diff options
author | Huacai Chen <chenhc@lemote.com> | 2014-11-04 06:15:31 (GMT) |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 2014-11-24 06:45:02 (GMT) |
commit | e292ccde216e571faad475e4331c188f22a28182 (patch) | |
tree | 18bd2792fa52b3cd3f1aa2bc305262b75f80d8f8 /arch | |
parent | 89467e73d3881a470ce4ffdcba1d5a5ed618379a (diff) | |
download | linux-e292ccde216e571faad475e4331c188f22a28182.tar.xz |
MIPS: Loongson-3: Add RS780/SBX00 HPET support
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@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/8329/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/mips/include/asm/hpet.h | 73 | ||||
-rw-r--r-- | arch/mips/loongson/Kconfig | 12 | ||||
-rw-r--r-- | arch/mips/loongson/common/time.c | 5 | ||||
-rw-r--r-- | arch/mips/loongson/loongson-3/Makefile | 2 | ||||
-rw-r--r-- | arch/mips/loongson/loongson-3/hpet.c | 257 | ||||
-rw-r--r-- | arch/mips/loongson/loongson-3/irq.c | 2 |
6 files changed, 350 insertions, 1 deletions
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) { |