[PATCH 2/5] Clocklib: debugfs support

Dmitry Baryshkov
2008-04-20T08:31:31Z

Provide /sys/kernel/debug/clock to ease debugging.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
---
Documentation/ABI/testing/debugfs-clock | 49 ++++++++++++++++++++
include/linux/clklib.h | 2 +
kernel/clklib.c | 74 +++++++++++++++++++++++++++++++
3 files changed, 125 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/debugfs-clock

diff --git a/Documentation/ABI/testing/debugfs-clock b/Documentation/ABI/testing/debugfs-clock
new file mode 100644
index 0000000..79196e9
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-clock
@@ -0,0 +1,49 @@
+What: /debug/clock
+Date: Apr. 2008
+KernelVersion: 2.6.26
+Contact: Dmitry Baryshkov <dbaryshkov@gmail.com>
+Description:
+
+debugfs interface
+-----------------
+ The /debug/clock file displays information about registered
+ clocks, their rates, usage counters, etc.
+
+Example:
+-------
+cat /sys/kernel/debug/clock
+
+GPIO11_CLK use=4 rate= 3686400 Hz
+ 3_6MHz_CLK use=4 rate= 3686400 Hz
+ 32K_CLK use=1 rate= 32768 Hz
+ MMCCLK use=1 rate= 32768 Hz for cell tmio-mmc
+ TMIOUSBCLK use=1 rate= 0 Hz
+ USBCLK use=1 rate= 0 Hz for cell tmio-ohci
+ TMIOMCLK use=1 rate= 48000000 Hz
+ FBCLK use=1 rate= 48000000 Hz for cell tmio-fb
+HWUARTCLK use=0 rate= 14745600 Hz
+ UARTCLK use=0 rate= 14745600 Hz for device pxa2xx-uart.3
+LCDCLK use=0 rate= 99530000 Hz
+FFUARTCLK use=1 rate= 14745600 Hz
+ UARTCLK use=1 rate= 14745600 Hz for device pxa2xx-uart.0
+BTUARTCLK use=0 rate= 14745600 Hz
+ UARTCLK use=0 rate= 14745600 Hz for device pxa2xx-uart.1
+STUARTCLK use=0 rate= 14745600 Hz
+ UARTCLK use=0 rate= 14745600 Hz for device pxa2xx-uart.2
+ SIRCLK use=0 rate= 14745600 Hz
+UDCCLK use=0 rate= 47923000 Hz
+PXAMMCCLK use=0 rate= 19169000 Hz
+ MMCCLK use=0 rate= 19169000 Hz for device pxa2xx-mci.0
+I2CCLK use=1 rate= 31949000 Hz
+SSP_CLK use=0 rate= 3686400 Hz
+ SSPCLK use=0 rate= 3686400 Hz for device pxa25x-ssp.0
+NSSPCLK use=1 rate= 3686400 Hz
+ SSPCLK use=1 rate= 3686400 Hz for device pxa25x-nssp.1
+ASSPCLK use=0 rate= 3686400 Hz
+ SSPCLK use=0 rate= 3686400 Hz for device pxa25x-nssp.2
+PWM0CLK use=0 rate= 3686400 Hz
+ PWMCLK use=0 rate= 3686400 Hz for device pxa25x-pwm.0
+PWM1CLK use=0 rate= 3686400 Hz
+ PWMCLK use=0 rate= 3686400 Hz for device pxa25x-pwm.1
+AC97CLK use=0 rate= 24576000 Hz
+FICPCLK use=0 rate= 47923000 Hz
diff --git a/include/linux/clklib.h b/include/linux/clklib.h
index f0af195..3bc8886 100644
--- a/include/linux/clklib.h
+++ b/include/linux/clklib.h
@@ -19,6 +19,7 @@ struct seq_file;
* @get_rate: obtain the current clock rate of a specified clock
* @set_rate: set the clock rate for a specified clock
* @round_rate: adjust a reate to the exact rate a clock can provide
+ * @format: output any additional information for a clock
*
* This structure specifies clock operations that are used to configure
* specific clock.
@@ -30,6 +31,7 @@ struct clk_ops {
unsigned long (*get_rate)(struct clk *clk);
int (*set_rate)(struct clk *, unsigned long);
long (*round_rate)(struct clk *, unsigned long);
+ int (*format)(struct clk *, struct seq_file *);
};

/**
diff --git a/kernel/clklib.c b/kernel/clklib.c
index 7b82554..9234c99 100644
--- a/kernel/clklib.c
+++ b/kernel/clklib.c
@@ -390,3 +390,77 @@ int __must_check clk_alloc_functions(
return 0;
}
EXPORT_SYMBOL(clk_alloc_functions);
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#define NAME_FIELD_LEN 20
+
+static void dump_clocks(struct seq_file *s, struct clk *parent, int nest)
+{
+ struct clk *clk;
+ int i;
+
+ list_for_each_entry(clk, &clocks, node) {
+ if (clk->parent == parent) {
+ for (i = 0; i < nest; i++) {
+ seq_putc(s, ' ');
+ seq_putc(s, ' ');
+ }
+ seq_puts(s, clk->name);
+
+ i = 2 * nest + strlen(clk->name);
+ if (i >= NAME_FIELD_LEN)
+ i = NAME_FIELD_LEN - 1;
+ for (; i < NAME_FIELD_LEN; i++) {
+ seq_putc(s, ' ');
+ }
+ seq_printf(s, "%c use=%d rate=%10lu Hz",
+ clk->ops && clk->ops->set_parent ? '*' : ' ',
+ clk->users,
+ __clk_get_rate(clk));
+ if (clk->ops && clk->ops->format)
+ clk->ops->format(clk, s);
+ seq_putc(s, '\n');
+
+ dump_clocks(s, clk, nest + 1);
+ }
+ }
+}
+
+static int clocklib_show(struct seq_file *s, void *unused)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&clocks_lock, flags);
+
+ dump_clocks(s, NULL, 0);
+
+ spin_unlock_irqrestore(&clocks_lock, flags);
+
+ return 0;
+}
+
+static int clocklib_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, clocklib_show, NULL);
+}
+
+static struct file_operations clocklib_operations = {
+ .open = clocklib_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init clocklib_debugfs_init(void)
+{
+ debugfs_create_file("clock", S_IFREG | S_IRUGO,
+ NULL, NULL, &clocklib_operations);
+ return 0;
+}
+subsys_initcall(clocklib_debugfs_init);
+
+#endif /* DEBUG_FS */
--
1.5.4.4