linux/drivers/cpufreq/qoriq-cpufreq.c

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/*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* CPU Frequency Scaling driver for Freescale QorIQ SoCs.
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <asm/smp.h> /* for get_hard_smp_processor_id() in UP configs */
/**
* struct cpu_data
* @parent: the parent node of cpu clock
* @table: frequency table
*/
struct cpu_data {
struct device_node *parent;
struct cpufreq_frequency_table *table;
};
/**
* struct soc_data - SoC specific data
* @freq_mask: mask the disallowed frequencies
* @flag: unique flags
*/
struct soc_data {
u32 freq_mask[4];
u32 flag;
};
#define FREQ_MASK 1
/* see hardware specification for the allowed frqeuencies */
static const struct soc_data sdata[] = {
{ /* used by p2041 and p3041 */
.freq_mask = {0x8, 0x8, 0x2, 0x2},
.flag = FREQ_MASK,
},
{ /* used by p5020 */
.freq_mask = {0x8, 0x2},
.flag = FREQ_MASK,
},
{ /* used by p4080, p5040 */
.freq_mask = {0},
.flag = 0,
},
};
/*
* the minimum allowed core frequency, in Hz
* for chassis v1.0, >= platform frequency
* for chassis v2.0, >= platform frequency / 2
*/
static u32 min_cpufreq;
static const u32 *fmask;
#if defined(CONFIG_ARM)
static int get_cpu_physical_id(int cpu)
{
return topology_core_id(cpu);
}
#else
static int get_cpu_physical_id(int cpu)
{
return get_hard_smp_processor_id(cpu);
}
#endif
static u32 get_bus_freq(void)
{
struct device_node *soc;
u32 sysfreq;
soc = of_find_node_by_type(NULL, "soc");
if (!soc)
return 0;
if (of_property_read_u32(soc, "bus-frequency", &sysfreq))
sysfreq = 0;
of_node_put(soc);
return sysfreq;
}
static struct device_node *cpu_to_clk_node(int cpu)
{
struct device_node *np, *clk_np;
if (!cpu_present(cpu))
return NULL;
np = of_get_cpu_node(cpu, NULL);
if (!np)
return NULL;
clk_np = of_parse_phandle(np, "clocks", 0);
if (!clk_np)
return NULL;
of_node_put(np);
return clk_np;
}
/* traverse cpu nodes to get cpu mask of sharing clock wire */
static void set_affected_cpus(struct cpufreq_policy *policy)
{
struct device_node *np, *clk_np;
struct cpumask *dstp = policy->cpus;
int i;
np = cpu_to_clk_node(policy->cpu);
if (!np)
return;
for_each_present_cpu(i) {
clk_np = cpu_to_clk_node(i);
if (!clk_np)
continue;
if (clk_np == np)
cpumask_set_cpu(i, dstp);
of_node_put(clk_np);
}
of_node_put(np);
}
/* reduce the duplicated frequencies in frequency table */
static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
int count)
{
int i, j;
for (i = 1; i < count; i++) {
for (j = 0; j < i; j++) {
if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID ||
freq_table[j].frequency !=
freq_table[i].frequency)
continue;
freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
break;
}
}
}
/* sort the frequencies in frequency table in descenting order */
static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
int count)
{
int i, j, ind;
unsigned int freq, max_freq;
struct cpufreq_frequency_table table;
for (i = 0; i < count - 1; i++) {
max_freq = freq_table[i].frequency;
ind = i;
for (j = i + 1; j < count; j++) {
freq = freq_table[j].frequency;
if (freq == CPUFREQ_ENTRY_INVALID ||
freq <= max_freq)
continue;
ind = j;
max_freq = freq;
}
if (ind != i) {
/* exchange the frequencies */
table.driver_data = freq_table[i].driver_data;
table.frequency = freq_table[i].frequency;
freq_table[i].driver_data = freq_table[ind].driver_data;
freq_table[i].frequency = freq_table[ind].frequency;
freq_table[ind].driver_data = table.driver_data;
freq_table[ind].frequency = table.frequency;
}
}
}
static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
struct device_node *np;
int i, count, ret;
u32 freq, mask;
struct clk *clk;
struct cpufreq_frequency_table *table;
struct cpu_data *data;
unsigned int cpu = policy->cpu;
u64 u64temp;
np = of_get_cpu_node(cpu, NULL);
if (!np)
return -ENODEV;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
goto err_np;
policy->clk = of_clk_get(np, 0);
if (IS_ERR(policy->clk)) {
pr_err("%s: no clock information\n", __func__);
goto err_nomem2;
}
data->parent = of_parse_phandle(np, "clocks", 0);
if (!data->parent) {
pr_err("%s: could not get clock information\n", __func__);
goto err_nomem2;
}
count = of_property_count_strings(data->parent, "clock-names");
table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
if (!table) {
pr_err("%s: no memory\n", __func__);
goto err_node;
}
if (fmask)
mask = fmask[get_cpu_physical_id(cpu)];
else
mask = 0x0;
for (i = 0; i < count; i++) {
clk = of_clk_get(data->parent, i);
freq = clk_get_rate(clk);
/*
* the clock is valid if its frequency is not masked
* and large than minimum allowed frequency.
