mirror of
https://github.com/torvalds/linux.git
synced 2024-11-06 03:51:48 +00:00
7f4b04614a
Currently cpufreq frequency table has two fields: frequency and driver_data. driver_data is only for drivers' internal use and cpufreq core shouldn't use it at all. But with the introduction of BOOST frequencies, this assumption was broken and we started using it as a flag instead. There are two problems due to this: - It is against the description of this field, as driver's data is used by the core now. - if drivers fill it with -3 for any frequency, then those frequencies are never considered by cpufreq core as it is exactly same as value of CPUFREQ_BOOST_FREQ, i.e. ~2. The best way to get this fixed is by creating another field flags which will be used for such flags. This patch does that. Along with that various drivers need modifications due to the change of struct cpufreq_frequency_table. Reviewed-by: Gautham R Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
247 lines
6.7 KiB
C
247 lines
6.7 KiB
C
/*
|
|
* 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_device.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[] = {
|
|
{0, CPUFREQ_HIGH, 0},
|
|
{0, CPUFREQ_LOW, 0},
|
|
{0, 0, CPUFREQ_TABLE_END},
|
|
};
|
|
|
|
/* 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 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_target(struct cpufreq_policy *policy,
|
|
unsigned int index)
|
|
{
|
|
return maple_scom_switch_freq(index);
|
|
}
|
|
|
|
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)
|
|
{
|
|
return cpufreq_generic_init(policy, maple_cpu_freqs, 12000);
|
|
}
|
|
|
|
static struct cpufreq_driver maple_cpufreq_driver = {
|
|
.name = "maple",
|
|
.flags = CPUFREQ_CONST_LOOPS,
|
|
.init = maple_cpufreq_cpu_init,
|
|
.verify = cpufreq_generic_frequency_table_verify,
|
|
.target_index = maple_cpufreq_target,
|
|
.get = maple_cpufreq_get_speed,
|
|
.attr = cpufreq_generic_attr,
|
|
};
|
|
|
|
static int __init maple_cpufreq_init(void)
|
|
{
|
|
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;
|
|
|
|
/* Get first CPU node */
|
|
cpunode = of_cpu_device_node_get(0);
|
|
if (cpunode == NULL) {
|
|
printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
|
|
goto bail_noprops;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
return rc;
|
|
|
|
bail_noprops:
|
|
of_node_put(cpunode);
|
|
|
|
return rc;
|
|
}
|
|
|
|
module_init(maple_cpufreq_init);
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|