ACPI: thinkpad-acpi: add debug mode

Add a debug mode parameter and verbose debug mode Kconfig option.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

4 files changed, 39 insertions, 0 deletions

diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt
index af18d294cf1a..82fd8228fd41 100644
--- a/Documentation/thinkpad-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -699,3 +699,16 @@ for example:
 
         modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
 
+Enabling debugging output
+-------------------------
+
+The module takes a debug paramater which can be used to selectively
+enable various classes of debugging output, for example:
+
+         modprobe ibm_acpi debug=0xffff
+
+will enable all debugging output classes.  It takes a bitmask, so
+to enable more than one output class, just add their values.
+
+There is also a kernel build option to enable more debugging
+information, which may be necessary to debug driver problems.
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 2cd96a3dff54..44e4c8fb7a74 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -137,6 +137,16 @@ config THINKPAD_ACPI
 
           If you have an IBM or Lenovo ThinkPad laptop, say Y or M here.
 
+config THINKPAD_ACPI_DEBUG
+        bool "Verbose debug mode"
+        depends on THINKPAD_ACPI
+        default n
+        ---help---
+          Enables extra debugging information, at the expense of a slightly
+          increase in driver size.
+
+          If you are not sure, say N here.
+
 config THINKPAD_ACPI_DOCK
         bool "Legacy Docking Station Support"
         depends on THINKPAD_ACPI
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index 4131a7875ad7..7fa906fd45c0 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -2684,6 +2684,9 @@ static int __init set_ibm_param(const char *val, struct kernel_param *kp)
 static int experimental;
 module_param(experimental, int, 0);
 
+static u32 dbg_level;
+module_param_named(debug, dbg_level, uint, 0);
+
 #define IBM_PARAM(feature) \
         module_param_call(feature, set_ibm_param, NULL, NULL, 0)
 
diff --git a/drivers/misc/thinkpad_acpi.h b/drivers/misc/thinkpad_acpi.h
index 02a297e0525f..b2348d7a07c4 100644
--- a/drivers/misc/thinkpad_acpi.h
+++ b/drivers/misc/thinkpad_acpi.h
@@ -74,6 +74,18 @@
 #define enabled(status,bit) ((status) & (1 << (bit)) ? "enabled" : "disabled")
 #define strlencmp(a,b) (strncmp((a), (b), strlen(b)))
 
+/* Debugging */
+#define TPACPI_DBG_ALL          0xffff
+#define dbg_printk(a_dbg_level, format, arg...) \
+        do { if (dbg_level & a_dbg_level) \
+                printk(IBM_DEBUG "%s: " format, __func__ , ## arg); } while (0)
+#ifdef CONFIG_THINKPAD_ACPI_DEBUG
+#define vdbg_printk(a_dbg_level, format, arg...) \
+        dbg_printk(a_dbg_level, format, ## arg)
+#else
+#define vdbg_printk(a_dbg_level, format, arg...)
+#endif
+
 /* ACPI HIDs */
 #define IBM_HKEY_HID    "IBM0068"
 #define IBM_PCI_HID     "PNP0A03"
@@ -112,6 +124,7 @@ static char *next_cmd(char **cmds);
 
 /* Module */
 static int experimental;
+static u32 dbg_level;
 static char *ibm_thinkpad_ec_found;
 
 static char* check_dmi_for_ec(void);