2021-12-20 05:37:33

by Edwin Chiu

[permalink] [raw]
Subject: [PATCH v2 0/2] Add cpuidle driver for Sunplus SP7021

This is a patch series for cpuidle driver for Sunplus SP7021 SoC.

Sunplus SP7021 is an ARM Cortex A7 (4 cores) based SoC. It integrates
many peripherals (ex: UART, I2C, SPI, SDIO, eMMC, USB, SD card and
etc.) into a single chip. It is designed for industrial control.

Refer to:
https://sunplus-tibbo.atlassian.net/wiki/spaces/doc/overview
https://tibbo.com/store/plus1.html

Edwin Chiu (2):
dt-bingings:arm:sunplus:add sp7021 compatible string to
sunplus,idle-state.yaml
cpuidle:sunplus:create cpuidle driver for sunplus sp7021

.../bindings/arm/sunplus/sunplus,idle-state.yaml | 55 +++++++
MAINTAINERS | 9 ++
drivers/cpuidle/Kconfig.arm | 7 +
drivers/cpuidle/Makefile | 1 +
drivers/cpuidle/cpuidle-sunplus.c | 180 +++++++++++++++++++++
include/linux/platform_data/cpuidle-sunplus.h | 13 ++
6 files changed, 265 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml
create mode 100644 drivers/cpuidle/cpuidle-sunplus.c
create mode 100644 include/linux/platform_data/cpuidle-sunplus.h

--
2.7.4



2021-12-20 05:37:35

by Edwin Chiu

[permalink] [raw]
Subject: [PATCH v2 1/2] dt-bingings:arm:sunplus:add sp7021 compatible string to sunplus,idle-state.yaml

Add the compatible string for cpuidle state on sp7021

Signed-off-by: Edwin Chiu <[email protected]>
---
Changes in v2
- Align email address of sob and sender

.../bindings/arm/sunplus/sunplus,idle-state.yaml | 55 ++++++++++++++++++++++
MAINTAINERS | 5 ++
2 files changed, 60 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml

diff --git a/Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml b/Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml
new file mode 100644
index 0000000..649e953
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) Sunplus Co., Ltd. 2021
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/sunplus/sunplus,idle-state.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sunplus cpuidle state
+
+maintainers:
+ - edwin.chiu <[email protected]>
+
+description: |
+ Sunplus SOC cpuidle state
+
+properties:
+ compatible:
+ const: arm,idle-state
+
+ entry-latency-us:
+ description:
+ Worst case latency in microseconds required to enter the idle state.
+
+ exit-latency-us:
+ description:
+ Worst case latency in microseconds required to exit the idle state.
+ The exit-latency-us duration may be guaranteed only after
+ entry-latency-us has passed.
+
+ min-residency-us:
+ description:
+ Minimum residency duration in microseconds, inclusive of preparation
+ and entry, for this idle state to be considered worthwhile energy wise
+ (refer to section 2 of this document for a complete description).
+
+required:
+ - compatible
+ - entry-latency-us
+ - exit-latency-us
+ - min-residency-us
+
+additionalProperties: true
+
+examples:
+ - |
+ idle-states {
+ CLUSTER_SLEEP_BIG: cluster-sleep-big {
+ compatible = "arm,idle-state";
+ entry-latency-us = <8000>;
+ exit-latency-us = <700>;
+ min-residency-us = <9000>;
+ };
+ };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 3b79fd4..41957c7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17945,6 +17945,11 @@ L: [email protected]
S: Maintained
F: drivers/net/ethernet/dlink/sundance.c

+SUNPLUS CPUIDLE DRIVER
+M: Edwin Chiu <[email protected]>
+S: Maintained
+F: Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml
+
SUPERH
M: Yoshinori Sato <[email protected]>
M: Rich Felker <[email protected]>
--
2.7.4


