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Wed, 18 Oct 2023 21:58:45 +0000 From: Frank Li To: miquel.raynal@bootlin.com, conor.culhane@silvaco.com, alexandre.belloni@bootlin.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, corbet@lwn.net, joe@perches.com, Frank.Li@nxp.com, linux-i3c@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Cc: gregkh@linuxfoundation.org, imx@lists.linux.dev, jirislaby@kernel.org, linux-serial@vger.kernel.org Subject: [PATCH 4/5] i3c: slave: func: add tty driver Date: Wed, 18 Oct 2023 17:58:08 -0400 Message-Id: <20231018215809.3477437-5-Frank.Li@nxp.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231018215809.3477437-1-Frank.Li@nxp.com> References: <20231018215809.3477437-1-Frank.Li@nxp.com> X-ClientProxiedBy: SJ0PR03CA0225.namprd03.prod.outlook.com (2603:10b6:a03:39f::20) To AM6PR04MB4838.eurprd04.prod.outlook.com (2603:10a6:20b:4::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: AM6PR04MB4838:EE_|DB9PR04MB9750:EE_ X-MS-Office365-Filtering-Correlation-Id: da267885-dddc-4eb2-fdcb-08dbd0256670 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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Signed-off-by: Frank Li --- 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 + */ + +#include +#include +#include +#include +#include + +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"); +