// SPDX-License-Identifier: GPL-2.0-only /* * * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org> */ #include <linux/io.h> #include <linux/serial_reg.h> #include <asm/addrspace.h> #include <asm/setup.h> #ifdef CONFIG_SOC_RT288X #define EARLY_UART_BASE 0x300c00 #define CHIPID_BASE 0x300004 #elif defined(CONFIG_SOC_MT7621) #define EARLY_UART_BASE 0x1E000c00 #define CHIPID_BASE 0x1E000004 #else #define EARLY_UART_BASE 0x10000c00 #define CHIPID_BASE 0x10000004 #endif #define MT7628_CHIP_NAME1 0x20203832 #define UART_REG_TX 0x04 #define UART_REG_LCR 0x0c #define UART_REG_LSR 0x14 #define UART_REG_LSR_RT2880 0x1c static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE); static __iomem void *chipid_membase = (__iomem void *) KSEG1ADDR(CHIPID_BASE); static int init_complete; static inline void uart_w32(u32 val, unsigned reg) { __raw_writel(val, uart_membase + reg); } static inline u32 uart_r32(unsigned reg) { return __raw_readl(uart_membase + reg); } static inline int soc_is_mt7628(void) { return IS_ENABLED(CONFIG_SOC_MT7620) && (__raw_readl(chipid_membase) == MT7628_CHIP_NAME1); } static void find_uart_base(void) { int i; if (!soc_is_mt7628()) return; for (i = 0; i < 3; i++) { u32 reg = uart_r32(UART_REG_LCR + (0x100 * i)); if (!reg) continue; uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE + (0x100 * i)); break; } } void prom_putchar(char ch) { if (!init_complete) { find_uart_base(); init_complete = 1; } if (IS_ENABLED(CONFIG_SOC_MT7621) || soc_is_mt7628()) { uart_w32((unsigned char)ch, UART_TX); while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) ; } else { while ((uart_r32(UART_REG_LSR_RT2880) & UART_LSR_THRE) == 0) ; uart_w32((unsigned char)ch, UART_REG_TX); while ((uart_r32(UART_REG_LSR_RT2880) & UART_LSR_THRE) == 0) ; } }