lkml.org 
[lkml]   [2019]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] serial: Add Tegra Combined UART driver
On Wed, Jan 23, 2019 at 11:28:19AM +0100, Thierry Reding wrote:
> The Tegra Combined UART (TCU) is a mailbox-based mechanism that allows
> multiplexing multiple "virtual UARTs" into a single hardware serial
> port. The TCU is the primary serial port on Tegra194 devices.
>
> Add a TCU driver utilizing the mailbox framework, as the used mailboxes
> are part of Tegra HSP blocks that are already controlled by the Tegra
> HSP mailbox driver.
>
> Based on work by Mikko Perttunen <mperttunen@nvidia.com>.
>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In case 0day hasn't reported it:

arm64:allmodconfig:

ERROR: "mbox_flush" [drivers/tty/serial/tegra-tcu.ko] undefined!

mbox_flush() isn't exported.

Guenter

> ---
> drivers/tty/serial/Kconfig | 22 +++
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/tegra-tcu.c | 298 +++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 324 insertions(+)
> create mode 100644 drivers/tty/serial/tegra-tcu.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 089a6f285d5e..72966bc0ac76 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -335,6 +335,28 @@ config SERIAL_TEGRA
> are enabled). This driver uses the APB DMA to achieve higher baudrate
> and better performance.
>
> +config SERIAL_TEGRA_TCU
> + tristate "NVIDIA Tegra Combined UART"
> + depends on ARCH_TEGRA && TEGRA_HSP_MBOX
> + select SERIAL_CORE
> + help
> + Support for the mailbox-based TCU (Tegra Combined UART) serial port.
> + TCU is a virtual serial port that allows multiplexing multiple data
> + streams into a single hardware serial port.
> +
> +config SERIAL_TEGRA_TCU_CONSOLE
> + bool "Support for console on a Tegra TCU serial port"
> + depends on SERIAL_TEGRA_TCU=y
> + select SERIAL_CORE_CONSOLE
> + default y
> + ---help---
> + If you say Y here, it will be possible to use a the Tegra TCU as the
> + system console (the system console is the device which receives all
> + kernel messages and warnings and which allows logins in single user
> + mode).
> +
> + If unsure, say Y.
> +
> config SERIAL_MAX3100
> tristate "MAX3100 support"
> depends on SPI
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 1511e8a9f856..40b702aaa85e 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -77,6 +77,7 @@ obj-$(CONFIG_SERIAL_LANTIQ) += lantiq.o
> obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
> obj-$(CONFIG_SERIAL_SIRFSOC) += sirfsoc_uart.o
> obj-$(CONFIG_SERIAL_TEGRA) += serial-tegra.o
> +obj-$(CONFIG_SERIAL_TEGRA_TCU) += tegra-tcu.o
> obj-$(CONFIG_SERIAL_AR933X) += ar933x_uart.o
> obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
> obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> diff --git a/drivers/tty/serial/tegra-tcu.c b/drivers/tty/serial/tegra-tcu.c
> new file mode 100644
> index 000000000000..aaf8748a6147
> --- /dev/null
> +++ b/drivers/tty/serial/tegra-tcu.c
> @@ -0,0 +1,298 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
> + */
> +
> +#include <linux/console.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial.h>
> +#include <linux/serial_core.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +#define TCU_MBOX_BYTE(i, x) ((x) << (i * 8))
> +#define TCU_MBOX_BYTE_V(x, i) (((x) >> (i * 8)) & 0xff)
> +#define TCU_MBOX_NUM_BYTES(x) ((x) << 24)
> +#define TCU_MBOX_NUM_BYTES_V(x) (((x) >> 24) & 0x3)
> +
> +struct tegra_tcu {
> + struct uart_driver driver;
> +#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
> + struct console console;
> +#endif
> + struct uart_port port;
> +
> + struct mbox_client tx_client, rx_client;
> + struct mbox_chan *tx, *rx;
> +};
> +
