703327ddcc
The patch allows to see kernel messages on AR934X SoCs in early boot stage. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Acked-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com> Cc: linux-mips@linux-mips.org Cc: mcgrof@infradead.org Patchwork: https://patchwork.linux-mips.org/patch/3504/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
98 lines
2.3 KiB
C
98 lines
2.3 KiB
C
/*
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* Atheros AR7XXX/AR9XXX SoC early printk support
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*
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* Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
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* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*/
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#include <linux/io.h>
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#include <linux/errno.h>
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#include <linux/serial_reg.h>
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#include <asm/addrspace.h>
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#include <asm/mach-ath79/ath79.h>
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#include <asm/mach-ath79/ar71xx_regs.h>
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#include <asm/mach-ath79/ar933x_uart.h>
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static void (*_prom_putchar) (unsigned char);
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static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val)
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{
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u32 t;
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do {
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t = __raw_readl(reg);
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if ((t & mask) == val)
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break;
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} while (1);
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}
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static void prom_putchar_ar71xx(unsigned char ch)
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{
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void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE));
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prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE);
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__raw_writel(ch, base + UART_TX * 4);
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prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE);
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}
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static void prom_putchar_ar933x(unsigned char ch)
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{
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void __iomem *base = (void __iomem *)(KSEG1ADDR(AR933X_UART_BASE));
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prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR,
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AR933X_UART_DATA_TX_CSR);
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__raw_writel(AR933X_UART_DATA_TX_CSR | ch, base + AR933X_UART_DATA_REG);
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prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR,
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AR933X_UART_DATA_TX_CSR);
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}
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static void prom_putchar_dummy(unsigned char ch)
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{
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/* nothing to do */
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}
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static void prom_putchar_init(void)
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{
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void __iomem *base;
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u32 id;
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base = (void __iomem *)(KSEG1ADDR(AR71XX_RESET_BASE));
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id = __raw_readl(base + AR71XX_RESET_REG_REV_ID);
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id &= REV_ID_MAJOR_MASK;
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switch (id) {
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case REV_ID_MAJOR_AR71XX:
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case REV_ID_MAJOR_AR7240:
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case REV_ID_MAJOR_AR7241:
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case REV_ID_MAJOR_AR7242:
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case REV_ID_MAJOR_AR913X:
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case REV_ID_MAJOR_AR9341:
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case REV_ID_MAJOR_AR9342:
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case REV_ID_MAJOR_AR9344:
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_prom_putchar = prom_putchar_ar71xx;
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break;
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case REV_ID_MAJOR_AR9330:
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case REV_ID_MAJOR_AR9331:
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_prom_putchar = prom_putchar_ar933x;
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break;
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default:
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_prom_putchar = prom_putchar_dummy;
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break;
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}
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}
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void prom_putchar(unsigned char ch)
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{
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if (!_prom_putchar)
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prom_putchar_init();
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_prom_putchar(ch);
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}
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