[PATCH] ppc64: SMU based macs cpufreq support

CPU freq support using 970FX powertune facility for iMac G5 and SMU
based single CPU desktop.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Benjamin Herrenschmidt 2005-11-07 14:27:33 +11:00 committed by Paul Mackerras
parent a82765b6ee
commit 4350147a81
11 changed files with 572 additions and 25 deletions

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@ -404,6 +404,14 @@ config CPU_FREQ_PMAC
this currently includes some models of iBook & Titanium
PowerBook.
config CPU_FREQ_PMAC64
bool "Support for some Apple G5s"
depends on CPU_FREQ && PMAC_SMU && PPC64
select CPU_FREQ_TABLE
help
This adds support for frequency switching on Apple iMac G5,
and some of the more recent desktop G5 machines as well.
config PPC601_SYNC_FIX
bool "Workarounds for PPC601 bugs"
depends on 6xx && (PPC_PREP || PPC_PMAC)

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@ -603,6 +603,76 @@ _GLOBAL(real_writeb)
blr
#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
/*
* SCOM access functions for 970 (FX only for now)
*
* unsigned long scom970_read(unsigned int address);
* void scom970_write(unsigned int address, unsigned long value);
*
* The address passed in is the 24 bits register address. This code
* is 970 specific and will not check the status bits, so you should
* know what you are doing.
*/
_GLOBAL(scom970_read)
/* interrupts off */
mfmsr r4
ori r0,r4,MSR_EE
xori r0,r0,MSR_EE
mtmsrd r0,1
/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
* (including parity). On current CPUs they must be 0'd,
* and finally or in RW bit
*/
rlwinm r3,r3,8,0,15
ori r3,r3,0x8000
/* do the actual scom read */
sync
mtspr SPRN_SCOMC,r3
isync
mfspr r3,SPRN_SCOMD
isync
mfspr r0,SPRN_SCOMC
isync
/* XXX: fixup result on some buggy 970's (ouch ! we lost a bit, bah
* that's the best we can do). Not implemented yet as we don't use
* the scom on any of the bogus CPUs yet, but may have to be done
* ultimately
*/
/* restore interrupts */
mtmsrd r4,1
blr
_GLOBAL(scom970_write)
/* interrupts off */
mfmsr r5
ori r0,r5,MSR_EE
xori r0,r0,MSR_EE
mtmsrd r0,1
/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
* (including parity). On current CPUs they must be 0'd.
*/
rlwinm r3,r3,8,0,15
sync
mtspr SPRN_SCOMD,r4 /* write data */
isync
mtspr SPRN_SCOMC,r3 /* write command */
isync
mfspr 3,SPRN_SCOMC
isync
/* restore interrupts */
mtmsrd r5,1
blr
/*
* Create a kernel thread
* kernel_thread(fn, arg, flags)

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@ -1,7 +1,8 @@
obj-y += pic.o setup.o time.o feature.o pci.o \
sleep.o low_i2c.o cache.o
obj-$(CONFIG_PMAC_BACKLIGHT) += backlight.o
obj-$(CONFIG_CPU_FREQ_PMAC) += cpufreq.o
obj-$(CONFIG_CPU_FREQ_PMAC) += cpufreq_32.o
obj-$(CONFIG_CPU_FREQ_PMAC64) += cpufreq_64.o
obj-$(CONFIG_NVRAM) += nvram.o
# ppc64 pmac doesn't define CONFIG_NVRAM but needs nvram stuff
obj-$(CONFIG_PPC64) += nvram.o

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@ -397,18 +397,16 @@ static int pmac_cpufreq_target( struct cpufreq_policy *policy,
unsigned int relation)
{
unsigned int newstate = 0;
int rc;
if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
target_freq, relation, &newstate))
return -EINVAL;
return do_set_cpu_speed(newstate, 1);
}
rc = do_set_cpu_speed(newstate, 1);
unsigned int pmac_get_one_cpufreq(int i)
{
/* Supports only one CPU for now */
return (i == 0) ? cur_freq : 0;
ppc_proc_freq = cur_freq * 1000ul;
return rc;
}
static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
@ -464,7 +462,7 @@ static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
/* If we resume, first check if we have a get() function */
if (get_speed_proc)
cur_freq = get_speed_proc();
else
else)
cur_freq = 0;
/* We don't, hrm... we don't really know our speed here, best
@ -474,6 +472,8 @@ static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
do_set_cpu_speed(sleep_freq == low_freq ?
CPUFREQ_LOW : CPUFREQ_HIGH, 0);
ppc_proc_freq = cur_freq * 1000ul;
no_schedule = 0;
return 0;
}
@ -547,7 +547,7 @@ static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
*/
if (low_freq < 98000000)
low_freq = 101000000;
/* Convert those to CPU core clocks */
low_freq = (low_freq * (*ratio)) / 2000;
hi_freq = (hi_freq * (*ratio)) / 2000;
@ -714,6 +714,7 @@ out:
pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
ppc_proc_freq = cur_freq * 1000ul;
printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",

