drivers/cpufreq/maple-cpufreq.c - kernel/msm-4.19 - Gitiles

 /*
  *  Copyright (C) 2011 Dmitry Eremin-Solenikov
  *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
  *  and                       Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
  *
  * 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.
  *
  * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
  * that is iMac G5 and latest single CPU desktop.
  */

 #undef DEBUG

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/completion.h>
 #include <linux/mutex.h>
 #include <linux/time.h>
 #include <linux/of.h>

 #define DBG(fmt...) pr_debug(fmt)

 /* see 970FX user manual */

 #define SCOM_PCR 0x0aa001			/* PCR scom addr */

 #define PCR_HILO_SELECT		0x80000000U	/* 1 = PCR, 0 = PCRH */
 #define PCR_SPEED_FULL		0x00000000U	/* 1:1 speed value */
 #define PCR_SPEED_HALF		0x00020000U	/* 1:2 speed value */
 #define PCR_SPEED_QUARTER	0x00040000U	/* 1:4 speed value */
 #define PCR_SPEED_MASK		0x000e0000U	/* speed mask */
 #define PCR_SPEED_SHIFT		17
 #define PCR_FREQ_REQ_VALID	0x00010000U	/* freq request valid */
 #define PCR_VOLT_REQ_VALID	0x00008000U	/* volt request valid */
 #define PCR_TARGET_TIME_MASK	0x00006000U	/* target time */
 #define PCR_STATLAT_MASK	0x00001f00U	/* STATLAT value */
 #define PCR_SNOOPLAT_MASK	0x000000f0U	/* SNOOPLAT value */
 #define PCR_SNOOPACC_MASK	0x0000000fU	/* SNOOPACC value */

 #define SCOM_PSR 0x408001			/* PSR scom addr */
 /* warning: PSR is a 64 bits register */
 #define PSR_CMD_RECEIVED	0x2000000000000000U   /* command received */
 #define PSR_CMD_COMPLETED	0x1000000000000000U   /* command completed */
 #define PSR_CUR_SPEED_MASK	0x0300000000000000U   /* current speed */
 #define PSR_CUR_SPEED_SHIFT	(56)

 /*
  * The G5 only supports two frequencies (Quarter speed is not supported)
  */
 #define CPUFREQ_HIGH                  0
 #define CPUFREQ_LOW                   1

 static struct cpufreq_frequency_table maple_cpu_freqs[] = {
 	{CPUFREQ_HIGH,		0},
 	{CPUFREQ_LOW,		0},
 	{0,			CPUFREQ_TABLE_END},
 };

 static struct freq_attr *maple_cpu_freqs_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	NULL,
 };

 /* Power mode data is an array of the 32 bits PCR values to use for
  * the various frequencies, retrieved from the device-tree
  */
 static int maple_pmode_cur;

 static DEFINE_MUTEX(maple_switch_mutex);

 static const u32 *maple_pmode_data;
 static int maple_pmode_max;

 /*
  * SCOM based frequency switching for 970FX rev3
  */
 static int maple_scom_switch_freq(int speed_mode)
 {
 	unsigned long flags;
 	int to;

 	local_irq_save(flags);

 	/* Clear PCR high */
 	scom970_write(SCOM_PCR, 0);
 	/* Clear PCR low */
 	scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
 	/* Set PCR low */
 	scom970_write(SCOM_PCR, PCR_HILO_SELECT |
 		      maple_pmode_data[speed_mode]);

 	/* Wait for completion */
 	for (to = 0; to < 10; to++) {
 		unsigned long psr = scom970_read(SCOM_PSR);

 		if ((psr & PSR_CMD_RECEIVED) == 0 &&
 		    (((psr >> PSR_CUR_SPEED_SHIFT) ^
 		      (maple_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
 		    == 0)
 			break;
 		if (psr & PSR_CMD_COMPLETED)
 			break;
 		udelay(100);
 	}

 	local_irq_restore(flags);

 	maple_pmode_cur = speed_mode;
 	ppc_proc_freq = maple_cpu_freqs[speed_mode].frequency * 1000ul;

 	return 0;
 }

 static int maple_scom_query_freq(void)
 {
 	unsigned long psr = scom970_read(SCOM_PSR);
 	int i;

 	for (i = 0; i <= maple_pmode_max; i++)
 		if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
 		      (maple_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
 			break;
 	return i;
 }

