Merge back cpufreq material for 3.19-rc1.

Documentation/cpu-freq/intel-pstate.txt

···
 Intel P-state driver
 --------------------
 
-This driver implements a scaling driver with an internal governor for
-Intel Core processors.  The driver follows the same model as the
-Transmeta scaling driver (longrun.c) and implements the setpolicy()
-instead of target().  Scaling drivers that implement setpolicy() are
-assumed to implement internal governors by the cpufreq core. All the
-logic for selecting the current P state is contained within the
-driver; no external governor is used by the cpufreq core.
+This driver provides an interface to control the P state selection for
+SandyBridge+ Intel processors.  The driver can operate two different
+modes based on the processor model legacy and Hardware P state (HWP)
+mode.
 
-Intel SandyBridge+ processors are supported.
+In legacy mode the driver implements a scaling driver with an internal
+governor for Intel Core processors.  The driver follows the same model
+as the Transmeta scaling driver (longrun.c) and implements the
+setpolicy() instead of target().  Scaling drivers that implement
+setpolicy() are assumed to implement internal governors by the cpufreq
+core. All the logic for selecting the current P state is contained
+within the driver; no external governor is used by the cpufreq core.
 
-New sysfs files for controlling P state selection have been added to
+In HWP mode P state selection is implemented in the processor
+itself. The driver provides the interfaces between the cpufreq core and
+the processor to control P state selection based on user preferences
+and reporting frequency to the cpufreq core.  In this mode the
+internal governor code is disabled.
+
+In addtion to the interfaces provided by the cpufreq core for
+controlling frequency the driver provides sysfs files for
+controlling P state selection. These files have been added to
 /sys/devices/system/cpu/intel_pstate/
 
       max_perf_pct: limits the maximum P state that will be requested by
···
 driver selects a single P state the actual frequency the processor
 will run at is selected by the processor itself.
 
-New debugfs files have also been added to /sys/kernel/debug/pstate_snb/
+For legacy mode debugfs files have also been added to allow tuning of
+the internal governor algorythm. These files are located at
+/sys/kernel/debug/pstate_snb/ These files are NOT present in HWP mode.
 
       deadband
       d_gain_pct

Documentation/kernel-parameters.txt

···
 		       disable
 		         Do not enable intel_pstate as the default
 		         scaling driver for the supported processors
+		       no_hwp
+		         Do not enable hardware P state control (HWP)
+			 if available.
 
 	intremap=	[X86-64, Intel-IOMMU]
 			on	enable Interrupt Remapping (default)

arch/x86/include/asm/cpufeature.h

···
 #define X86_FEATURE_DTHERM	( 7*32+ 7) /* Digital Thermal Sensor */
 #define X86_FEATURE_HW_PSTATE	( 7*32+ 8) /* AMD HW-PState */
 #define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */
+#define X86_FEATURE_HWP		( 7*32+ 10) /* "hwp" Intel HWP */
+#define X86_FEATURE_HWP_NOITFY	( 7*32+ 11) /* Intel HWP_NOTIFY */
+#define X86_FEATURE_HWP_ACT_WINDOW ( 7*32+ 12) /* Intel HWP_ACT_WINDOW */
+#define X86_FEATURE_HWP_EPP	( 7*32+13) /* Intel HWP_EPP */
+#define X86_FEATURE_HWP_PKG_REQ ( 7*32+14) /* Intel HWP_PKG_REQ */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW  ( 8*32+ 0) /* Intel TPR Shadow */

arch/x86/include/uapi/asm/msr-index.h

···
 #define MSR_CC6_DEMOTION_POLICY_CONFIG	0x00000668
 #define MSR_MC6_DEMOTION_POLICY_CONFIG	0x00000669
 