*/
if (freq < min_cpufreq || (mask & (1 << i)))
table[i].frequency = CPUFREQ_ENTRY_INVALID;
else
table[i].frequency = freq / 1000;
table[i].driver_data = i;
}
freq_table_redup(table, count);
freq_table_sort(table, count);
table[i].frequency = CPUFREQ_TABLE_END;
/* set the min and max frequency properly */
ret = cpufreq_table_validate_and_show(policy, table);
if (ret) {
pr_err("invalid frequency table: %d\n", ret);
goto err_nomem1;
}
data->table = table;
/* update ->cpus if we have cluster, no harm if not */
set_affected_cpus(policy);
policy->driver_data = data;
/* Minimum transition latency is 12 platform clocks */
u64temp = 12ULL * NSEC_PER_SEC;
do_div(u64temp, get_bus_freq());
policy->cpuinfo.transition_latency = u64temp + 1;
of_node_put(np);
return 0;
err_nomem1:
kfree(table);
err_node:
of_node_put(data->parent);
err_nomem2:
policy->driver_data = NULL;
kfree(data);
err_np:
of_node_put(np);
return -ENODEV;
}
static int __exit qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
struct cpu_data *data = policy->driver_data;
of_node_put(data->parent);
kfree(data->table);
kfree(data);
policy->driver_data = NULL;
return 0;
}
static int qoriq_cpufreq_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 clk *parent;
struct cpu_data *data = policy->driver_data;
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
parent = of_clk_get(data->parent, data->table[index].driver_data);
return clk_set_parent(policy->clk, parent);
}
static struct cpufreq_driver qoriq_cpufreq_driver = {
.name = "qoriq_cpufreq",
.flags = CPUFREQ_CONST_LOOPS,
.init = qoriq_cpufreq_cpu_init,
.exit = __exit_p(qoriq_cpufreq_cpu_exit),
.verify = cpufreq_generic_frequency_table_verify,
.target_index = qoriq_cpufreq_target,
.get = cpufreq_generic_get,
.attr = cpufreq_generic_attr,
};
static const struct of_device_id node_matches[] __initconst = {
{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
{ .compatible = "fsl,qoriq-clockgen-2.0", },
{}
};
static int __init qoriq_cpufreq_init(void)
{
int ret;
struct device_node *np;
const struct of_device_id *match;
const struct soc_data *data;
np = of_find_matching_node(NULL, node_matches);
if (!np)
return -ENODEV;
match = of_match_node(node_matches, np);
data = match->data;
if (data) {
if (data->flag)
fmask = data->freq_mask;
min_cpufreq = get_bus_freq();
} else {
min_cpufreq = get_bus_freq() / 2;
}
of_node_put(np);
ret = cpufreq_register_driver(&qoriq_cpufreq_driver);
if (!ret)
pr_info("Freescale QorIQ CPU frequency scaling driver\n");
return ret;
}
module_init(qoriq_cpufreq_init);
static void __exit qoriq_cpufreq_exit(void)
{
cpufreq_unregister_driver(&qoriq_cpufreq_driver);
}
module_exit(qoriq_cpufreq_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
MODULE_DESCRIPTION("cpufreq driver for Freescale QorIQ series SoCs");