->xlock, flags); + + if (!is_empty) + queue_work(system_unbound_wq, &sport->work); + + return ret; +} + +static int i3c_put_char(struct tty_struct *tty, unsigned char ch) +{ + struct ttyi3c_port *sport = tty->driver_data; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&sport->xlock, flags); + ret = kfifo_put(&sport->port.xmit_fifo, ch); + spin_unlock_irqrestore(&sport->xlock, flags); + + return ret; +} + +static void i3c_flush_chars(struct tty_struct *tty) +{ + struct ttyi3c_port *sport = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&sport->xlock, flags); + if (!kfifo_is_empty(&sport->port.xmit_fifo)) + queue_work(system_unbound_wq, &sport->work); + spin_unlock_irqrestore(&sport->xlock, flags); +} + +static unsigned int i3c_write_room(struct tty_struct *tty) +{ + struct ttyi3c_port *sport = tty->driver_data; + + return kfifo_avail(&sport->port.xmit_fifo); +} + +static void i3c_throttle(struct tty_struct *tty) +{ + struct ttyi3c_port *sport = tty->driver_data; + + i3c_target_ctrl_cancel_all_reqs(sport->i3cdev->ctrl, false); +} + +static void i3c_unthrottle(struct tty_struct *tty) +{ + struct ttyi3c_port *sport = tty->driver_data; + + i3c_port_activate(&sport->port, tty); +} + +static int i3c_open(struct tty_struct *tty, struct file *filp) +{ + struct ttyi3c_port *sport = container_of(tty->port, struct ttyi3c_port, port); + int ret; + + tty->driver_data = sport; + + if (!i3c_target_ctrl_get_addr(sport->i3cdev->ctrl)) { + dev_dbg(&sport->i3cdev->dev, "No target addr assigned, try hotjoin"); + ret = i3c_target_ctrl_hotjoin(sport->i3cdev->ctrl); + if (ret) { + dev_err(&sport->i3cdev->dev, "Hotjoin failure, check connection"); + return ret; + } + } + + return tty_port_open(&sport->port, tty, filp); +} + +static void i3c_close(struct tty_struct *tty, struct file *filp) +{ + tty_port_close(tty->port, tty, filp); +} + +static void i3c_wait_until_sent(struct tty_struct *tty, int timeout) +{ + struct ttyi3c_port *sport = tty->driver_data; + int val; + int ret; + u8 ibi = I3C_TTY_IBI_TX; + int retry = 100; + + if (!kfifo_is_empty(&sport->port.xmit_fifo)) { + do { + ret = wait_for_completion_timeout(&sport->txcomplete, timeout / 100); + if (ret) + break; + i3c_target_ctrl_raise_ibi(sport->i3cdev->ctrl, &ibi, 1); + } while (retry--); + + reinit_completion(&sport->txcomplete); + } + + read_poll_timeout(i3c_target_ctrl_fifo_status, val, !val, 100, timeout, false, + sport->i3cdev->ctrl, true); + + i3c_target_ctrl_set_status_format1(sport->i3cdev->ctrl, sport->status & (~I3C_TX_NOEMPTY)); +} + +static const struct tty_operations i3c_tty_ops = { + .open = i3c_open, + .close = i3c_close, + .write = i3c_write, + .put_char = i3c_put_char, + .flush_chars = i3c_flush_chars, + .write_room = i3c_write_room, + .throttle = i3c_throttle, + .unthrottle = i3c_unthrottle, + .wait_until_sent = i3c_wait_until_sent, +}; + +DECLARE_I3C_TARGET_FUNC(tty, i3c_tty_probe, NULL, &i3c_func_ops); + +static int __init i3c_tty_init(void) +{ + int ret; + + i3c_tty_driver = tty_alloc_driver( + I3C_TTY_MINORS, TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV); + + if (IS_ERR(i3c_tty_driver)) + return PTR_ERR(i3c_tty_driver); + + i3c_tty_driver->driver_name = "ttySI3C", i3c_tty_driver->name = "ttySI3C", + i3c_tty_driver->minor_start = 0, + i3c_tty_driver->type = TTY_DRIVER_TYPE_SERIAL, + i3c_tty_driver->subtype = SERIAL_TYPE_NORMAL, + i3c_tty_driver->init_termios = tty_std_termios; + i3c_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | + CLOCAL; + i3c_tty_driver->init_termios.c_lflag = 0; + + tty_set_operations(i3c_tty_driver, &i3c_tty_ops); + + ret = tty_register_driver(i3c_tty_driver); + if (ret) + goto err_register_tty_driver; + + ret = i3c_target_func_register_driver(&ttyi3c_func); + if (ret) + goto err_register_i3c_driver; + + return 0; + +err_register_i3c_driver: + tty_unregister_driver(i3c_tty_driver); + +err_register_tty_driver: + tty_driver_kref_put(i3c_tty_driver); + + return ret; +} + +static void __exit i3c_tty_exit(void) +{ + i3c_target_func_unregister_driver(&ttyi3c_func); + tty_unregister_driver(i3c_tty_driver); + tty_driver_kref_put(i3c_tty_driver); + idr_destroy(&i3c_tty_minors); +} + +module_init(i3c_tty_init); +module_exit(i3c_tty_exit); + +MODULE_LICENSE("GPL"); + -- 2.34.1