 /*
  * Common interface to the cpufreq core
  */

 static int maple_cpufreq_verify(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy, maple_cpu_freqs);
 }

 static int maple_cpufreq_target(struct cpufreq_policy *policy,
 	unsigned int target_freq, unsigned int relation)
 {
 	unsigned int newstate = 0;
 	struct cpufreq_freqs freqs;
 	int rc;

 	if (cpufreq_frequency_table_target(policy, maple_cpu_freqs,
 			target_freq, relation, &newstate))
 		return -EINVAL;

 	if (maple_pmode_cur == newstate)
 		return 0;

 	mutex_lock(&maple_switch_mutex);

 	freqs.old = maple_cpu_freqs[maple_pmode_cur].frequency;
 	freqs.new = maple_cpu_freqs[newstate].frequency;
 	freqs.cpu = 0;

 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 	rc = maple_scom_switch_freq(newstate);
 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

 	mutex_unlock(&maple_switch_mutex);

 	return rc;
 }

 static unsigned int maple_cpufreq_get_speed(unsigned int cpu)
 {
 	return maple_cpu_freqs[maple_pmode_cur].frequency;
 }

 static int maple_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	policy->cpuinfo.transition_latency = 12000;
 	policy->cur = maple_cpu_freqs[maple_scom_query_freq()].frequency;
 	/* secondary CPUs are tied to the primary one by the
 	 * cpufreq core if in the secondary policy we tell it that
 	 * it actually must be one policy together with all others. */
 	cpumask_setall(policy->cpus);
 	cpufreq_frequency_table_get_attr(maple_cpu_freqs, policy->cpu);

 	return cpufreq_frequency_table_cpuinfo(policy,
 		maple_cpu_freqs);
 }


 static struct cpufreq_driver maple_cpufreq_driver = {
 	.name		= "maple",
 	.owner		= THIS_MODULE,
 	.flags		= CPUFREQ_CONST_LOOPS,
 	.init		= maple_cpufreq_cpu_init,
 	.verify		= maple_cpufreq_verify,
 	.target		= maple_cpufreq_target,
 	.get		= maple_cpufreq_get_speed,
 	.attr		= maple_cpu_freqs_attr,
 };

 static int __init maple_cpufreq_init(void)
 {
 	struct device_node *cpus;
 	struct device_node *cpunode;
 	unsigned int psize;
 	unsigned long max_freq;
 	const u32 *valp;
 	u32 pvr_hi;
 	int rc = -ENODEV;

 	/*
 	 * Behave here like powermac driver which checks machine compatibility
 	 * to ease merging of two drivers in future.
 	 */
 	if (!of_machine_is_compatible("Momentum,Maple") &&
 	    !of_machine_is_compatible("Momentum,Apache"))
 		return 0;

 	cpus = of_find_node_by_path("/cpus");
 	if (cpus == NULL) {
 		DBG("No /cpus node !\n");
 		return -ENODEV;
 	}

 	/* Get first CPU node */
 	for (cpunode = NULL;
 	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
 		const u32 *reg = of_get_property(cpunode, "reg", NULL);
 		if (reg == NULL || (*reg) != 0)
 			continue;
 		if (!strcmp(cpunode->type, "cpu"))
 			break;
 	}
 	if (cpunode == NULL) {
 		printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
 		goto bail_cpus;
 	}

 	/* Check 970FX for now */
 	/* we actually don't care on which CPU to access PVR */
 	pvr_hi = PVR_VER(mfspr(SPRN_PVR));
 	if (pvr_hi != 0x3c && pvr_hi != 0x44) {
 		printk(KERN_ERR "cpufreq: Unsupported CPU version (%x)\n",
 				pvr_hi);
 		goto bail_noprops;
 	}

