1 /* 2 * Atheros AR7XXX/AR9XXX SoC early printk support 3 * 4 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org> 5 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License version 2 as published 9 * by the Free Software Foundation. 10 */ 11 12 #include <linux/io.h> 13 #include <linux/errno.h> 14 #include <linux/serial_reg.h> 15 #include <asm/addrspace.h> 16 #include <asm/setup.h> 17 18 #include <asm/mach-ath79/ath79.h> 19 #include <asm/mach-ath79/ar71xx_regs.h> 20 #include <asm/mach-ath79/ar933x_uart.h> 21 22 static void (*_prom_putchar)(char); 23 24 static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val) 25 { 26 u32 t; 27 28 do { 29 t = __raw_readl(reg); 30 if ((t & mask) == val) 31 break; 32 } while (1); 33 } 34 35 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) 36 37 static void prom_putchar_ar71xx(char ch) 38 { 39 void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE)); 40 41 prom_putchar_wait(base + UART_LSR * 4, BOTH_EMPTY, BOTH_EMPTY); 42 __raw_writel((unsigned char)ch, base + UART_TX * 4); 43 prom_putchar_wait(base + UART_LSR * 4, BOTH_EMPTY, BOTH_EMPTY); 44 } 45 46 static void prom_putchar_ar933x(char ch) 47 { 48 void __iomem *base = (void __iomem *)(KSEG1ADDR(AR933X_UART_BASE)); 49 50 prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR, 51 AR933X_UART_DATA_TX_CSR); 52 __raw_writel(AR933X_UART_DATA_TX_CSR | (unsigned char)ch, 53 base + AR933X_UART_DATA_REG); 54 prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR, 55 AR933X_UART_DATA_TX_CSR); 56 } 57 58 static void prom_putchar_dummy(char ch) 59 { 60 /* nothing to do */ 61 } 62 63 static void prom_enable_uart(u32 id) 64 { 65 void __iomem *gpio_base; 66 u32 uart_en; 67 u32 t; 68 69 switch (id) { 70 case REV_ID_MAJOR_AR71XX: 71 uart_en = AR71XX_GPIO_FUNC_UART_EN; 72 break; 73 74 case REV_ID_MAJOR_AR7240: 75 case REV_ID_MAJOR_AR7241: 76 case REV_ID_MAJOR_AR7242: 77 uart_en = AR724X_GPIO_FUNC_UART_EN; 78 break; 79 80 case REV_ID_MAJOR_AR913X: 81 uart_en = AR913X_GPIO_FUNC_UART_EN; 82 break; 83 84 case REV_ID_MAJOR_AR9330: 85 case REV_ID_MAJOR_AR9331: 86 uart_en = AR933X_GPIO_FUNC_UART_EN; 87 break; 88 89 case REV_ID_MAJOR_AR9341: 90 case REV_ID_MAJOR_AR9342: 91 case REV_ID_MAJOR_AR9344: 92 /* TODO */ 93 default: 94 return; 95 } 96 97 gpio_base = (void __iomem *)KSEG1ADDR(AR71XX_GPIO_BASE); 98 t = __raw_readl(gpio_base + AR71XX_GPIO_REG_FUNC); 99 t |= uart_en; 100 __raw_writel(t, gpio_base + AR71XX_GPIO_REG_FUNC); 101 } 102 103 static void prom_putchar_init(void) 104 { 105 void __iomem *base; 106 u32 id; 107 108 base = (void __iomem *)(KSEG1ADDR(AR71XX_RESET_BASE)); 109 id = __raw_readl(base + AR71XX_RESET_REG_REV_ID); 110 id &= REV_ID_MAJOR_MASK; 111 112 switch (id) { 113 case REV_ID_MAJOR_AR71XX: 114 case REV_ID_MAJOR_AR7240: 115 case REV_ID_MAJOR_AR7241: 116 case REV_ID_MAJOR_AR7242: 117 case REV_ID_MAJOR_AR913X: 118 case REV_ID_MAJOR_AR9341: 119 case REV_ID_MAJOR_AR9342: 120 case REV_ID_MAJOR_AR9344: 121 case REV_ID_MAJOR_QCA9533: 122 case REV_ID_MAJOR_QCA9533_V2: 123 case REV_ID_MAJOR_QCA9556: 124 case REV_ID_MAJOR_QCA9558: 125 case REV_ID_MAJOR_TP9343: 126 case REV_ID_MAJOR_QCA956X: 127 _prom_putchar = prom_putchar_ar71xx; 128 break; 129 130 case REV_ID_MAJOR_AR9330: 131 case REV_ID_MAJOR_AR9331: 132 _prom_putchar = prom_putchar_ar933x; 133 break; 134 135 default: 136 _prom_putchar = prom_putchar_dummy; 137 return; 138 } 139 140 prom_enable_uart(id); 141 } 142 143 void prom_putchar(char ch) 144 { 145 if (!_prom_putchar) 146 prom_putchar_init(); 147 148 _prom_putchar(ch); 149 } 150