Re: [PATCH v6 2/2] tty: add rpmsg driver
Hi Richard,
On 9/5/19 12:50 PM, Richard Genoud wrote:
Hi Arnaud,
Le 04/09/2019 à 15:09, Arnaud Pouliquen a écrit :
This driver exposes a standard tty interface on top of the rpmsg
framework through a rpmsg service.
This driver supports multi-instances, offering a /dev/ttyRPMSGx entry
per rpmsg endpoint.
Signed-off-by: Arnaud Pouliquen
Signed-off-by: Fabien Dessenne
---
Documentation/serial/tty_rpmsg.rst | 45
drivers/tty/Kconfig| 9 +
drivers/tty/Makefile | 1 +
drivers/tty/rpmsg_tty.c| 418 +
4 files changed, 473 insertions(+)
create mode 100644 Documentation/serial/tty_rpmsg.rst
create mode 100644 drivers/tty/rpmsg_tty.c
diff --git a/Documentation/serial/tty_rpmsg.rst
b/Documentation/serial/tty_rpmsg.rst
new file mode 100644
index ..fc1d3fba73c5
--- /dev/null
+++ b/Documentation/serial/tty_rpmsg.rst
@@ -0,0 +1,45 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=
+The rpmsg TTY
+=
+
+The rpmsg tty driver implements serial communication on the RPMsg bus to makes
possible for user-space programs to send and receive rpmsg messages as a
standard tty protocol.
+
+The remote processor can instantiate a new tty by requesting:
+- a "rpmsg-tty-raw" RPMsg service, for TTY raw data support without flow
control
+- a "rpmsg-tty-ctrl" RPMSg service, for TTY support with flow control.
+
+Information related to the RPMsg and associated tty device is available in
+/sys/bus/rpmsg/devices/.
+
+RPMsg TTY without control
+-
+
+The default end point associated with the "rpmsg-tty-raw" service is directly
+used for data exchange. No flow control is available.
+
+To be compliant with this driver, the remote firmware must create its data end point
associated with the "rpmsg-tty-raw" service.
+
+RPMsg TTY with control
+-
+
+The default end point associated with the "rpmsg-tty-ctrl" service is reserved
for
+the control. A second endpoint must be created for data exchange.
+
+The control channel is used to transmit to the remote processor the CTS status,
+as well as the end point address for data transfer.
+
+To be compatible with this driver, the remote firmware must create or use its end point
associated with "rpmsg-tty-ctrl" service, plus a second endpoint for the data
flow.
+On Linux rpmsg_tty probes, the data endpoint address and the CTS (set to
disable)
+is sent to the remote processor.
+The remote processor has to respect following rules:
+- It only transmits data when Linux remote cts is enable, otherwise message
+ could be lost.
+- It can pause/resume reception by sending a control message (rely on CTS
state).
+
+Control message structure:
+struct rpmsg_tty_ctrl {
+ u8 cts; /* remote reception status */
+ u16 d_ept_addr; /* data endpoint address */
+};
Correct me if I'm wrong, but I think this structure should be packed,
shouldn't it ?
It's working ok on the STM32MP127, between M4 and A7, but the alignment
may be not the same on another architecture ?
you are right, i have to fix this.
Thanks,
Arnaud
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index c7623f99ac0f..1046bf4aa709 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -454,6 +454,15 @@ config VCC
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.
+
config LDISC_AUTOLOAD
bool "Automatically load TTY Line Disciplines"
default y
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index 020b1cd9294f..c2465e7ebc2a 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -34,5 +34,6 @@ 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 ..3e4d0e1a6663
--- /dev/null
+++ b/drivers/tty/rpmsg_tty.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2019 - All Rights Reserved
+ * Authors: Arnaud Pouliquen for STMicroelectronics.
+ */
+
+#include
+#include
+#include
+#include
+#include
+
+#define MAX_TTY_RPMSG 32
+
+#define TTY_CH_NAME_RAW"rpmsg-tty-raw"
+#define TTY_CH_NAME_WITH_CTS "rpmsg-tty-ctrl"
+
+static DEFINE_IDR(tty_idr);/* tty instance id */
+static DEFINE_MUTEX(idr_lock); /* protects tty_idr */
+
+static struct tty_driver *rpmsg_tty_driver;
+
+struct
Re: [PATCH v6 2/2] tty: add rpmsg driver
Hi Arnaud,
Le 04/09/2019 à 15:09, Arnaud Pouliquen a écrit :
> This driver exposes a standard tty interface on top of the rpmsg
> framework through a rpmsg service.