+/* Hardware P state interface */
+#define MSR_PPERF			0x0000064e
+#define MSR_PERF_LIMIT_REASONS		0x0000064f
+#define MSR_PM_ENABLE			0x00000770
+#define MSR_HWP_CAPABILITIES		0x00000771
+#define MSR_HWP_REQUEST_PKG		0x00000772
+#define MSR_HWP_INTERRUPT		0x00000773
+#define MSR_HWP_REQUEST 		0x00000774
+#define MSR_HWP_STATUS			0x00000777
+
+/* CPUID.6.EAX */
+#define HWP_BASE_BIT			(1<<7)
+#define HWP_NOTIFICATIONS_BIT		(1<<8)
+#define HWP_ACTIVITY_WINDOW_BIT		(1<<9)
+#define HWP_ENERGY_PERF_PREFERENCE_BIT	(1<<10)
+#define HWP_PACKAGE_LEVEL_REQUEST_BIT	(1<<11)
+
+/* IA32_HWP_CAPABILITIES */
+#define HWP_HIGHEST_PERF(x)		(x & 0xff)
+#define HWP_GUARANTEED_PERF(x)		((x & (0xff << 8)) >>8)
+#define HWP_MOSTEFFICIENT_PERF(x)	((x & (0xff << 16)) >>16)
+#define HWP_LOWEST_PERF(x)		((x & (0xff << 24)) >>24)
+
+/* IA32_HWP_REQUEST */
+#define HWP_MIN_PERF(x) 		(x & 0xff)
+#define HWP_MAX_PERF(x) 		((x & 0xff) << 8)
+#define HWP_DESIRED_PERF(x)		((x & 0xff) << 16)
+#define HWP_ENERGY_PERF_PREFERENCE(x)	((x & 0xff) << 24)
+#define HWP_ACTIVITY_WINDOW(x)		((x & 0xff3) << 32)
+#define HWP_PACKAGE_CONTROL(x)		((x & 0x1) << 42)
+
+/* IA32_HWP_STATUS */
+#define HWP_GUARANTEED_CHANGE(x)	(x & 0x1)
+#define HWP_EXCURSION_TO_MINIMUM(x)	(x & 0x4)
+
+/* IA32_HWP_INTERRUPT */
+#define HWP_CHANGE_TO_GUARANTEED_INT(x)	(x & 0x1)
+#define HWP_EXCURSION_TO_MINIMUM_INT(x)	(x & 0x2)
+
 #define MSR_AMD64_MC0_MASK		0xc0010044
 
 #define MSR_IA32_MCx_CTL(x)		(MSR_IA32_MC0_CTL + 4*(x))
···
 #define MSR_IA32_MISC_ENABLE		0x000001a0
 
 #define MSR_IA32_TEMPERATURE_TARGET	0x000001a2
+
+#define MSR_MISC_PWR_MGMT		0x000001aa
 
 #define MSR_IA32_ENERGY_PERF_BIAS	0x000001b0
 #define ENERGY_PERF_BIAS_PERFORMANCE	0

arch/x86/kernel/cpu/scattered.c

···
 		{ X86_FEATURE_ARAT,		CR_EAX, 2, 0x00000006, 0 },
 		{ X86_FEATURE_PLN,		CR_EAX, 4, 0x00000006, 0 },
 		{ X86_FEATURE_PTS,		CR_EAX, 6, 0x00000006, 0 },
+		{ X86_FEATURE_HWP,		CR_EAX, 7, 0x00000006, 0 },
+		{ X86_FEATURE_HWP_NOITFY,	CR_EAX, 8, 0x00000006, 0 },
+		{ X86_FEATURE_HWP_ACT_WINDOW,	CR_EAX, 9, 0x00000006, 0 },
+		{ X86_FEATURE_HWP_EPP,		CR_EAX,10, 0x00000006, 0 },
+		{ X86_FEATURE_HWP_PKG_REQ,	CR_EAX,11, 0x00000006, 0 },
 		{ X86_FEATURE_APERFMPERF,	CR_ECX, 0, 0x00000006, 0 },
 		{ X86_FEATURE_EPB,		CR_ECX, 3, 0x00000006, 0 },
 		{ X86_FEATURE_HW_PSTATE,	CR_EDX, 7, 0x80000007, 0 },

drivers/cpufreq/Kconfig

···
 
 config CPU_FREQ_DEFAULT_GOV_POWERSAVE
 	bool "powersave"
-	depends on EXPERT
 	select CPU_FREQ_GOV_POWERSAVE
 	help
 	  Use the CPUFreq governor 'powersave' as default. This sets
···
 	  support software configurable cpu frequency.
 
 	  Loongson2F and it's successors support this feature.
+
+	  For details, take a look at <file:Documentation/cpu-freq/>.
+
+	  If in doubt, say N.
+
+config LOONGSON1_CPUFREQ
+	tristate "Loongson1 CPUFreq Driver"
+	help
+	  This option adds a CPUFreq driver for loongson1 processors which
+	  support software configurable cpu frequency.
 
