Split imx earlycon driver from imx serial driver "imx.c" as separated driver. imx serial driver can be built as module, but earlycon driver only support build in.
Unified · Split
| @@ -515,6 +515,14 @@ config SERIAL_IMX_CONSOLE · 514 unmodified lines | ||
| 515 | 515 | "console=ttymxc0". (Try "man bootparam" or see the documentation of |
| 516 | 516 | your bootloader about how to pass options to the kernel at boot time.) |
| 517 | 517 | |
| 518 | +config SERIAL_IMX_EARLYCON | |
| 519 | + bool "Earlycon on IMX serial port" | |
| 520 | + depends on OF | |
| 521 | + select SERIAL_EARLYCON | |
| 522 | + help | |
| 523 | + If you have enabled the earlycon on the Freescale IMX | |
| 524 | + CPU you can make it the earlycon by answering Y to this option. | |
| 525 | + | |
| 518 | 526 | config SERIAL_UARTLITE |
| 519 | 527 | tristate "Xilinx uartlite serial port support" |
| 520 | 528 | depends on HAS_IOMEM |
| @@ -0,0 +1,50 @@ | ||
| 1 | +// SPDX-License-Identifier: GPL-2.0+ | |
| 2 | +/* | |
| 3 | + * Copyright 2020 NXP | |
| 4 | + */ | |
| 5 | + | |
| 6 | +#include <linux/module.h> | |
| 7 | +#include <linux/ioport.h> | |
| 8 | +#include <linux/init.h> | |
| 9 | +#include <linux/serial_core.h> | |
| 10 | +#include <linux/serial.h> | |
| 11 | +#include <linux/delay.h> | |
| 12 | +#include <linux/of.h> | |
| 13 | +#include <linux/io.h> | |
| 14 | + | |
| 15 | +#define URTX0 0x40 /* Transmitter Register */ | |
| 16 | +#define UTS_TXFULL (1<<4) /* TxFIFO full */ | |
| 17 | +#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/ | |
| 18 | + | |
| 19 | +static void imx_uart_console_early_putchar(struct uart_port *port, int ch) | |
| 20 | +{ | |
| 21 | + while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL) | |
| 22 | + cpu_relax(); | |
| 23 | + | |
| 24 | + writel_relaxed(ch, port->membase + URTX0); | |
| 25 | +} | |
| 26 | + | |
| 27 | +static void imx_uart_console_early_write(struct console *con, const char *s, | |
| 28 | + unsigned count) | |
| 29 | +{ | |
| 30 | + struct earlycon_device *dev = con->data; | |
| 31 | + | |
| 32 | + uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar); | |
| 33 | +} | |
| 34 | + | |
| 35 | +static int __init | |
| 36 | +imx_console_early_setup(struct earlycon_device *dev, const char *opt) | |
| 37 | +{ | |
| 38 | + if (!dev->port.membase) | |
| 39 | + return -ENODEV; | |
| 40 | + | |
| 41 | + dev->con->write = imx_uart_console_early_write; | |
| 42 | + | |
| 43 | + return 0; | |
| 44 | +} | |
| 45 | +OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup); | |
| 46 | +OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup); | |
| 47 | + | |
| 48 | +MODULE_AUTHOR("NXP"); | |
| 49 | +MODULE_DESCRIPTION("IMX earlycon driver"); | |
| 50 | +MODULE_LICENSE("GPL"); | |