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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.4 */5 6#include <linux/console.h>7#include <linux/mailbox_client.h>8#include <linux/module.h>9#include <linux/of.h>10#include <linux/platform_device.h>11#include <linux/serial.h>12#include <linux/serial_core.h>13#include <linux/slab.h>14#include <linux/tty.h>15#include <linux/tty_flip.h>16 17#define TCU_MBOX_BYTE(i, x) ((x) << (i * 8))18#define TCU_MBOX_BYTE_V(x, i) (((x) >> (i * 8)) & 0xff)19#define TCU_MBOX_NUM_BYTES(x) ((x) << 24)20#define TCU_MBOX_NUM_BYTES_V(x) (((x) >> 24) & 0x3)21 22struct tegra_tcu {23 struct uart_driver driver;24#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)25 struct console console;26#endif27 struct uart_port port;28 29 struct mbox_client tx_client, rx_client;30 struct mbox_chan *tx, *rx;31};32 33static unsigned int tegra_tcu_uart_tx_empty(struct uart_port *port)34{35 return TIOCSER_TEMT;36}37 38static void tegra_tcu_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)39{40}41 42static unsigned int tegra_tcu_uart_get_mctrl(struct uart_port *port)43{44 return 0;45}46 47static void tegra_tcu_uart_stop_tx(struct uart_port *port)48{49}50 51static void tegra_tcu_write_one(struct tegra_tcu *tcu, u32 value,52 unsigned int count)53{54 void *msg;55 56 value |= TCU_MBOX_NUM_BYTES(count);57 msg = (void *)(unsigned long)value;58 mbox_send_message(tcu->tx, msg);59 mbox_flush(tcu->tx, 1000);60}61 62static void tegra_tcu_write(struct tegra_tcu *tcu, const char *s,63 unsigned int count)64{65 unsigned int written = 0, i = 0;66 bool insert_nl = false;67 u32 value = 0;68 69 while (i < count) {70 if (insert_nl) {71 value |= TCU_MBOX_BYTE(written++, '\n');72 insert_nl = false;73 i++;74 } else if (s[i] == '\n') {75 value |= TCU_MBOX_BYTE(written++, '\r');76 insert_nl = true;77 } else {78 value |= TCU_MBOX_BYTE(written++, s[i++]);79 }80 81 if (written == 3) {82 tegra_tcu_write_one(tcu, value, 3);83 value = written = 0;84 }85 }86 87 if (written)88 tegra_tcu_write_one(tcu, value, written);89}90 91static void tegra_tcu_uart_start_tx(struct uart_port *port)92{93 struct tegra_tcu *tcu = port->private_data;94 struct tty_port *tport = &port->state->port;95 unsigned char *tail;96 unsigned int count;97 98 for (;;) {99 count = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail,100 UART_XMIT_SIZE);101 if (!count)102 break;103 104 tegra_tcu_write(tcu, tail, count);105 uart_xmit_advance(port, count);106 }107 108 uart_write_wakeup(port);109}110 111static void tegra_tcu_uart_stop_rx(struct uart_port *port)112{113}114 115static void tegra_tcu_uart_break_ctl(struct uart_port *port, int ctl)116{117}118 119static int tegra_tcu_uart_startup(struct uart_port *port)120{121 return 0;122}123 124static void tegra_tcu_uart_shutdown(struct uart_port *port)125{126}127 128static void tegra_tcu_uart_set_termios(struct uart_port *port,129 struct ktermios *new,130 const struct ktermios *old)131{132}133 134static const struct uart_ops tegra_tcu_uart_ops = {135 .tx_empty = tegra_tcu_uart_tx_empty,136 .set_mctrl = tegra_tcu_uart_set_mctrl,137 .get_mctrl = tegra_tcu_uart_get_mctrl,138 .stop_tx = tegra_tcu_uart_stop_tx,139 .start_tx = tegra_tcu_uart_start_tx,140 .stop_rx = tegra_tcu_uart_stop_rx,141 .break_ctl = tegra_tcu_uart_break_ctl,142 .startup = tegra_tcu_uart_startup,143 .shutdown = tegra_tcu_uart_shutdown,144 .set_termios = tegra_tcu_uart_set_termios,145};146 147#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)148static void tegra_tcu_console_write(struct console *cons, const char *s,149 unsigned int count)150{151 struct tegra_tcu *tcu = container_of(cons, struct tegra_tcu, console);152 153 tegra_tcu_write(tcu, s, count);154}155 156static int tegra_tcu_console_setup(struct console *cons, char *options)157{158 return 0;159}160#endif161 162static void tegra_tcu_receive(struct mbox_client *cl, void *msg)163{164 