On 4/5/19 12:12 PM, xiang xiao wrote: > On Fri, Apr 5, 2019 at 12:14 AM Arnaud Pouliquen > <arnaud.pouliquen@xxxxxx> wrote: >> >> Hello Xiang, >> >> >> On 4/3/19 2:47 PM, xiang xiao wrote: >>> On Thu, Mar 21, 2019 at 11:48 PM Fabien Dessenne <fabien.dessenne@xxxxxx> wrote: >>>> >>>> This driver exposes a standard tty interface on top of the rpmsg >>>> framework through the "rpmsg-tty-channel" rpmsg service. >>>> >>>> This driver supports multi-instances, offering a /dev/ttyRPMSGx entry >>>> per rpmsg endpoint. >>>> >>> >>> How to support multi-instances from the same remoteproc instance? I >>> saw that the channel name is fixed to "rpmsg-tty-channel" which mean >>> only one channel can be created for each remote side. >> The driver is multi-instance based on muti-endpoints on top of the >> "rpmsg-tty-channel" service. >> On remote side you just have to call rpmsg_create_ept with destination >> address set to ANY. The result is a NS service announcement that trigs a >> probe with a new endpoint. >> You can find code example for the remote side here: >> https://github.com/STMicroelectronics/STM32CubeMP1/blob/master/Projects/STM32MP157C-DK2/Applications/OpenAMP/OpenAMP_TTY_echo/Src/main.c > > Demo code create two uarts(huart0 and huart1), and both use the same > channel name( "rpmsg-tty-channel"). > But rpmsg_create_channel in kernel will complain the duplication: > /* make sure a similar channel doesn't already exist */ > tmp = rpmsg_find_device(dev, chinfo); > if (tmp) { > /* decrement the matched device's refcount back */ > put_device(tmp); > dev_err(dev, "channel %s:%x:%x already exist\n", > chinfo->name, chinfo->src, chinfo->dst); > return NULL; > } > Do you have some local change not upstream yet? Nothing is missing. There is no complain as the function rpmsg_device_match returns 0, because the chinfo->dst (that corresponds to the remote ept address) is different. If i well remember you have also a similar implementation of the service on your side. Do you see any incompatibility with your implementation? > >> using some wrapper functions available here: >> https://github.com/STMicroelectronics/STM32CubeMP1/tree/master/Middlewares/Third_Party/OpenAMP >> >> >> Best Regards >> Arnaud >> >>> >>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> >>>> Signed-off-by: Fabien Dessenne <fabien.dessenne@xxxxxx> >>>> --- >>>> drivers/tty/Kconfig | 9 ++ >>>> drivers/tty/Makefile | 1 + >>>> drivers/tty/rpmsg_tty.c | 309 ++++++++++++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 319 insertions(+) >>>> create mode 100644 drivers/tty/rpmsg_tty.c >>>> >>>> diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig >>>> index 0840d27..42696e6 100644 >>>> --- a/drivers/tty/Kconfig >>>> +++ b/drivers/tty/Kconfig >>>> @@ -441,4 +441,13 @@ config VCC >>>> depends on SUN_LDOMS >>>> help >>>> Support for Sun logical domain consoles. >>>> + >>>> +config RPMSG_TTY >>>> + tristate "RPMSG tty driver" >>>> + depends on RPMSG >>>> + help >>>> + Say y here to export rpmsg endpoints as tty devices, usually found >>>> + in /dev/ttyRPMSGx. >>>> + This makes it possible for user-space programs to send and receive >>>> + rpmsg messages as a standard tty protocol. >>>> endif # TTY >>>> diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile >>>> index c72cafd..90a98a2 100644 >>>> --- a/drivers/tty/Makefile >>>> +++ b/drivers/tty/Makefile >>>> @@ -33,5 +33,6 @@ obj-$(CONFIG_PPC_EPAPR_HV_BYTECHAN) += ehv_bytechan.o >>>> obj-$(CONFIG_GOLDFISH_TTY) += goldfish.o >>>> obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o >>>> obj-$(CONFIG_VCC) += vcc.o >>>> +obj-$(CONFIG_RPMSG_TTY) += rpmsg_tty.o >>>> >>>> obj-y += ipwireless/ >>>> diff --git a/drivers/tty/rpmsg_tty.c b/drivers/tty/rpmsg_tty.c >>>> new file mode 100644 >>>> index 0000000..9c2a629 >>>> --- /dev/null >>>> +++ b/drivers/tty/rpmsg_tty.c >>>> @@ -0,0 +1,309 @@ >>>> +// SPDX-License-Identifier: GPL-2.0 >>>> +/* >>>> + * Copyright (C) STMicroelectronics 2019 - All Rights Reserved >>>> + * Authors: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> for STMicroelectronics. >>>> + * Fabien Dessenne <fabien.dessenne@xxxxxx> for STMicroelectronics. >>>> + * Derived from the imx-rpmsg and omap-rpmsg implementations. >>>> + */ >>>> + >>>> +#include <linux/module.h> >>>> +#include <linux/rpmsg.h> >>>> +#include <linux/slab.h> >>>> +#include <linux/tty.h> >>>> +#include <linux/tty_flip.h> >>>> + >>>> +#define MAX_TTY_RPMSG 32 >>>> + >>>> +static DEFINE_IDR(tty_idr); /* tty instance id */ >>>> +static DEFINE_MUTEX(idr_lock); /* protects tty_idr */ >>>> + >>>> +static struct tty_driver *rpmsg_tty_driver; >>>> + >>>> +struct rpmsg_tty_port { >>>> + struct tty_port port; /* TTY port data */ >>>> + unsigned int id; /* TTY rpmsg index */ >>>> + spinlock_t rx_lock; /* message reception lock */ >>>> + struct rpmsg_device *rpdev; /* rpmsg device */ >>>> +}; >>>> + >>>> +static int rpmsg_tty_cb(struct rpmsg_device *rpdev, void *data, int len, >>>> + void *priv, u32 src) >>>> +{ >>>> + int space; >>>> + unsigned char *cbuf; >>>> + struct rpmsg_tty_port *cport = dev_get_drvdata(&rpdev->dev); >>>> + >>>> + dev_dbg(&rpdev->dev, "msg(<- src 0x%x) len %d\n", src, len); >>>> + >>>> + print_hex_dump_debug(__func__, DUMP_PREFIX_NONE, 16, 1, data, len, >>>> + true); >>>> + >>>> + /* Flush the recv-ed none-zero data to tty node */ >>>> + if (!len) >>>> + return -EINVAL; >>>> + >>>> + spin_lock(&cport->rx_lock); >>>> + space = tty_prepare_flip_string(&cport->port, &cbuf, len); >>>> + if (space <= 0) { >>>> + dev_err(&rpdev->dev, "No memory for tty_prepare_flip_string\n"); >>>> + spin_unlock(&cport->rx_lock); >>>> + return -ENOMEM; >>>> + } >>>> + >>>> + if (space != len) >>>> + dev_warn(&rpdev->dev, "Trunc buffer from %d to %d\n", >>>> + len, space); >>>> + >>>> + memcpy(cbuf, data, space); >>>> + tty_flip_buffer_push(&cport->port); >>>> + spin_unlock(&cport->rx_lock); >>>> + >>>> + return 0; >>>> +} >>>> + >>>> +static int rpmsg_tty_install(struct tty_driver *driver, struct tty_struct *tty) >>>> +{ >>>> + struct rpmsg_tty_port *cport = idr_find(&tty_idr, tty->index); >>>> + >>>> + if (!cport) { >>>> + dev_err(tty->dev, "cannot get cport\n"); >>>> + return -ENODEV; >>>> + } >>>> + >>>> + return tty_port_install(&cport->port, driver, tty); >>>> +} >>>> + >>>> +static int rpmsg_tty_open(struct tty_struct *tty, struct file *filp) >>>> +{ >>>> + return tty_port_open(tty->port, tty, filp); >>>> +} >>>> + >>>> +static void rpmsg_tty_close(struct tty_struct *tty, struct file *filp) >>>> +{ >>>> + return tty_port_close(tty->port, tty, filp); >>>> +} >>>> + >>>> +static int rpmsg_tty_write(struct tty_struct *tty, const unsigned char *buf, >>>> + int total) >>>> +{ >>>> + int count, ret = 0; >>>> + const unsigned char *tbuf; >>>> + struct rpmsg_tty_port *cport = idr_find(&tty_idr, tty->index); >>>> + struct rpmsg_device *rpdev; >>>> + int msg_size; >>>> + >>>> + if (!cport) { >>>> + dev_err(tty->dev, "cannot get cport\n"); >>>> + return -ENODEV; >>>> + } >>>> + >>>> + rpdev = cport->rpdev; >>>> + >>>> + dev_dbg(&rpdev->dev, "%s: send message from tty->index = %d\n", >>>> + __func__, tty->index); >>>> + >>>> + if (!buf) { >>>> + dev_err(&rpdev->dev, "buf shouldn't be null.\n"); >>>> + return -ENOMEM; >>>> + } >>>> + >>>> + msg_size = rpmsg_get_buf_payload_size(rpdev->ept); >>>> + if (msg_size < 0) >>>> + return msg_size; >>>> + >>>> + count = total; >>>> + tbuf = buf; >>>> + do { >>>> + /* send a message to our remote processor */ >>>> + ret = rpmsg_send(rpdev->ept, (void *)tbuf, >>>> + min(count, msg_size)); >>>> + if (ret) { >>>> + dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret); >>>> + return ret; >>>> + } >>>> + >>>> + if (count > msg_size) { >>>> + count -= msg_size; >>>> + tbuf += msg_size; >>>> + } else { >>>> + count = 0; >>>> + } >>>> + } while (count > 0); >>>> + >>> >>> We need the flow control(or handshake) here, otherwise it's very easy >>> to lose the data if kernel keep send the data as fast as possible. >>> >>>> + return total; >>>> +} >>>> + >>>> +static int rpmsg_tty_write_room(struct tty_struct *tty) >>>> +{ >>>> + struct rpmsg_tty_port *cport = idr_find(&tty_idr, tty->index); >>>> + >>>> + if (!cport) { >>>> + dev_err(tty->dev, "cannot get cport\n"); >>>> + return -ENODEV; >>>> + } >>>> + >>>> + /* report the space in the rpmsg buffer */ >>>> + return rpmsg_get_buf_payload_size(cport->rpdev->ept); >>>> +} >>>> + >>>> +static const struct tty_operations rpmsg_tty_ops = { >>>> + .install = rpmsg_tty_install, >>>> + .open = rpmsg_tty_open, >>>> + .close = rpmsg_tty_close, >>>> + .write = rpmsg_tty_write, >>>> + .write_room = rpmsg_tty_write_room, >>>> +}; >>>> + >>>> +struct rpmsg_tty_port *rpmsg_tty_alloc_cport(void) >>>> +{ >>>> + struct rpmsg_tty_port *cport; >>>> + >>>> + cport = kzalloc(sizeof(*cport), GFP_KERNEL); >>>> + if (!cport) >>>> + return ERR_PTR(-ENOMEM); >>>> + >>>> + mutex_lock(&idr_lock); >>>> + cport->id = idr_alloc(&tty_idr, cport, 0, MAX_TTY_RPMSG, GFP_KERNEL); >>>> + mutex_unlock(&idr_lock); >>>> + >>>> + if (cport->id < 0) { >>>> + kfree(cport); >>>> + return ERR_PTR(-ENOSPC); >>>> + } >>>> + >>>> + return cport; >>>> +} >>>> + >>>> +static void rpmsg_tty_release_cport(struct rpmsg_tty_port *cport) >>>> +{ >>>> + mutex_lock(&idr_lock); >>>> + idr_remove(&tty_idr, cport->id); >>>> + mutex_unlock(&idr_lock); >>>> + >>>> + kfree(cport); >>>> +} >>>> + >>>> +static int rpmsg_tty_probe(struct rpmsg_device *rpdev) >>>> +{ >>>> + struct rpmsg_tty_port *cport; >>>> + struct device *tty_dev; >>>> + int ret; >>>> + >>>> + cport = rpmsg_tty_alloc_cport(); >>>> + if (IS_ERR(cport)) { >>>> + dev_err(&rpdev->dev, "failed to alloc tty port\n"); >>>> + return PTR_ERR(cport); >>>> + } >>>> + >>>> + tty_port_init(&cport->port); >>>> + cport->port.low_latency = cport->port.flags | ASYNC_LOW_LATENCY; >>>> + >>>> + tty_dev = tty_port_register_device(&cport->port, rpmsg_tty_driver, >>>> + cport->id, &rpdev->dev); >>>> + if (IS_ERR(tty_dev)) { >>>> + dev_err(&rpdev->dev, "failed to register tty port\n"); >>>> + ret = PTR_ERR(tty_dev); >>>> + goto err_destroy; >>>> + } >>>> + >>>> + spin_lock_init(&cport->rx_lock); >>>> + cport->rpdev = rpdev; >>>> + >>>> + dev_set_drvdata(&rpdev->dev, cport); >>>> + >>>> + dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x : ttyRPMSG%d\n", >>>> + rpdev->src, rpdev->dst, cport->id); >>>> + >>>> + return 0; >>>> + >>>> +err_destroy: >>>> + tty_port_destroy(&cport->port); >>>> + rpmsg_tty_release_cport(cport); >>>> + return ret; >>>> +} >>>> + >>>> +static void rpmsg_tty_remove(struct rpmsg_device *rpdev) >>>> +{ >>>> + struct rpmsg_tty_port *cport = dev_get_drvdata(&rpdev->dev); >>>> + >>>> + dev_info(&rpdev->dev, "removing rpmsg tty device %d\n", cport->id); >>>> + >>>> + /* User hang up to release the tty */ >>>> + if (tty_port_initialized(&cport->port)) >>>> + tty_port_tty_hangup(&cport->port, false); >>>> + >>>> + tty_unregister_device(rpmsg_tty_driver, cport->id); >>>> + tty_port_destroy(&cport->port); >>>> + >>>> + rpmsg_tty_release_cport(cport); >>>> +} >>>> + >>>> +static struct rpmsg_device_id rpmsg_driver_tty_id_table[] = { >>>> + { .name = "rpmsg-tty-channel" }, >>>> + { }, >>>> +}; >>>> +MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_tty_id_table); >>>> + >>>> +static struct rpmsg_driver rpmsg_tty_rpmsg_drv = { >>>> + .drv.name = KBUILD_MODNAME, >>>> + .id_table = rpmsg_driver_tty_id_table, >>>> + .probe = rpmsg_tty_probe, >>>> + .callback = rpmsg_tty_cb, >>>> + .remove = rpmsg_tty_remove, >>>> +}; >>>> + >>>> +static int __init rpmsg_tty_init(void) >>>> +{ >>>> + int err; >>>> + >>>> + rpmsg_tty_driver = tty_alloc_driver(MAX_TTY_RPMSG, TTY_DRIVER_REAL_RAW | >>>> + TTY_DRIVER_DYNAMIC_DEV); >>>> + if (IS_ERR(rpmsg_tty_driver)) >>>> + return PTR_ERR(rpmsg_tty_driver); >>>> + >>>> + rpmsg_tty_driver->driver_name = "rpmsg_tty"; >>>> + rpmsg_tty_driver->name = "ttyRPMSG"; >>>> + rpmsg_tty_driver->major = 0; >>>> + rpmsg_tty_driver->type = TTY_DRIVER_TYPE_CONSOLE; >>>> + rpmsg_tty_driver->init_termios = tty_std_termios; >>>> + >>>> + tty_set_operations(rpmsg_tty_driver, &rpmsg_tty_ops); >>>> + >>>> + err = tty_register_driver(rpmsg_tty_driver); >>>> + if (err < 0) { >>>> + pr_err("Couldn't install rpmsg tty driver: err %d\n", err); >>>> + goto error_put; >>>> + } >>>> + >>>> + err = register_rpmsg_driver(&rpmsg_tty_rpmsg_drv); >>>> + if (err < 0) { >>>> + pr_err("Couldn't register rpmsg tty driver: err %d\n", err); >>>> + goto error_unregister; >>>> + } >>>> + >>>> + return 0; >>>> + >>>> +error_unregister: >>>> + tty_unregister_driver(rpmsg_tty_driver); >>>> + >>>> +error_put: >>>> + put_tty_driver(rpmsg_tty_driver); >>>> + >>>> + return err; >>>> +} >>>> + >>>> +static void __exit rpmsg_tty_exit(void) >>>> +{ >>>> + unregister_rpmsg_driver(&rpmsg_tty_rpmsg_drv); >>>> + tty_unregister_driver(rpmsg_tty_driver); >>>> + put_tty_driver(rpmsg_tty_driver); >>>> + idr_destroy(&tty_idr); >>>> +} >>>> + >>>> +module_init(rpmsg_tty_init); >>>> +module_exit(rpmsg_tty_exit); >>>> + >>>> +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>"); >>>> +MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@xxxxxx>"); >>>> +MODULE_DESCRIPTION("virtio remote processor messaging tty driver"); >>>> +MODULE_LICENSE("GPL v2"); >>>> -- >>>> 2.7.4 >>>>
