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/*
* Copyright (C) 2013 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#define PU_SOC_VOLTAGE_NORMAL 1250000
#define PU_SOC_VOLTAGE_HIGH 1275000
#define FREQ_1P2_GHZ 1200000000
static struct regulator *arm_reg;
static struct regulator *pu_reg;
static struct regulator *soc_reg;
enum IMX6_CPUFREQ_CLKS {
ARM,
PLL1_SYS,
STEP,
PLL1_SW,
PLL2_PFD2_396M,
/* MX6UL requires two more clks */
PLL2_BUS,
SECONDARY_SEL,
};
#define IMX6Q_CPUFREQ_CLK_NUM 5
#define IMX6UL_CPUFREQ_CLK_NUM 7
static int num_clks;
static struct clk_bulk_data clks[] = {
{ .id = "arm" },
{ .id = "pll1_sys" },
{ .id = "step" },
{ .id = "pll1_sw" },
{ .id = "pll2_pfd2_396m" },
{ .id = "pll2_bus" },
{ .id = "secondary_sel" },
};
static struct device *cpu_dev;
static bool free_opp;
static struct cpufreq_frequency_table *freq_table;
static unsigned int max_freq;
static unsigned int transition_latency;
static u32 *imx6_soc_volt;
static u32 soc_opp_count;
static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
{
struct dev_pm_opp *opp;
unsigned long freq_hz, volt, volt_old;
unsigned int old_freq, new_freq;
bool pll1_sys_temp_enabled = false;
int ret;
new_freq = freq_table[index].frequency;
freq_hz = new_freq * 1000;
old_freq = clk_get_rate(clks[ARM].clk) / 1000;
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
if (IS_ERR(opp)) {
dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
return PTR_ERR(opp);
}
volt = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
volt_old = regulator_get_voltage(arm_reg);
dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
old_freq / 1000, volt_old / 1000,
new_freq / 1000, volt / 1000);
/* scaling up? scale voltage before frequency */
if (new_freq > old_freq) {
if (!IS_ERR(pu_reg)) {
ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
return ret;
}
}
ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
return ret;
}
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
if (ret) {
dev_err(cpu_dev,
"failed to scale vddarm up: %d\n", ret);
return ret;
}
}
/*
* The setpoints are selected per PLL/PDF frequencies, so we need to
* reprogram PLL for frequency scaling. The procedure of reprogramming
* PLL1 is as below.
* For i.MX6UL, it has a secondary clk mux, the cpu frequency change
* flow is slightly different from other i.MX6 OSC.
* The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below:
* - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
* - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
* - Disable pll2_pfd2_396m_clk
*/
if (of_machine_is_compatible("fsl,imx6ul") ||
of_machine_is_compatible("fsl,imx6ull")) {
/*
* When changing pll1_sw_clk's parent to pll1_sys_clk,
* CPU may run at higher than 528MHz, this will lead to
* the system unstable if the voltage is lower than the
* voltage of 528MHz, so lower the CPU frequency to one
* half before changing CPU frequency.
*/
clk_set_rate(clks[ARM].clk, (old_freq >> 1) * 1000);
clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk))
clk_set_parent(clks[SECONDARY_SEL].clk,
clks[PLL2_BUS].clk);
else
clk_set_parent(clks[SECONDARY_SEL].clk,
clks[PLL2_PFD2_396M].clk);
clk_set_parent(clks[STEP].clk, clks[SECONDARY_SEL].clk);
clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
if (freq_hz > clk_get_rate(clks[PLL2_BUS].clk)) {
clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
}
} else {
clk_set_parent(clks[STEP].clk, clks[PLL2_PFD2_396M].clk);
clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk)) {
clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
} else {
/* pll1_sys needs to be enabled for divider rate change to work. */
pll1_sys_temp_enabled = true;
clk_prepare_enable(clks[PLL1_SYS].clk);
}
}
/* Ensure the arm clock divider is what we expect */
ret = clk_set_rate(clks[ARM].clk, new_freq * 1000);
if (ret) {
dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
regulator_set_voltage_tol(arm_reg, volt_old, 0);
return ret;
}
/* PLL1 is only needed until after ARM-PODF is set. */
if (pll1_sys_temp_enabled)
clk_disable_unprepare(clks[PLL1_SYS].clk);
/* scaling down? scale voltage after frequency */
if (new_freq < old_freq) {
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
if (ret) {
dev_warn(cpu_dev,
"failed to scale vddarm down: %d\n", ret);
ret = 0;
}
ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
ret = 0;
}
if (!IS_ERR(pu_reg)) {
ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
ret = 0;
}
}
}
return 0;
}
static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
{
int ret;
policy->clk = clks[ARM].clk;
ret = cpufreq_generic_init(policy, freq_table, transition_latency);
policy->suspend_freq = max_freq;
return ret;
}
static struct cpufreq_driver imx6q_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = imx6q_set_target,
.get = cpufreq_generic_get,
.init = imx6q_cpufreq_init,
.name = "imx6q-cpufreq",
.attr = cpufreq_generic_attr,
.suspend = cpufreq_generic_suspend,
};
#define OCOTP_CFG3 0x440
#define OCOTP_CFG3_SPEED_SHIFT 16
#define OCOTP_CFG3_SPEED_1P2GHZ 0x3
#define OCOTP_CFG3_SPEED_996MHZ 0x2
#define OCOTP_CFG3_SPEED_852MHZ 0x1
static void imx6q_opp_check_speed_grading(struct device *dev)
{
struct device_node *np;
void __iomem *base;
u32 val;
np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
if (!np)
return;
base = of_iomap(np, 0);
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