>
> This driver supports multi-instances, offering a /dev/ttyRPMSGx entry
> per rpmsg endpoint.
>
> Signed-off-by: Arnaud Pouliquen
> Signed-off-by: Fabien Dessenne
> ---
> Documentation/serial/tty_rpmsg.rst | 45
> drivers/tty/Kconfig| 9 +
> drivers/tty/Makefile | 1 +
> drivers/tty/rpmsg_tty.c| 418
> +
> 4 files changed, 473 insertions(+)
> create mode 100644 Documentation/serial/tty_rpmsg.rst
> create mode 100644 drivers/tty/rpmsg_tty.c
>
> diff --git a/Documentation/serial/tty_rpmsg.rst
> b/Documentation/serial/tty_rpmsg.rst
> new file mode 100644
> index ..fc1d3fba73c5
> --- /dev/null
> +++ b/Documentation/serial/tty_rpmsg.rst
> @@ -0,0 +1,45 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=
> +The rpmsg TTY
> +=
> +
> +The rpmsg tty driver implements serial communication on the RPMsg bus to
> makes possible for user-space programs to send and receive rpmsg messages as
> a standard tty protocol.
> +
> +The remote processor can instantiate a new tty by requesting:
> +- a "rpmsg-tty-raw" RPMsg service, for TTY raw data support without flow
> control
> +- a "rpmsg-tty-ctrl" RPMSg service, for TTY support with flow control.
> +
> +Information related to the RPMsg and associated tty device is available in
> +/sys/bus/rpmsg/devices/.
> +
> +RPMsg TTY without control
> +-
> +
> +The default end point associated with the "rpmsg-tty-raw" service is directly
> +used for data exchange. No flow control is available.
> +
> +To be compliant with this driver, the remote firmware must create its data
> end point associated with the "rpmsg-tty-raw" service.
> +
> +RPMsg TTY with control
> +-
> +
> +The default end point associated with the "rpmsg-tty-ctrl" service is
> reserved for
> +the control. A second endpoint must be created for data exchange.
> +
> +The control channel is used to transmit to the remote processor the CTS
> status,
> +as well as the end point address for data transfer.
> +
> +To be compatible with this driver, the remote firmware must create or use
> its end point associated with "rpmsg-tty-ctrl" service, plus a second
> endpoint for the data flow.
> +On Linux rpmsg_tty probes, the data endpoint address and the CTS (set to
> disable)
> +is sent to the remote processor.
> +The remote processor has to respect following rules:
> +- It only transmits data when Linux remote cts is enable, otherwise message
> + could be lost.
> +- It can pause/resume reception by sending a control message (rely on CTS
> state).
> +
> +Control message structure:
> +struct rpmsg_tty_ctrl {
> + u8 cts; /* remote reception status */
> + u16 d_ept_addr; /* data endpoint address */
> +};
Correct me if I'm wrong, but I think this structure should be packed,
shouldn't it ?
It's working ok on the STM32MP127, between M4 and A7, but the alignment
may be not the same on another architecture ?
> diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
> index c7623f99ac0f..1046bf4aa709 100644
> --- a/drivers/tty/Kconfig
> +++ b/drivers/tty/Kconfig
> @@ -454,6 +454,15 @@ config VCC
> 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.
> +
> config LDISC_AUTOLOAD
> bool "Automatically load TTY Line Disciplines"
> default y
> diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
> index 020b1cd9294f..c2465e7ebc2a 100644
> --- a/drivers/tty/Makefile
> +++ b/drivers/tty/Makefile
> @@ -34,5 +34,6 @@ 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 ..3e4d0e1a6663
> --- /dev/null
> +++ b/drivers/tty/rpmsg_tty.c
> @@ -0,0 +1,418 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) STMicroelectronics 2019 - All Rights Reserved
> + * Authors: Arnaud Pouliquen for
> STMicroelectronics.