> +static unsigned int tegra_tcu_uart_tx_empty(struct uart_port *port)
> +{
> + return TIOCSER_TEMT;
> +}
> +
> +static void tegra_tcu_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> +}
> +
> +static unsigned int tegra_tcu_uart_get_mctrl(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +static void tegra_tcu_uart_stop_tx(struct uart_port *port)
> +{
> +}
> +
> +static void tegra_tcu_write_one(struct tegra_tcu *tcu, u32 value,
> + unsigned int count)
> +{
> + void *msg;
> +
> + value |= TCU_MBOX_NUM_BYTES(count);
> + msg = (void *)(unsigned long)value;
> + mbox_send_message(tcu->tx, msg);
> + mbox_flush(tcu->tx, 1000);
> +}
> +
> +static void tegra_tcu_write(struct tegra_tcu *tcu, const char *s,
> + unsigned int count)
> +{
> + unsigned int written = 0, i = 0;
> + bool insert_nl = false;
> + u32 value = 0;
> +
> + while (i < count) {
> + if (insert_nl) {
> + value |= TCU_MBOX_BYTE(written++, '\n');
> + insert_nl = false;
> + i++;
> + } else if (s[i] == '\n') {
> + value |= TCU_MBOX_BYTE(written++, '\r');
> + insert_nl = true;
> + } else {
> + value |= TCU_MBOX_BYTE(written++, s[i++]);
> + }
> +
> + if (written == 3) {
> + tegra_tcu_write_one(tcu, value, 3);
> + value = written = 0;
> + }
> + }
> +
> + if (written)
> + tegra_tcu_write_one(tcu, value, written);
> +}
> +
> +static void tegra_tcu_uart_start_tx(struct uart_port *port)
> +{
> + struct tegra_tcu *tcu = port->private_data;
> + struct circ_buf *xmit = &port->state->xmit;
> + unsigned long count;
> +
> + for (;;) {
> + count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
> + if (!count)
> + break;
> +
> + tegra_tcu_write(tcu, &xmit->buf[xmit->tail], count);
> + xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
> + }
> +
> + uart_write_wakeup(port);
> +}
> +
> +static void tegra_tcu_uart_stop_rx(struct uart_port *port)
> +{
> +}
> +
> +static void tegra_tcu_uart_break_ctl(struct uart_port *port, int ctl)
> +{
> +}
> +
> +static int tegra_tcu_uart_startup(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +static void tegra_tcu_uart_shutdown(struct uart_port *port)
> +{
> +}
> +
> +static void tegra_tcu_uart_set_termios(struct uart_port *port,
> + struct ktermios *new,
> + struct ktermios *old)
> +{
> +}
> +
> +static const struct uart_ops tegra_tcu_uart_ops = {
> + .tx_empty = tegra_tcu_uart_tx_empty,
> + .set_mctrl = tegra_tcu_uart_set_mctrl,
> + .get_mctrl = tegra_tcu_uart_get_mctrl,
> + .stop_tx = tegra_tcu_uart_stop_tx,
> + .start_tx = tegra_tcu_uart_start_tx,
> + .stop_rx = tegra_tcu_uart_stop_rx,
> + .break_ctl = tegra_tcu_uart_break_ctl,
> + .startup = tegra_tcu_uart_startup,
> + .shutdown = tegra_tcu_uart_shutdown,
> + .set_termios = tegra_tcu_uart_set_termios,
> +};
> +
> +#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
> +static void tegra_tcu_console_write(struct console *cons, const char *s,
> + unsigned int count)
> +{
> + struct tegra_tcu *tcu = container_of(cons, struct tegra_tcu, console);
> +
> + tegra_tcu_write(tcu, s, count);
> +}
> +
> +static int tegra_tcu_console_setup(struct console *cons, char *options)
> +{
> + return 0;
> +}
> +#endif
> +
> +static void tegra_tcu_receive(struct mbox_client *cl, void *msg)
> +{
> + struct tegra_tcu *tcu = container_of(cl, struct tegra_tcu, rx_client);
> + struct tty_port *port = &tcu->port.state->port;
> + u32 value = (u32)(unsigned long)msg;
> + unsigned int num_bytes, i;
> +
> + num_bytes = TCU_MBOX_NUM_BYTES_V(value);
> +
> + for (i = 0; i < num_bytes; i++)
> + tty_insert_flip_char(port, TCU_MBOX_BYTE_V(value, i),
> + TTY_NORMAL);
> +
> + tty_flip_buffer_push(port);
> +}
> +
> +static int tegra_tcu_probe(struct platform_device *pdev)
> +{
> + struct uart_port *port;
> + struct tegra_tcu *tcu;