struct tegra_tcu *tcu = container_of(cl, struct tegra_tcu, rx_client);165 struct tty_port *port = &tcu->port.state->port;166 u32 value = (u32)(unsigned long)msg;167 unsigned int num_bytes, i;168 169 num_bytes = TCU_MBOX_NUM_BYTES_V(value);170 171 for (i = 0; i < num_bytes; i++)172 tty_insert_flip_char(port, TCU_MBOX_BYTE_V(value, i),173 TTY_NORMAL);174 175 tty_flip_buffer_push(port);176}177 178static int tegra_tcu_probe(struct platform_device *pdev)179{180 struct uart_port *port;181 struct tegra_tcu *tcu;182 int err;183 184 tcu = devm_kzalloc(&pdev->dev, sizeof(*tcu), GFP_KERNEL);185 if (!tcu)186 return -ENOMEM;187 188 tcu->tx_client.dev = &pdev->dev;189 tcu->rx_client.dev = &pdev->dev;190 tcu->rx_client.rx_callback = tegra_tcu_receive;191 192 tcu->tx = mbox_request_channel_byname(&tcu->tx_client, "tx");193 if (IS_ERR(tcu->tx)) {194 err = PTR_ERR(tcu->tx);195 dev_err(&pdev->dev, "failed to get tx mailbox: %d\n", err);196 return err;197 }198 199#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)200 /* setup the console */201 strcpy(tcu->console.name, "ttyTCU");202 tcu->console.device = uart_console_device;203 tcu->console.flags = CON_PRINTBUFFER | CON_ANYTIME;204 tcu->console.index = -1;205 tcu->console.write = tegra_tcu_console_write;206 tcu->console.setup = tegra_tcu_console_setup;207 tcu->console.data = &tcu->driver;208#endif209 210 /* setup the driver */211 tcu->driver.owner = THIS_MODULE;212 tcu->driver.driver_name = "tegra-tcu";213 tcu->driver.dev_name = "ttyTCU";214#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)215 tcu->driver.cons = &tcu->console;216#endif217 tcu->driver.nr = 1;218 219 err = uart_register_driver(&tcu->driver);220 if (err) {221 dev_err(&pdev->dev, "failed to register UART driver: %d\n",222 err);223 goto free_tx;224 }225 226 /* setup the port */227 port = &tcu->port;228 spin_lock_init(&port->lock);229 port->dev = &pdev->dev;230 port->type = PORT_TEGRA_TCU;231 port->ops = &tegra_tcu_uart_ops;232 port->fifosize = 1;233 port->iotype = UPIO_MEM;234 port->flags = UPF_BOOT_AUTOCONF;235 port->private_data = tcu;236 237 err = uart_add_one_port(&tcu->driver, port);238 if (err) {239 dev_err(&pdev->dev, "failed to add UART port: %d\n", err);240 goto unregister_uart;241 }242 243 /*244 * Request RX channel after creating port to ensure tcu->port245 * is ready for any immediate incoming bytes.246 */247 tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");248 if (IS_ERR(tcu->rx)) {249 err = PTR_ERR(tcu->rx);250 dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);251 goto remove_uart_port;252 }253 254 platform_set_drvdata(pdev, tcu);255#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)256 register_console(&tcu->console);257#endif258 259 return 0;260 261remove_uart_port:262 uart_remove_one_port(&tcu->driver, &tcu->port);263unregister_uart:264 uart_unregister_driver(&tcu->driver);265free_tx:266 mbox_free_channel(tcu->tx);267 268 return err;269}270 271static void tegra_tcu_remove(struct platform_device *pdev)272{273 struct tegra_tcu *tcu = platform_get_drvdata(pdev);274 275#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)276 unregister_console(&tcu->console);277#endif278 mbox_free_channel(tcu->rx);279 uart_remove_one_port(&tcu->driver, &tcu->port);280 uart_unregister_driver(&tcu->driver);281 mbox_free_channel(tcu->tx);282}283 284static const struct of_device_id tegra_tcu_match[] = {285 { .compatible = "nvidia,tegra194-tcu" },286 { }287};288MODULE_DEVICE_TABLE(of, tegra_tcu_match);289 290static struct platform_driver tegra_tcu_driver = {291 .driver = {292 .name = "tegra-tcu",293 .of_match_table = tegra_tcu_match,294 },295 .probe = tegra_tcu_probe,296 .remove_new = tegra_tcu_remove,297};298module_platform_driver(tegra_tcu_driver);299 300MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");301MODULE_LICENSE("GPL v2");302MODULE_DESCRIPTION("NVIDIA Tegra Combined UART driver");303