diff options
Diffstat (limited to 'arch/mips/ath79/early_printk.c')
| -rw-r--r-- | arch/mips/ath79/early_printk.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/mips/ath79/early_printk.c b/arch/mips/ath79/early_printk.c new file mode 100644 index 000000000..4b1063117 --- /dev/null +++ b/arch/mips/ath79/early_printk.c @@ -0,0 +1,149 @@ +/* + * Atheros AR7XXX/AR9XXX SoC early printk support + * + * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/io.h> +#include <linux/errno.h> +#include <linux/serial_reg.h> +#include <asm/addrspace.h> +#include <asm/setup.h> + +#include <asm/mach-ath79/ath79.h> +#include <asm/mach-ath79/ar71xx_regs.h> +#include <asm/mach-ath79/ar933x_uart.h> + +static void (*_prom_putchar)(char); + +static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val) +{ + u32 t; + + do { + t = __raw_readl(reg); + if ((t & mask) == val) + break; + } while (1); +} + +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + +static void prom_putchar_ar71xx(char ch) +{ + void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE)); + + prom_putchar_wait(base + UART_LSR * 4, BOTH_EMPTY, BOTH_EMPTY); + __raw_writel((unsigned char)ch, base + UART_TX * 4); + prom_putchar_wait(base + UART_LSR * 4, BOTH_EMPTY, BOTH_EMPTY); +} + +static void prom_putchar_ar933x(char ch) +{ + void __iomem *base = (void __iomem *)(KSEG1ADDR(AR933X_UART_BASE)); + + prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR, + AR933X_UART_DATA_TX_CSR); + __raw_writel(AR933X_UART_DATA_TX_CSR | (unsigned char)ch, + base + AR933X_UART_DATA_REG); + prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR, + AR933X_UART_DATA_TX_CSR); +} + +static void prom_putchar_dummy(char ch) +{ + /* nothing to do */ +} + +static void prom_enable_uart(u32 id) +{ + void __iomem *gpio_base; + u32 uart_en; + u32 t; + + switch (id) { + case REV_ID_MAJOR_AR71XX: + uart_en = AR71XX_GPIO_FUNC_UART_EN; + break; + + case REV_ID_MAJOR_AR7240: + case REV_ID_MAJOR_AR7241: + case REV_ID_MAJOR_AR7242: + uart_en = AR724X_GPIO_FUNC_UART_EN; + break; + + case REV_ID_MAJOR_AR913X: + uart_en = AR913X_GPIO_FUNC_UART_EN; + break; + + case REV_ID_MAJOR_AR9330: + case REV_ID_MAJOR_AR9331: + uart_en = AR933X_GPIO_FUNC_UART_EN; + break; + + case REV_ID_MAJOR_AR9341: + case REV_ID_MAJOR_AR9342: + case REV_ID_MAJOR_AR9344: + /* TODO */ + default: + return; + } + + gpio_base = (void __iomem *)KSEG1ADDR(AR71XX_GPIO_BASE); + t = __raw_readl(gpio_base + AR71XX_GPIO_REG_FUNC); + t |= uart_en; + __raw_writel(t, gpio_base + AR71XX_GPIO_REG_FUNC); +} + +static void prom_putchar_init(void) +{ + void __iomem *base; + u32 id; + + base = (void __iomem *)(KSEG1ADDR(AR71XX_RESET_BASE)); + id = __raw_readl(base + AR71XX_RESET_REG_REV_ID); + id &= REV_ID_MAJOR_MASK; + + switch (id) { + case REV_ID_MAJOR_AR71XX: + case REV_ID_MAJOR_AR7240: + case REV_ID_MAJOR_AR7241: + case REV_ID_MAJOR_AR7242: + case REV_ID_MAJOR_AR913X: + case REV_ID_MAJOR_AR9341: + case REV_ID_MAJOR_AR9342: + case REV_ID_MAJOR_AR9344: + case REV_ID_MAJOR_QCA9533: + case REV_ID_MAJOR_QCA9533_V2: + case REV_ID_MAJOR_QCA9556: + case REV_ID_MAJOR_QCA9558: + case REV_ID_MAJOR_TP9343: + case REV_ID_MAJOR_QCA956X: + _prom_putchar = prom_putchar_ar71xx; + break; + + case REV_ID_MAJOR_AR9330: + case REV_ID_MAJOR_AR9331: + _prom_putchar = prom_putchar_ar933x; + break; + + default: + _prom_putchar = prom_putchar_dummy; + return; + } + + prom_enable_uart(id); +} + +void prom_putchar(char ch) +{ + if (!_prom_putchar) + prom_putchar_init(); + + _prom_putchar(ch); +} |