2021-12-20 05:37:38

by Edwin Chiu

[permalink] [raw]
Subject: [PATCH v2 2/2] cpuidle:sunplus:create cpuidle driver for sunplus sp7021

Create cpuidle driver for sunplus sp7021 chip

Signed-off-by: Edwin Chiu <[email protected]>
---
Changes in v2
- Rearrangement #include sequence
- Change // to /*~*/
- Align author email address to same as sob

MAINTAINERS | 4 +
drivers/cpuidle/Kconfig.arm | 7 +
drivers/cpuidle/Makefile | 1 +
drivers/cpuidle/cpuidle-sunplus.c | 180 ++++++++++++++++++++++++++
include/linux/platform_data/cpuidle-sunplus.h | 13 ++
5 files changed, 205 insertions(+)
create mode 100644 drivers/cpuidle/cpuidle-sunplus.c
create mode 100644 include/linux/platform_data/cpuidle-sunplus.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 41957c7..c5eab79 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17949,6 +17949,10 @@ SUNPLUS CPUIDLE DRIVER
M: Edwin Chiu <[email protected]>
S: Maintained
F: Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml
+F: drivers/cpuidle/Kconfig.arm
+F: drivers/cpuidle/Makefile
+F: drivers/cpuidle/cpuidle-sunplus.c
+F: include/linux/platform_data/cpuidle-sunplus.h

SUPERH
M: Yoshinori Sato <[email protected]>
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 334f83e..ad9956c 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -117,3 +117,10 @@ config ARM_QCOM_SPM_CPUIDLE
The Subsystem Power Manager (SPM) controls low power modes for the
CPU and L2 cores. It interface with various system drivers to put
the cores in low power modes.
+
+config ARM_SUNPLUS_CPUIDLE
+ bool "CPU Idle Driver For SUNPLUS SoCs"
+ depends on !ARM64
+ select DT_IDLE_STATES
+ help
+ Select this to enable cpuidle on SP7021 processors.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 26bbc5e..0a020d1 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle-psci.o
obj-$(CONFIG_ARM_PSCI_CPUIDLE_DOMAIN) += cpuidle-psci-domain.o
obj-$(CONFIG_ARM_TEGRA_CPUIDLE) += cpuidle-tegra.o
obj-$(CONFIG_ARM_QCOM_SPM_CPUIDLE) += cpuidle-qcom-spm.o
+obj-$(CONFIG_ARM_SUNPLUS_CPUIDLE) += cpuidle-sunplus.o

