From: Tang Yuantian <yuantian.tang@xxxxxxxxxxxxx>
Add cpufreq driver for Freescale e500mc, e5500 and e6500 SoCs
which are capable of changing the frequency of CPU dynamically
Signed-off-by: Tang Yuantian <Yuantian.Tang@xxxxxxxxxxxxx>
Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
---
v3:
- change sizeof(struct name).. to sizeof(*p)
- remove the struct cpufreq_data, use global variable instead
- resolve setting policy->cpus incorrectly
- add CPUFREQ_POSTCHANGE notifier when setting frequency error
v2:
- add depends on OF and COMMON_CLK in Kconfig
- use clk.h instead of clk-provider.h
- change per_cpu variable from struct to pointer
drivers/cpufreq/Kconfig.powerpc | 10 ++
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/ppc-corenet-cpufreq.c | 247 ++++++++++++++++++++++++++++++++++
3 files changed, 258 insertions(+)
create mode 100644 drivers/cpufreq/ppc-corenet-cpufreq.c
diff --git a/drivers/cpufreq/Kconfig.powerpc b/drivers/cpufreq/Kconfig.powerpc
index e76992f..3a0d8d0 100644
--- a/drivers/cpufreq/Kconfig.powerpc
+++ b/drivers/cpufreq/Kconfig.powerpc
@@ -5,3 +5,13 @@ 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.
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 863fd18..2416559 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -61,3 +61,4 @@ obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o
##################################################################################
# PowerPC platform drivers
obj-$(CONFIG_CPU_FREQ_MAPLE) += maple-cpufreq.o
+obj-$(CONFIG_PPC_CORENET_CPUFREQ) += ppc-corenet-cpufreq.o
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
new file mode 100644
index 0000000..08e820ee
--- /dev/null
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -0,0 +1,247 @@
+/*
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/types.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;
+};
+
+/* serialize frequency changes */
+static DEFINE_MUTEX(cpufreq_lock);
+
+static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
+static unsigned int cpus_per_cluster;
+
+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 frequency 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;
+ }
+ }
+}
+
+static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct device_node *np;
+ int i, count, ret;
+ 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)
+ return -ENOMEM;
+
+ data->clk = of_clk_get(np, 0);
+ 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_nomem2;
+ }
+
+ for (i = 0; i < count; i++) {
+ table[i].index = i;
+ clk = of_clk_get(data->parent, i);
+ table[i].frequency = clk_get_rate(clk) / 1000;
+ }
+ freq_table_redup(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;
+
+ /* align the cpu id with cluster if any */
+ i = (cpu / cpus_per_cluster) * cpus_per_cluster;
+ for (count = 0; count < cpus_per_cluster; count++)
+ cpumask_set_cpu(i + count, policy->cpus);
+
+ policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+ policy->cur = corenet_cpufreq_get_speed(policy->cpu);
+
+ cpufreq_frequency_table_get_attr(table, cpu);
+
+ return 0;
+
+err_nomem1:
+ kfree(table);
+err_nomem2:
+ per_cpu(cpu_data, cpu) = NULL;
+ kfree(data);
+
+ return -ENODEV;
+}
+
+static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
+
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ kfree(data->table);
+ kfree(data);
+
+ 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;
+ freqs.cpu = policy->cpu;
+
+ mutex_lock(&cpufreq_lock);
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ parent = of_clk_get(data->parent, new);
+ ret = clk_set_parent(data->clk, parent);
+ if (ret) {
+ freqs.new = freqs.old;
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ mutex_unlock(&cpufreq_lock);
+ return ret;
+ }
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ mutex_unlock(&cpufreq_lock);
+
+ return 0;
+}
+
+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[] __initconst = {
+ { .compatible = "fsl,qoriq-clockgen-1.0", .data = (void *)1, },
+ { .compatible = "fsl,qoriq-clockgen-2", .data = (void *)8, },
+ {}
+};
+
+static int __init ppc_corenet_cpufreq_init(void)
+{
+ int ret = 0;
+ struct device_node *np;
+ const struct of_device_id *match;
+
+ np = of_find_matching_node(NULL, node_matches);
+ if (!np)
+ return -ENODEV;
+
+ match = of_match_node(node_matches, np);
+ cpus_per_cluster = (unsigned long)match->data;
+ 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;
+}
+module_init(ppc_corenet_cpufreq_init);
+
+static void __exit ppc_corenet_cpufreq_exit(void)
+{
+ cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
+}
+module_exit(ppc_corenet_cpufreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");
--
1.8.0
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