 	  For details, take a look at <file:Documentation/cpu-freq/>.
 

drivers/cpufreq/Makefile

···
 obj-$(CONFIG_ETRAXFS)			+= cris-etraxfs-cpufreq.o
 obj-$(CONFIG_IA64_ACPI_CPUFREQ)		+= ia64-acpi-cpufreq.o
 obj-$(CONFIG_LOONGSON2_CPUFREQ)		+= loongson2_cpufreq.o
+obj-$(CONFIG_LOONGSON1_CPUFREQ)		+= ls1x-cpufreq.o
 obj-$(CONFIG_SH_CPU_FREQ)		+= sh-cpufreq.o
 obj-$(CONFIG_SPARC_US2E_CPUFREQ)	+= sparc-us2e-cpufreq.o
 obj-$(CONFIG_SPARC_US3_CPUFREQ)		+= sparc-us3-cpufreq.o

drivers/cpufreq/cpufreq-dt.c

···
 	old_freq = clk_get_rate(cpu_clk) / 1000;
 
 	if (!IS_ERR(cpu_reg)) {
+		unsigned long opp_freq;
+
 		rcu_read_lock();
 		opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
 		if (IS_ERR(opp)) {
···
 			return PTR_ERR(opp);
 		}
 		volt = dev_pm_opp_get_voltage(opp);
+		opp_freq = dev_pm_opp_get_freq(opp);
 		rcu_read_unlock();
 		tol = volt * priv->voltage_tolerance / 100;
 		volt_old = regulator_get_voltage(cpu_reg);
+		dev_dbg(cpu_dev, "Found OPP: %ld kHz, %ld uV\n",
+			opp_freq / 1000, volt);
 	}
 
 	dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
-		old_freq / 1000, volt_old ? volt_old / 1000 : -1,
+		old_freq / 1000, (volt_old > 0) ? volt_old / 1000 : -1,
 		new_freq / 1000, volt ? volt / 1000 : -1);
 
 	/* scaling up?  scale voltage before frequency */
···
 	ret = clk_set_rate(cpu_clk, freq_exact);
 	if (ret) {
 		dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
-		if (!IS_ERR(cpu_reg))
+		if (!IS_ERR(cpu_reg) && volt_old > 0)
 			regulator_set_voltage_tol(cpu_reg, volt_old, tol);
 		return ret;
 	}

drivers/cpufreq/cpufreq.c

···
 static ssize_t store_##file_name					\
 (struct cpufreq_policy *policy, const char *buf, size_t count)		\
 {									\
-	int ret;							\
+	int ret, temp;							\
 	struct cpufreq_policy new_policy;				\
 									\
 	ret = cpufreq_get_policy(&new_policy, policy->cpu);		\
···
 	if (ret != 1)							\
 		return -EINVAL;						\
 									\
+	temp = new_policy.object;					\
 	ret = cpufreq_set_policy(policy, &new_policy);		\
-	policy->user_policy.object = policy->object;			\
+	if (!ret)							\
+		policy->user_policy.object = temp;			\
 									\
 	return ret ? ret : count;					\
 }

drivers/cpufreq/intel_pstate.c

···
 
 static struct pstate_adjust_policy pid_params;
 static struct pstate_funcs pstate_funcs;
+static int hwp_active;
 
 struct perf_limits {
 	int no_turbo;
···
 		 cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
 }
 
+#define PCT_TO_HWP(x) (x * 255 / 100)
+static void intel_pstate_hwp_set(void)
+{
+	int min, max, cpu;
+	u64 value, freq;
+
+	get_online_cpus();
+
+	for_each_online_cpu(cpu) {
+		rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
+		min = PCT_TO_HWP(limits.min_perf_pct);
+		value &= ~HWP_MIN_PERF(~0L);
+		value |= HWP_MIN_PERF(min);
+
+		max = PCT_TO_HWP(limits.max_perf_pct);
+		if (limits.no_turbo) {
+			rdmsrl( MSR_HWP_CAPABILITIES, freq);
+			max = HWP_GUARANTEED_PERF(freq);
+		}
+
+		value &= ~HWP_MAX_PERF(~0L);
+		value |= HWP_MAX_PERF(max);
+		wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
+	}
+
+	put_online_cpus();
+}
+
 /************************** debugfs begin ************************/
 static int pid_param_set(void *data, u64 val)
 {
···
 	struct dentry *debugfs_parent;
 	int i = 0;
 
