summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/hpet.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/hpet.c')
-rw-r--r--arch/x86/kernel/hpet.c66
1 files changed, 57 insertions, 9 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ad0de0c2714e..9cc7b4392f7c 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -94,13 +94,18 @@ static int hpet_verbose;
static int __init hpet_setup(char *str)
{
- if (str) {
+ while (str) {
+ char *next = strchr(str, ',');
+
+ if (next)
+ *next++ = 0;
if (!strncmp("disable", str, 7))
boot_hpet_disable = 1;
if (!strncmp("force", str, 5))
hpet_force_user = 1;
if (!strncmp("verbose", str, 7))
hpet_verbose = 1;
+ str = next;
}
return 1;
}
@@ -319,8 +324,6 @@ static void hpet_set_mode(enum clock_event_mode mode,
now = hpet_readl(HPET_COUNTER);
cmp = now + (unsigned int) delta;
cfg = hpet_readl(HPET_Tn_CFG(timer));
- /* Make sure we use edge triggered interrupts */
- cfg &= ~HPET_TN_LEVEL;
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_Tn_CFG(timer));
@@ -787,15 +790,16 @@ static int hpet_clocksource_register(void)
return 0;
}
+static u32 *hpet_boot_cfg;
+
/**
* hpet_enable - Try to setup the HPET timer. Returns 1 on success.
*/
int __init hpet_enable(void)
{
- unsigned long hpet_period;
- unsigned int id;
+ u32 hpet_period, cfg, id;
u64 freq;
- int i;
+ unsigned int i, last;
if (!is_hpet_capable())
return 0;
@@ -847,15 +851,45 @@ int __init hpet_enable(void)
id = hpet_readl(HPET_ID);
hpet_print_config();
+ last = (id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
+
#ifdef CONFIG_HPET_EMULATE_RTC
/*
* The legacy routing mode needs at least two channels, tick timer
* and the rtc emulation channel.
*/
- if (!(id & HPET_ID_NUMBER))
+ if (!last)
goto out_nohpet;
#endif
+ cfg = hpet_readl(HPET_CFG);
+ hpet_boot_cfg = kmalloc((last + 2) * sizeof(*hpet_boot_cfg),
+ GFP_KERNEL);
+ if (hpet_boot_cfg)
+ *hpet_boot_cfg = cfg;
+ else
+ pr_warn("HPET initial state will not be saved\n");
+ cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
+ hpet_writel(cfg, HPET_Tn_CFG(i));
+ if (cfg)
+ pr_warn("HPET: Unrecognized bits %#x set in global cfg\n",
+ cfg);
+
+ for (i = 0; i <= last; ++i) {
+ cfg = hpet_readl(HPET_Tn_CFG(i));
+ if (hpet_boot_cfg)
+ hpet_boot_cfg[i + 1] = cfg;
+ cfg &= ~(HPET_TN_ENABLE | HPET_TN_LEVEL | HPET_TN_FSB);
+ hpet_writel(cfg, HPET_Tn_CFG(i));
+ cfg &= ~(HPET_TN_PERIODIC | HPET_TN_PERIODIC_CAP
+ | HPET_TN_64BIT_CAP | HPET_TN_32BIT | HPET_TN_ROUTE
+ | HPET_TN_FSB | HPET_TN_FSB_CAP);
+ if (cfg)
+ pr_warn("HPET: Unrecognized bits %#x set in cfg#%u\n",
+ cfg, i);
+ }
+ hpet_print_config();
+
if (hpet_clocksource_register())
goto out_nohpet;
@@ -923,14 +957,28 @@ fs_initcall(hpet_late_init);
void hpet_disable(void)
{
if (is_hpet_capable() && hpet_virt_address) {
- unsigned int cfg = hpet_readl(HPET_CFG);
+ unsigned int cfg = hpet_readl(HPET_CFG), id, last;
- if (hpet_legacy_int_enabled) {
+ if (hpet_boot_cfg)
+ cfg = *hpet_boot_cfg;
+ else if (hpet_legacy_int_enabled) {
cfg &= ~HPET_CFG_LEGACY;
hpet_legacy_int_enabled = 0;
}
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
+
+ if (!hpet_boot_cfg)
+ return;
+
+ id = hpet_readl(HPET_ID);
+ last = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
+
+ for (id = 0; id <= last; ++id)
+ hpet_writel(hpet_boot_cfg[id + 1], HPET_Tn_CFG(id));
+
+ if (*hpet_boot_cfg & HPET_CFG_ENABLE)
+ hpet_writel(*hpet_boot_cfg, HPET_CFG);
}
}