@@ -323,6 +323,28 @@ 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
@@ -76,6 +76,7 @@ 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
new file mode 100644
@@ -0,0 +1,299 @@
+// 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);
+}
+
+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->tx_client.tx_block = true;
+ tcu->tx_client.tx_tout = 10000;
+ 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");
@@ -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