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@ -0,0 +1,323 @@
/*
* 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.
*/
#include <linux/config.h>
#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/slab.h>
#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/irq.h>
#include <asm/sections.h>
#include <asm/cputable.h>
#include <asm/time.h>
#include <asm/smu.h>
#undef DEBUG
#ifdef DEBUG
#define DBG(fmt...) printk(fmt)
#else
#define DBG(fmt...)
#endif
/* 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 g5_cpu_freqs[] = {
{CPUFREQ_HIGH, 0},
{CPUFREQ_LOW, 0},
{0, CPUFREQ_TABLE_END},
};
static struct freq_attr* g5_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, retreived from the device-tree
*/
static u32 *g5_pmode_data;
static int g5_pmode_max;
static int g5_pmode_cur;
static DECLARE_MUTEX(g5_switch_mutex);
static struct smu_sdbp_fvt *g5_fvt_table; /* table of op. points */
static int g5_fvt_count; /* number of op. points */
static int g5_fvt_cur; /* current op. point */
/* ----------------- real hardware interface */
static void g5_switch_volt(int speed_mode)
{
struct smu_simple_cmd cmd;
DECLARE_COMPLETION(comp);
smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
&comp, 'V', 'S', 'L', 'E', 'W',
0xff, g5_fvt_cur+1, speed_mode);
wait_for_completion(&comp);
}
static int g5_switch_freq(int speed_mode)
{
struct cpufreq_freqs freqs;
int to;
if (g5_pmode_cur == speed_mode)
return 0;
down(&g5_switch_mutex);
freqs.old = g5_cpu_freqs[g5_pmode_cur].frequency;
freqs.new = g5_cpu_freqs[speed_mode].frequency;
freqs.cpu = 0;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
/* If frequency is going up, first ramp up the voltage */
if (speed_mode < g5_pmode_cur)
g5_switch_volt(speed_mode);
/* 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 |
g5_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) ^
(g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
== 0)
break;
if (psr & PSR_CMD_COMPLETED)
break;
udelay(100);
}
/* If frequency is going down, last ramp the voltage */
if (speed_mode > g5_pmode_cur)
g5_switch_volt(speed_mode);
g5_pmode_cur = speed_mode;
ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
up(&g5_switch_mutex);
return 0;
}
static int g5_query_freq(void)
{
unsigned long psr = scom970_read(SCOM_PSR);
int i;
for (i = 0; i <= g5_pmode_max; i++)
if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
(g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
break;
return i;
}
/* ----------------- cpufreq bookkeeping */
static int g5_cpufreq_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, g5_cpu_freqs);
}
static int g5_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
unsigned int newstate = 0;
if (cpufreq_frequency_table_target(policy, g5_cpu_freqs,
target_freq, relation, &newstate))
return -EINVAL;
return g5_switch_freq(newstate);
}
static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
{
return g5_cpu_freqs[g5_pmode_cur].frequency;
}
static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
if (policy->cpu != 0)
return -ENODEV;
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
policy->cur = g5_cpu_freqs[g5_query_freq()].frequency;
cpufreq_frequency_table_get_attr(g5_cpu_freqs, policy->cpu);
return cpufreq_frequency_table_cpuinfo(policy,
g5_cpu_freqs);
}
static struct cpufreq_driver g5_cpufreq_driver = {
.name = "powermac",
.owner = THIS_MODULE,
.flags = CPUFREQ_CONST_LOOPS,
.init = g5_cpufreq_cpu_init,
.verify = g5_cpufreq_verify,
.target = g5_cpufreq_target,
.get = g5_cpufreq_get_speed,
.attr = g5_cpu_freqs_attr,
};
static int __init g5_cpufreq_init(void)
{
struct device_node *cpunode;
unsigned int psize, ssize;
struct smu_sdbp_header *shdr;
unsigned long max_freq;
u32 *valp;
int rc = -ENODEV;
/* Look for CPU and SMU nodes */
cpunode = of_find_node_by_type(NULL, "cpu");
if (!cpunode) {
DBG("No CPU node !\n");
return -ENODEV;
}
/* Check 970FX for now */
valp = (u32 *)get_property(cpunode, "cpu-version", NULL);
if (!valp) {
DBG("No cpu-version property !\n");
goto bail_noprops;
}
if (((*valp) >> 16) != 0x3c) {
DBG("Wrong CPU version: %08x\n", *valp);
goto bail_noprops;
}
/* Look for the powertune data in the device-tree */
g5_pmode_data = (u32 *)get_property(cpunode, "power-mode-data",&psize);
if (!g5_pmode_data) {
DBG("No power-mode-data !\n");
goto bail_noprops;
}
g5_pmode_max = psize / sizeof(u32) - 1;
/* Look for the FVT table */
shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
if (!shdr)
goto bail_noprops;
g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
ssize = (shdr->len * sizeof(u32)) - sizeof(struct smu_sdbp_header);
g5_fvt_count = ssize / sizeof(struct smu_sdbp_fvt);
g5_fvt_cur = 0;
/* Sanity checking */
if (g5_fvt_count < 1 || g5_pmode_max < 1)
goto bail_noprops;
/*
* 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 = (u32 *)get_property(cpunode, "clock-frequency", NULL);
if (!valp)
return -ENODEV;
max_freq = (*valp)/1000;
g5_cpu_freqs[0].frequency = max_freq;
g5_cpu_freqs[1].frequency = max_freq/2;
/* Check current frequency */
g5_pmode_cur = g5_query_freq();
if (g5_pmode_cur > 1)
/* We don't support anything but 1:1 and 1:2, fixup ... */
g5_pmode_cur = 1;
/* Force apply current frequency to make sure everything is in
* sync (voltage is right for example). Firmware may leave us with
* a strange setting ...
*/
g5_switch_freq(g5_pmode_cur);
printk(KERN_INFO "Registering G5 CPU frequency driver\n");
printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
g5_cpu_freqs[1].frequency/1000,
g5_cpu_freqs[0].frequency/1000,
g5_cpu_freqs[g5_pmode_cur].frequency/1000);
rc = cpufreq_register_driver(&g5_cpufreq_driver);
/* We keep the CPU node on hold... hopefully, Apple G5 don't have
* hotplug CPU with a dynamic device-tree ...
*/
return rc;
bail_noprops:
of_node_put(cpunode);
return rc;
}
module_init(g5_cpufreq_init);
MODULE_LICENSE("GPL");

