@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/sched.h>
+#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -33,6 +34,7 @@
#define HZ_PER_KHZ 1000
static struct class *devfreq_class;
+static struct dentry *devfreq_debugfs;
/*
* devfreq core provides delayed work based load monitoring helper
@@ -1717,6 +1719,74 @@ static struct attribute *devfreq_attrs[] = {
};
ATTRIBUTE_GROUPS(devfreq);
+/**
+ * devfreq_summary_show() - Show the summary of the registered devfreq devices
+ * via 'devfreq_summary' debugfs file.
+ */
+static int devfreq_summary_show(struct seq_file *s, void *data)
+{
+ struct devfreq *devfreq;
+ struct devfreq *p_devfreq = NULL;
+ unsigned long cur_freq, min_freq, max_freq;
+ unsigned int polling_ms;
+
+ seq_printf(s, "%-30s %-10s %-10s %-15s %-10s %-12s %-12s %-12s\n",
+ "dev_name",
+ "dev",
+ "parent_dev",
+ "governor",
+ "polling_ms",
+ "cur_freq_hz",
+ "min_freq_hz",
+ "max_freq_hz");
+ seq_printf(s, "%-30s %-10s %-10s %-15s %-10s %-12s %-12s %-12s\n",
+ "------------------------------",
+ "----------",
+ "----------",
+ "---------------",
+ "----------",
+ "------------",
+ "------------",
+ "------------");
+
+ mutex_lock(&devfreq_list_lock);
+
+ list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+ if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
+ DEVFREQ_NAME_LEN)) {
+ struct devfreq_passive_data *data = devfreq->data;
+
+ if (data)
+ p_devfreq = data->parent;
+ } else {
+ p_devfreq = NULL;
+ }
+#endif
+ mutex_lock(&devfreq->lock);
+ cur_freq = devfreq->previous_freq,
+ get_freq_range(devfreq, &min_freq, &max_freq);
+ polling_ms = devfreq->profile->polling_ms,
+ mutex_unlock(&devfreq->lock);
+
+ seq_printf(s,
+ "%-30s %-10s %-10s %-15s %-10d %-12ld %-12ld %-12ld\n",
+ dev_name(devfreq->dev.parent),
+ dev_name(&devfreq->dev),
+ p_devfreq ? dev_name(&p_devfreq->dev) : "",
+ devfreq->governor_name,
+ polling_ms,
+ cur_freq,
+ min_freq,
+ max_freq);
+ }
+
+ mutex_unlock(&devfreq_list_lock);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
+
static int __init devfreq_init(void)
{
devfreq_class = class_create(THIS_MODULE, "devfreq");
@@ -1733,6 +1803,16 @@ static int __init devfreq_init(void)
}
devfreq_class->dev_groups = devfreq_groups;
+ devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
+ if (PTR_ERR(devfreq_debugfs) != -ENODEV && IS_ERR(devfreq_debugfs)) {
+ devfreq_debugfs = NULL;
+ pr_warn("%s: couldn't create debugfs dir\n", __FILE__);
+ } else {
+ debugfs_create_file("devfreq_summary", 0444,
+ devfreq_debugfs, NULL,
+ &devfreq_summary_fops);
+ }
+
return 0;
}
subsys_initcall(devfreq_init);
Add debugfs interface to provide debugging information of devfreq device. It contains 'devfreq_summary' entry to show the summary of registered devfreq devices as following and the additional debugfs file will be added. - /sys/kernel/debug/devfreq/devfreq_summary [Detailed description of each field of 'devfreq_summary' debugfs file] - dev_name : Device name of h/w. - dev : Device name made by devfreq core. - parent_dev : If devfreq device uses the passive governor, show parent devfreq device name. - governor : Devfreq governor. - polling_ms : If devfreq device uses the simple_ondemand governor, polling_ms is necessary for the period. (unit: millisecond) - cur_freq_hz : Current Frequency (unit: hz) - old_freq_hz : Frequency before changing. (unit: hz) - new_freq_hz : Frequency after changed. (unit: hz) [For example on Exynos5422-based Odroid-XU3 board] - In order to show the multiple governors on devfreq_summay result, change the governor of devfreq0 from simple_ondemand to userspace. $ cat /sys/kernel/debug/devfreq/devfreq_summary dev_name dev parent_dev governor polling_ms cur_freq_hz min_freq_hz max_freq_hz ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------ 10c20000.memory-controller devfreq0 userspace 0 206000000 165000000 825000000 soc:bus_wcore devfreq1 simple_ondemand 50 532000000 88700000 532000000 soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000 soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000 soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000 soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000 soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000 soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000 soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000 soc:bus_g2d devfreq9 devfreq1 passive 0 0 83250000 333000000 soc:bus_g2d_acp devfreq10 devfreq1 passive 0 0 66500000 266000000 soc:bus_jpeg devfreq11 devfreq1 passive 0 0 75000000 300000000 soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 0 83250000 166500000 soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 0 120000000 200000000 soc:bus_disp1 devfreq14 devfreq1 passive 0 0 120000000 300000000 soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 0 150000000 300000000 soc:bus_mscl devfreq16 devfreq1 passive 0 0 84000000 666000000 Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> --- drivers/devfreq/devfreq.c | 80 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+)