]> git.ipfire.org Git - thirdparty/kernel/linux.git/commitdiff
serial: tegra-utc: Add driver for Tegra UART Trace Controller (UTC)
authorKartik Rajput <kkartik@nvidia.com>
Thu, 13 Feb 2025 12:56:12 +0000 (18:26 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 14 Feb 2025 09:06:50 +0000 (10:06 +0100)
The Tegra264 SoC supports the UART Trace Controller (UTC), which allows
multiple firmware clients (up to 16) to share a single physical UART.
Each client is provided with its own interrupt and has access to a
128-character wide FIFO for both transmit (TX) and receive (RX)
operations.

Add tegra-utc driver to support Tegra UART Trace Controller (UTC)
client.

Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250213125612.4705-3-kkartik@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/Kconfig
drivers/tty/serial/Makefile
drivers/tty/serial/tegra-utc.c [new file with mode: 0644]

index f21cad6aaa475c615dbfb34319ab29d91806f6a5..79a8186d336138e77dd6a034287c59cdd2ec168a 100644 (file)
@@ -287,6 +287,29 @@ config SERIAL_TEGRA_TCU_CONSOLE
 
          If unsure, say Y.
 
+config SERIAL_TEGRA_UTC
+       tristate "NVIDIA Tegra UART Trace Controller"
+       depends on ARCH_TEGRA || COMPILE_TEST
+       select SERIAL_CORE
+       help
+         Support for Tegra UTC (UART Trace controller) client serial port.
+
+         UTC is a HW based serial port that allows multiplexing multiple data
+         streams of up to 16 UTC clients into a single hardware serial port.
+
+config SERIAL_TEGRA_UTC_CONSOLE
+       bool "Support for console on a Tegra UTC serial port"
+       depends on SERIAL_TEGRA_UTC
+       select SERIAL_CORE_CONSOLE
+       default SERIAL_TEGRA_UTC
+       help
+         If you say Y here, it will be possible to use a Tegra UTC client 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 "MAX3100/3110/3111/3222 support"
        depends on SPI
index 3019260d9120b19634830bdde921e58a0e6d306d..d58d9f719889d11c5060e5f86b0fdb0bcbac6664 100644 (file)
@@ -86,6 +86,7 @@ obj-$(CONFIG_SERIAL_STM32)            += stm32-usart.o
 obj-$(CONFIG_SERIAL_SUNPLUS)           += sunplus-uart.o
 obj-$(CONFIG_SERIAL_TEGRA)             += serial-tegra.o
 obj-$(CONFIG_SERIAL_TEGRA_TCU)         += tegra-tcu.o
+obj-$(CONFIG_SERIAL_TEGRA_UTC)         += tegra-utc.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)                += timbuart.o
 obj-$(CONFIG_SERIAL_TXX9)              += serial_txx9.o
 obj-$(CONFIG_SERIAL_UARTLITE)          += uartlite.o
diff --git a/drivers/tty/serial/tegra-utc.c b/drivers/tty/serial/tegra-utc.c
new file mode 100644 (file)
index 0000000..39b14fe
--- /dev/null
@@ -0,0 +1,625 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// NVIDIA Tegra UTC (UART Trace Controller) driver.
