linux/drivers/cpufreq/s3c64xx-cpufreq.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2009 Wolfson Microelectronics plc
*
* S3C64xx CPUfreq Support
*/
#define pr_fmt(fmt) "cpufreq: " fmt
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
static struct regulator *vddarm;
static unsigned long regulator_latency;
struct s3c64xx_dvfs {
unsigned int vddarm_min;
unsigned int vddarm_max;
};
static struct s3c64xx_dvfs s3c64xx_dvfs_table[] = {
[0] = { 1000000, 1150000 },
[1] = { 1050000, 1150000 },
[2] = { 1100000, 1150000 },
[3] = { 1200000, 1350000 },
[4] = { 1300000, 1350000 },
};
static struct cpufreq_frequency_table s3c64xx_freq_table[] = {
{ 0, 0, 66000 },
{ 0, 0, 100000 },
{ 0, 0, 133000 },
{ 0, 1, 200000 },
{ 0, 1, 222000 },
{ 0, 1, 266000 },
{ 0, 2, 333000 },
{ 0, 2, 400000 },
{ 0, 2, 532000 },
{ 0, 2, 533000 },
{ 0, 3, 667000 },
{ 0, 4, 800000 },
{ 0, 0, CPUFREQ_TABLE_END },
};
static int s3c64xx_cpufreq_set_target(struct cpufreq_policy *policy,
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
unsigned int index)
{
struct s3c64xx_dvfs *dvfs;
unsigned int old_freq, new_freq;
int ret;
old_freq = clk_get_rate(policy->clk) / 1000;
new_freq = s3c64xx_freq_table[index].frequency;
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
dvfs = &s3c64xx_dvfs_table[s3c64xx_freq_table[index].driver_data];
#ifdef CONFIG_REGULATOR
if (vddarm && new_freq > old_freq) {
ret = regulator_set_voltage(vddarm,
dvfs->vddarm_min,
dvfs->vddarm_max);
if (ret != 0) {
pr_err("Failed to set VDDARM for %dkHz: %d\n",
new_freq, ret);
return ret;
}
}
#endif
ret = clk_set_rate(policy->clk, new_freq * 1000);
if (ret < 0) {
pr_err("Failed to set rate %dkHz: %d\n",
new_freq, ret);
return ret;
}
#ifdef CONFIG_REGULATOR
if (vddarm && new_freq < old_freq) {
ret = regulator_set_voltage(vddarm,
dvfs->vddarm_min,
dvfs->vddarm_max);
if (ret != 0) {
pr_err("Failed to set VDDARM for %dkHz: %d\n",
new_freq, ret);
if (clk_set_rate(policy->clk, old_freq * 1000) < 0)
pr_err("Failed to restore original clock rate\n");
return ret;
}
}
#endif
pr_debug("Set actual frequency %lukHz\n",
clk_get_rate(policy->clk) / 1000);
return 0;
}
#ifdef CONFIG_REGULATOR
static void s3c64xx_cpufreq_config_regulator(void)
{
int count, v, i, found;
struct cpufreq_frequency_table *freq;
struct s3c64xx_dvfs *dvfs;
count = regulator_count_voltages(vddarm);
if (count < 0) {
pr_err("Unable to check supported voltages\n");
}
if (!count)
goto out;
cpufreq_for_each_valid_entry(freq, s3c64xx_freq_table) {
dvfs = &s3c64xx_dvfs_table[freq->driver_data];
found = 0;
for (i = 0; i < count; i++) {
v = regulator_list_voltage(vddarm, i);
if (v >= dvfs->vddarm_min && v <= dvfs->vddarm_max)
found = 1;
}
if (!found) {
pr_debug("%dkHz unsupported by regulator\n",
freq->frequency);
freq->frequency = CPUFREQ_ENTRY_INVALID;
}
}
out:
/* Guess based on having to do an I2C/SPI write; in future we
* will be able to query the regulator performance here. */
regulator_latency = 1 * 1000 * 1000;
}
#endif
static int s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
{
struct cpufreq_frequency_table *freq;
if (policy->cpu != 0)
return -EINVAL;
policy->clk = clk_get(NULL, "armclk");
if (IS_ERR(policy->clk)) {
pr_err("Unable to obtain ARMCLK: %ld\n",
PTR_ERR(policy->clk));
return PTR_ERR(policy->clk);
}
#ifdef CONFIG_REGULATOR
vddarm = regulator_get(NULL, "vddarm");
if (IS_ERR(vddarm)) {
pr_err("Failed to obtain VDDARM: %ld\n", PTR_ERR(vddarm));
pr_err("Only frequency scaling available\n");
vddarm = NULL;
} else {
s3c64xx_cpufreq_config_regulator();
}
#endif
cpufreq_for_each_entry(freq, s3c64xx_freq_table) {
unsigned long r;
/* Check for frequencies we can generate */
r = clk_round_rate(policy->clk, freq->frequency * 1000);
r /= 1000;
if (r != freq->frequency) {
pr_debug("%dkHz unsupported by clock\n",
freq->frequency);
freq->frequency = CPUFREQ_ENTRY_INVALID;
}
/* If we have no regulator then assume startup
* frequency is the maximum we can support. */
if (!vddarm && freq->frequency > clk_get_rate(policy->clk) / 1000)
freq->frequency = CPUFREQ_ENTRY_INVALID;
}
/* Datasheet says PLL stabalisation time (if we were to use
* the PLLs, which we don't currently) is ~300us worst case,
* but add some fudge.
*/
cpufreq_generic_init(policy, s3c64xx_freq_table,
(500 * 1000) + regulator_latency);
return 0;
}
static struct cpufreq_driver s3c64xx_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.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 = s3c64xx_cpufreq_set_target,
.get = cpufreq_generic_get,
.init = s3c64xx_cpufreq_driver_init,
.name = "s3c",
};
static int __init s3c64xx_cpufreq_init(void)
{
return cpufreq_register_driver(&s3c64xx_cpufreq_driver);
}
module_init(s3c64xx_cpufreq_init);