Add tty over I3C slave function driver.
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
drivers/i3c/Kconfig | 1 +
drivers/i3c/Makefile | 1 +
drivers/i3c/func/Kconfig | 9 +
drivers/i3c/func/Makefile | 3 +
drivers/i3c/func/tty.c | 548 ++++++++++++++++++++++++++++++++++++++
5 files changed, 562 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 802a9b3576f13..9b87cb4a84d85 100644
--- a/drivers/i3c/Kconfig
+++ b/drivers/i3c/Kconfig
@@ -50,4 +50,5 @@ config I3C_SLAVE_CONFIGFS
if I3C_SLAVE
source "drivers/i3c/slave/Kconfig"
+source "drivers/i3c/func/Kconfig"
endif # I3C_SLAVE
diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile
index ef1acbe13fe60..7814bf2dd9b40 100644
--- a/drivers/i3c/Makefile
+++ b/drivers/i3c/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_I3C) += master/
obj-$(CONFIG_I3C_SLAVE) += slave.o
obj-$(CONFIG_I3C_SLAVE_CONFIGFS) += i3c-cfs.o
obj-$(CONFIG_I3C_SLAVE) += slave/
+obj-$(CONFIG_I3C_SLAVE) += func/
diff --git a/drivers/i3c/func/Kconfig b/drivers/i3c/func/Kconfig
new file mode 100644
index 0000000000000..3ebf5bd2592a2
--- /dev/null
+++ b/drivers/i3c/func/Kconfig
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config I3C_SLAVE_FUNC_TTY
+ tristate "PCI Endpoint Test driver"
+ depends on I3C_SLAVE
+ help
+ I3C Slave TTY Function Driver.
+
+ General TTY over I3C slave controller function drivers.
diff --git a/drivers/i3c/func/Makefile b/drivers/i3c/func/Makefile
new file mode 100644
index 0000000000000..db3262e402edd
--- /dev/null
+++ b/drivers/i3c/func/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_I3C_SLAVE_FUNC_TTY) += tty.o
diff --git a/drivers/i3c/func/tty.c b/drivers/i3c/func/tty.c
new file mode 100644
index 0000000000000..ea48db49b2764
--- /dev/null
+++ b/drivers/i3c/func/tty.c
@@ -0,0 +1,548 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 NXP
+ * Author: Frank Li <Frank.Li@xxxxxxx>
+ */
+
+#include <linux/iopoll.h>
+#include <linux/i3c/slave.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+
+static DEFINE_IDR(i3c_tty_minors);
+static DEFINE_MUTEX(i3c_tty_minors_lock);
+
+static struct tty_driver *i3c_tty_driver;
+
+#define I3C_TTY_MINORS 256
+
+#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_slave_func *i3cdev;
+ struct circ_buf xmit;
+ int tail_in_queue;
+ struct completion txcomplete;
+ spinlock_t xlock;
+ void *buffer;
+ struct work_struct work;
+ struct workqueue_struct *workqueue;
+ u16 status;
+};
+
+static void i3c_slave_tty_rx_complete(struct i3c_request *req)
+{
+ struct ttyi3c_port *port = req->context;
+
+ if (req->status == I3C_REQUEST_CANCEL) {
+ i3c_slave_ctrl_free_request(req);
+ return;
+ }
+
+ for (int i = 0; i < req->actual; i++)
+ tty_insert_flip_char(&port->port, *(u8 *)(req->buf + i), 0);
+
+ tty_flip_buffer_push(&port->port);
+ req->actual = 0;
+ req->status = 0;
+ i3c_slave_ctrl_queue(req, GFP_KERNEL);
+}
+
+static void i3c_slave_tty_tx_complete(struct i3c_request *req)
+{
+ struct ttyi3c_port *sport = req->context;
+ struct circ_buf *xmit = &sport->xmit;
+ unsigned long flags;
+ int cnt;
+
+ if (req->status == I3C_REQUEST_CANCEL) {