+	if (hwp_active)
+		return;
 	debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
 	if (IS_ERR_OR_NULL(debugfs_parent))
 		return;
···
 		pr_warn("Turbo disabled by BIOS or unavailable on processor\n");
 		return -EPERM;
 	}
+
 	limits.no_turbo = clamp_t(int, input, 0, 1);
+
+	if (hwp_active)
+		intel_pstate_hwp_set();
 
 	return count;
 }
···
 	limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
 	limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 
+	if (hwp_active)
+		intel_pstate_hwp_set();
 	return count;
 }
 
···
 	limits.min_perf_pct = clamp_t(int, input, 0 , 100);
 	limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 
+	if (hwp_active)
+		intel_pstate_hwp_set();
 	return count;
 }
 
···
 	rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group);
 	BUG_ON(rc);
 }
-
 /************************** sysfs end ************************/
+
+static void intel_pstate_hwp_enable(void)
+{
+	hwp_active++;
+	pr_info("intel_pstate HWP enabled\n");
+
+	wrmsrl( MSR_PM_ENABLE, 0x1);
+}
+
 static int byt_get_min_pstate(void)
 {
 	u64 value;
···
 	cpu->prev_mperf = mperf;
 }
 
+static inline void intel_hwp_set_sample_time(struct cpudata *cpu)
+{
+	int delay;
+
+	delay = msecs_to_jiffies(50);
+	mod_timer_pinned(&cpu->timer, jiffies + delay);
+}
+
 static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 {
 	int delay;
···
 	intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
 }
 
+static void intel_hwp_timer_func(unsigned long __data)
+{
+	struct cpudata *cpu = (struct cpudata *) __data;
+
+	intel_pstate_sample(cpu);
+	intel_hwp_set_sample_time(cpu);
+}
+
 static void intel_pstate_timer_func(unsigned long __data)
 {
 	struct cpudata *cpu = (struct cpudata *) __data;
···
 	ICPU(0x3f, core_params),
 	ICPU(0x45, core_params),
 	ICPU(0x46, core_params),
+	ICPU(0x47, core_params),
 	ICPU(0x4c, byt_params),
 	ICPU(0x4f, core_params),
 	ICPU(0x56, core_params),
 	{}
 };
 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
+
+static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] = {
+	ICPU(0x56, core_params),
+	{}
+};
 
 static int intel_pstate_init_cpu(unsigned int cpunum)
 {
···
 	intel_pstate_get_cpu_pstates(cpu);
 
 	init_timer_deferrable(&cpu->timer);
-	cpu->timer.function = intel_pstate_timer_func;
 	cpu->timer.data = (unsigned long)cpu;
 	cpu->timer.expires = jiffies + HZ/100;
+
+	if (!hwp_active)
+		cpu->timer.function = intel_pstate_timer_func;
+	else
+		cpu->timer.function = intel_hwp_timer_func;
+
 	intel_pstate_busy_pid_reset(cpu);
 	intel_pstate_sample(cpu);
 
···
 		limits.no_turbo = 0;
 		return 0;
 	}
+
 	limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
 	limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
 	limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
···
 	limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100);
 	limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
 	limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
+
+	if (hwp_active)
+		intel_pstate_hwp_set();
 
 	return 0;
 }
···
 	pr_info("intel_pstate CPU %d exiting\n", cpu_num);
 
 	del_timer_sync(&all_cpu_data[cpu_num]->timer);
+	if (hwp_active)
+		return;
+
 	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
 }
 
···
 };
 
 static int __initdata no_load;
+static int __initdata no_hwp;
 
 static int intel_pstate_msrs_not_valid(void)
 {
···
 {
 	struct acpi_table_header hdr;
 	struct hw_vendor_info *v_info;
+	const struct x86_cpu_id *id;
+	u64 misc_pwr;
+
+	id = x86_match_cpu(intel_pstate_cpu_oob_ids);
+	if (id) {
+		rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
+		if ( misc_pwr & (1 << 8))
+			return true;
+	}
 
 	if (acpi_disabled ||
 	    ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr)))
···
 	int cpu, rc = 0;
 	const struct x86_cpu_id *id;
 	struct cpu_defaults *cpu_info;
+	struct cpuinfo_x86 *c = &boot_cpu_data;
 
