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699cc4dfd1
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. Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20200724070815.11445-3-fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright 2020 NXP
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*/
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/serial_core.h>
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#include <linux/serial.h>
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#include <linux/delay.h>
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#include <linux/of.h>
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#include <linux/io.h>
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#define URTX0 0x40 /* Transmitter Register */
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#define UTS_TXFULL (1<<4) /* TxFIFO full */
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#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
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static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
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{
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while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
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cpu_relax();
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writel_relaxed(ch, port->membase + URTX0);
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}
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static void imx_uart_console_early_write(struct console *con, const char *s,
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unsigned count)
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{
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struct earlycon_device *dev = con->data;
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uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
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}
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static int __init
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imx_console_early_setup(struct earlycon_device *dev, const char *opt)
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{
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if (!dev->port.membase)
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return -ENODEV;
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dev->con->write = imx_uart_console_early_write;
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return 0;
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}
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OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
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OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
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MODULE_AUTHOR("NXP");
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MODULE_DESCRIPTION("IMX earlycon driver");
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MODULE_LICENSE("GPL");
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