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Subject[PATCH v2 2/2] cpuidle:sunplus:create cpuidle driver for sunplus sp7021
Date
Create cpuidle driver for sunplus sp7021 chip

Signed-off-by: Edwin Chiu <edwinchiu0505tw@gmail.com>
---
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 <edwinchiu0505tw@gmail.com>
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 <ysato@users.sourceforge.jp>
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 <edwinchiu0505tw@gmail.com>");
+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
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