###############################################################################
# MIPS drivers
diff --git a/drivers/cpuidle/cpuidle-sunplus.c b/drivers/cpuidle/cpuidle-sunplus.c
new file mode 100644
index 0000000..88671e6
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-sunplus.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARM/ARM64 generic CPU idle driver.
+ *
+ */
+#define pr_fmt(fmt) "CPUidle arm: " fmt
+
+#include <asm/suspend.h>
+#include <linux/cpu_cooling.h>
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/platform_data/cpuidle-sunplus.h>
+
+#include "dt_idle_states.h"
+
+static int sp7021_wfi_finisher(unsigned long flags)
+{
+ cpu_v7_do_idle(); /* idle to WFI */
+
+ return -1;
+}
+
+static int sp7021_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ int ret;
+
+ /* if idx=0, call cpu_do_idle() */
+ if (!idx) {
+ cpu_v7_do_idle();
+ return idx;
+ }
+
+ /* if idx>0, call cpu_suspend() */
+ ret = cpu_pm_enter();
+ if (!ret) {
+ /*
+ * Pass idle state index to cpuidle_suspend which in turn
+ * will call the CPU ops suspend protocol with idle index as a
+ * parameter.
+ */
+ ret = cpu_suspend(idx, sp7021_wfi_finisher);
+ }
+ cpu_pm_exit();
+
+ return ret ? -1:idx;
+}
+
+static struct cpuidle_driver sp7021_idle_driver __initdata = {
+ .name = "sp7021_idle",
+ .owner = THIS_MODULE,
+ /*
+ * State at index 0 is standby wfi and considered standard
+ * on all ARM platforms. If in some platforms simple wfi
+ * can't be used as "state 0", DT bindings must be implemented
+ * to work around this issue and allow installing a special
+ * handler for idle state index 0.
+ */
+ .states[0] = {
+ .enter = sp7021_enter_idle_state,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = UINT_MAX,
+ .name = "WFI",
+ .desc = "ARM WFI",
+ }
+};
+
+static const struct of_device_id sp7021_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = sp7021_enter_idle_state },
+ { },
+};
+
+/*
+ * arm_idle_init - Initializes arm cpuidle driver
+ *
+ * Initializes arm cpuidle driver for all CPUs, if any CPU fails
+ * to register cpuidle driver then rollback to cancel all CPUs
+ * registration.
+ */
+static int __init sp7021_idle_init(void)
+{
+ int cpu, ret;
+ struct cpuidle_driver *drv;
+ struct cpuidle_device *dev;
+
+ drv = kmemdup(&sp7021_idle_driver, sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+ /*
+ * Initialize idle states data, starting at index 1. This
+ * driver is DT only, if no DT idle states are detected (ret
+ * == 0) let the driver initialization fail accordingly since
+ * there is no reason to initialize the idle driver if only
+ * wfi is supported.
+ */
+ ret = dt_init_idle_driver(drv, sp7021_idle_state_match, 1);
+ if (ret <= 0)
+ return ret ? : -ENODEV;
+
+ ret = cpuidle_register_driver(drv);
+ if (ret) {
+ pr_err("Failed to register cpuidle driver\n");
+ return ret;
+ }
+
+ /*
+ * Call arch CPU operations in order to initialize
+ * idle states suspend back-end specific data
+ */
+ for_each_possible_cpu(cpu) {
+ /*
+ * Skip the cpuidle device initialization if the reported
+ * failure is a HW misconfiguration/breakage (-ENXIO)
+ */
+ if (ret == -ENXIO)
+ continue;
+
+ if (ret) {
+ pr_err("CPU %d failed to init idle CPU ops\n", cpu);
+ goto out_fail;
+ }
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ ret = -ENOMEM;
+ goto out_fail;
+ }
+ dev->cpu = cpu;
+
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("Failed to register cpuidle device for CPU %d\n", cpu);
+ kfree(dev);
+ goto out_fail;
+ }
+ }
+
+ return 0;
+
+out_fail:
+ while (--cpu >= 0) {
+ dev = per_cpu(cpuidle_devices, cpu);
+ cpuidle_unregister_device(dev);
+ kfree(dev);
+ }
+ cpuidle_unregister_driver(drv);
+
+ return ret;
+}
+
+static int __init idle_init(void)
+{
+ int ret;
+
+ if (of_machine_is_compatible("sunplus,sp7021-achip")) {
+ sp7021_idle_init();
+ ret = 0;
+ } else
+ ret = -1;
+
+ if (ret) {
+ pr_err("failed to cpuidle init\n");
+ return ret;
+ }
+
+ return ret;
+}
+device_initcall(idle_init);
+
+MODULE_AUTHOR("Edwin Chiu <[email protected]>");
+MODULE_DESCRIPTION("Sunplus sp7021 cpuidle driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_data/cpuidle-sunplus.h b/include/linux/platform_data/cpuidle-sunplus.h
new file mode 100644
index 0000000..d63efad
--- /dev/null
+++ b/include/linux/platform_data/cpuidle-sunplus.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __CPUIDLE_SP7021_H
+#define __CPUIDLE_SP7021_H
+
+extern int cpu_v7_do_idle(void);
+
+#endif
--
2.7.4


2021-12-20 09:38:20

by Daniel Lezcano

[permalink] [raw]
Subject: Re: [PATCH v2 0/2] Add cpuidle driver for Sunplus SP7021


Hi Edwin,

sorry but I don't get the series. The bindings and the generic cpuidle
should already take into account the idle path.