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@ -193,18 +193,6 @@ static void pmac_show_cpuinfo(struct seq_file *m)
pmac_newworld ? "NewWorld" : "OldWorld");
}
static void pmac_show_percpuinfo(struct seq_file *m, int i)
{
#ifdef CONFIG_CPU_FREQ_PMAC
extern unsigned int pmac_get_one_cpufreq(int i);
unsigned int freq = pmac_get_one_cpufreq(i);
if (freq != 0) {
seq_printf(m, "clock\t\t: %dMHz\n", freq/1000);
return;
}
#endif /* CONFIG_CPU_FREQ_PMAC */
}
#ifndef CONFIG_ADB_CUDA
int find_via_cuda(void)
{
@ -767,7 +755,6 @@ struct machdep_calls __initdata pmac_md = {
.setup_arch = pmac_setup_arch,
.init_early = pmac_init_early,
.show_cpuinfo = pmac_show_cpuinfo,
.show_percpuinfo = pmac_show_percpuinfo,
.init_IRQ = pmac_pic_init,
.get_irq = mpic_get_irq, /* changed later */
.pcibios_fixup = pmac_pcibios_fixup,

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@ -173,6 +173,16 @@ config KEXEC
support. As of this writing the exact hardware interface is
strongly in flux, so no good recommendation can be made.
source "drivers/cpufreq/Kconfig"
config CPU_FREQ_PMAC64
bool "Support for some Apple G5s"
depends on CPU_FREQ && PMAC_SMU && PPC64
select CPU_FREQ_TABLE
help
This adds support for frequency switching on Apple iMac G5,
and some of the more recent desktop G5 machines as well.
config IBMVIO
depends on PPC_PSERIES || PPC_ISERIES
bool

