linux_dsm_epyc7002/drivers/clk/tegra/clk-tegra-fixed.c
Sowjanya Komatineni 50d4da9b10 clk: tegra: Support for OSC context save and restore
This patch adds support for saving OSC clock frequency and the
drive-strength during OSC clock init and creates an API to restore
OSC control register value from the saved context.

This API is invoked by Tegra210 clock driver during system resume
to restore the  OSC clock settings.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-11-11 14:53:02 +01:00

114 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012, 2013, NVIDIA CORPORATION. All rights reserved.
*/
#include <linux/io.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
#define OSC_CTRL_MASK (0x3f2 | \
(0xf << OSC_CTRL_OSC_FREQ_SHIFT))
static u32 osc_ctrl_ctx;
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_ctrl_ctx = val & OSC_CTRL_MASK;
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, 0, *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, 0, 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;
}
}
void tegra_clk_osc_resume(void __iomem *clk_base)
{
u32 val;
val = readl_relaxed(clk_base + OSC_CTRL) & ~OSC_CTRL_MASK;
val |= osc_ctrl_ctx;
writel_relaxed(val, clk_base + OSC_CTRL);
fence_udelay(2, clk_base);
}