+
+#include <linux/bits.h>
+#include <linux/console.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/iopoll.h>
+#include <linux/kfifo.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.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>
+#include <linux/types.h>
+
+#define TEGRA_UTC_ENABLE                       0x000
+#define TEGRA_UTC_ENABLE_CLIENT_ENABLE         BIT(0)
+
+#define TEGRA_UTC_FIFO_THRESHOLD               0x008
+
+#define TEGRA_UTC_COMMAND                      0x00c
+#define TEGRA_UTC_COMMAND_RESET                        BIT(0)
+#define TEGRA_UTC_COMMAND_FLUSH                        BIT(1)
+
+#define TEGRA_UTC_DATA                         0x020
+
+#define TEGRA_UTC_FIFO_STATUS                  0x100
+#define TEGRA_UTC_FIFO_EMPTY                   BIT(0)
+#define TEGRA_UTC_FIFO_FULL                    BIT(1)
+#define TEGRA_UTC_FIFO_REQ                     BIT(2)
+#define TEGRA_UTC_FIFO_OVERFLOW                        BIT(3)
+#define TEGRA_UTC_FIFO_TIMEOUT                 BIT(4)
+
+#define TEGRA_UTC_FIFO_OCCUPANCY               0x104
+
+#define TEGRA_UTC_INTR_STATUS                  0x108
+#define TEGRA_UTC_INTR_SET                     0x10c
+#define TEGRA_UTC_INTR_MASK                    0x110
+#define TEGRA_UTC_INTR_CLEAR                   0x114
+#define TEGRA_UTC_INTR_EMPTY                   BIT(0)
+#define TEGRA_UTC_INTR_FULL                    BIT(1)
+#define TEGRA_UTC_INTR_REQ                     BIT(2)
+#define TEGRA_UTC_INTR_OVERFLOW                        BIT(3)
+#define TEGRA_UTC_INTR_TIMEOUT                 BIT(4)
+
+#define TEGRA_UTC_UART_NR                      16
+
+#define TEGRA_UTC_INTR_COMMON  (TEGRA_UTC_INTR_REQ | TEGRA_UTC_INTR_FULL | TEGRA_UTC_INTR_EMPTY)
+
+struct tegra_utc_port {
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+       struct console console;
+#endif
+       struct uart_port port;
+
+       void __iomem *rx_base;
+       void __iomem *tx_base;
+
+       u32 tx_irqmask;
+       u32 rx_irqmask;
+
+       unsigned int fifosize;
+       u32 tx_threshold;
+       u32 rx_threshold;
+};
+
+static u32 tegra_utc_rx_readl(struct tegra_utc_port *tup, unsigned int offset)
+{
+       void __iomem *addr = tup->rx_base + offset;
+
+       return readl_relaxed(addr);
+}
+
+static void tegra_utc_rx_writel(struct tegra_utc_port *tup, u32 val, unsigned int offset)
+{
+       void __iomem *addr = tup->rx_base + offset;
+
+       writel_relaxed(val, addr);
+}
+
+static u32 tegra_utc_tx_readl(struct tegra_utc_port *tup, unsigned int offset)
+{
+       void __iomem *addr = tup->tx_base + offset;
+
+       return readl_relaxed(addr);
+}
+
+static void tegra_utc_tx_writel(struct tegra_utc_port *tup, u32 val, unsigned int offset)
+{
+       void __iomem *addr = tup->tx_base + offset;
+
+       writel_relaxed(val, addr);
+}
+
+static void tegra_utc_enable_tx_irq(struct tegra_utc_port *tup)
+{
+       tup->tx_irqmask = TEGRA_UTC_INTR_REQ;
+
+       tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_MASK);
+       tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_SET);
+}
+
+static void tegra_utc_disable_tx_irq(struct tegra_utc_port *tup)
+{
+       tup->tx_irqmask = 0x0;
+
+       tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_MASK);
+       tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_SET);
+}
+
+static void tegra_utc_stop_tx(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       tegra_utc_disable_tx_irq(tup);
+}
+
+static void tegra_utc_init_tx(struct tegra_utc_port *tup)
+{
+       /* Disable TX. */
+       tegra_utc_tx_writel(tup, 0x0, TEGRA_UTC_ENABLE);
+
+       /* Update the FIFO Threshold. */
+       tegra_utc_tx_writel(tup, tup->tx_threshold, TEGRA_UTC_FIFO_THRESHOLD);
+
+       /* Clear and mask all the interrupts. */
+       tegra_utc_tx_writel(tup, TEGRA_UTC_INTR_COMMON, TEGRA_UTC_INTR_CLEAR);
