x86: GEODE: MFGPT: Use "just-in-time" detection for the MFGPT timers

There isn't much value to always detecting the MFGPT timers on
Geode platforms; detection is only needed when something wants
to use the timers.  Move the detection code so that it gets
called the first time a timer is allocated.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 28 insertions, 16 deletions

diff --git a/arch/x86/kernel/geode_32.c b/arch/x86/kernel/geode_32.c
index 9c7f7d395968..9dad6ca6cd70 100644
--- a/arch/x86/kernel/geode_32.c
+++ b/arch/x86/kernel/geode_32.c
@@ -163,14 +163,11 @@ EXPORT_SYMBOL_GPL(geode_gpio_setup_event);
 
 static int __init geode_southbridge_init(void)
 {
-        int timers;
-
         if (!is_geode())
                 return -ENODEV;
 
         init_lbars();
-        timers = geode_mfgpt_detect();
-        printk(KERN_INFO "geode:  %d MFGPT timers available.\n", timers);
+        (void) mfgpt_timer_setup();
         return 0;
 }
 
diff --git a/arch/x86/kernel/mfgpt_32.c b/arch/x86/kernel/mfgpt_32.c
index 5cf3a839530c..abdb7c71199a 100644
--- a/arch/x86/kernel/mfgpt_32.c
+++ b/arch/x86/kernel/mfgpt_32.c
@@ -74,28 +74,37 @@ __setup("mfgptfix", mfgpt_fix);
  * In other cases (such as with VSAless OpenFirmware), the system firmware
  * leaves timers available for us to use.
  */
-int __init geode_mfgpt_detect(void)
+
+
+static int timers = -1;
+
+static void geode_mfgpt_detect(void)
 {
-        int count = 0, i;
+        int i;
         u16 val;
 
+        timers = 0;
+
         if (disable) {
-                printk(KERN_INFO "geode-mfgpt:  Skipping MFGPT setup\n");
-                return 0;
+                printk(KERN_INFO "geode-mfgpt:  MFGPT support is disabled\n");
+                goto done;
+        }
+
+        if (!geode_get_dev_base(GEODE_DEV_MFGPT)) {
+                printk(KERN_INFO "geode-mfgpt:  MFGPT LBAR is not set up\n");
+                goto done;
         }
 
         for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
                 val = geode_mfgpt_read(i, MFGPT_REG_SETUP);
                 if (!(val & MFGPT_SETUP_SETUP)) {
                         mfgpt_timers[i].avail = 1;
-                        count++;
+                        timers++;
                 }
         }
 
-        /* set up clock event device, if desired */
-        i = mfgpt_timer_setup();
-
-        return count;
+done:
+        printk(KERN_INFO "geode-mfgpt:  %d MFGPT timers available.\n", timers);
 }
 
 int geode_mfgpt_toggle_event(int timer, int cmp, int event, int enable)
@@ -183,10 +192,16 @@ int geode_mfgpt_alloc_timer(int timer, int domain)
 {
         int i;
 
-        if (!geode_get_dev_base(GEODE_DEV_MFGPT))
-                return -ENODEV;
+        if (timers == -1) {
+                /* timers haven't been detected yet */
+                geode_mfgpt_detect();
+        }
+
+        if (!timers)
+                return -1;
+
         if (timer >= MFGPT_MAX_TIMERS)
-                return -EIO;
+                return -1;
 
         if (timer < 0) {
                 /* Try to find an available timer */