 	/* Look for the powertune data in the device-tree */
 	/*
 	 * On Maple this property is provided by PIBS in dual-processor config,
 	 * not provided by PIBS in CPU0 config and also not provided by SLOF,
 	 * so YMMV
 	 */
 	maple_pmode_data = of_get_property(cpunode, "power-mode-data", &psize);
 	if (!maple_pmode_data) {
 		DBG("No power-mode-data !\n");
 		goto bail_noprops;
 	}
 	maple_pmode_max = psize / sizeof(u32) - 1;

 	/*
 	 * From what I see, clock-frequency is always the maximal frequency.
 	 * The current driver can not slew sysclk yet, so we really only deal
 	 * with powertune steps for now. We also only implement full freq and
 	 * half freq in this version. So far, I haven't yet seen a machine
 	 * supporting anything else.
 	 */
 	valp = of_get_property(cpunode, "clock-frequency", NULL);
 	if (!valp)
 		return -ENODEV;
 	max_freq = (*valp)/1000;
 	maple_cpu_freqs[0].frequency = max_freq;
 	maple_cpu_freqs[1].frequency = max_freq/2;

 	/* Force apply current frequency to make sure everything is in
 	 * sync (voltage is right for example). Firmware may leave us with
 	 * a strange setting ...
 	 */
 	msleep(10);
 	maple_pmode_cur = -1;
 	maple_scom_switch_freq(maple_scom_query_freq());

 	printk(KERN_INFO "Registering Maple CPU frequency driver\n");
 	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
 		maple_cpu_freqs[1].frequency/1000,
 		maple_cpu_freqs[0].frequency/1000,
 		maple_cpu_freqs[maple_pmode_cur].frequency/1000);

 	rc = cpufreq_register_driver(&maple_cpufreq_driver);

 	of_node_put(cpunode);
 	of_node_put(cpus);

 	return rc;

 bail_noprops:
 	of_node_put(cpunode);
 bail_cpus:
 	of_node_put(cpus);

 	return rc;
 }

 module_init(maple_cpufreq_init);


 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2011 Dmitry Eremin-Solenikov
	* Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
	* and Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
	*
	* 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.
	*
	* This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
	* that is iMac G5 and latest single CPU desktop.
	*/

	#undef DEBUG

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/sched.h>
	#include <linux/cpufreq.h>
	#include <linux/init.h>
	#include <linux/completion.h>
	#include <linux/mutex.h>
	#include <linux/time.h>
	#include <linux/of.h>

	#define DBG(fmt...) pr_debug(fmt)

	/* see 970FX user manual */

	#define SCOM_PCR 0x0aa001 /* PCR scom addr */

	#define PCR_HILO_SELECT 0x80000000U /* 1 = PCR, 0 = PCRH */
	#define PCR_SPEED_FULL 0x00000000U /* 1:1 speed value */
	#define PCR_SPEED_HALF 0x00020000U /* 1:2 speed value */
	#define PCR_SPEED_QUARTER 0x00040000U /* 1:4 speed value */
	#define PCR_SPEED_MASK 0x000e0000U /* speed mask */
	#define PCR_SPEED_SHIFT 17
	#define PCR_FREQ_REQ_VALID 0x00010000U /* freq request valid */
	#define PCR_VOLT_REQ_VALID 0x00008000U /* volt request valid */
	#define PCR_TARGET_TIME_MASK 0x00006000U /* target time */
	#define PCR_STATLAT_MASK 0x00001f00U /* STATLAT value */
	#define PCR_SNOOPLAT_MASK 0x000000f0U /* SNOOPLAT value */
	#define PCR_SNOOPACC_MASK 0x0000000fU /* SNOOPACC value */

