| /* | 
 |  *  CPU frequency scaling for OMAP using OPP information | 
 |  * | 
 |  *  Copyright (C) 2005 Nokia Corporation | 
 |  *  Written by Tony Lindgren <tony@atomide.com> | 
 |  * | 
 |  *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King | 
 |  * | 
 |  * Copyright (C) 2007-2011 Texas Instruments, Inc. | 
 |  * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar | 
 |  * | 
 |  * 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. | 
 |  */ | 
 | #include <linux/types.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/sched.h> | 
 | #include <linux/cpufreq.h> | 
 | #include <linux/delay.h> | 
 | #include <linux/init.h> | 
 | #include <linux/err.h> | 
 | #include <linux/clk.h> | 
 | #include <linux/io.h> | 
 | #include <linux/opp.h> | 
 | #include <linux/cpu.h> | 
 | #include <linux/module.h> | 
 | #include <linux/regulator/consumer.h> | 
 |  | 
 | #include <asm/smp_plat.h> | 
 | #include <asm/cpu.h> | 
 |  | 
 | #include <plat/clock.h> | 
 | #include <plat/omap-pm.h> | 
 | #include <plat/common.h> | 
 | #include <plat/omap_device.h> | 
 |  | 
 | #include <mach/hardware.h> | 
 |  | 
 | /* OPP tolerance in percentage */ | 
 | #define	OPP_TOLERANCE	4 | 
 |  | 
 | #ifdef CONFIG_SMP | 
 | struct lpj_info { | 
 | 	unsigned long	ref; | 
 | 	unsigned int	freq; | 
 | }; | 
 |  | 
 | static DEFINE_PER_CPU(struct lpj_info, lpj_ref); | 
 | static struct lpj_info global_lpj_ref; | 
 | #endif | 
 |  | 
 | static struct cpufreq_frequency_table *freq_table; | 
 | static atomic_t freq_table_users = ATOMIC_INIT(0); | 
 | static struct clk *mpu_clk; | 
 | static char *mpu_clk_name; | 
 | static struct device *mpu_dev; | 
 | static struct regulator *mpu_reg; | 
 |  | 
 | static int omap_verify_speed(struct cpufreq_policy *policy) | 
 | { | 
 | 	if (!freq_table) | 
 | 		return -EINVAL; | 
 | 	return cpufreq_frequency_table_verify(policy, freq_table); | 
 | } | 
 |  | 
 | static unsigned int omap_getspeed(unsigned int cpu) | 
 | { | 
 | 	unsigned long rate; | 
 |  | 
 | 	if (cpu >= NR_CPUS) | 
 | 		return 0; | 
 |  | 
 | 	rate = clk_get_rate(mpu_clk) / 1000; | 
 | 	return rate; | 
 | } | 
 |  | 
 | static int omap_target(struct cpufreq_policy *policy, | 
 | 		       unsigned int target_freq, | 
 | 		       unsigned int relation) | 
 | { | 
 | 	unsigned int i; | 
 | 	int r, ret = 0; | 
 | 	struct cpufreq_freqs freqs; | 
 | 	struct opp *opp; | 
 | 	unsigned long freq, volt = 0, volt_old = 0, tol = 0; | 
 |  | 
 | 	if (!freq_table) { | 
 | 		dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__, | 
 | 				policy->cpu); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	ret = cpufreq_frequency_table_target(policy, freq_table, target_freq, | 
 | 			relation, &i); | 
 | 	if (ret) { | 
 | 		dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n", | 
 | 			__func__, policy->cpu, target_freq, ret); | 
 | 		return ret; | 
 | 	} | 
 | 	freqs.new = freq_table[i].frequency; | 
 | 	if (!freqs.new) { | 
 | 		dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__, | 
 | 			policy->cpu, target_freq); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	freqs.old = omap_getspeed(policy->cpu); | 
 | 	freqs.cpu = policy->cpu; | 
 |  | 
 | 	if (freqs.old == freqs.new && policy->cur == freqs.new) | 
 | 		return ret; | 
 |  | 
 | 	/* notifiers */ | 
 | 	for_each_cpu(i, policy->cpus) { | 
 | 		freqs.cpu = i; | 