 	if (no_load)
 		return -ENODEV;
···
 	all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
 	if (!all_cpu_data)
 		return -ENOMEM;
+
+	if (cpu_has(c,X86_FEATURE_HWP) && !no_hwp)
+		intel_pstate_hwp_enable();
 
 	rc = cpufreq_register_driver(&intel_pstate_driver);
 	if (rc)
···
 
 	if (!strcmp(str, "disable"))
 		no_load = 1;
+	if (!strcmp(str, "no_hwp"))
+		no_hwp = 1;
 	return 0;
 }
 early_param("intel_pstate", intel_pstate_setup);

drivers/cpufreq/ls1x-cpufreq.c

···
+/*
+ * CPU Frequency Scaling for Loongson 1 SoC
+ *
+ * Copyright (C) 2014 Zhang, Keguang <[e-mail]>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <asm/mach-loongson1/cpufreq.h>
+#include <asm/mach-loongson1/loongson1.h>
+
+static struct {
+	struct device *dev;
+	struct clk *clk;	/* CPU clk */
+	struct clk *mux_clk;	/* MUX of CPU clk */
+	struct clk *pll_clk;	/* PLL clk */
+	struct clk *osc_clk;	/* OSC clk */
+	unsigned int max_freq;
+	unsigned int min_freq;
+} ls1x_cpufreq;
+
+static int ls1x_cpufreq_notifier(struct notifier_block *nb,
+				 unsigned long val, void *data)
+{
+	if (val == CPUFREQ_POSTCHANGE)
+		current_cpu_data.udelay_val = loops_per_jiffy;
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block ls1x_cpufreq_notifier_block = {
+	.notifier_call = ls1x_cpufreq_notifier
+};
+
+static int ls1x_cpufreq_target(struct cpufreq_policy *policy,
+			       unsigned int index)
+{
+	unsigned int old_freq, new_freq;
+
+	old_freq = policy->cur;
+	new_freq = policy->freq_table[index].frequency;
+
+	/*
+	 * The procedure of reconfiguring CPU clk is as below.
+	 *
+	 *  - Reparent CPU clk to OSC clk
+	 *  - Reset CPU clock (very important)
+	 *  - Reconfigure CPU DIV
+	 *  - Reparent CPU clk back to CPU DIV clk
+	 */
+
+	dev_dbg(ls1x_cpufreq.dev, "%u KHz --> %u KHz\n", old_freq, new_freq);
+	clk_set_parent(policy->clk, ls1x_cpufreq.osc_clk);
+	__raw_writel(__raw_readl(LS1X_CLK_PLL_DIV) | RST_CPU_EN | RST_CPU,
+		     LS1X_CLK_PLL_DIV);
+	__raw_writel(__raw_readl(LS1X_CLK_PLL_DIV) & ~(RST_CPU_EN | RST_CPU),
+		     LS1X_CLK_PLL_DIV);
+	clk_set_rate(ls1x_cpufreq.mux_clk, new_freq * 1000);
+	clk_set_parent(policy->clk, ls1x_cpufreq.mux_clk);
+
+	return 0;
+}
+
+static int ls1x_cpufreq_init(struct cpufreq_policy *policy)
+{
+	struct cpufreq_frequency_table *freq_tbl;
+	unsigned int pll_freq, freq;
+	int steps, i, ret;
+
+	pll_freq = clk_get_rate(ls1x_cpufreq.pll_clk) / 1000;
+
+	steps = 1 << DIV_CPU_WIDTH;
+	freq_tbl = kzalloc(sizeof(*freq_tbl) * steps, GFP_KERNEL);
+	if (!freq_tbl) {
+		dev_err(ls1x_cpufreq.dev,
+			"failed to alloc cpufreq_frequency_table\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0; i < (steps - 1); i++) {
+		freq = pll_freq / (i + 1);
+		if ((freq < ls1x_cpufreq.min_freq) ||
+		    (freq > ls1x_cpufreq.max_freq))
+			freq_tbl[i].frequency = CPUFREQ_ENTRY_INVALID;
+		else
+			freq_tbl[i].frequency = freq;
+		dev_dbg(ls1x_cpufreq.dev,
+			"cpufreq table: index %d: frequency %d\n", i,
+			freq_tbl[i].frequency);
+	}
+	freq_tbl[i].frequency = CPUFREQ_TABLE_END;
+
+	policy->clk = ls1x_cpufreq.clk;
+	ret = cpufreq_generic_init(policy, freq_tbl, 0);
+	if (ret)
+		kfree(freq_tbl);
+out:
+	return ret;
+}
+