+       tegra_utc_disable_tx_irq(tup);
+
+       /* Enable TX. */
+       tegra_utc_tx_writel(tup, TEGRA_UTC_ENABLE_CLIENT_ENABLE, TEGRA_UTC_ENABLE);
+}
+
+static void tegra_utc_init_rx(struct tegra_utc_port *tup)
+{
+       tup->rx_irqmask = TEGRA_UTC_INTR_REQ | TEGRA_UTC_INTR_TIMEOUT;
+
+       tegra_utc_rx_writel(tup, TEGRA_UTC_COMMAND_RESET, TEGRA_UTC_COMMAND);
+       tegra_utc_rx_writel(tup, tup->rx_threshold, TEGRA_UTC_FIFO_THRESHOLD);
+
+       /* Clear all the pending interrupts. */
+       tegra_utc_rx_writel(tup, TEGRA_UTC_INTR_TIMEOUT | TEGRA_UTC_INTR_OVERFLOW |
+                           TEGRA_UTC_INTR_COMMON, TEGRA_UTC_INTR_CLEAR);
+       tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_MASK);
+       tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_SET);
+
+       /* Enable RX. */
+       tegra_utc_rx_writel(tup, TEGRA_UTC_ENABLE_CLIENT_ENABLE, TEGRA_UTC_ENABLE);
+}
+
+static bool tegra_utc_tx_chars(struct tegra_utc_port *tup)
+{
+       struct uart_port *port = &tup->port;
+       unsigned int pending;
+       u8 c;
+
+       pending = uart_port_tx(port, c,
+                    !(tegra_utc_tx_readl(tup, TEGRA_UTC_FIFO_STATUS) & TEGRA_UTC_FIFO_FULL),
+                    tegra_utc_tx_writel(tup, c, TEGRA_UTC_DATA));
+
+       return pending;
+}
+
+static void tegra_utc_rx_chars(struct tegra_utc_port *tup)
+{
+       struct tty_port *port = &tup->port.state->port;
+       unsigned int max_chars = 256;
+       u32 status;
+       int sysrq;
+       u32 ch;
+
+       while (max_chars--) {
+               status = tegra_utc_rx_readl(tup, TEGRA_UTC_FIFO_STATUS);
+               if (status & TEGRA_UTC_FIFO_EMPTY)
+                       break;
+
+               ch = tegra_utc_rx_readl(tup, TEGRA_UTC_DATA);
+               tup->port.icount.rx++;
+
+               if (status & TEGRA_UTC_FIFO_OVERFLOW)
+                       tup->port.icount.overrun++;
+
+               uart_port_unlock(&tup->port);
+               sysrq = uart_handle_sysrq_char(&tup->port, ch);
+               uart_port_lock(&tup->port);
+
+               if (!sysrq)
+                       tty_insert_flip_char(port, ch, TTY_NORMAL);
+       }
+
+       tty_flip_buffer_push(port);
+}
+
+static irqreturn_t tegra_utc_isr(int irq, void *dev_id)
+{
+       struct tegra_utc_port *tup = dev_id;
+       unsigned int handled = 0;
+       u32 status;
+
+       uart_port_lock(&tup->port);
+
+       /* Process RX_REQ and RX_TIMEOUT interrupts. */
+       do {
+               status = tegra_utc_rx_readl(tup, TEGRA_UTC_INTR_STATUS) & tup->rx_irqmask;
+               if (status) {
+                       tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_CLEAR);
+                       tegra_utc_rx_chars(tup);
+                       handled = 1;
+               }
+       } while (status);
+
+       /* Process TX_REQ interrupt. */
+       do {
+               status = tegra_utc_tx_readl(tup, TEGRA_UTC_INTR_STATUS) & tup->tx_irqmask;
+               if (status) {
+                       tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_CLEAR);
+                       tegra_utc_tx_chars(tup);
+                       handled = 1;
+               }
+       } while (status);
+
+       uart_port_unlock(&tup->port);
+
+       return IRQ_RETVAL(handled);
+}
+
+static unsigned int tegra_utc_tx_empty(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       return tegra_utc_tx_readl(tup, TEGRA_UTC_FIFO_OCCUPANCY) ? 0 : TIOCSER_TEMT;
+}
+
+static void tegra_utc_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int tegra_utc_get_mctrl(struct uart_port *port)
+{
+       return 0;
+}
+
+static void tegra_utc_start_tx(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       if (tegra_utc_tx_chars(tup))
+               tegra_utc_enable_tx_irq(tup);
+}
+
+static void tegra_utc_stop_rx(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       tup->rx_irqmask = 0x0;