> + */
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +#define MAX_TTY_RPMSG32
> +
> +#define TTY_CH_NAME_RAW "rpmsg-tty-raw"
> +#define TTY_CH_NAME_WITH_CTS "rpmsg-tty-ctrl"
> +
> +static DEFINE_IDR(tty_idr); /* tty instance id
[PATCH v6 2/2] tty: add rpmsg driver
This driver exposes a standard tty interface on top of the rpmsg
framework through a rpmsg service.
This driver supports multi-instances, offering a /dev/ttyRPMSGx entry
per rpmsg endpoint.
Signed-off-by: Arnaud Pouliquen
Signed-off-by: Fabien Dessenne
---
Documentation/serial/tty_rpmsg.rst | 45
drivers/tty/Kconfig| 9 +
drivers/tty/Makefile | 1 +
drivers/tty/rpmsg_tty.c| 418 +
4 files changed, 473 insertions(+)
create mode 100644 Documentation/serial/tty_rpmsg.rst
create mode 100644 drivers/tty/rpmsg_tty.c
diff --git a/Documentation/serial/tty_rpmsg.rst
b/Documentation/serial/tty_rpmsg.rst
new file mode 100644
index ..fc1d3fba73c5
--- /dev/null
+++ b/Documentation/serial/tty_rpmsg.rst
@@ -0,0 +1,45 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=
+The rpmsg TTY
+=
+
+The rpmsg tty driver implements serial communication on the RPMsg bus to makes
possible for user-space programs to send and receive rpmsg messages as a
standard tty protocol.
+
+The remote processor can instantiate a new tty by requesting:
+- a "rpmsg-tty-raw" RPMsg service, for TTY raw data support without flow
control
+- a "rpmsg-tty-ctrl" RPMSg service, for TTY support with flow control.
+
+Information related to the RPMsg and associated tty device is available in
+/sys/bus/rpmsg/devices/.
+
+RPMsg TTY without control
+-
+
+The default end point associated with the "rpmsg-tty-raw" service is directly
+used for data exchange. No flow control is available.
+
+To be compliant with this driver, the remote firmware must create its data end
point associated with the "rpmsg-tty-raw" service.
+
+RPMsg TTY with control
+-
+
+The default end point associated with the "rpmsg-tty-ctrl" service is reserved
for
+the control. A second endpoint must be created for data exchange.
+
+The control channel is used to transmit to the remote processor the CTS status,
+as well as the end point address for data transfer.
+
+To be compatible with this driver, the remote firmware must create or use its
end point associated with "rpmsg-tty-ctrl" service, plus a second endpoint for
the data flow.
+On Linux rpmsg_tty probes, the data endpoint address and the CTS (set to
disable)
+is sent to the remote processor.
+The remote processor has to respect following rules:
+- It only transmits data when Linux remote cts is enable, otherwise message
+ could be lost.
+- It can pause/resume reception by sending a control message (rely on CTS
state).
+
+Control message structure:
+struct rpmsg_tty_ctrl {
+ u8 cts; /* remote reception status */
+ u16 d_ept_addr; /* data endpoint address */
+};
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index c7623f99ac0f..1046bf4aa709 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -454,6 +454,15 @@ config VCC
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.
+
config LDISC_AUTOLOAD
bool "Automatically load TTY Line Disciplines"
default y
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index 020b1cd9294f..c2465e7ebc2a 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -34,5 +34,6 @@ 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 ..3e4d0e1a6663
--- /dev/null
+++ b/drivers/tty/rpmsg_tty.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2019 - All Rights Reserved
+ * Authors: Arnaud Pouliquen for STMicroelectronics.
+ */
+
+#include
+#include
+#include
+#include
+#include
+
+#define MAX_TTY_RPMSG 32
+
+#define TTY_CH_NAME_RAW"rpmsg-tty-raw"
+#define TTY_CH_NAME_WITH_CTS "rpmsg-tty-ctrl"
+
+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_ctrl {
+ u8 cts; /* remote reception status */
+ u16 d_ept_addr; /* data endpoint address */
+};
+
+struct rpmsg_tty_port {
+ struct tty_port port;/* TTY port data */
+ int id; /* TTY rpmsg index */
+ boolcts; /* remote reception status */
+ struct rpmsg_device