 | 		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | 
 | 	} | 
 |  | 
 | 	freq = freqs.new * 1000; | 
 |  | 
 | 	if (mpu_reg) { | 
 | 		opp = opp_find_freq_ceil(mpu_dev, &freq); | 
 | 		if (IS_ERR(opp)) { | 
 | 			dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n", | 
 | 				__func__, freqs.new); | 
 | 			return -EINVAL; | 
 | 		} | 
 | 		volt = opp_get_voltage(opp); | 
 | 		tol = volt * OPP_TOLERANCE / 100; | 
 | 		volt_old = regulator_get_voltage(mpu_reg); | 
 | 	} | 
 |  | 
 | 	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",  | 
 | 		freqs.old / 1000, volt_old ? volt_old / 1000 : -1, | 
 | 		freqs.new / 1000, volt ? volt / 1000 : -1); | 
 |  | 
 | 	/* scaling up?  scale voltage before frequency */ | 
 | 	if (mpu_reg && (freqs.new > freqs.old)) { | 
 | 		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol); | 
 | 		if (r < 0) { | 
 | 			dev_warn(mpu_dev, "%s: unable to scale voltage up.\n", | 
 | 				 __func__); | 
 | 			freqs.new = freqs.old; | 
 | 			goto done; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	ret = clk_set_rate(mpu_clk, freqs.new * 1000); | 
 |  | 
 | 	/* scaling down?  scale voltage after frequency */ | 
 | 	if (mpu_reg && (freqs.new < freqs.old)) { | 
 | 		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol); | 
 | 		if (r < 0) { | 
 | 			dev_warn(mpu_dev, "%s: unable to scale voltage down.\n", | 
 | 				 __func__); | 
 | 			ret = clk_set_rate(mpu_clk, freqs.old * 1000); | 
 | 			freqs.new = freqs.old; | 
 | 			goto done; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	freqs.new = omap_getspeed(policy->cpu); | 
 | #ifdef CONFIG_SMP | 
 | 	/* | 
 | 	 * Note that loops_per_jiffy is not updated on SMP systems in | 
 | 	 * cpufreq driver. So, update the per-CPU loops_per_jiffy value | 
 | 	 * on frequency transition. We need to update all dependent CPUs. | 
 | 	 */ | 
 | 	for_each_cpu(i, policy->cpus) { | 
 | 		struct lpj_info *lpj = &per_cpu(lpj_ref, i); | 
 | 		if (!lpj->freq) { | 
 | 			lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy; | 
 | 			lpj->freq = freqs.old; | 
 | 		} | 
 |  | 
 | 		per_cpu(cpu_data, i).loops_per_jiffy = | 
 | 			cpufreq_scale(lpj->ref, lpj->freq, freqs.new); | 
 | 	} | 
 |  | 
 | 	/* And don't forget to adjust the global one */ | 
 | 	if (!global_lpj_ref.freq) { | 
 | 		global_lpj_ref.ref = loops_per_jiffy; | 
 | 		global_lpj_ref.freq = freqs.old; | 
 | 	} | 
 | 	loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq, | 
 | 					freqs.new); | 
 | #endif | 
 |  | 
 | done: | 
 | 	/* notifiers */ | 
 | 	for_each_cpu(i, policy->cpus) { | 
 | 		freqs.cpu = i; | 
 | 		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | 
 | 	} | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static inline void freq_table_free(void) | 
 | { | 
 | 	if (atomic_dec_and_test(&freq_table_users)) | 
 | 		opp_free_cpufreq_table(mpu_dev, &freq_table); | 
 | } | 
 |  | 
 | static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy) | 
 | { | 
 | 	int result = 0; | 
 |  | 
 | 	mpu_clk = clk_get(NULL, mpu_clk_name); | 
 | 	if (IS_ERR(mpu_clk)) | 
 | 		return PTR_ERR(mpu_clk); | 
 |  | 
 | 	if (policy->cpu >= NR_CPUS) { | 
 | 		result = -EINVAL; | 
 | 		goto fail_ck; | 
 | 	} | 
 |  | 
 | 	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu); | 
 |  | 
 | 	if (!freq_table) | 
 | 		result = opp_init_cpufreq_table(mpu_dev, &freq_table); | 
 |  | 
 | 	if (result) { | 
