| 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/errno.h> |
| 13 | #include <linux/io.h> |
| 14 | #include <linux/serial_reg.h> |
| 15 | #include <asm/addrspace.h> |
| 16 | |
| 17 | #include <asm/mach-ar71xx/ar71xx.h> |
| 18 | #include <asm/mach-ar71xx/ar933x_uart.h> |
| 19 | |
| 20 | static void (*_prom_putchar) (unsigned char); |
| 21 | |
| 22 | static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val) |
| 23 | { |
| 24 | u32 t; |
| 25 | |
| 26 | do { |
| 27 | t = __raw_readl(reg); |
| 28 | if ((t & mask) == val) |
| 29 | break; |
| 30 | } while (1); |
| 31 | } |
| 32 | |
| 33 | static void prom_putchar_ar71xx(unsigned char ch) |
| 34 | { |
| 35 | void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE)); |
| 36 | |
| 37 | prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE); |
| 38 | __raw_writel(ch, base + UART_TX * 4); |
| 39 | prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE); |
| 40 | } |
| 41 | |
| 42 | static void prom_putchar_ar933x(unsigned char ch) |
| 43 | { |
| 44 | void __iomem *base = (void __iomem *)(KSEG1ADDR(AR933X_UART_BASE)); |
| 45 | |
| 46 | prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR, |
| 47 | AR933X_UART_DATA_TX_CSR); |
| 48 | __raw_writel(AR933X_UART_DATA_TX_CSR | ch, base + AR933X_UART_DATA_REG); |
| 49 | prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR, |
| 50 | AR933X_UART_DATA_TX_CSR); |
| 51 | } |
| 52 | |
| 53 | static void prom_putchar_dummy(unsigned char ch) |
| 54 | { |
| 55 | /* nothing to do */ |
| 56 | } |
| 57 | |
| 58 | static void prom_putchar_init(void) |
| 59 | { |
| 60 | void __iomem *base; |
| 61 | u32 id; |
| 62 | |
| 63 | base = (void __iomem *)(KSEG1ADDR(AR71XX_RESET_BASE)); |
| 64 | id = __raw_readl(base + AR71XX_RESET_REG_REV_ID); |
| 65 | id &= REV_ID_MAJOR_MASK; |
| 66 | |
| 67 | switch (id) { |
| 68 | case REV_ID_MAJOR_AR71XX: |
| 69 | case REV_ID_MAJOR_AR7240: |
| 70 | case REV_ID_MAJOR_AR7241: |
| 71 | case REV_ID_MAJOR_AR7242: |
| 72 | case REV_ID_MAJOR_AR913X: |
| 73 | case REV_ID_MAJOR_AR9341: |
| 74 | case REV_ID_MAJOR_AR9342: |
| 75 | case REV_ID_MAJOR_AR9344: |
| 76 | _prom_putchar = prom_putchar_ar71xx; |
| 77 | break; |
| 78 | |
| 79 | case REV_ID_MAJOR_AR9330: |
| 80 | case REV_ID_MAJOR_AR9331: |
| 81 | _prom_putchar = prom_putchar_ar933x; |
| 82 | break; |
| 83 | |
| 84 | default: |
| 85 | _prom_putchar = prom_putchar_dummy; |
| 86 | break; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | void prom_putchar(unsigned char ch) |
| 91 | { |
| 92 | if (!_prom_putchar) |
| 93 | prom_putchar_init(); |
| 94 | |
| 95 | _prom_putchar(ch); |
| 96 | } |
| 97 | |
