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/*
* Copyright (C) 2010-2012 NVIDIA Corporation
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/io.h>
#include <mach/clk.h>
#include <mach/iomap.h>
#include "clock.h"
#define clk_writel(value, reg) \
__raw_writel(value, (u32)reg_clk_base + (reg))
#define clk_readl(reg) \
__raw_readl((u32)reg_clk_base + (reg))
#define OSC_FREQ_DET 0x58
#define OSC_FREQ_DET_TRIG (1<<31)
#define OSC_FREQ_DET_STATUS 0x5C
#define OSC_FREQ_DET_BUSY (1<<31)
#define OSC_FREQ_DET_CNT_MASK 0xFFFF
static void __iomem *reg_clk_base = IO_ADDRESS(TEGRA_CLK_RESET_BASE);
static unsigned long osc_input_freq;
unsigned long tegra_clk_measure_input_freq(void)
{
u32 clock_autodetect;
if (osc_input_freq)
return osc_input_freq;
clk_writel(OSC_FREQ_DET_TRIG | 1, OSC_FREQ_DET);
do {} while (clk_readl(OSC_FREQ_DET_STATUS) & OSC_FREQ_DET_BUSY);
clock_autodetect = clk_readl(OSC_FREQ_DET_STATUS);
if (clock_autodetect >= 732 - 3 && clock_autodetect <= 732 + 3)
osc_input_freq = 12000000;
else if (clock_autodetect >= 794 - 3 && clock_autodetect <= 794 + 3)
osc_input_freq = 13000000;
else if (clock_autodetect >= 1172 - 3 && clock_autodetect <= 1172 + 3)
osc_input_freq = 19200000;
else if (clock_autodetect >= 1587 - 3 && clock_autodetect <= 1587 + 3)
osc_input_freq = 26000000;
#ifndef CONFIG_ARCH_TEGRA_2x_SOC
else if (clock_autodetect >= 1025 - 3 && clock_autodetect <= 1025 + 3)
osc_input_freq = 16800000;
else if (clock_autodetect >= 2344 - 3 && clock_autodetect <= 2344 + 3)
osc_input_freq = 38400000;
else if (clock_autodetect >= 2928 - 3 && clock_autodetect <= 2928 + 3)
osc_input_freq = 48000000;
#endif
else {
pr_err("%s: Unexpected clock autodetect value %d", __func__,
clock_autodetect);
BUG();
}
return osc_input_freq;
}
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