cpuidle: add Calxeda SOC idle support

Add support for core powergating on Calxeda platforms. Initially, this supports ECX-1000 (highbank), but support will be added for ECX-2000 later. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Len Brown <len.brown@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>

cpuidle: add Calxeda SOC idle support
Add support for core powergating on Calxeda platforms. Initially, this supports ECX-1000 (highbank), but support will be added for ECX-2000 later. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Len Brown <len.brown@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Rob Herring
1 parent 8f0d8163b5
Showing 3 changed files with 173 additions and 0 deletions Side-by-side Diff
drivers/cpuidle/Kconfig
drivers/cpuidle/Makefile
drivers/cpuidle/cpuidle-calxeda.c
@@ -21,4 +21,14 @@
  
 config ARCH_NEEDS_CPU_IDLE_COUPLED
 	def_bool n
+
+if CPU_IDLE
+
+config CPU_IDLE_CALXEDA
+	bool "CPU Idle Driver for Calxeda processors"
+	depends on ARCH_HIGHBANK
+	help
+	  Select this to enable cpuidle on Calxeda processors.
+
+endif
@@ -4,4 +4,6 @@
  
 obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
 obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
+
+obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o
+/*
+ * Copyright 2012 Calxeda, Inc.
+ *
+ * Based on arch/arm/plat-mxc/cpuidle.c:
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/time.h>
+#include <linux/delay.h>
+#include <linux/suspend.h>
+#include <asm/cpuidle.h>
+#include <asm/proc-fns.h>
+#include <asm/smp_scu.h>
+#include <asm/suspend.h>
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+
+extern void highbank_set_cpu_jump(int cpu, void *jump_addr);
+extern void *scu_base_addr;
+
+static struct cpuidle_device __percpu *calxeda_idle_cpuidle_devices;
+
+static inline unsigned int get_auxcr(void)
+{
+	unsigned int val;
+	asm("mrc p15, 0, %0, c1, c0, 1	@ get AUXCR" : "=r" (val) : : "cc");
+	return val;
+}
+
+static inline void set_auxcr(unsigned int val)
+{
+	asm volatile("mcr p15, 0, %0, c1, c0, 1	@ set AUXCR"
+	  : : "r" (val) : "cc");
+	isb();
+}
+
+static noinline void calxeda_idle_restore(void)
+{
+	set_cr(get_cr() | CR_C);
+	set_auxcr(get_auxcr() | 0x40);
+	scu_power_mode(scu_base_addr, SCU_PM_NORMAL);
+}
+
+static int calxeda_idle_finish(unsigned long val)
+{
+	/* Already flushed cache, but do it again as the outer cache functions
+	 * dirty the cache with spinlocks */
+	flush_cache_all();
+
+	set_auxcr(get_auxcr() & ~0x40);
+	set_cr(get_cr() & ~CR_C);
+
+	scu_power_mode(scu_base_addr, SCU_PM_DORMANT);
+
+	cpu_do_idle();
+
+	/* Restore things if we didn't enter power-gating */
+	calxeda_idle_restore();
+	return 1;
+}
+
+static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	highbank_set_cpu_jump(smp_processor_id(), cpu_resume);
+	cpu_suspend(0, calxeda_idle_finish);
+	return index;
+}
+
+static void calxeda_idle_cpuidle_devices_uninit(void)
+{
+	int i;
+	struct cpuidle_device *dev;
+
+	for_each_possible_cpu(i) {
+		dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, i);
+		cpuidle_unregister_device(dev);
+	}
+
+	free_percpu(calxeda_idle_cpuidle_devices);
+}
+
+static struct cpuidle_driver calxeda_idle_driver = {
+	.name = "calxeda_idle",