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@ -560,7 +560,7 @@ _GLOBAL(real_readb)
isync
blr
/*
/*
* Do an IO access in real mode
*/
_GLOBAL(real_writeb)
@ -592,6 +592,76 @@ _GLOBAL(real_writeb)
blr
#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
/*
* SCOM access functions for 970 (FX only for now)
*
* unsigned long scom970_read(unsigned int address);
* void scom970_write(unsigned int address, unsigned long value);
*
* The address passed in is the 24 bits register address. This code
* is 970 specific and will not check the status bits, so you should
* know what you are doing.
*/
_GLOBAL(scom970_read)
/* interrupts off */
mfmsr r4
ori r0,r4,MSR_EE
xori r0,r0,MSR_EE
mtmsrd r0,1
/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
* (including parity). On current CPUs they must be 0'd,
* and finally or in RW bit
*/
rlwinm r3,r3,8,0,15
ori r3,r3,0x8000
/* do the actual scom read */
sync
mtspr SPRN_SCOMC,r3
isync
mfspr r3,SPRN_SCOMD
isync
mfspr r0,SPRN_SCOMC
isync
/* XXX: fixup result on some buggy 970's (ouch ! we lost a bit, bah
* that's the best we can do). Not implemented yet as we don't use
* the scom on any of the bogus CPUs yet, but may have to be done
* ultimately
*/
/* restore interrupts */
mtmsrd r4,1
blr
_GLOBAL(scom970_write)
/* interrupts off */
mfmsr r5
ori r0,r5,MSR_EE
xori r0,r0,MSR_EE
mtmsrd r0,1
/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
* (including parity). On current CPUs they must be 0'd.
*/
rlwinm r3,r3,8,0,15
sync
mtspr SPRN_SCOMD,r4 /* write data */
isync
mtspr SPRN_SCOMC,r3 /* write command */
isync
mfspr 3,SPRN_SCOMC
isync
/* restore interrupts */
mtmsrd r5,1
blr
/*
* Create a kernel thread
* kernel_thread(fn, arg, flags)

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@ -845,6 +845,18 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
return 0;
}
struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
{
char pname[32];
if (!smu)
return NULL;
sprintf(pname, "sdb-partition-%02x", id);
return (struct smu_sdbp_header *)get_property(smu->of_node,
pname, size);
}
EXPORT_SYMBOL(smu_get_sdb_partition);
/*

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@ -396,6 +396,9 @@
#define SPRN_VRSAVE 0x100 /* Vector Register Save Register */
#define SPRN_XER 0x001 /* Fixed Point Exception Register */
#define SPRN_SCOMC 0x114 /* SCOM Access Control */
#define SPRN_SCOMD 0x115 /* SCOM Access DATA */
/* Performance monitor SPRs */
#ifdef CONFIG_PPC64
#define SPRN_MMCR0 795
@ -594,7 +597,11 @@ static inline void ppc64_runlatch_off(void)
mtspr(SPRN_CTRLT, ctrl);
}
}
#endif
extern unsigned long scom970_read(unsigned int address);
extern void scom970_write(unsigned int address, unsigned long value);
#endif /* CONFIG_PPC64 */
#define __get_SP() ({unsigned long sp; \
asm volatile("mr %0,1": "=r" (sp)); sp;})

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@ -144,7 +144,11 @@
* - lenght 8 ("VSLEWxyz") has 3 additional bytes appended, and is
* used to set the voltage slewing point. The SMU replies with "DONE"
* I yet have to figure out their exact meaning of those 3 bytes in
* both cases.
* both cases. They seem to be:
* x = processor mask
* y = op. point index
* z = processor freq. step index
* I haven't yet decyphered result codes
*
*/
#define SMU_CMD_POWER_COMMAND 0xaa
@ -333,6 +337,60 @@ extern int smu_queue_i2c(struct smu_i2c_cmd *cmd);
#endif /* __KERNEL__ */
/*
* - SMU "sdb" partitions informations -
*/
/*
* Partition header format
*/
struct smu_sdbp_header {
__u8 id;
__u8 len;
__u8 version;
__u8 flags;
};
/*
* 32 bits integers are usually encoded with 2x16 bits swapped,
* this demangles them
*/
#define SMU_U32_MIX(x) ((((x) << 16) & 0xffff0000u) | (((x) >> 16) & 0xffffu))
/* This is the definition of the SMU sdb-partition-0x12 table (called
* CPU F/V/T operating points in Darwin). The definition for all those
* SMU tables should be moved to some separate file
*/
#define SMU_SDB_FVT_ID 0x12
struct smu_sdbp_fvt {
__u32 sysclk; /* Base SysClk frequency in Hz for
* this operating point
*/
__u8 pad;
__u8 maxtemp; /* Max temp. supported by this
* operating point
*/
__u16 volts[3]; /* CPU core voltage for the 3
* PowerTune modes, a mode with
* 0V = not supported.
*/
};
#ifdef __KERNEL__
/*
* This returns the pointer to an SMU "sdb" partition data or NULL
* if not found. The data format is described below
*/
extern struct smu_sdbp_header *smu_get_sdb_partition(int id,
unsigned int *size);
#endif /* __KERNEL__ */
/*
* - Userland interface -
*/