linux/drivers/cpufreq/imx6q-cpufreq.c

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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/delay.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.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;
static struct clk *arm_clk;
static struct clk *pll1_sys_clk;
static struct clk *pll1_sw_clk;
static struct clk *step_clk;
static struct clk *pll2_pfd2_396m_clk;
static struct device *cpu_dev;
static struct cpufreq_frequency_table *freq_table;
static unsigned int transition_latency;
static unsigned int imx6q_get_speed(unsigned int cpu)
{
return clk_get_rate(arm_clk) / 1000;
}
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 14:15:48 +00:00
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;
int ret;
new_freq = freq_table[index].frequency;
freq_hz = new_freq * 1000;
old_freq = clk_get_rate(arm_clk) / 1000;
rcu_read_lock();
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
if (IS_ERR(opp)) {
rcu_read_unlock();
dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
return PTR_ERR(opp);
}
volt = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
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) {
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;
}
/*
* Need to increase vddpu and vddsoc for safety
* if we are about to run at 1.2 GHz.
*/
if (new_freq == FREQ_1P2_GHZ / 1000) {
regulator_set_voltage_tol(pu_reg,
PU_SOC_VOLTAGE_HIGH, 0);
regulator_set_voltage_tol(soc_reg,
PU_SOC_VOLTAGE_HIGH, 0);
}
}
/*
* 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.
*
* - 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
*/
clk_set_parent(step_clk, pll2_pfd2_396m_clk);
clk_set_parent(pll1_sw_clk, step_clk);
if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) {
clk_set_rate(pll1_sys_clk, new_freq * 1000);
clk_set_parent(pll1_sw_clk, pll1_sys_clk);
}
/* Ensure the arm clock divider is what we expect */
ret = clk_set_rate(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;
}
/* 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;
}
if (old_freq == FREQ_1P2_GHZ / 1000) {
regulator_set_voltage_tol(pu_reg,
PU_SOC_VOLTAGE_NORMAL, 0);
regulator_set_voltage_tol(soc_reg,
PU_SOC_VOLTAGE_NORMAL, 0);
}
}
return 0;
}
static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
{
return cpufreq_generic_init(policy, freq_table, transition_latency);
}
static struct cpufreq_driver imx6q_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 14:15:48 +00:00
.target_index = imx6q_set_target,
.get = imx6q_get_speed,
.init = imx6q_cpufreq_init,
.exit = cpufreq_generic_exit,
.name = "imx6q-cpufreq",
.attr = cpufreq_generic_attr,
};
static int imx6q_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *np;
struct dev_pm_opp *opp;
unsigned long min_volt, max_volt;
int num, ret;
cpu_dev = get_cpu_device(0);
if (!cpu_dev) {
pr_err("failed to get cpu0 device\n");
return -ENODEV;
}
np = of_node_get(cpu_dev->of_node);
if (!np) {
dev_err(cpu_dev, "failed to find cpu0 node\n");
return -ENOENT;
}
arm_clk = devm_clk_get(cpu_dev, "arm");
pll1_sys_clk = devm_clk_get(cpu_dev, "pll1_sys");
pll1_sw_clk = devm_clk_get(cpu_dev, "pll1_sw");
step_clk = devm_clk_get(cpu_dev, "step");
pll2_pfd2_396m_clk = devm_clk_get(cpu_dev, "pll2_pfd2_396m");
if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) ||
IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) {
dev_err(cpu_dev, "failed to get clocks\n");
ret = -ENOENT;
goto put_node;
}
arm_reg = devm_regulator_get(cpu_dev, "arm");
pu_reg = devm_regulator_get(cpu_dev, "pu");
soc_reg = devm_regulator_get(cpu_dev, "soc");
if (IS_ERR(arm_reg) || IS_ERR(pu_reg) || IS_ERR(soc_reg)) {
dev_err(cpu_dev, "failed to get regulators\n");
ret = -ENOENT;
goto put_node;
}
/* We expect an OPP table supplied by platform */
num = dev_pm_opp_get_opp_count(cpu_dev);
if (num < 0) {
ret = num;
dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
goto put_node;
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto put_node;
}
if (of_property_read_u32(np, "clock-latency", &transition_latency))
transition_latency = CPUFREQ_ETERNAL;
/*
* OPP is maintained in order of increasing frequency, and
* freq_table initialised from OPP is therefore sorted in the
* same order.
*/
rcu_read_lock();
opp = dev_pm_opp_find_freq_exact(cpu_dev,
freq_table[0].frequency * 1000, true);
min_volt = dev_pm_opp_get_voltage(opp);
opp = dev_pm_opp_find_freq_exact(cpu_dev,
freq_table[--num].frequency * 1000, true);
max_volt = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
if (ret > 0)
transition_latency += ret * 1000;
/* Count vddpu and vddsoc latency in for 1.2 GHz support */
if (freq_table[num].frequency == FREQ_1P2_GHZ / 1000) {
ret = regulator_set_voltage_time(pu_reg, PU_SOC_VOLTAGE_NORMAL,
PU_SOC_VOLTAGE_HIGH);
if (ret > 0)
transition_latency += ret * 1000;
ret = regulator_set_voltage_time(soc_reg, PU_SOC_VOLTAGE_NORMAL,
PU_SOC_VOLTAGE_HIGH);
if (ret > 0)
transition_latency += ret * 1000;
}
ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
if (ret) {
dev_err(cpu_dev, "failed register driver: %d\n", ret);
goto free_freq_table;
}
of_node_put(np);
return 0;
free_freq_table:
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
put_node:
of_node_put(np);
return ret;
}
static int imx6q_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&imx6q_cpufreq_driver);
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
return 0;
}
static struct platform_driver imx6q_cpufreq_platdrv = {
.driver = {
.name = "imx6q-cpufreq",
.owner = THIS_MODULE,
},
.probe = imx6q_cpufreq_probe,
.remove = imx6q_cpufreq_remove,
};
module_platform_driver(imx6q_cpufreq_platdrv);
MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
MODULE_LICENSE("GPL");