+	.en_core_tk_irqen = 1,
+	.states = {
+		ARM_CPUIDLE_WFI_STATE,
+		{
+			.name = "PG",
+			.desc = "Power Gate",
+			.flags = CPUIDLE_FLAG_TIME_VALID,
+			.exit_latency = 30,
+			.power_usage = 50,
+			.target_residency = 200,
+			.enter = calxeda_pwrdown_idle,
+		},
+	},
+	.state_count = 2,
+};
+
+static int __init calxeda_cpuidle_init(void)
+{
+	int cpu_id;
+	int ret;
+	struct cpuidle_device *dev;
+	struct cpuidle_driver *drv = &calxeda_idle_driver;
+
+	if (!of_machine_is_compatible("calxeda,highbank"))
+		return -ENODEV;
+
+	ret = cpuidle_register_driver(drv);
+	if (ret)
+		return ret;
+
+	calxeda_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+	if (calxeda_idle_cpuidle_devices == NULL) {
+		ret = -ENOMEM;
+		goto unregister_drv;
+	}
+
+	/* initialize state data for each cpuidle_device */
+	for_each_possible_cpu(cpu_id) {
+		dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, cpu_id);
+		dev->cpu = cpu_id;
+		dev->state_count = drv->state_count;
+
+		ret = cpuidle_register_device(dev);
+		if (ret) {
+			pr_err("Failed to register cpu %u, error: %d\n",
+			       cpu_id, ret);
+			goto uninit;
+		}
+	}
+
+	return 0;
+
+uninit:
+	calxeda_idle_cpuidle_devices_uninit();
+unregister_drv:
+	cpuidle_unregister_driver(drv);
+	return ret;
+}
+module_init(calxeda_cpuidle_init);
...	...	@@ -21,4 +21,14 @@
21	21
22	22	config ARCH_NEEDS_CPU_IDLE_COUPLED
23	23	def_bool n
	24	+
	25	+if CPU_IDLE
	26	+
	27	+config CPU_IDLE_CALXEDA
	28	+ bool "CPU Idle Driver for Calxeda processors"
	29	+ depends on ARCH_HIGHBANK
	30	+ help
	31	+ Select this to enable cpuidle on Calxeda processors.
	32	+
	33	+endif
...	...	@@ -4,4 +4,6 @@
4	4
5	5	obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
6	6	obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
	7	+
	8	+obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o
	1	+/*
	2	+ * Copyright 2012 Calxeda, Inc.
	3	+ *
	4	+ * Based on arch/arm/plat-mxc/cpuidle.c:
	5	+ * Copyright 2012 Freescale Semiconductor, Inc.
	6	+ * Copyright 2012 Linaro Ltd.
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or modify it
	9	+ * under the terms and conditions of the GNU General Public License,
	10	+ * version 2, as published by the Free Software Foundation.
	11	+ *
	12	+ * This program is distributed in the hope it will be useful, but WITHOUT
	13	+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	14	+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	15	+ * more details.
	16	+ *
	17	+ * You should have received a copy of the GNU General Public License along with
	18	+ * this program. If not, see <http://www.gnu.org/licenses/>.
	19	+ */
	20	+
	21	+#include <linux/cpuidle.h>
	22	+#include <linux/init.h>
	23	+#include <linux/io.h>
	24	+#include <linux/of.h>
	25	+#include <linux/time.h>
	26	+#include <linux/delay.h>
	27	+#include <linux/suspend.h>
	28	+#include <asm/cpuidle.h>
	29	+#include <asm/proc-fns.h>
	30	+#include <asm/smp_scu.h>
	31	+#include <asm/suspend.h>
	32	+#include <asm/cacheflush.h>
	33	+#include <asm/cp15.h>
	34	+
	35	+extern void highbank_set_cpu_jump(int cpu, void *jump_addr);
	36	+extern void *scu_base_addr;
	37	+
	38	+static struct cpuidle_device __percpu *calxeda_idle_cpuidle_devices;
	39	+
	40	+static inline unsigned int get_auxcr(void)
