diff options
Diffstat (limited to 'arch/arm/mach-tegra/include/mach/uncompress.h')
| -rw-r--r-- | arch/arm/mach-tegra/include/mach/uncompress.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/include/mach/uncompress.h b/arch/arm/mach-tegra/include/mach/uncompress.h new file mode 100644 index 00000000..5a440f31 --- /dev/null +++ b/arch/arm/mach-tegra/include/mach/uncompress.h @@ -0,0 +1,162 @@ +/* + * 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> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#ifndef __MACH_TEGRA_UNCOMPRESS_H +#define __MACH_TEGRA_UNCOMPRESS_H + +#include <linux/types.h> +#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; + +static void putc(int c) +{ + if (uart == NULL) + return; + + while (!(uart[UART_LSR << DEBUG_UART_SHIFT] & UART_LSR_THRE)) + barrier(); + uart[UART_TX << DEBUG_UART_SHIFT] = c; +} + +static inline void flush(void) +{ +} + +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) +{ + 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; + volatile u32 *apb_misc = (volatile u32 *)TEGRA_APB_MISC_BASE; + u32 chip, div; + + /* + * 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; + + chip = (apb_misc[0x804 / 4] >> 8) & 0xff; + if (chip == 0x20) + div = 0x0075; + else + div = 0x00dd; + + uart[UART_LCR << DEBUG_UART_SHIFT] |= UART_LCR_DLAB; + uart[UART_DLL << DEBUG_UART_SHIFT] = div & 0xff; + uart[UART_DLM << DEBUG_UART_SHIFT] = div >> 8; + uart[UART_LCR << DEBUG_UART_SHIFT] = 3; +} + +static inline void arch_decomp_wdog(void) +{ +} + +#endif |