+       tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_MASK);
+       tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_SET);
+}
+
+static void tegra_utc_hw_init(struct tegra_utc_port *tup)
+{
+       tegra_utc_init_tx(tup);
+       tegra_utc_init_rx(tup);
+}
+
+static int tegra_utc_startup(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+       int ret;
+
+       tegra_utc_hw_init(tup);
+
+       /* Interrupt is dedicated to this UTC client. */
+       ret = request_irq(port->irq, tegra_utc_isr, 0, dev_name(port->dev), tup);
+       if (ret < 0)
+               dev_err(port->dev, "failed to register interrupt handler\n");
+
+       return ret;
+}
+
+static void tegra_utc_shutdown(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       tegra_utc_rx_writel(tup, 0x0, TEGRA_UTC_ENABLE);
+       free_irq(port->irq, tup);
+}
+
+static void tegra_utc_set_termios(struct uart_port *port, struct ktermios *termios,
+                                 const struct ktermios *old)
+{
+       /* The Tegra UTC clients supports only 8-N-1 configuration without HW flow control */
+       termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
+       termios->c_cflag &= ~(CMSPAR | CRTSCTS);
+       termios->c_cflag |= CS8 | CLOCAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static int tegra_utc_poll_init(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       tegra_utc_hw_init(tup);
+       return 0;
+}
+
+static int tegra_utc_get_poll_char(struct uart_port *port)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       if (tegra_utc_rx_readl(tup, TEGRA_UTC_FIFO_STATUS) & TEGRA_UTC_FIFO_EMPTY)
+               return NO_POLL_CHAR;
+
+       return tegra_utc_rx_readl(tup, TEGRA_UTC_DATA);
+}
+
+static void tegra_utc_put_poll_char(struct uart_port *port, unsigned char ch)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+       u32 val;
+
+       read_poll_timeout_atomic(tegra_utc_tx_readl, val, !(val & TEGRA_UTC_FIFO_FULL),
+                                0, USEC_PER_SEC, false, tup, TEGRA_UTC_FIFO_STATUS);
+
+       tegra_utc_tx_writel(tup, ch, TEGRA_UTC_DATA);
+}
+
+#endif
+
+static const struct uart_ops tegra_utc_uart_ops = {
+       .tx_empty = tegra_utc_tx_empty,
+       .set_mctrl = tegra_utc_set_mctrl,
+       .get_mctrl = tegra_utc_get_mctrl,
+       .stop_tx = tegra_utc_stop_tx,
+       .start_tx = tegra_utc_start_tx,
+       .stop_rx = tegra_utc_stop_rx,
+       .startup = tegra_utc_startup,
+       .shutdown = tegra_utc_shutdown,
+       .set_termios = tegra_utc_set_termios,
+#ifdef CONFIG_CONSOLE_POLL
+       .poll_init = tegra_utc_poll_init,
+       .poll_get_char = tegra_utc_get_poll_char,
+       .poll_put_char = tegra_utc_put_poll_char,
+#endif
+};
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+#define TEGRA_UTC_DEFAULT_FIFO_THRESHOLD       4
+#define TEGRA_UTC_EARLYCON_MAX_BURST_SIZE      128
+
+static void tegra_utc_putc(struct uart_port *port, unsigned char c)
+{
+       writel(c, port->membase + TEGRA_UTC_DATA);
+}
+
+static void tegra_utc_early_write(struct console *con, const char *s, unsigned int n)
+{
+       struct earlycon_device *dev = con->data;
+
+       while (n) {
+               u32 burst_size = TEGRA_UTC_EARLYCON_MAX_BURST_SIZE;
+
+               burst_size -= readl(dev->port.membase + TEGRA_UTC_FIFO_OCCUPANCY);
+               if (n < burst_size)
+                       burst_size = n;
+
+               uart_console_write(&dev->port, s, burst_size, tegra_utc_putc);
+
+               n -= burst_size;
+               s += burst_size;
+       }
+}
+
+static int __init tegra_utc_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+       if (!device->port.membase)
+               return -ENODEV;
+
+       /* Configure TX */
+       writel(TEGRA_UTC_COMMAND_FLUSH | TEGRA_UTC_COMMAND_RESET,
