CPUFreq driver need external timer, so add hpet at first.
In Loongson 3, only Core-0 can receive external interrupt. As a result,
timekeeping cannot absolutely use HPET timer. We use a hybrid solution:
Core-0 use HPET as its clock event device, but other cores still use
MIPS; clock source is global and doesn't need interrupt, so use HPET.
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
Signed-off-by: Hongliang Tao <taohl@xxxxxxxxxx>
---
arch/mips/include/asm/hpet.h | 73 +++++++++
arch/mips/loongson/Kconfig | 12 ++
arch/mips/loongson/common/time.c | 5 +
arch/mips/loongson/loongson-3/Makefile | 2 +
arch/mips/loongson/loongson-3/hpet.c | 257 ++++++++++++++++++++++++++++++++
arch/mips/loongson/loongson-3/irq.c | 2 +-
6 files changed, 350 insertions(+), 1 deletions(-)
create mode 100644 arch/mips/include/asm/hpet.h
create mode 100644 arch/mips/loongson/loongson-3/hpet.c
diff --git a/arch/mips/include/asm/hpet.h b/arch/mips/include/asm/hpet.h
new file mode 100644
index 0000000..18a8f77
--- /dev/null
+++ b/arch/mips/include/asm/hpet.h
@@ -0,0 +1,73 @@
+#ifndef _ASM_HPET_H
+#define _ASM_HPET_H
+
+#ifdef CONFIG_RS780_HPET
+
+#define HPET_MMAP_SIZE 1024
+
+#define HPET_ID 0x000
+#define HPET_PERIOD 0x004
+#define HPET_CFG 0x010
+#define HPET_STATUS 0x020
+#define HPET_COUNTER 0x0f0
+
+#define HPET_Tn_CFG(n) (0x100 + 0x20 * n)
+#define HPET_Tn_CMP(n) (0x108 + 0x20 * n)
+#define HPET_Tn_ROUTE(n) (0x110 + 0x20 * n)
+
+#define HPET_T0_IRS 0x001
+#define HPET_T1_IRS 0x002
+#define HPET_T3_IRS 0x004
+
+#define HPET_T0_CFG 0x100
+#define HPET_T0_CMP 0x108
+#define HPET_T0_ROUTE 0x110
+#define HPET_T1_CFG 0x120
+#define HPET_T1_CMP 0x128
+#define HPET_T1_ROUTE 0x130
+#define HPET_T2_CFG 0x140
+#define HPET_T2_CMP 0x148
+#define HPET_T2_ROUTE 0x150
+
+#define HPET_ID_REV 0x000000ff
+#define HPET_ID_NUMBER 0x00001f00
+#define HPET_ID_64BIT 0x00002000
+#define HPET_ID_LEGSUP 0x00008000
+#define HPET_ID_VENDOR 0xffff0000
+#define HPET_ID_NUMBER_SHIFT 8
+#define HPET_ID_VENDOR_SHIFT 16
+
+#define HPET_CFG_ENABLE 0x001
+#define HPET_CFG_LEGACY 0x002
+#define HPET_LEGACY_8254 2
+#define HPET_LEGACY_RTC 8
+
+#define HPET_TN_LEVEL 0x0002
+#define HPET_TN_ENABLE 0x0004
+#define HPET_TN_PERIODIC 0x0008
+#define HPET_TN_PERIODIC_CAP 0x0010
+#define HPET_TN_64BIT_CAP 0x0020
+#define HPET_TN_SETVAL 0x0040
+#define HPET_TN_32BIT 0x0100
+#define HPET_TN_ROUTE 0x3e00
+#define HPET_TN_FSB 0x4000
+#define HPET_TN_FSB_CAP 0x8000
+#define HPET_TN_ROUTE_SHIFT 9
+
+/* Max HPET Period is 10^8 femto sec as in HPET spec */
+#define HPET_MAX_PERIOD 100000000UL
+/*
+ * Min HPET period is 10^5 femto sec just for safety. If it is less than this,
+ * then 32 bit HPET counter wrapsaround in less than 0.5 sec.
+ */
+#define HPET_MIN_PERIOD 100000UL
+
+#define HPET_ADDR 0x20000
+#define HPET_MMIO_ADDR 0x90000e0000020000
+#define HPET_FREQ 14318780
+#define HPET_COMPARE_VAL ((HPET_FREQ + HZ / 2) / HZ)
+#define HPET_T0_IRQ 0
+
+extern void __init setup_hpet_timer(void);
+#endif /* CONFIG_RS780_HPET */
+#endif /* _ASM_HPET_H */
diff --git a/arch/mips/loongson/Kconfig b/arch/mips/loongson/Kconfig
index 72f830ac..156de85 100644
--- a/arch/mips/loongson/Kconfig
+++ b/arch/mips/loongson/Kconfig
@@ -108,6 +108,18 @@ config CS5536_MFGPT
If unsure, say Yes.
+config RS780_HPET
+ bool "RS780/SBX00 HPET Timer"
+ depends on LOONGSON_MACH3X
+ select MIPS_EXTERNAL_TIMER
+ help
+ This option enables the hpet timer of AMD RS780/SBX00.