	#define SCOM_PSR 0x408001 /* PSR scom addr */
	/* warning: PSR is a 64 bits register */
	#define PSR_CMD_RECEIVED 0x2000000000000000U /* command received */
	#define PSR_CMD_COMPLETED 0x1000000000000000U /* command completed */
	#define PSR_CUR_SPEED_MASK 0x0300000000000000U /* current speed */
	#define PSR_CUR_SPEED_SHIFT (56)

	/*
	* The G5 only supports two frequencies (Quarter speed is not supported)
	*/
	#define CPUFREQ_HIGH 0
	#define CPUFREQ_LOW 1

	static struct cpufreq_frequency_table maple_cpu_freqs[] = {
	{CPUFREQ_HIGH, 0},
	{CPUFREQ_LOW, 0},
	{0, CPUFREQ_TABLE_END},
	};

	static struct freq_attr *maple_cpu_freqs_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
	};

	/* Power mode data is an array of the 32 bits PCR values to use for
	* the various frequencies, retrieved from the device-tree
	*/
	static int maple_pmode_cur;

	static DEFINE_MUTEX(maple_switch_mutex);

	static const u32 *maple_pmode_data;
	static int maple_pmode_max;

	/*
	* SCOM based frequency switching for 970FX rev3
	*/
	static int maple_scom_switch_freq(int speed_mode)
	{
	unsigned long flags;
	int to;

	local_irq_save(flags);

	/* Clear PCR high */
	scom970_write(SCOM_PCR, 0);
	/* Clear PCR low */
	scom970_write(SCOM_PCR, PCR_HILO_SELECT \| 0);
	/* Set PCR low */
	scom970_write(SCOM_PCR, PCR_HILO_SELECT \|
	maple_pmode_data[speed_mode]);

	/* Wait for completion */
	for (to = 0; to < 10; to++) {
	unsigned long psr = scom970_read(SCOM_PSR);

	if ((psr & PSR_CMD_RECEIVED) == 0 &&
	(((psr >> PSR_CUR_SPEED_SHIFT) ^
	(maple_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
	== 0)
	break;
	if (psr & PSR_CMD_COMPLETED)
	break;
	udelay(100);
	}

	local_irq_restore(flags);

	maple_pmode_cur = speed_mode;
	ppc_proc_freq = maple_cpu_freqs[speed_mode].frequency * 1000ul;

	return 0;
	}

	static int maple_scom_query_freq(void)
	{
	unsigned long psr = scom970_read(SCOM_PSR);
	int i;

	for (i = 0; i <= maple_pmode_max; i++)
	if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
	(maple_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
	break;
	return i;
	}

	/*
	* Common interface to the cpufreq core
	*/

	static int maple_cpufreq_verify(struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy, maple_cpu_freqs);
	}

	static int maple_cpufreq_target(struct cpufreq_policy *policy,
	unsigned int target_freq, unsigned int relation)
	{
	unsigned int newstate = 0;
	struct cpufreq_freqs freqs;
	int rc;

	if (cpufreq_frequency_table_target(policy, maple_cpu_freqs,
	target_freq, relation, &newstate))
	return -EINVAL;

	if (maple_pmode_cur == newstate)
	return 0;

	mutex_lock(&maple_switch_mutex);

	freqs.old = maple_cpu_freqs[maple_pmode_cur].frequency;
	freqs.new = maple_cpu_freqs[newstate].frequency;
	freqs.cpu = 0;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	rc = maple_scom_switch_freq(newstate);
	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	mutex_unlock(&maple_switch_mutex);

	return rc;
	}

	static unsigned int maple_cpufreq_get_speed(unsigned int cpu)
	{
	return maple_cpu_freqs[maple_pmode_cur].frequency;
	}

	static int maple_cpufreq_cpu_init(struct cpufreq_policy *policy)
	{
	policy->cpuinfo.transition_latency = 12000;
	policy->cur = maple_cpu_freqs[maple_scom_query_freq()].frequency;
	/* secondary CPUs are tied to the primary one by the
	* cpufreq core if in the secondary policy we tell it that
	* it actually must be one policy together with all others. */
	cpumask_setall(policy->cpus);
	cpufreq_frequency_table_get_attr(maple_cpu_freqs, policy->cpu);

