On 4/5/19 4:03 PM, xiang xiao wrote: > On Fri, Apr 5, 2019 at 8:33 PM Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> wrote: >> >> >> >> 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. >> > > Yes, you are right. > >> If i well remember you have also a similar implementation of the service >> on your side. Do you see any incompatibility with your implementation? >> > > Our implementation is similar to yours, but has two major difference: > 1.Each instance has a different channel name but share the same prefix > "rpmsg-tty*", the benefit is that: > a.Device name(/dev/tty*) is derived from rpmsg-tty*, instead the > random /dev/ttyRPMSGx > b.Don't need tty_idr to allocate the unique device id I understand the need but in your implementation it look like you hack the rpmsg service to instantiate your tty... you introduce a kind of meta rpmsg tty service with sub-service related to the serial content. Not sure that this could be upstreamed... proposal to integrate your need in the ST driver: it seems possible to have /dev/ttyRPMSGx with x corresponding to the remote endpoint address? So if you want to have a fixed tty name you can fix the remote endpoint. Is it something reasonable for you? > 2.Each transfer need get response from peer to avoid the buffer > overflow. This is very important if the peer use pull > model(read/write) instead of push model(callback). I not sure to understand your point... You mean that you assume that the driver should be blocked until a response from the remote side? This seems not compatible with a "generic" tty and with Johan remarks: "Just a drive-by comment; it looks like rpmsg_send() may block, but the tty-driver write() callback must never sleep." Why no just let rpmsg should manage the case with no Tx buffer free, with a rpmsg_trysend... > > Here is the patch for kernel side: > https://github.com/xiaoxiang781216/linux/commit/f04d2386eb11e0781f0eb47d99fae838abf7eb53 > https://github.com/xiaoxiang781216/linux/commit/1a41be362d916eb9104bf21065cb38a0a63d2e91 > > And RTOS side: > https://github.com/PineconeCode/nuttx/blob/song-u1/include/nuttx/serial/uart_rpmsg.h > https://github.com/PineconeCode/nuttx/blob/song-u1/drivers/serial/uart_rpmsg.c > > Maybe, we can consider how to unify these two implementation into one. Yes sure. > >>> >>>> 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 >>>>>>
