Re: [PATCH v10 1/2] clocksource: loongson2_hpet: add hpet driver support
From: Daniel Lezcano
Date: Tue Nov 22 2022 - 09:59:48 EST
On 03/11/2022 14:12, Yinbo Zhu wrote:
HPET (High Precision Event Timer) defines a new set of timers, which
are used by the operating system to schedule threads, interrupt the
kernel and interrupt the multimedia timer server. The operating
system can assign different timers to different applications. By
configuration, each timer can generate interrupt independently.
The Loongson-2 HPET module includes a main count and three comparators,
all of which are 32 bits wide. Among the three comparators, only
one comparator supports periodic interrupt, all three comparators
support non periodic interrupts.
What is the difference with arch/mips/loongson64/hpet.c ?
Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
---
Change in v10:
1. Replace "goto err" with "return -ENOMEM" if of_iomap fail.
2. This patch need rely on clock patch, which patchwork
link was "https://patchwork.kernel.org/project/linux-clk/list/?series=691497";.
Change in v9:
1. Replace string "register" with "request" in hpet_request_irq.
2. Move the varible "ret" to the begining position in
loongson2_hpet_init and initialized it.
3. Adjust if judgement in clk_get_rate context, there was less
less indentation in the normal path.
4. This patch need rely on clock patch, which patchwork
link was "https://patchwork.kernel.org/project/linux-clk/list/?series=691497";.
Change in v8:
1. Add all history change log information.
Change in v7:
1. Replace setup_irq with request_irq.
Change in v6:
1. Move comma to the end of the previous line if that comma at
the beginning of the line.
Change in v5:
1. Replace string loongson2 with Loongson-2 in commit message
and Kconfig file.
2. Replace string LOONGSON2 with LOONGSON-2 in MAINTAINERS.
3. Make include asm headers after all linux headers.
4. Add blank place before comma if comma when the comma is at
the beginning of the line.
Change in v4:
1. Use common clock framework ops to gain apb clock.
2. This patch need rely on clock patch, which patchwork
link was "https://patchwork.kernel.org/project/linux-clk/list/?series=688892";.
Change in v3:
1. NO change, but other patch in this series of patches set
has changes
Change in v2:
1. NO change, but other patch in this series of patches set
has changes
MAINTAINERS | 6 +
arch/loongarch/kernel/time.c | 4 +-
drivers/clocksource/Kconfig | 9 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/loongson2_hpet.c | 334 +++++++++++++++++++++++++++
5 files changed, 353 insertions(+), 1 deletion(-)
create mode 100644 drivers/clocksource/loongson2_hpet.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 7afaf6d72800..52519695a458 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12026,6 +12026,12 @@ F: Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
F: drivers/clk/clk-loongson2.c
F: include/dt-bindings/clock/loongson,ls2k-clk.h
+LOONGSON-2 SOC SERIES HPET DRIVER
+M: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
+L: linux-kernel@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/clocksource/loongson2_hpet.c
+
LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
M: Sathya Prakash <sathya.prakash@xxxxxxxxxxxx>
M: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx>
diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
index 09f20bc81798..0d8b37763086 100644
--- a/arch/loongarch/kernel/time.c
+++ b/arch/loongarch/kernel/time.c
@@ -216,7 +216,9 @@ int __init constant_clocksource_init(void)
void __init time_init(void)
{
of_clk_init(NULL);
-
+#ifdef CONFIG_TIMER_PROBE
+ timer_probe();
+#endif
This change should go in another patch.
#ifdef is not needed
if (!cpu_has_cpucfg)
const_clock_freq = cpu_clock_freq;
else
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 4469e7f555e9..f114ee47e6f7 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -721,4 +721,13 @@ config GOLDFISH_TIMER
help
Support for the timer/counter of goldfish-rtc
+config LOONGSON2_HPET
+ bool "Loongson-2 High Precision Event Timer (HPET)"
+ select TIMER_PROBE
TIMER_OF selects TIMER_PROBE
+ select TIMER_OF
+ help
+ This option enables Loongson-2 High Precision Event Timer
+ (HPET) module driver. It supports the oneshot, the periodic
+ modes and high resolution. It is used as a clocksource and
+ a clockevent.
endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 64ab547de97b..1a3abb770f11 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -88,3 +88,4 @@ obj-$(CONFIG_MICROCHIP_PIT64B) += timer-microchip-pit64b.o
obj-$(CONFIG_MSC313E_TIMER) += timer-msc313e.o
obj-$(CONFIG_GOLDFISH_TIMER) += timer-goldfish.o
obj-$(CONFIG_GXP_TIMER) += timer-gxp.o
+obj-$(CONFIG_LOONGSON2_HPET) += loongson2_hpet.o
Please rename to timer-loongson.c
diff --git a/drivers/clocksource/loongson2_hpet.c b/drivers/clocksource/loongson2_hpet.c
new file mode 100644
index 000000000000..9b828f9728ca
--- /dev/null
+++ b/drivers/clocksource/loongson2_hpet.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Author: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/init.h>
+#include <linux/percpu.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/clk.h>
+#include <asm/time.h>
+
+/* HPET regs */
+#define HPET_CFG 0x010
+#define HPET_STATUS 0x020
+#define HPET_COUNTER 0x0f0
+#define HPET_T0_IRS 0x001
+#define HPET_T0_CFG 0x100
+#define HPET_T0_CMP 0x108
+#define HPET_CFG_ENABLE 0x001
+#define HPET_TN_LEVEL 0x0002
+#define HPET_TN_ENABLE 0x0004
+#define HPET_TN_PERIODIC 0x0008
+#define HPET_TN_SETVAL 0x0040
+#define HPET_TN_32BIT 0x0100
+
+#define HPET_MIN_CYCLES 16
+#define HPET_MIN_PROG_DELTA (HPET_MIN_CYCLES * 12)
+#define HPET_COMPARE_VAL ((hpet_freq + HZ / 2) / HZ)
+
+void __iomem *hpet_mmio_base;
+unsigned int hpet_freq;
+unsigned int hpet_t0_irq;
+unsigned int hpet_irq_flags;
+unsigned int hpet_t0_cfg;
+
+static DEFINE_SPINLOCK(hpet_lock);
+DEFINE_PER_CPU(struct clock_event_device, hpet_clockevent_device);
+
+static int hpet_read(int offset)
Please replace hpet by loogson as the former is already in the mips
namespace.