#include <linux/console.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.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 tty_port *tport = &port->state->port;
unsigned char *tail;
unsigned int count;
for (;;) {
count = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail,
UART_XMIT_SIZE);
if (!count)
break;
tegra_tcu_write(tcu, tail, count);
uart_xmit_advance(port, count);
}
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,
const 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;
}
#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_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
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_tx;
}
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;
}
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 remove_uart_port;
}
platform_set_drvdata(pdev, tcu);
#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
register_console(&tcu->console);
#endif
return 0;
remove_uart_port:
uart_remove_one_port(&tcu->driver, &tcu->port);
unregister_uart:
uart_unregister_driver(&tcu->driver);
free_tx:
mbox_free_channel(tcu->tx);
return err;
}
static void 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
mbox_free_channel(tcu->rx);
uart_remove_one_port(&tcu->driver, &tcu->port);
uart_unregister_driver(&tcu->driver);
mbox_free_channel(tcu->tx);
}
static const struct of_device_id tegra_tcu_match[] = {
{ .compatible = "nvidia,tegra194-tcu" },
{ }
};
MODULE_DEVICE_TABLE(of, tegra_tcu_match);
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");