	41	+{
	42	+ unsigned int val;
	43	+ asm("mrc p15, 0, %0, c1, c0, 1 @ get AUXCR" : "=r" (val) : : "cc");
	44	+ return val;
	45	+}
	46	+
	47	+static inline void set_auxcr(unsigned int val)
	48	+{
	49	+ asm volatile("mcr p15, 0, %0, c1, c0, 1 @ set AUXCR"
	50	+ : : "r" (val) : "cc");
	51	+ isb();
	52	+}
	53	+
	54	+static noinline void calxeda_idle_restore(void)
	55	+{
	56	+ set_cr(get_cr() \| CR_C);
	57	+ set_auxcr(get_auxcr() \| 0x40);
	58	+ scu_power_mode(scu_base_addr, SCU_PM_NORMAL);
	59	+}
	60	+
	61	+static int calxeda_idle_finish(unsigned long val)
	62	+{
	63	+ /* Already flushed cache, but do it again as the outer cache functions
	64	+ * dirty the cache with spinlocks */
	65	+ flush_cache_all();
	66	+
	67	+ set_auxcr(get_auxcr() & ~0x40);
	68	+ set_cr(get_cr() & ~CR_C);
	69	+
	70	+ scu_power_mode(scu_base_addr, SCU_PM_DORMANT);
	71	+
	72	+ cpu_do_idle();
	73	+
	74	+ /* Restore things if we didn't enter power-gating */
	75	+ calxeda_idle_restore();
	76	+ return 1;
	77	+}
	78	+
	79	+static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
	80	+ struct cpuidle_driver *drv,
	81	+ int index)
	82	+{
	83	+ highbank_set_cpu_jump(smp_processor_id(), cpu_resume);
	84	+ cpu_suspend(0, calxeda_idle_finish);
	85	+ return index;
	86	+}
	87	+
	88	+static void calxeda_idle_cpuidle_devices_uninit(void)
	89	+{
	90	+ int i;
	91	+ struct cpuidle_device *dev;
	92	+
	93	+ for_each_possible_cpu(i) {
	94	+ dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, i);
	95	+ cpuidle_unregister_device(dev);
	96	+ }
	97	+
	98	+ free_percpu(calxeda_idle_cpuidle_devices);
	99	+}
	100	+
	101	+static struct cpuidle_driver calxeda_idle_driver = {
	102	+ .name = "calxeda_idle",
	103	+ .en_core_tk_irqen = 1,
	104	+ .states = {
	105	+ ARM_CPUIDLE_WFI_STATE,
	106	+ {
	107	+ .name = "PG",
	108	+ .desc = "Power Gate",
	109	+ .flags = CPUIDLE_FLAG_TIME_VALID,
	110	+ .exit_latency = 30,
	111	+ .power_usage = 50,
	112	+ .target_residency = 200,
	113	+ .enter = calxeda_pwrdown_idle,
	114	+ },
	115	+ },
	116	+ .state_count = 2,
	117	+};
	118	+
	119	+static int __init calxeda_cpuidle_init(void)
	120	+{
	121	+ int cpu_id;
	122	+ int ret;
	123	+ struct cpuidle_device *dev;
	124	+ struct cpuidle_driver *drv = &calxeda_idle_driver;
	125	+
	126	+ if (!of_machine_is_compatible("calxeda,highbank"))
	127	+ return -ENODEV;
	128	+
	129	+ ret = cpuidle_register_driver(drv);
	130	+ if (ret)
	131	+ return ret;
	132	+
	133	+ calxeda_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
	134	+ if (calxeda_idle_cpuidle_devices == NULL) {
	135	+ ret = -ENOMEM;
	136	+ goto unregister_drv;
	137	+ }
	138	+
	139	+ /* initialize state data for each cpuidle_device */
	140	+ for_each_possible_cpu(cpu_id) {
	141	+ dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, cpu_id);
	142	+ dev->cpu = cpu_id;
	143	+ dev->state_count = drv->state_count;
	144	+
	145	+ ret = cpuidle_register_device(dev);
	146	+ if (ret) {
	147	+ pr_err("Failed to register cpu %u, error: %d\n",
	148	+ cpu_id, ret);
	149	+ goto uninit;
	150	+ }
	151	+ }
	152	+
	153	+ return 0;
	154	+
	155	+uninit:
	156	+ calxeda_idle_cpuidle_devices_uninit();
	157	+unregister_drv:
	158	+ cpuidle_unregister_driver(drv);
	159	+ return ret;
	160	+}
	161	+module_init(calxeda_cpuidle_init);