Re: [PATCH v7 2/3] clocksource: Add JH7110 timer driver

From: Daniel Lezcano
Date: Tue Oct 24 2023 - 10:57:07 EST



Hi Xingyu,


On 19/10/2023 07:35, Xingyu Wu wrote:
Add timer driver for the StarFive JH7110 SoC.

As it is a new timer, please add a proper nice description explaining the timer hardware, thanks.

Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/clocksource/Kconfig | 11 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-jh7110.c | 380 +++++++++++++++++++++++++++++
4 files changed, 399 insertions(+)
create mode 100644 drivers/clocksource/timer-jh7110.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7a7bd8bd80e9..91c09b399131 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20473,6 +20473,13 @@ S: Maintained
F: Documentation/devicetree/bindings/sound/starfive,jh7110-tdm.yaml
F: sound/soc/starfive/jh7110_tdm.c
+STARFIVE JH7110 TIMER DRIVER
+M: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
+M: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
+S: Supported
+F: Documentation/devicetree/bindings/timer/starfive,jh7110-timer.yaml
+F: drivers/clocksource/timer-jh7110.c
+
STARFIVE JH71X0 CLOCK DRIVERS
M: Emil Renner Berthing <kernel@xxxxxxxx>
M: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 0ba0dc4ecf06..821abcc1e517 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -641,6 +641,17 @@ config RISCV_TIMER
is accessed via both the SBI and the rdcycle instruction. This is
required for all RISC-V systems.
+config STARFIVE_JH7110_TIMER
+ bool "Timer for the STARFIVE JH7110 SoC"
+ depends on ARCH_STARFIVE || COMPILE_TEST

You may want to use ARCH_STARFIVE only if the platform can make this timer optional. Otherwise, set the option from the platform Kconfig and put the bool "bla bla" if COMPILE_TEST

+ select TIMER_OF
+ select CLKSRC_MMIO
+ default ARCH_STARFIVE

no "default"

+ help
+ This enables the timer for StarFive JH7110 SoC. On RISC-V platform,
+ the system has started RISCV_TIMER, but you can also use this timer
+ which can provide four channels to do a lot more things on JH7110 SoC.
+
config CLINT_TIMER
bool "CLINT Timer for the RISC-V platform" if COMPILE_TEST
depends on GENERIC_SCHED_CLOCK && RISCV
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 368c3461dab8..b66ac05ec086 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_INGENIC_TIMER) += ingenic-timer.o
obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
obj-$(CONFIG_X86_NUMACHIP) += numachip.o
obj-$(CONFIG_RISCV_TIMER) += timer-riscv.o
+obj-$(CONFIG_STARFIVE_JH7110_TIMER) += timer-jh7110.o
obj-$(CONFIG_CLINT_TIMER) += timer-clint.o
obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
diff --git a/drivers/clocksource/timer-jh7110.c b/drivers/clocksource/timer-jh7110.c
new file mode 100644
index 000000000000..71de29a3ec91
--- /dev/null
+++ b/drivers/clocksource/timer-jh7110.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Starfive JH7110 Timer driver
+ *
+ * Copyright (C) 2022-2023 StarFive Technology Co., Ltd.
+ *
+ * Author:
+ * Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
+ * Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/sched_clock.h>

Please double check the headers and remove the pointless ones.


+/* Bias: Ch0-0x0, Ch1-0x40, Ch2-0x80, and so on. */
+#define JH7110_TIMER_CH_LEN 0x40
+#define JH7110_TIMER_CH_BASE(x) ((x) * JH7110_TIMER_CH_LEN)
+#define JH7110_TIMER_CH_MAX 4
+
+#define JH7110_CLOCK_SOURCE_RATING 200
+#define JH7110_VALID_BITS 32
+#define JH7110_DELAY_US 0
+#define JH7110_TIMEOUT_US 10000
+#define JH7110_CLOCKEVENT_RATING 300
+#define JH7110_TIMER_MAX_TICKS 0xffffffff
+#define JH7110_TIMER_MIN_TICKS 0xf
+#define JH7110_TIMER_RELOAD_VALUE 0
+
+#define JH7110_TIMER_INT_STATUS 0x00 /* RO[0:4]: Interrupt Status for channel0~4 */
+#define JH7110_TIMER_CTL 0x04 /* RW[0]: 0-continuous run, 1-single run */
+#define JH7110_TIMER_LOAD 0x08 /* RW: load value to counter */
+#define JH7110_TIMER_ENABLE 0x10 /* RW[0]: timer enable register */
+#define JH7110_TIMER_RELOAD 0x14 /* RW: write 1 or 0 both reload counter */
+#define JH7110_TIMER_VALUE 0x18 /* RO: timer value register */
+#define JH7110_TIMER_INT_CLR 0x20 /* RW: timer interrupt clear register */
+#define JH7110_TIMER_INT_MASK 0x24 /* RW[0]: timer interrupt mask register */
+
+#define JH7110_TIMER_INT_CLR_ENA BIT(0)
+#define JH7110_TIMER_INT_CLR_AVA_MASK BIT(1)
+
+struct jh7110_clkevt {
+ struct clock_event_device evt;
+ struct clocksource cs;
+ bool cs_is_valid;
+ struct clk *clk;
+ struct reset_control *rst;
+ u32 rate;
+ u32 reload_val;
+ void __iomem *base;
+ char name[sizeof("jh7110-timer.chX")];
+};
+
+struct jh7110_timer_priv {
+ struct clk *pclk;
+ struct reset_control *prst;
+ struct jh7110_clkevt clkevt[JH7110_TIMER_CH_MAX];

Why do you need several clock events and clock sources ?

[ ... ]


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