+ i3c_slave_ctrl_free_request(req);
+ return;
+ }
+
+ spin_lock_irqsave(&sport->xlock, flags);
+ xmit->tail = (xmit->tail + req->actual) & (UART_XMIT_SIZE - 1);
+ cnt = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ if (cnt == 0)
+ complete(&sport->txcomplete);
+ else
+ queue_work(sport->workqueue, &sport->work);
+
+ spin_unlock_irqrestore(&sport->xlock, flags);
+
+ if (cnt < WAKEUP_CHARS)
+ tty_port_tty_wakeup(&sport->port);
+
+ i3c_slave_ctrl_free_request(req);
+}
+
+static void i3c_slave_tty_i3c_work(struct work_struct *work)
+{
+ struct ttyi3c_port *sport = container_of(work, struct ttyi3c_port, work);
+ struct circ_buf *xmit = &sport->xmit;
+ int cnt = CIRC_CNT(xmit->head, sport->tail_in_queue, UART_XMIT_SIZE);
+ u8 ibi;
+
+ if (cnt == 0)
+ return;
+
+ while (cnt > 0) {
+ struct i3c_request *req = i3c_slave_ctrl_alloc_request(sport->i3cdev->ctrl,
+ GFP_KERNEL);
+ if (!req)
+ return;
+
+ req->length = CIRC_CNT_TO_END(xmit->head, sport->tail_in_queue, UART_XMIT_SIZE);
+
+ req->buf = xmit->buf + sport->tail_in_queue;
+ req->complete = i3c_slave_tty_tx_complete;
+ req->context = sport;
+ req->tx = true;
+
+ if (i3c_slave_ctrl_queue(req, GFP_KERNEL))
+ return;
+
+ sport->tail_in_queue += req->length;
+ sport->tail_in_queue &= UART_XMIT_SIZE - 1;
+
+ cnt = CIRC_CNT(xmit->head, sport->tail_in_queue, UART_XMIT_SIZE);
+ }
+
+ ibi = I3C_TTY_IBI_TX;
+ i3c_slave_ctrl_raise_ibi(sport->i3cdev->ctrl, &ibi, 1);
+}
+
+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_slave_ctrl_features *feature;
+ struct i3c_slave_func *func = sport->i3cdev;
+ struct i3c_request *req;
+ int rxfifo_size;
+ int offset = 0;
+
+ feature = i3c_slave_ctrl_get_features(func->ctrl);
+ if (!feature)
+ return -EINVAL;
+
+ rxfifo_size = feature->rx_fifo_sz;
+
+ if (!rxfifo_size)
+ rxfifo_size = I3C_TTY_TRANS_SIZE;
+
+ do {
+ req = i3c_slave_ctrl_alloc_request(func->ctrl, GFP_KERNEL);
+ if (!req)
+ goto err;
+
+ req->buf = (void *) (sport->buffer + offset);
+ req->length = rxfifo_size;
+ req->context = sport;
+ req->complete = i3c_slave_tty_rx_complete;
+ offset += rxfifo_size;
+
+ if (i3c_slave_ctrl_queue(req, GFP_KERNEL))
+ goto err;
+ } while (req && (offset + rxfifo_size) < UART_XMIT_SIZE);
+
+ reinit_completion(&sport->txcomplete);
+
+ return 0;
+err:
+ i3c_slave_ctrl_cancel_all_reqs(func->ctrl, false);
+ 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_slave_ctrl_cancel_all_reqs(sport->i3cdev->ctrl, true);
+ i3c_slave_ctrl_cancel_all_reqs(sport->i3cdev->ctrl, false);
+
+ sport->xmit.tail = sport->tail_in_queue = sport->xmit.head;
+
+ i3c_slave_ctrl_fifo_flush(sport->i3cdev->ctrl, true);
+ i3c_slave_ctrl_fifo_flush(sport->i3cdev->ctrl, false);
+}
+
+static void i3c_port_destruct(struct tty_port *port)
+{
+ struct ttyi3c_port *sport =
+ container_of(port, struct ttyi3c_port, port);
+
+ mutex_lock(&i3c_tty_minors_lock);
+ idr_remove(&i3c_tty_minors, sport->minor);
+ mutex_unlock(&i3c_tty_minors_lock);
+}
+
+static const struct tty_port_operations i3c_port_ops = {
+ .shutdown = i3c_port_shutdown,
+ .activate = i3c_port_activate,