+
+ If you want to enable the Loongson3 CPUFreq Driver, Please enable
+ this option at first, otherwise, You will get wrong system time.
+
+ If unsure, say Yes.
+
config LOONGSON_SUSPEND
bool
default y
diff --git a/arch/mips/loongson/common/time.c b/arch/mips/loongson/common/time.c
index 262a1f6..e1a5382a 100644
--- a/arch/mips/loongson/common/time.c
+++ b/arch/mips/loongson/common/time.c
@@ -12,6 +12,7 @@
*/
#include <asm/mc146818-time.h>
#include <asm/time.h>
+#include <asm/hpet.h>
#include <loongson.h>
#include <cs5536/cs5536_mfgpt.h>
@@ -21,7 +22,11 @@ void __init plat_time_init(void)
/* setup mips r4k timer */
mips_hpt_frequency = cpu_clock_freq / 2;
+#ifdef CONFIG_RS780_HPET
+ setup_hpet_timer();
+#else
setup_mfgpt0_timer();
+#endif
}
void read_persistent_clock(struct timespec *ts)
diff --git a/arch/mips/loongson/loongson-3/Makefile b/arch/mips/loongson/loongson-3/Makefile
index 69809a3..622fead 100644
--- a/arch/mips/loongson/loongson-3/Makefile
+++ b/arch/mips/loongson/loongson-3/Makefile
@@ -6,3 +6,5 @@ obj-y += irq.o cop2-ex.o platform.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_NUMA) += numa.o
+
+obj-$(CONFIG_RS780_HPET) += hpet.o
diff --git a/arch/mips/loongson/loongson-3/hpet.c b/arch/mips/loongson/loongson-3/hpet.c
new file mode 100644
index 0000000..e898d68
--- /dev/null
+++ b/arch/mips/loongson/loongson-3/hpet.c
@@ -0,0 +1,257 @@
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/percpu.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+
+#include <asm/hpet.h>
+#include <asm/time.h>
+
+#define SMBUS_CFG_BASE (loongson_sysconf.ht_control_base + 0x0300a000)
+#define SMBUS_PCI_REG40 0x40
+#define SMBUS_PCI_REG64 0x64
+#define SMBUS_PCI_REGB4 0xb4
+
+static DEFINE_SPINLOCK(hpet_lock);
+DEFINE_PER_CPU(struct clock_event_device, hpet_clockevent_device);
+
+static unsigned int smbus_read(int offset)
+{
+ return *(volatile unsigned int *)(SMBUS_CFG_BASE + offset);
+}
+
+static void smbus_write(int offset, int data)
+{
+ *(volatile unsigned int *)(SMBUS_CFG_BASE + offset) = data;
+}
+
+static void smbus_enable(int offset, int bit)
+{
+ unsigned int cfg = smbus_read(offset);
+
+ cfg |= bit;
+ smbus_write(offset, cfg);
+}
+
+static int hpet_read(int offset)
+{
+ return *(volatile unsigned int *)(HPET_MMIO_ADDR + offset);
+}
+
+static void hpet_write(int offset, int data)
+{
+ *(volatile unsigned int *)(HPET_MMIO_ADDR + offset) = data;
+}
+
+static void hpet_start_counter(void)
+{
+ unsigned int cfg = hpet_read(HPET_CFG);
+
+ cfg |= HPET_CFG_ENABLE;
+ hpet_write(HPET_CFG, cfg);
+}
+
+static void hpet_stop_counter(void)
+{
+ unsigned int cfg = hpet_read(HPET_CFG);
+
+ cfg &= ~HPET_CFG_ENABLE;
+ hpet_write(HPET_CFG, cfg);
+}
+
+static void hpet_reset_counter(void)
+{
+ hpet_write(HPET_COUNTER, 0);
+ hpet_write(HPET_COUNTER + 4, 0);
+}
+
+static void hpet_restart_counter(void)
+{
+ hpet_stop_counter();
+ hpet_reset_counter();
+ hpet_start_counter();
+}
+
+static void hpet_enable_legacy_int(void)
+{
+ /* Do nothing on Loongson-3 */
+}
+
+static void hpet_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ int cfg = 0;
+
+ spin_lock(&hpet_lock);
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ pr_info("set clock event to periodic mode!\n");
+ /* stop counter */
+ hpet_stop_counter();
+
+ /* enables the timer0 to generate a periodic interrupt */
+ cfg = hpet_read(HPET_T0_CFG);
+ cfg &= ~HPET_TN_LEVEL;
+ cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
+ HPET_TN_SETVAL | HPET_TN_32BIT;
+ hpet_write(HPET_T0_CFG, cfg);
+
+ /* set the comparator */
+ hpet_write(HPET_T0_CMP, HPET_COMPARE_VAL);
+ udelay(1);
+ hpet_write(HPET_T0_CMP, HPET_COMPARE_VAL);
+
+ /* start counter */
+ hpet_start_counter();
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ cfg = hpet_read(HPET_T0_CFG);
+ cfg &= ~HPET_TN_ENABLE;
+ hpet_write(HPET_T0_CFG, cfg);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ pr_info("set clock event to one shot mode!\n");
