Commit defa4c73 authored by Tang Yuantian's avatar Tang Yuantian Committed by Rafael J. Wysocki

cpufreq: powerpc: Add cpufreq driver for Freescale e500mc SoCs

Add cpufreq driver for Freescale e500mc, e5500 and e6500 SoCs
which are capable of changing the CPU frequency dynamically
Signed-off-by: default avatarTang Yuantian <Yuantian.Tang@freescale.com>
Signed-off-by: default avatarLi Yang <leoli@freescale.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent a262e94c
......@@ -23,3 +23,13 @@ config CPU_FREQ_MAPLE
help
This adds support for frequency switching on Maple 970FX
Evaluation Board and compatible boards (IBM JS2x blades).
config PPC_CORENET_CPUFREQ
tristate "CPU frequency scaling driver for Freescale E500MC SoCs"
depends on PPC_E500MC && OF && COMMON_CLK
select CPU_FREQ_TABLE
select CLK_PPC_CORENET
help
This adds the CPUFreq driver support for Freescale e500mc,
e5500 and e6500 series SoCs which are capable of changing
the CPU's frequency dynamically.
......@@ -79,6 +79,7 @@ obj-$(CONFIG_CPU_FREQ_CBE) += ppc-cbe-cpufreq.o
ppc-cbe-cpufreq-y += ppc_cbe_cpufreq_pervasive.o ppc_cbe_cpufreq.o
obj-$(CONFIG_CPU_FREQ_CBE_PMI) += ppc_cbe_cpufreq_pmi.o
obj-$(CONFIG_CPU_FREQ_MAPLE) += maple-cpufreq.o
obj-$(CONFIG_PPC_CORENET_CPUFREQ) += ppc-corenet-cpufreq.o
##################################################################################
# Other platform drivers
......
/*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* CPU Frequency Scaling driver for Freescale PowerPC corenet 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 <sysdev/fsl_soc.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>
/**
* struct cpu_data - per CPU data struct
* @clk: the clk of CPU
* @parent: the parent node of cpu clock
* @table: frequency table
*/
struct cpu_data {
struct clk *clk;
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;
/* serialize frequency changes */
static DEFINE_MUTEX(cpufreq_lock);
static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
/* cpumask in a cluster */
static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);
#ifndef CONFIG_SMP
static inline const struct cpumask *cpu_core_mask(int cpu)
{
return cpumask_of(0);
}
#endif
static unsigned int corenet_cpufreq_get_speed(unsigned int cpu)
{
struct cpu_data *data = per_cpu(cpu_data, cpu);
return clk_get_rate(data->clk) / 1000;
}
/* 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 corenet_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;
np = of_get_cpu_node(cpu, NULL);
if (!np)
return -ENODEV;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
pr_err("%s: no memory\n", __func__);
goto err_np;
}
data->clk = of_clk_get(np, 0);
if (IS_ERR(data->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_hard_smp_processor_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_frequency_table_cpuinfo(policy, table);
if (ret) {
pr_err("invalid frequency table: %d\n", ret);
goto err_nomem1;
}
data->table = table;
per_cpu(cpu_data, cpu) = data;
/* update ->cpus if we have cluster, no harm if not */
cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
for_each_cpu(i, per_cpu(cpu_mask, cpu))
per_cpu(cpu_data, i) = data;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
policy->cur = corenet_cpufreq_get_speed(policy->cpu);
cpufreq_frequency_table_get_attr(table, cpu);
of_node_put(np);
return 0;
err_nomem1:
kfree(table);
err_node:
of_node_put(data->parent);
err_nomem2:
per_cpu(cpu_data, cpu) = NULL;
kfree(data);
err_np:
of_node_put(np);
return -ENODEV;
}
static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
unsigned int cpu;
cpufreq_frequency_table_put_attr(policy->cpu);
of_node_put(data->parent);
kfree(data->table);
kfree(data);
for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
per_cpu(cpu_data, cpu) = NULL;
return 0;
}
static int corenet_cpufreq_verify(struct cpufreq_policy *policy)
{
struct cpufreq_frequency_table *table =
per_cpu(cpu_data, policy->cpu)->table;
return cpufreq_frequency_table_verify(policy, table);
}
static int corenet_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
struct cpufreq_freqs freqs;
unsigned int new;
struct clk *parent;
int ret;
struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
cpufreq_frequency_table_target(policy, data->table,
target_freq, relation, &new);
if (policy->cur == data->table[new].frequency)
return 0;
freqs.old = policy->cur;
freqs.new = data->table[new].frequency;
mutex_lock(&cpufreq_lock);
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
parent = of_clk_get(data->parent, data->table[new].driver_data);
ret = clk_set_parent(data->clk, parent);
if (ret)
freqs.new = freqs.old;
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
mutex_unlock(&cpufreq_lock);
return ret;
}
static struct freq_attr *corenet_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
.name = "ppc_cpufreq",
.owner = THIS_MODULE,
.flags = CPUFREQ_CONST_LOOPS,
.init = corenet_cpufreq_cpu_init,
.exit = __exit_p(corenet_cpufreq_cpu_exit),
.verify = corenet_cpufreq_verify,
.target = corenet_cpufreq_target,
.get = corenet_cpufreq_get_speed,
.attr = corenet_cpufreq_attr,
};
static const struct of_device_id node_matches[] __initdata = {
{ .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 ppc_corenet_cpufreq_init(void)
{
int ret;
struct device_node *np;
const struct of_device_id *match;
const struct soc_data *data;
unsigned int cpu;
np = of_find_matching_node(NULL, node_matches);
if (!np)
return -ENODEV;
for_each_possible_cpu(cpu) {
if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
goto err_mask;
cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
}
match = of_match_node(node_matches, np);
data = match->data;
if (data) {
if (data->flag)
fmask = data->freq_mask;
min_cpufreq = fsl_get_sys_freq();
} else {
min_cpufreq = fsl_get_sys_freq() / 2;
}
of_node_put(np);
ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
if (!ret)
pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
return ret;
err_mask:
for_each_possible_cpu(cpu)
free_cpumask_var(per_cpu(cpu_mask, cpu));
return -ENOMEM;
}
module_init(ppc_corenet_cpufreq_init);
static void __exit ppc_corenet_cpufreq_exit(void)
{
unsigned int cpu;
for_each_possible_cpu(cpu)
free_cpumask_var(per_cpu(cpu_mask, cpu));
cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
}
module_exit(ppc_corenet_cpufreq_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");
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