+ .destruct = i3c_port_destruct,
+};
+
+static int i3c_slave_tty_bind(struct i3c_slave_func *func)
+{
+ struct ttyi3c_port *sport;
+ struct device *tty_dev;
+ int minor;
+ int ret;
+
+ sport = dev_get_drvdata(&func->dev);
+
+ if (i3c_slave_ctrl_set_config(func->ctrl, func)) {
+ dev_err(&func->dev, "failure set i3c config\n");
+ return -EINVAL;
+ }
+
+ sport->buffer = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!sport->buffer)
+ return -ENOMEM;
+
+ sport->xmit.buf = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!sport->xmit.buf)
+ goto err_alloc_xmit;
+
+
+ spin_lock_init(&sport->xlock);
+ init_completion(&sport->txcomplete);
+
+ mutex_lock(&i3c_tty_minors_lock);
+ ret = minor = idr_alloc(&i3c_tty_minors, sport, 0, I3C_TTY_MINORS, GFP_KERNEL);
+ mutex_unlock(&i3c_tty_minors_lock);
+
+ 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_slave_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:
+ mutex_lock(&i3c_tty_minors_lock);
+ idr_remove(&i3c_tty_minors, sport->minor);
+ mutex_unlock(&i3c_tty_minors_lock);
+err_idr_alloc:
+ i3c_slave_ctrl_cancel_all_reqs(func->ctrl, false);
+ free_page((unsigned long)sport->xmit.buf);
+err_alloc_xmit:
+ free_page((unsigned long)sport->buffer);
+
+ dev_err(&func->dev, "bind failure\n");
+
+ return ret;
+}
+
+static void i3c_slave_tty_unbind(struct i3c_slave_func *func)
+{
+ struct ttyi3c_port *sport;
+
+ sport = dev_get_drvdata(&func->dev);
+
+ cancel_work_sync(&sport->work);
+
+ i3c_slave_ctrl_disable(func->ctrl);
+ i3c_slave_ctrl_cancel_all_reqs(func->ctrl, 0);
+ i3c_slave_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_slave_func_ops i3c_func_ops = {
+ .bind = i3c_slave_tty_bind,
+ .unbind = i3c_slave_tty_unbind,
+};
+
+static int i3c_tty_probe(struct i3c_slave_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);
+
+ port->workqueue = alloc_workqueue("%s", 0, 0, dev_name(&func->dev));
+ if (!port->workqueue)
+ return -ENOMEM;
+
+ INIT_WORK(&port->work, i3c_slave_tty_i3c_work);
+
+ return 0;
+}
+
+static void i3c_tty_remove(struct i3c_slave_func *func)
+{
+ struct ttyi3c_port *port;
+
+ port = dev_get_drvdata(&func->dev);
+
+ destroy_workqueue(port->workqueue);
+}
+
+static struct ttyi3c_port *i3c_get_by_minor(unsigned int minor)
+{
+ struct ttyi3c_port *sport;
+
+ mutex_lock(&i3c_tty_minors_lock);
+ sport = idr_find(&i3c_tty_minors, minor);
+ mutex_unlock(&i3c_tty_minors_lock);
+
+ return sport;
+}
+
+static int i3c_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ struct ttyi3c_port *sport;
+ int ret;
+
+ sport = i3c_get_by_minor(tty->index);
+ if (!sport)
+ return -ENODEV;
+
+ ret = tty_standard_install(driver, tty);
+ if (ret)
+ return ret;
+
+ tty->driver_data = sport;
+
+ 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;
+ struct circ_buf *circ = &sport->xmit;
+ unsigned long flags;
+ int c, ret = 0;
+
+ spin_lock_irqsave(&sport->xlock, flags);
+ while (1) {
+ c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
+ if (count < c)
+ c = count;
+ if (c <= 0)
+ break;
+
+ memcpy(circ->buf + circ->head, buf, c);
+ circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+ i3c_slave_ctrl_set_status_format1(sport->i3cdev->ctrl, sport->status | I3C_TX_NOEMPTY);
+ spin_unlock_irqrestore(&sport->xlock, flags);
+
+ if (circ->head != circ->tail)
+ queue_work(sport->workqueue, &sport->work);
+
+ return ret;
+}
+
+static int i3c_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ struct ttyi3c_port *sport = tty->driver_data;
+ struct circ_buf *circ = &sport->xmit;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&sport->xlock, flags);
+
+ if (sport && CIRC_SPACE(circ->head, circ->tail, UART_XMIT_SIZE) != 0) {
+ circ->buf[circ->head] = ch;
+ circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
+ ret = 1;
+ }
+
+ spin_unlock_irqrestore(&sport->xlock, flags);
+
+ return ret;
+}
+
+static void i3c_flush_chars(struct tty_struct *tty)
+{
+ struct ttyi3c_port *sport = tty->driver_data;
+ struct circ_buf *circ = &sport->xmit;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->xlock, flags);
+ if (CIRC_SPACE(circ->head, circ->tail, UART_XMIT_SIZE))
+ queue_work(sport->workqueue, &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;
+ struct circ_buf *circ = &sport->xmit;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&sport->xlock, flags);
+ ret = CIRC_SPACE(circ->head, circ->tail, UART_XMIT_SIZE);
+ spin_unlock_irqrestore(&sport->xlock, flags);
+
+ return ret;
+}
+
+static void i3c_throttle(struct tty_struct *tty)
+{
+ struct ttyi3c_port *sport = tty->driver_data;
+
+ i3c_slave_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 = tty->driver_data;
+ int ret;
+
+ if (!i3c_slave_ctrl_get_addr(sport->i3cdev->ctrl)) {
+ dev_info(&sport->i3cdev->dev, "No slave addr assigned, try hotjoin");
+ ret = i3c_slave_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)
+{
+ struct ttyi3c_port *sport = tty->driver_data;
+
+ if (!sport)
+ return;
+
+ 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;
+ struct circ_buf *circ = &sport->xmit;
+ int val;
+ int ret;
+ u8 ibi = I3C_TTY_IBI_TX;
+ int retry = 100;
+
+ if (circ->head != circ->tail) {
+
+ do {
+ ret = wait_for_completion_timeout(&sport->txcomplete, timeout / 100);
+ if (ret)
+ break;
+ i3c_slave_ctrl_raise_ibi(sport->i3cdev->ctrl, &ibi, 1);
+ } while (retry--);
+
+ reinit_completion(&sport->txcomplete);
+ }
+
+ read_poll_timeout(i3c_slave_ctrl_fifo_status, val, !val, 100, timeout, false,
+ sport->i3cdev->ctrl, true);
+
+ i3c_slave_ctrl_set_status_format1(sport->i3cdev->ctrl, sport->status & (~I3C_TX_NOEMPTY));
+}
+
+static const struct tty_operations i3c_tty_ops = {
+ .install = i3c_install,
+ .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_SLAVE_FUNC(tty, i3c_tty_probe, i3c_tty_remove, &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) {
+ tty_driver_kref_put(i3c_tty_driver);
+ return ret;
+ }
+
+ ret = i3c_slave_func_register_driver(&ttyi3c_func);
+ if (ret) {
+ tty_unregister_driver(i3c_tty_driver);
+ tty_driver_kref_put(i3c_tty_driver);
+ }
+
+ return ret;
+}
+
+static void __exit i3c_tty_exit(void)
+{
+ i3c_slave_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
