OpenCloudOS-Kernel/drivers/clk/tegra/clk-tegra-fixed.c

114 lines
2.8 KiB
C

/*
* Copyright (c) 2012, 2013, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/clk/tegra.h>
#include "clk.h"
#include "clk-id.h"
#define OSC_CTRL 0x50
#define OSC_CTRL_OSC_FREQ_SHIFT 28
#define OSC_CTRL_PLL_REF_DIV_SHIFT 26
int __init tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *clks,
unsigned long *input_freqs, unsigned int num,
unsigned int clk_m_div, unsigned long *osc_freq,
unsigned long *pll_ref_freq)
{
struct clk *clk, *osc;
struct clk **dt_clk;
u32 val, pll_ref_div;
unsigned osc_idx;
val = readl_relaxed(clk_base + OSC_CTRL);
osc_idx = val >> OSC_CTRL_OSC_FREQ_SHIFT;
if (osc_idx < num)
*osc_freq = input_freqs[osc_idx];
else
*osc_freq = 0;
if (!*osc_freq) {
WARN_ON(1);
return -EINVAL;
}
osc = clk_register_fixed_rate(NULL, "osc", NULL, CLK_IS_ROOT,
*osc_freq);
dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m, clks);
if (!dt_clk)
return 0;
clk = clk_register_fixed_factor(NULL, "clk_m", "osc",
0, 1, clk_m_div);
*dt_clk = clk;
/* pll_ref */
val = (val >> OSC_CTRL_PLL_REF_DIV_SHIFT) & 3;
pll_ref_div = 1 << val;
dt_clk = tegra_lookup_dt_id(tegra_clk_pll_ref, clks);
if (!dt_clk)
return 0;
clk = clk_register_fixed_factor(NULL, "pll_ref", "osc",
0, 1, pll_ref_div);
*dt_clk = clk;
if (pll_ref_freq)
*pll_ref_freq = *osc_freq / pll_ref_div;
return 0;
}
void __init tegra_fixed_clk_init(struct tegra_clk *tegra_clks)
{
struct clk *clk;
struct clk **dt_clk;
/* clk_32k */
dt_clk = tegra_lookup_dt_id(tegra_clk_clk_32k, tegra_clks);
if (dt_clk) {
clk = clk_register_fixed_rate(NULL, "clk_32k", NULL,
CLK_IS_ROOT, 32768);
*dt_clk = clk;
}
/* clk_m_div2 */
dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m_div2, tegra_clks);
if (dt_clk) {
clk = clk_register_fixed_factor(NULL, "clk_m_div2", "clk_m",
CLK_SET_RATE_PARENT, 1, 2);
*dt_clk = clk;
}
/* clk_m_div4 */
dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m_div4, tegra_clks);
if (dt_clk) {
clk = clk_register_fixed_factor(NULL, "clk_m_div4", "clk_m",
CLK_SET_RATE_PARENT, 1, 4);
*dt_clk = clk;
}
}