+               device->port.membase + TEGRA_UTC_COMMAND);
+       writel(TEGRA_UTC_DEFAULT_FIFO_THRESHOLD, device->port.membase + TEGRA_UTC_FIFO_THRESHOLD);
+
+       /* Clear and mask all the interrupts. */
+       writel(TEGRA_UTC_INTR_COMMON, device->port.membase + TEGRA_UTC_INTR_CLEAR);
+
+       writel(0x0, device->port.membase + TEGRA_UTC_INTR_MASK);
+       writel(0x0, device->port.membase + TEGRA_UTC_INTR_SET);
+
+       /* Enable TX. */
+       writel(TEGRA_UTC_ENABLE_CLIENT_ENABLE, device->port.membase + TEGRA_UTC_ENABLE);
+
+       device->con->write = tegra_utc_early_write;
+
+       return 0;
+}
+OF_EARLYCON_DECLARE(tegra_utc, "nvidia,tegra264-utc", tegra_utc_early_console_setup);
+
+static void tegra_utc_console_putchar(struct uart_port *port, unsigned char ch)
+{
+       struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+       tegra_utc_tx_writel(tup, ch, TEGRA_UTC_DATA);
+}
+
+static void tegra_utc_console_write_atomic(struct console *cons, struct nbcon_write_context *wctxt)
+{
+       struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+       unsigned int len;
+       char *outbuf;
+
+       if (!nbcon_enter_unsafe(wctxt))
+               return;
+
+       outbuf = wctxt->outbuf;
+       len = wctxt->len;
+
+       while (len) {
+               u32 burst_size = tup->fifosize;
+
+               burst_size -= tegra_utc_tx_readl(tup, TEGRA_UTC_FIFO_OCCUPANCY);
+               if (len < burst_size)
+                       burst_size = len;
+
+               uart_console_write(&tup->port, outbuf, burst_size, tegra_utc_console_putchar);
+
+               outbuf += burst_size;
+               len -= burst_size;
+       };
+
+       nbcon_exit_unsafe(wctxt);
+}
+
+static void tegra_utc_console_write_thread(struct console *cons, struct nbcon_write_context *wctxt)
+{
+       struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+       unsigned int len = READ_ONCE(wctxt->len);
+       unsigned int i;
+       u32 val;
+
+       for (i = 0; i < len; i++) {
+               if (!nbcon_enter_unsafe(wctxt))
+                       break;
+
+               read_poll_timeout_atomic(tegra_utc_tx_readl, val, !(val & TEGRA_UTC_FIFO_FULL),
+                                        0, USEC_PER_SEC, false, tup, TEGRA_UTC_FIFO_STATUS);
+               uart_console_write(&tup->port, wctxt->outbuf + i, 1, tegra_utc_console_putchar);
+
+               if (!nbcon_exit_unsafe(wctxt))
+                       break;
+       }
+}
+
+static void tegra_utc_console_device_lock(struct console *cons, unsigned long *flags)
+{
+       struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+       struct uart_port *port = &tup->port;
+
+       __uart_port_lock_irqsave(port, flags);
+}
+
+static void tegra_utc_console_device_unlock(struct console *cons, unsigned long flags)
+{
+       struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+       struct uart_port *port = &tup->port;
+
+       __uart_port_unlock_irqrestore(port, flags);
+}
+
+static int tegra_utc_console_setup(struct console *cons, char *options)
+{
+       struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+
+       tegra_utc_init_tx(tup);
+
+       return 0;
+}
+#endif
+
+static struct uart_driver tegra_utc_driver = {
+       .driver_name    = "tegra-utc",
+       .dev_name       = "ttyUTC",
+       .nr             = TEGRA_UTC_UART_NR,
+};
+
+static int tegra_utc_setup_port(struct device *dev, struct tegra_utc_port *tup)
+{
+       tup->port.dev                   = dev;
+       tup->port.fifosize              = tup->fifosize;
+       tup->port.flags                 = UPF_BOOT_AUTOCONF;
+       tup->port.iotype                = UPIO_MEM;
+       tup->port.ops                   = &tegra_utc_uart_ops;
+       tup->port.type                  = PORT_TEGRA_TCU;
+       tup->port.private_data          = tup;
