On Tue, Mar 26, 2013 at 8:06 AM, <Yuantian.Tang@xxxxxxxxxxxxx> wrote:
> diff --git a/drivers/cpufreq/Kconfig.powerpc b/drivers/cpufreq/Kconfig.powerpc
> index e76992f..6339db4 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
depends on OF and COMMON_CLK too?
> + 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
> diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
> +#include <linux/module.h>
> +#include <linux/types.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/cpufreq.h>
> +#include <linux/init.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/io.h>
> +#include <linux/clk-provider.h>
You shouldn't need this normally.
> +#include <linux/cpu.h>
Keep them in alphabetical order, so that we don't anyone twice by mistake.
> +/**
> + * struct cpufreq_data - cpufreq driver data
> + * @cpus_per_cluster: CPU numbers per cluster
> + * @cpufreq_lock: the mutex lock
> + */
> +struct cpufreq_data {
> + int cpus_per_cluster;
> + struct mutex cpufreq_lock;
> +};
> +
> +/**
> + * struct cpu_data - per CPU data struct
For your case where you have 8 cpus in a cluster, only one of 8 variables
would be used... Better to create an array of struct with elements:
cpu and data.
> + * @np: the node of CPU
> + * @parent: the parent node of np
> + * @table: frequency table point
> + */
> +struct cpu_data {
> + struct device_node *np;
> + struct device_node *parent;
> + struct cpufreq_frequency_table *table;
> +};
> +
> +static DEFINE_PER_CPU(struct cpu_data, cpu_data);
> +static struct cpufreq_data freq_data;
> +
> +static unsigned int corenet_cpufreq_get_speed(unsigned int cpu)
> +{
> + struct clk *clk;
> + struct cpu_data *data = &per_cpu(cpu_data, cpu);
> +
> + clk = of_clk_get(data->np, 0);
You want to do this everytime? Want to store it?
> + return clk_get_rate(clk) / 1000;
> +}
> +
> +/* reduce the duplicated frequency in frequency table */
> +static int freq_table_redup(struct cpufreq_frequency_table *freq_table,
> + int cur)
> +{
> + int i;
> +
> + for (i = 0; i < cur; i++) {
> + if (freq_table[i].frequency == CPUFREQ_ENTRY_INVALID ||
> + freq_table[i].frequency != freq_table[cur].frequency)
> + continue;
> +
> + freq_table[cur].index = -1;
don't need this.
> + freq_table[cur].frequency = CPUFREQ_ENTRY_INVALID;
> + break;
> + }
> +
> + return (i == cur) ? 0 : 1;
return value isn't used by caller.
> +}
> +
> +static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
> +{
> + unsigned int cpu = policy->cpu;
> + int i, count;
> + struct clk *clk;
> + struct cpufreq_frequency_table *table;
> + struct cpu_data *data;
> +
> + data = &per_cpu(cpu_data, cpu);
> + data->np = of_get_cpu_node(cpu, NULL);
> + if (!data->np)
> + return -ENODEV;
> +
> + data->parent = of_parse_phandle(data->np, "clocks", 0);
You need to details your DTB bindings in Documentation/devicetree/bindings and
cc devicetree-discuss@xxxxxxxxxxxxxxxx.
> + if (!data->parent)
> + return -ENODEV;
of_node_put(np)??
> +
> + count = of_property_count_strings(data->parent, "clock-names");
> + table = kcalloc(count + 1,
kzalloc??
> + sizeof(struct cpufreq_frequency_table), GFP_KERNEL);
sizeof(*table)
> + if (!table)
> + return -ENOMEM;
> +
> + for (i = cpu; i < freq_data.cpus_per_cluster + cpu; i++)
> + cpumask_set_cpu(i, policy->cpus);
> +
> + 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, i);
Don't call it everytime, fix all these in a single call.
> + }
> + table[i].index = -1;
-1 ??
> + table[i].frequency = CPUFREQ_TABLE_END;
> +
> + data->table = table;
> + cpufreq_frequency_table_get_attr(table, cpu);
This must be done only when init() passed. What if
cpufreq_frequency_table_cpuinfo() failed?
> +
> + /* FIXME: what's the actual transition time? in ns */
> + policy->cpuinfo.transition_latency = 2000;
CPUFREQ_ETERNAL??
> + policy->cur = corenet_cpufreq_get_speed(policy->cpu);
> +
> + /* set the min and max frequency properly */
> + return cpufreq_frequency_table_cpuinfo(policy, table);
> +}
> +
> +static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
> +{
> + cpufreq_frequency_table_put_attr(policy->cpu);
> +
> + return 0;
> +}
> +
> +static int corenet_cpufreq_verify(struct cpufreq_policy *policy)
> +{
> + struct cpufreq_frequency_table *table;
> +
> + table = (&per_cpu(cpu_data, policy->cpu))->table;
> + if (!table)
> + return -EINVAL;
This should never be true.
> + 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 *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(&freq_data.cpufreq_lock);
> + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
> +
> + clk = of_clk_get(data->np, 0);
> + parent = of_clk_get(data->parent, new);
> + ret = clk_set_parent(clk, parent);
> + if (ret) {
> + mutex_unlock(&freq_data.cpufreq_lock);
> + return ret;
> + }
> +
> + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> + mutex_unlock(&freq_data.cpufreq_lock);
> +
> + return 0;
> +}
> +
> +static struct freq_attr *corenet_cpu_clks_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_cpu_clks_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);
> + freq_data.cpus_per_cluster = (long)match->data;
> + mutex_init(&freq_data.cpufreq_lock);
> + of_node_put(np);
> +
> + ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
> + if (ret)
> + return ret;
> +
> + pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
> +
> + return ret;
> +}
> +
> +static void __exit ppc_corenet_cpufreq_exit(void)
> +{
> + cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
> +}
> +
> +module_init(ppc_corenet_cpufreq_init);
> +module_exit(ppc_corenet_cpufreq_exit);
Place them right below their respective functions without any blank
line in between.
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@xxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SOCs");
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