diff options
Diffstat (limited to 'arch/arm/mach-tegra/include/mach/uncompress.h')
| -rw-r--r-- | arch/arm/mach-tegra/include/mach/uncompress.h | 111 |
1 files changed, 100 insertions, 11 deletions
diff --git a/arch/arm/mach-tegra/include/mach/uncompress.h b/arch/arm/mach-tegra/include/mach/uncompress.h index 4a8ac6b0b68b..5f5a0257489d 100644 --- a/arch/arm/mach-tegra/include/mach/uncompress.h +++ b/arch/arm/mach-tegra/include/mach/uncompress.h @@ -2,10 +2,14 @@ * arch/arm/mach-tegra/include/mach/uncompress.h * * Copyright (C) 2010 Google, Inc. + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2011-2012 NVIDIA CORPORATION. All Rights Reserved. * * Author: * Colin Cross <ccross@google.com> * Erik Gilling <konkers@google.com> + * Doug Anderson <dianders@chromium.org> + * Stephen Warren <swarren@nvidia.com> * * Copyright (C) 2010-2012 NVIDIA Corporation * @@ -27,6 +31,14 @@ #include <linux/serial_reg.h> #include <mach/iomap.h> +#include <mach/irammap.h> + +#define BIT(x) (1 << (x)) +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) + +#define DEBUG_UART_SHIFT 2 + +volatile u8 *uart; #if defined(CONFIG_TEGRA_DEBUG_UARTA) #define DEBUG_UART_CLK_SRC (TEGRA_CLK_RESET_BASE + 0x178) @@ -78,15 +90,12 @@ static void putc(int c) { - volatile u8 *uart = (volatile u8 *)TEGRA_DEBUG_UART_BASE; - int shift = 2; - if (uart == NULL) return; - while (!(uart[UART_LSR << shift] & UART_LSR_THRE)) + while (!(uart[UART_LSR << DEBUG_UART_SHIFT] & UART_LSR_THRE)) barrier(); - uart[UART_TX << shift] = c; + uart[UART_TX << DEBUG_UART_SHIFT] = c; } static inline void flush(void) @@ -102,15 +111,95 @@ static inline void konk_delay(int delay) } } +static inline void save_uart_address(void) +{ + u32 *buf = (u32 *)(TEGRA_IRAM_BASE + TEGRA_IRAM_DEBUG_UART_OFFSET); + + if (uart) { + buf[0] = TEGRA_IRAM_DEBUG_UART_COOKIE; + buf[1] = (u32)uart; + } else + buf[0] = 0; +} +/* + * Setup before decompression. This is where we do UART selection for + * earlyprintk and init the uart_base register. + */ static inline void arch_decomp_setup(void) { - volatile u8 *uart = (volatile u8 *)TEGRA_DEBUG_UART_BASE; - int shift = 2; volatile u32 *addr; u8 uart_dll = DEBUG_UART_DLL_216; u32 val; + static const struct { + u32 base; + u32 reset_reg; + u32 clock_reg; + u32 bit; + } uarts[] = { + { + TEGRA_UARTA_BASE, + TEGRA_CLK_RESET_BASE + 0x04, + TEGRA_CLK_RESET_BASE + 0x10, + 6, + }, + { + TEGRA_UARTB_BASE, + TEGRA_CLK_RESET_BASE + 0x04, + TEGRA_CLK_RESET_BASE + 0x10, + 7, + }, + { + TEGRA_UARTC_BASE, + TEGRA_CLK_RESET_BASE + 0x08, + TEGRA_CLK_RESET_BASE + 0x14, + 23, + }, + { + TEGRA_UARTD_BASE, + TEGRA_CLK_RESET_BASE + 0x0c, + TEGRA_CLK_RESET_BASE + 0x18, + 1, + }, + { + TEGRA_UARTE_BASE, + TEGRA_CLK_RESET_BASE + 0x0c, + TEGRA_CLK_RESET_BASE + 0x18, + 2, + }, + }; + int i; + + /* + * Look for the first UART that: + * a) Is not in reset. + * b) Is clocked. + * c) Has a 'D' in the scratchpad register. + * + * Note that on Tegra30, the first two conditions are required, since + * if not true, accesses to the UART scratch register will hang. + * Tegra20 doesn't have this issue. + * + * The intent is that the bootloader will tell the kernel which UART + * to use by setting up those conditions. If nothing found, we'll fall + * back to what's specified in TEGRA_DEBUG_UART_BASE. + */ + for (i = 0; i < ARRAY_SIZE(uarts); i++) { + if (*(u8 *)uarts[i].reset_reg & BIT(uarts[i].bit)) + continue; + + if (!(*(u8 *)uarts[i].clock_reg & BIT(uarts[i].bit))) + continue; + uart = (volatile u8 *)uarts[i].base; + if (uart[UART_SCR << DEBUG_UART_SHIFT] != 'D') + continue; + + break; + } + if (i == ARRAY_SIZE(uarts)) + uart = (volatile u8 *)TEGRA_DEBUG_UART_BASE; + save_uart_address(); if (uart == NULL) return; @@ -159,10 +248,10 @@ static inline void arch_decomp_setup(void) } /* Set up debug UART. */ - uart[UART_LCR << shift] |= UART_LCR_DLAB; - uart[UART_DLL << shift] = uart_dll; - uart[UART_DLM << shift] = 0x0; - uart[UART_LCR << shift] = 3; + uart[UART_LCR << DEBUG_UART_SHIFT] |= UART_LCR_DLAB; + uart[UART_DLL << DEBUG_UART_SHIFT] = uart_dll; + uart[UART_DLM << DEBUG_UART_SHIFT] = 0x0; + uart[UART_LCR << DEBUG_UART_SHIFT] = 3; } static inline void arch_decomp_wdog(void) |