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+       strscpy(tup->console.name, "ttyUTC", sizeof(tup->console.name));
+       tup->console.write_atomic       = tegra_utc_console_write_atomic;
+       tup->console.write_thread       = tegra_utc_console_write_thread;
+       tup->console.device_lock        = tegra_utc_console_device_lock;
+       tup->console.device_unlock      = tegra_utc_console_device_unlock;
+       tup->console.device             = uart_console_device;
+       tup->console.setup              = tegra_utc_console_setup;
+       tup->console.flags              = CON_PRINTBUFFER | CON_NBCON;
+       tup->console.data               = &tegra_utc_driver;
+#endif
+
+       return uart_read_port_properties(&tup->port);
+}
+
+static int tegra_utc_register_port(struct tegra_utc_port *tup)
+{
+       int ret;
+
+       ret = uart_add_one_port(&tegra_utc_driver, &tup->port);
+       if (ret)
+               return ret;
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+       register_console(&tup->console);
+#endif
+
+       return 0;
+}
+
+static int tegra_utc_probe(struct platform_device *pdev)
+{
+       const unsigned int *soc_fifosize;
+       struct device *dev = &pdev->dev;
+       struct tegra_utc_port *tup;
+       int ret;
+
+       tup = devm_kzalloc(dev, sizeof(*tup), GFP_KERNEL);
+       if (!tup)
+               return -ENOMEM;
+
+       ret = device_property_read_u32(dev, "tx-threshold", &tup->tx_threshold);
+       if (ret)
+               return dev_err_probe(dev, ret, "missing %s property\n", "tx-threshold");
+
+       ret = device_property_read_u32(dev, "rx-threshold", &tup->rx_threshold);
+       if (ret)
+               return dev_err_probe(dev, ret, "missing %s property\n", "rx-threshold");
+
+       soc_fifosize = device_get_match_data(dev);
+       tup->fifosize = *soc_fifosize;
+
+       tup->tx_base = devm_platform_ioremap_resource_byname(pdev, "tx");
+       if (IS_ERR(tup->tx_base))
+               return PTR_ERR(tup->tx_base);
+
+       tup->rx_base = devm_platform_ioremap_resource_byname(pdev, "rx");
+       if (IS_ERR(tup->rx_base))
+               return PTR_ERR(tup->rx_base);
+
+       ret = tegra_utc_setup_port(dev, tup);
+       if (ret)
+               dev_err_probe(dev, ret, "failed to setup uart port\n");
+
+       platform_set_drvdata(pdev, tup);
+
+       return tegra_utc_register_port(tup);
+}
+
+static void tegra_utc_remove(struct platform_device *pdev)
+{
+       struct tegra_utc_port *tup = platform_get_drvdata(pdev);
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+       unregister_console(&tup->console);
+#endif
+       uart_remove_one_port(&tegra_utc_driver, &tup->port);
+}
+
+static const unsigned int tegra264_utc_soc = 128;
+
+static const struct of_device_id tegra_utc_of_match[] = {
+       { .compatible = "nvidia,tegra264-utc", .data = &tegra264_utc_soc },
+       {}
+};
+MODULE_DEVICE_TABLE(of, tegra_utc_of_match);
+
+static struct platform_driver tegra_utc_platform_driver = {
+       .probe = tegra_utc_probe,
+       .remove = tegra_utc_remove,
+       .driver = {
+               .name = "tegra-utc",
+               .of_match_table = tegra_utc_of_match,
+       },
+};
+
+static int __init tegra_utc_init(void)
+{
+       int ret;
+
+       ret = uart_register_driver(&tegra_utc_driver);
+       if (ret)
+               return ret;
+
+       ret = platform_driver_register(&tegra_utc_platform_driver);
+       if (ret)
+               uart_unregister_driver(&tegra_utc_driver);
+
+       return ret;
+}
+module_init(tegra_utc_init);
+
+static void __exit tegra_utc_exit(void)
+{
+       platform_driver_unregister(&tegra_utc_platform_driver);
+       uart_unregister_driver(&tegra_utc_driver);
+}
+module_exit(tegra_utc_exit);
+
+MODULE_AUTHOR("Kartik Rajput <kkartik@nvidia.com>");
+MODULE_DESCRIPTION("Tegra UART Trace Controller");
+MODULE_LICENSE("GPL");