+static int ls1x_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	kfree(policy->freq_table);
+	return 0;
+}
+
+static struct cpufreq_driver ls1x_cpufreq_driver = {
+	.name		= "cpufreq-ls1x",
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= ls1x_cpufreq_target,
+	.get		= cpufreq_generic_get,
+	.init		= ls1x_cpufreq_init,
+	.exit		= ls1x_cpufreq_exit,
+	.attr		= cpufreq_generic_attr,
+};
+
+static int ls1x_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_notifier(&ls1x_cpufreq_notifier_block,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+	cpufreq_unregister_driver(&ls1x_cpufreq_driver);
+
+	return 0;
+}
+
+static int ls1x_cpufreq_probe(struct platform_device *pdev)
+{
+	struct plat_ls1x_cpufreq *pdata = pdev->dev.platform_data;
+	struct clk *clk;
+	int ret;
+
+	if (!pdata || !pdata->clk_name || !pdata->osc_clk_name)
+		return -EINVAL;
+
+	ls1x_cpufreq.dev = &pdev->dev;
+
+	clk = devm_clk_get(&pdev->dev, pdata->clk_name);
+	if (IS_ERR(clk)) {
+		dev_err(ls1x_cpufreq.dev, "unable to get %s clock\n",
+			pdata->clk_name);
+		ret = PTR_ERR(clk);
+		goto out;
+	}
+	ls1x_cpufreq.clk = clk;
+
+	clk = clk_get_parent(clk);
+	if (IS_ERR(clk)) {
+		dev_err(ls1x_cpufreq.dev, "unable to get parent of %s clock\n",
+			__clk_get_name(ls1x_cpufreq.clk));
+		ret = PTR_ERR(clk);
+		goto out;
+	}
+	ls1x_cpufreq.mux_clk = clk;
+
+	clk = clk_get_parent(clk);
+	if (IS_ERR(clk)) {
+		dev_err(ls1x_cpufreq.dev, "unable to get parent of %s clock\n",
+			__clk_get_name(ls1x_cpufreq.mux_clk));
+		ret = PTR_ERR(clk);
+		goto out;
+	}
+	ls1x_cpufreq.pll_clk = clk;
+
+	clk = devm_clk_get(&pdev->dev, pdata->osc_clk_name);
+	if (IS_ERR(clk)) {
+		dev_err(ls1x_cpufreq.dev, "unable to get %s clock\n",
+			pdata->osc_clk_name);
+		ret = PTR_ERR(clk);
+		goto out;
+	}
+	ls1x_cpufreq.osc_clk = clk;
+
+	ls1x_cpufreq.max_freq = pdata->max_freq;
+	ls1x_cpufreq.min_freq = pdata->min_freq;
+
+	ret = cpufreq_register_driver(&ls1x_cpufreq_driver);
+	if (ret) {
+		dev_err(ls1x_cpufreq.dev,
+			"failed to register cpufreq driver: %d\n", ret);
+		goto out;
+	}
+
+	ret = cpufreq_register_notifier(&ls1x_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+
+	if (!ret)
+		goto out;
+
+	dev_err(ls1x_cpufreq.dev, "failed to register cpufreq notifier: %d\n",
+		ret);
+
+	cpufreq_unregister_driver(&ls1x_cpufreq_driver);
+out:
+	return ret;
+}
+
+static struct platform_driver ls1x_cpufreq_platdrv = {
+	.driver = {
+		.name	= "ls1x-cpufreq",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ls1x_cpufreq_probe,
+	.remove		= ls1x_cpufreq_remove,
+};
+
+module_platform_driver(ls1x_cpufreq_platdrv);
+
+MODULE_AUTHOR("Kelvin Cheung <[e-mail]>");
+MODULE_DESCRIPTION("Loongson 1 CPUFreq driver");
+MODULE_LICENSE("GPL");

drivers/cpufreq/pcc-cpufreq.c

···
 	free_percpu(pcc_cpu_info);
 }
 
+static const struct acpi_device_id processor_device_ids[] = {
+	{ACPI_PROCESSOR_OBJECT_HID, },
+	{ACPI_PROCESSOR_DEVICE_HID, },
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, processor_device_ids);
+
 MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
 MODULE_VERSION(PCC_VERSION);
 MODULE_DESCRIPTION("Processor Clocking Control interface driver");