> + int err;
> +
> + tcu = devm_kzalloc(&pdev->dev, sizeof(*tcu), GFP_KERNEL);
> + if (!tcu)
> + return -ENOMEM;
> +
> + tcu->tx_client.dev = &pdev->dev;
> + tcu->rx_client.dev = &pdev->dev;
> + tcu->rx_client.rx_callback = tegra_tcu_receive;
> +
> + tcu->tx = mbox_request_channel_byname(&tcu->tx_client, "tx");
> + if (IS_ERR(tcu->tx)) {
> + err = PTR_ERR(tcu->tx);
> + dev_err(&pdev->dev, "failed to get tx mailbox: %d\n", err);
> + return err;
> + }
> +
> + tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");
> + if (IS_ERR(tcu->rx)) {
> + err = PTR_ERR(tcu->rx);
> + dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);
> + goto free_tx;
> + }
> +
> +#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
> + /* setup the console */
> + strcpy(tcu->console.name, "ttyTCU");
> + tcu->console.device = uart_console_device;
> + tcu->console.flags = CON_PRINTBUFFER | CON_ANYTIME;
> + tcu->console.index = -1;
> + tcu->console.write = tegra_tcu_console_write;
> + tcu->console.setup = tegra_tcu_console_setup;
> + tcu->console.data = &tcu->driver;
> +#endif
> +
> + /* setup the driver */
> + tcu->driver.owner = THIS_MODULE;
> + tcu->driver.driver_name = "tegra-tcu";
> + tcu->driver.dev_name = "ttyTCU";
> +#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
> + tcu->driver.cons = &tcu->console;
> +#endif
> + tcu->driver.nr = 1;
> +
> + err = uart_register_driver(&tcu->driver);
> + if (err) {
> + dev_err(&pdev->dev, "failed to register UART driver: %d\n",
> + err);
> + goto free_rx;
> + }
> +
> + /* setup the port */
> + port = &tcu->port;
> + spin_lock_init(&port->lock);
> + port->dev = &pdev->dev;
> + port->type = PORT_TEGRA_TCU;
> + port->ops = &tegra_tcu_uart_ops;
> + port->fifosize = 1;
> + port->iotype = UPIO_MEM;
> + port->flags = UPF_BOOT_AUTOCONF;
> + port->private_data = tcu;
> +
> + err = uart_add_one_port(&tcu->driver, port);
> + if (err) {
> + dev_err(&pdev->dev, "failed to add UART port: %d\n", err);
> + goto unregister_uart;
> + }
> +
> + platform_set_drvdata(pdev, tcu);
> +#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
> + register_console(&tcu->console);
> +#endif
> +
> + return 0;
> +
> +unregister_uart:
> + uart_unregister_driver(&tcu->driver);
> +free_rx:
> + mbox_free_channel(tcu->rx);
> +free_tx:
> + mbox_free_channel(tcu->tx);
> +
> + return err;
> +}
> +
> +static int tegra_tcu_remove(struct platform_device *pdev)
> +{
> + struct tegra_tcu *tcu = platform_get_drvdata(pdev);
> +
> +#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
> + unregister_console(&tcu->console);
> +#endif
> + uart_remove_one_port(&tcu->driver, &tcu->port);
> + uart_unregister_driver(&tcu->driver);
> + mbox_free_channel(tcu->rx);
> + mbox_free_channel(tcu->tx);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id tegra_tcu_match[] = {
> + { .compatible = "nvidia,tegra194-tcu" },
> + { }
> +};
> +
> +static struct platform_driver tegra_tcu_driver = {
> + .driver = {
> + .name = "tegra-tcu",
> + .of_match_table = tegra_tcu_match,
> + },
> + .probe = tegra_tcu_probe,
> + .remove = tegra_tcu_remove,
> +};
> +module_platform_driver(tegra_tcu_driver);
> +
> +MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("NVIDIA Tegra Combined UART driver");
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index df4a7534e239..6009ee2c2e99 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -79,6 +79,9 @@
> /* Nuvoton UART */
> #define PORT_NPCM 40
>
> +/* NVIDIA Tegra Combined UART */
> +#define PORT_TEGRA_TCU 41
> +
> /* Intel EG20 */
> #define PORT_PCH_8LINE 44
> #define PORT_PCH_2LINE 45
> --
> 2.7.4

\
 
 \ /
  Last update: 2019-02-07 15:40    [W:0.502 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site