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/*
* 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
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