Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | /*
* 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");
|