 | 		dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n", | 
 | 				__func__, policy->cpu, result); | 
 | 		goto fail_ck; | 
 | 	} | 
 |  | 
 | 	atomic_inc_return(&freq_table_users); | 
 |  | 
 | 	result = cpufreq_frequency_table_cpuinfo(policy, freq_table); | 
 | 	if (result) | 
 | 		goto fail_table; | 
 |  | 
 | 	cpufreq_frequency_table_get_attr(freq_table, policy->cpu); | 
 |  | 
 | 	policy->min = policy->cpuinfo.min_freq; | 
 | 	policy->max = policy->cpuinfo.max_freq; | 
 | 	policy->cur = omap_getspeed(policy->cpu); | 
 |  | 
 | 	/* | 
 | 	 * On OMAP SMP configuartion, both processors share the voltage | 
 | 	 * and clock. So both CPUs needs to be scaled together and hence | 
 | 	 * needs software co-ordination. Use cpufreq affected_cpus | 
 | 	 * interface to handle this scenario. Additional is_smp() check | 
 | 	 * is to keep SMP_ON_UP build working. | 
 | 	 */ | 
 | 	if (is_smp()) { | 
 | 		policy->shared_type = CPUFREQ_SHARED_TYPE_ANY; | 
 | 		cpumask_setall(policy->cpus); | 
 | 	} | 
 |  | 
 | 	/* FIXME: what's the actual transition time? */ | 
 | 	policy->cpuinfo.transition_latency = 300 * 1000; | 
 |  | 
 | 	return 0; | 
 |  | 
 | fail_table: | 
 | 	freq_table_free(); | 
 | fail_ck: | 
 | 	clk_put(mpu_clk); | 
 | 	return result; | 
 | } | 
 |  | 
 | static int omap_cpu_exit(struct cpufreq_policy *policy) | 
 | { | 
 | 	freq_table_free(); | 
 | 	clk_put(mpu_clk); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static struct freq_attr *omap_cpufreq_attr[] = { | 
 | 	&cpufreq_freq_attr_scaling_available_freqs, | 
 | 	NULL, | 
 | }; | 
 |  | 
 | static struct cpufreq_driver omap_driver = { | 
 | 	.flags		= CPUFREQ_STICKY, | 
 | 	.verify		= omap_verify_speed, | 
 | 	.target		= omap_target, | 
 | 	.get		= omap_getspeed, | 
 | 	.init		= omap_cpu_init, | 
 | 	.exit		= omap_cpu_exit, | 
 | 	.name		= "omap", | 
 | 	.attr		= omap_cpufreq_attr, | 
 | }; | 
 |  | 
 | static int __init omap_cpufreq_init(void) | 
 | { | 
 | 	if (cpu_is_omap24xx()) | 
 | 		mpu_clk_name = "virt_prcm_set"; | 
 | 	else if (cpu_is_omap34xx()) | 
 | 		mpu_clk_name = "dpll1_ck"; | 
 | 	else if (cpu_is_omap44xx()) | 
 | 		mpu_clk_name = "dpll_mpu_ck"; | 
 |  | 
 | 	if (!mpu_clk_name) { | 
 | 		pr_err("%s: unsupported Silicon?\n", __func__); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	mpu_dev = omap_device_get_by_hwmod_name("mpu"); | 
 | 	if (!mpu_dev) { | 
 | 		pr_warning("%s: unable to get the mpu device\n", __func__); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	mpu_reg = regulator_get(mpu_dev, "vcc"); | 
 | 	if (IS_ERR(mpu_reg)) { | 
 | 		pr_warning("%s: unable to get MPU regulator\n", __func__); | 
 | 		mpu_reg = NULL; | 
 | 	} else { | 
 | 		/*  | 
 | 		 * Ensure physical regulator is present. | 
 | 		 * (e.g. could be dummy regulator.) | 
 | 		 */ | 
 | 		if (regulator_get_voltage(mpu_reg) < 0) { | 
 | 			pr_warn("%s: physical regulator not present for MPU\n", | 
 | 				__func__); | 
 | 			regulator_put(mpu_reg); | 
 | 			mpu_reg = NULL; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return cpufreq_register_driver(&omap_driver); | 
 | } | 
 |  | 
 | static void __exit omap_cpufreq_exit(void) | 
 | { | 
 | 	cpufreq_unregister_driver(&omap_driver); | 
 | } | 
 |  | 
 | MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs"); | 
 | MODULE_LICENSE("GPL"); | 
 | module_init(omap_cpufreq_init); | 
 | module_exit(omap_cpufreq_exit); |