+ cfg = hpet_read(HPET_T0_CFG);
+ /* set timer0 type
+ * 1 : periodic interrupt
+ * 0 : non-periodic(oneshot) interrupt
+ */
+ cfg &= ~HPET_TN_PERIODIC;
+ cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
+ hpet_write(HPET_T0_CFG, cfg);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ hpet_enable_legacy_int();
+ break;
+ }
+ spin_unlock(&hpet_lock);
+}
+
+static int hpet_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ unsigned int cnt;
+ int res;
+
+ cnt = hpet_read(HPET_COUNTER);
+ cnt += delta;
+ hpet_write(HPET_T0_CMP, cnt);
+
+ res = ((int)(hpet_read(HPET_COUNTER) - cnt) > 0) ? -ETIME : 0;
+ return res;
+}
+
+static irqreturn_t hpet_irq_handler(int irq, void *data)
+{
+ int is_irq;
+ struct clock_event_device *cd;
+ unsigned int cpu = smp_processor_id();
+
+ is_irq = hpet_read(HPET_STATUS);
+ if (is_irq & HPET_T0_IRS) {
+ /* clear the TIMER0 irq status register */
+ hpet_write(HPET_STATUS, HPET_T0_IRS);
+ cd = &per_cpu(hpet_clockevent_device, cpu);
+ cd->event_handler(cd);
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+static struct irqaction hpet_irq = {
+ .handler = hpet_irq_handler,
+ .flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_TIMER,
+ .name = "hpet",
+};
+
+/*
+ * hpet address assignation and irq setting should be done in bios.
+ * but pmon don't do this, we just setup here directly.
+ * The operation under is normal. unfortunately, hpet_setup process
+ * is before pci initialize.
+ *
+ * {
+ * struct pci_dev *pdev;
+ *
+ * pdev = pci_get_device(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, NULL);
+ * pci_write_config_word(pdev, SMBUS_PCI_REGB4, HPET_ADDR);
+ *
+ * ...
+ * }
+ */
+static void hpet_setup(void)
+{
+ /* set hpet base address */
+ smbus_write(SMBUS_PCI_REGB4, HPET_ADDR);
+
+ /* enable decodeing of access to HPET MMIO*/
+ smbus_enable(SMBUS_PCI_REG40, (1 << 28));
+
+ /* HPET irq enable */
+ smbus_enable(SMBUS_PCI_REG64, (1 << 10));
+
+ hpet_enable_legacy_int();
+}
+
+void __init setup_hpet_timer(void)
+{
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *cd;
+
+ hpet_setup();
+
+ cd = &per_cpu(hpet_clockevent_device, cpu);
+ cd->name = "hpet";
+ cd->rating = 320;
+ cd->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+ cd->set_mode = hpet_set_mode;
+ cd->set_next_event = hpet_next_event;
+ cd->irq = HPET_T0_IRQ;
+ cd->cpumask = cpumask_of(cpu);
+ clockevent_set_clock(cd, HPET_FREQ);
+ cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
+ cd->min_delta_ns = 5000;
+
+ clockevents_register_device(cd);
+ setup_irq(HPET_T0_IRQ, &hpet_irq);
+ pr_info("hpet clock event device register\n");
+}
+
+static cycle_t hpet_read_counter(struct clocksource *cs)
+{
+ return (cycle_t)hpet_read(HPET_COUNTER);
+}
+
+static void hpet_suspend(struct clocksource *cs)
+{
+}
+
+static void hpet_resume(struct clocksource *cs)
+{
+ hpet_setup();
+ hpet_restart_counter();
+}
+
+static struct clocksource csrc_hpet = {
+ .name = "hpet",
+ /* mips clocksource rating is less than 300, so hpet is better. */
+ .rating = 300,
+ .read = hpet_read_counter,
+ .mask = CLOCKSOURCE_MASK(32),
+ /* oneshot mode work normal with this flag */
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .suspend = hpet_suspend,
+ .resume = hpet_resume,
+ .mult = 0,
+ .shift = 10,
+};
+
+int __init init_hpet_clocksource(void)
+{
+ csrc_hpet.mult = clocksource_hz2mult(HPET_FREQ, csrc_hpet.shift);
+ return clocksource_register_hz(&csrc_hpet, HPET_FREQ);
+}
+
+arch_initcall(init_hpet_clocksource);
diff --git a/arch/mips/loongson/loongson-3/irq.c b/arch/mips/loongson/loongson-3/irq.c
index 5813d94..21221ed 100644
--- a/arch/mips/loongson/loongson-3/irq.c
+++ b/arch/mips/loongson/loongson-3/irq.c
@@ -9,7 +9,7 @@
#include "smp.h"
-unsigned int ht_irq[] = {1, 3, 4, 5, 6, 7, 8, 12, 14, 15};
+unsigned int ht_irq[] = {0, 1, 3, 4, 5, 6, 7, 8, 12, 14, 15};
static void ht_irqdispatch(void)
{
--
1.7.7.3