	return cpufreq_frequency_table_cpuinfo(policy,
	maple_cpu_freqs);
	}


	static struct cpufreq_driver maple_cpufreq_driver = {
	.name = "maple",
	.owner = THIS_MODULE,
	.flags = CPUFREQ_CONST_LOOPS,
	.init = maple_cpufreq_cpu_init,
	.verify = maple_cpufreq_verify,
	.target = maple_cpufreq_target,
	.get = maple_cpufreq_get_speed,
	.attr = maple_cpu_freqs_attr,
	};

	static int __init maple_cpufreq_init(void)
	{
	struct device_node *cpus;
	struct device_node *cpunode;
	unsigned int psize;
	unsigned long max_freq;
	const u32 *valp;
	u32 pvr_hi;
	int rc = -ENODEV;

	/*
	* Behave here like powermac driver which checks machine compatibility
	* to ease merging of two drivers in future.
	*/
	if (!of_machine_is_compatible("Momentum,Maple") &&
	!of_machine_is_compatible("Momentum,Apache"))
	return 0;

	cpus = of_find_node_by_path("/cpus");
	if (cpus == NULL) {
	DBG("No /cpus node !\n");
	return -ENODEV;
	}

	/* Get first CPU node */
	for (cpunode = NULL;
	(cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
	const u32 *reg = of_get_property(cpunode, "reg", NULL);
	if (reg == NULL \|\| (*reg) != 0)
	continue;
	if (!strcmp(cpunode->type, "cpu"))
	break;
	}
	if (cpunode == NULL) {
	printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
	goto bail_cpus;
	}

	/* Check 970FX for now */
	/* we actually don't care on which CPU to access PVR */
	pvr_hi = PVR_VER(mfspr(SPRN_PVR));
	if (pvr_hi != 0x3c && pvr_hi != 0x44) {
	printk(KERN_ERR "cpufreq: Unsupported CPU version (%x)\n",
	pvr_hi);
	goto bail_noprops;
	}

	/* Look for the powertune data in the device-tree */
	/*
	* On Maple this property is provided by PIBS in dual-processor config,
	* not provided by PIBS in CPU0 config and also not provided by SLOF,
	* so YMMV
	*/
	maple_pmode_data = of_get_property(cpunode, "power-mode-data", &psize);
	if (!maple_pmode_data) {
	DBG("No power-mode-data !\n");
	goto bail_noprops;
	}
	maple_pmode_max = psize / sizeof(u32) - 1;

	/*
	* From what I see, clock-frequency is always the maximal frequency.
	* The current driver can not slew sysclk yet, so we really only deal
	* with powertune steps for now. We also only implement full freq and
	* half freq in this version. So far, I haven't yet seen a machine
	* supporting anything else.
	*/
	valp = of_get_property(cpunode, "clock-frequency", NULL);
	if (!valp)
	return -ENODEV;
	max_freq = (*valp)/1000;
	maple_cpu_freqs[0].frequency = max_freq;
	maple_cpu_freqs[1].frequency = max_freq/2;

	/* Force apply current frequency to make sure everything is in
	* sync (voltage is right for example). Firmware may leave us with
	* a strange setting ...
	*/
	msleep(10);
	maple_pmode_cur = -1;
	maple_scom_switch_freq(maple_scom_query_freq());

	printk(KERN_INFO "Registering Maple CPU frequency driver\n");
	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
	maple_cpu_freqs[1].frequency/1000,
	maple_cpu_freqs[0].frequency/1000,
	maple_cpu_freqs[maple_pmode_cur].frequency/1000);

	rc = cpufreq_register_driver(&maple_cpufreq_driver);

	of_node_put(cpunode);
	of_node_put(cpus);

	return rc;

	bail_noprops:
	of_node_put(cpunode);
	bail_cpus:
	of_node_put(cpus);

	return rc;
	}

	module_init(maple_cpufreq_init);


	MODULE_LICENSE("GPL");