mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 00:21:59 +00:00
14b03204c8
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org>
138 lines
3.0 KiB
C
138 lines
3.0 KiB
C
/*
|
|
* Copyright 2008 Analog Devices Inc.
|
|
*
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#include <linux/cdev.h>
|
|
#include <linux/device.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/types.h>
|
|
#include <linux/cpufreq.h>
|
|
|
|
#include <asm/delay.h>
|
|
#include <asm/dpmc.h>
|
|
|
|
#define DRIVER_NAME "bfin dpmc"
|
|
|
|
#define dprintk(msg...) \
|
|
cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, DRIVER_NAME, msg)
|
|
|
|
struct bfin_dpmc_platform_data *pdata;
|
|
|
|
/**
|
|
* bfin_set_vlev - Update VLEV field in VR_CTL Reg.
|
|
* Avoid BYPASS sequence
|
|
*/
|
|
static void bfin_set_vlev(unsigned int vlev)
|
|
{
|
|
unsigned pll_lcnt;
|
|
|
|
pll_lcnt = bfin_read_PLL_LOCKCNT();
|
|
|
|
bfin_write_PLL_LOCKCNT(1);
|
|
bfin_write_VR_CTL((bfin_read_VR_CTL() & ~VLEV) | vlev);
|
|
bfin_write_PLL_LOCKCNT(pll_lcnt);
|
|
}
|
|
|
|
/**
|
|
* bfin_get_vlev - Get CPU specific VLEV from platform device data
|
|
*/
|
|
static unsigned int bfin_get_vlev(unsigned int freq)
|
|
{
|
|
int i;
|
|
|
|
if (!pdata)
|
|
goto err_out;
|
|
|
|
freq >>= 16;
|
|
|
|
for (i = 0; i < pdata->tabsize; i++)
|
|
if (freq <= (pdata->tuple_tab[i] & 0xFFFF))
|
|
return pdata->tuple_tab[i] >> 16;
|
|
|
|
err_out:
|
|
printk(KERN_WARNING "DPMC: No suitable CCLK VDDINT voltage pair found\n");
|
|
return VLEV_120;
|
|
}
|
|
|
|
#ifdef CONFIG_CPU_FREQ
|
|
static int
|
|
vreg_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
|
|
{
|
|
struct cpufreq_freqs *freq = data;
|
|
|
|
if (val == CPUFREQ_PRECHANGE && freq->old < freq->new) {
|
|
bfin_set_vlev(bfin_get_vlev(freq->new));
|
|
udelay(pdata->vr_settling_time); /* Wait until Volatge settled */
|
|
|
|
} else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)
|
|
bfin_set_vlev(bfin_get_vlev(freq->new));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct notifier_block vreg_cpufreq_notifier_block = {
|
|
.notifier_call = vreg_cpufreq_notifier
|
|
};
|
|
#endif /* CONFIG_CPU_FREQ */
|
|
|
|
/**
|
|
* bfin_dpmc_probe -
|
|
*
|
|
*/
|
|
static int __devinit bfin_dpmc_probe(struct platform_device *pdev)
|
|
{
|
|
if (pdev->dev.platform_data)
|
|
pdata = pdev->dev.platform_data;
|
|
else
|
|
return -EINVAL;
|
|
|
|
return cpufreq_register_notifier(&vreg_cpufreq_notifier_block,
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
|
}
|
|
|
|
/**
|
|
* bfin_dpmc_remove -
|
|
*/
|
|
static int __devexit bfin_dpmc_remove(struct platform_device *pdev)
|
|
{
|
|
pdata = NULL;
|
|
return cpufreq_unregister_notifier(&vreg_cpufreq_notifier_block,
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
|
}
|
|
|
|
struct platform_driver bfin_dpmc_device_driver = {
|
|
.probe = bfin_dpmc_probe,
|
|
.remove = __devexit_p(bfin_dpmc_remove),
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
}
|
|
};
|
|
|
|
/**
|
|
* bfin_dpmc_init - Init driver
|
|
*/
|
|
static int __init bfin_dpmc_init(void)
|
|
{
|
|
return platform_driver_register(&bfin_dpmc_device_driver);
|
|
}
|
|
module_init(bfin_dpmc_init);
|
|
|
|
/**
|
|
* bfin_dpmc_exit - break down driver
|
|
*/
|
|
static void __exit bfin_dpmc_exit(void)
|
|
{
|
|
platform_driver_unregister(&bfin_dpmc_device_driver);
|
|
}
|
|
module_exit(bfin_dpmc_exit);
|
|
|
|
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
|
|
MODULE_DESCRIPTION("cpu power management driver for Blackfin");
|
|
MODULE_LICENSE("GPL");
|