Did I miss something ?


On 20/12/2021 06:37, Edwin Chiu wrote:
> This is a patch series for cpuidle driver for Sunplus SP7021 SoC.
>
> Sunplus SP7021 is an ARM Cortex A7 (4 cores) based SoC. It integrates
> many peripherals (ex: UART, I2C, SPI, SDIO, eMMC, USB, SD card and
> etc.) into a single chip. It is designed for industrial control.
>
> Refer to:
> https://sunplus-tibbo.atlassian.net/wiki/spaces/doc/overview
> https://tibbo.com/store/plus1.html
>
> Edwin Chiu (2):
> dt-bingings:arm:sunplus:add sp7021 compatible string to
> sunplus,idle-state.yaml
> cpuidle:sunplus:create cpuidle driver for sunplus sp7021
>
> .../bindings/arm/sunplus/sunplus,idle-state.yaml | 55 +++++++
> MAINTAINERS | 9 ++
> drivers/cpuidle/Kconfig.arm | 7 +
> drivers/cpuidle/Makefile | 1 +
> drivers/cpuidle/cpuidle-sunplus.c | 180 +++++++++++++++++++++
> include/linux/platform_data/cpuidle-sunplus.h | 13 ++
> 6 files changed, 265 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/sunplus/sunplus,idle-state.yaml
> create mode 100644 drivers/cpuidle/cpuidle-sunplus.c
> create mode 100644 include/linux/platform_data/cpuidle-sunplus.h
>


--
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2021-12-20 12:10:57

by Sudeep Holla

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] cpuidle:sunplus:create cpuidle driver for sunplus sp7021

On Mon, Dec 20, 2021 at 01:37:32PM +0800, Edwin Chiu wrote:
> Create cpuidle driver for sunplus sp7021 chip
>

Based on the driver here, I couldn't understand why you can't make use of
existing cpuidle-arm.c driver

--
Regards,
Sudeep

2021-12-28 08:45:26

by Edwin Chiu 邱垂峰

[permalink] [raw]
Subject: RE: [PATCH v2 2/2] cpuidle:sunplus:create cpuidle driver for sunplus sp7021

Hi Sudeep and Daniel:

Thanks your response.
My CPU is arm CA7 that is 32bits cpu.
If I directly used cpuidle-arm.c function with enable "Generic ARM/ARM64 CPU idle Driver",
the cpuidle driver mount fail with "unsupported enable-method property".

This is due to linux kernel no invoke CPUIDLE_METHOD_OF_DECLARE for arm 32bits cpu.
There have no define cpuidle_ops.init and cpuidle_ops.suspend function for arm 32bits cpu too.

So I create cpuidle-sunplus.c to execute my cpuidle function.
Please correct me if I got mistake.


?????p EdwinChiu
?????B???M??
T: +886-3-5786005 ext.2590
[email protected]
300 ?s?ˬ??Ƕ??ϳзs?@??19??

> -----Original Message-----
> From: Sudeep Holla <[email protected]>
> Sent: Monday, December 20, 2021 8:11 PM
> To: Edwin Chiu <[email protected]>
> Cc: [email protected]; Edwin Chiu ?????p <[email protected]>; [email protected];
> [email protected]; [email protected]; Sudeep Holla <[email protected]>;
> [email protected]; [email protected]
> Subject: Re: [PATCH v2 2/2] cpuidle:sunplus:create cpuidle driver for sunplus sp7021
>
> On Mon, Dec 20, 2021 at 01:37:32PM +0800, Edwin Chiu wrote:
> > Create cpuidle driver for sunplus sp7021 chip
> >
>
> Based on the driver here, I couldn't understand why you can't make use of existing cpuidle-arm.c driver
>
> --
> Regards,
> Sudeep