2 * Copyright 2008 Analog Devices Inc.
4 * Licensed under the GPL-2 or later.
7 #include <linux/cdev.h>
8 #include <linux/device.h>
9 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/types.h>
15 #include <linux/cpufreq.h>
17 #include <asm/delay.h>
20 #define DRIVER_NAME "bfin dpmc"
22 struct bfin_dpmc_platform_data *pdata;
25 * bfin_set_vlev - Update VLEV field in VR_CTL Reg.
26 * Avoid BYPASS sequence
28 static void bfin_set_vlev(unsigned int vlev)
32 pll_lcnt = bfin_read_PLL_LOCKCNT();
34 bfin_write_PLL_LOCKCNT(1);
35 bfin_write_VR_CTL((bfin_read_VR_CTL() & ~VLEV) | vlev);
36 bfin_write_PLL_LOCKCNT(pll_lcnt);
40 * bfin_get_vlev - Get CPU specific VLEV from platform device data
42 static unsigned int bfin_get_vlev(unsigned int freq)
51 for (i = 0; i < pdata->tabsize; i++)
52 if (freq <= (pdata->tuple_tab[i] & 0xFFFF))
53 return pdata->tuple_tab[i] >> 16;
56 printk(KERN_WARNING "DPMC: No suitable CCLK VDDINT voltage pair found\n");
60 #ifdef CONFIG_CPU_FREQ
62 static void bfin_idle_this_cpu(void *info)
64 unsigned long flags = 0;
65 unsigned long iwr0, iwr1, iwr2;
66 unsigned int cpu = smp_processor_id();
68 local_irq_save_hw(flags);
69 bfin_iwr_set_sup0(&iwr0, &iwr1, &iwr2);
71 platform_clear_ipi(cpu, IRQ_SUPPLE_0);
74 bfin_iwr_restore(iwr0, iwr1, iwr2);
76 local_irq_restore_hw(flags);
79 static void bfin_idle_cpu(void)
81 smp_call_function(bfin_idle_this_cpu, NULL, 0);
84 static void bfin_wakeup_cpu(void)
87 unsigned int this_cpu = smp_processor_id();
88 cpumask_t mask = cpu_online_map;
90 cpu_clear(this_cpu, mask);
91 for_each_cpu_mask(cpu, mask)
92 platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
96 static void bfin_idle_cpu(void) {}
97 static void bfin_wakeup_cpu(void) {}
101 vreg_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
103 struct cpufreq_freqs *freq = data;
105 if (freq->cpu != CPUFREQ_CPU)
108 if (val == CPUFREQ_PRECHANGE && freq->old < freq->new) {
110 bfin_set_vlev(bfin_get_vlev(freq->new));
111 udelay(pdata->vr_settling_time); /* Wait until Volatge settled */
113 } else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) {
115 bfin_set_vlev(bfin_get_vlev(freq->new));
122 static struct notifier_block vreg_cpufreq_notifier_block = {
123 .notifier_call = vreg_cpufreq_notifier
125 #endif /* CONFIG_CPU_FREQ */
131 static int __devinit bfin_dpmc_probe(struct platform_device *pdev)
133 if (pdev->dev.platform_data)
134 pdata = pdev->dev.platform_data;
138 return cpufreq_register_notifier(&vreg_cpufreq_notifier_block,
139 CPUFREQ_TRANSITION_NOTIFIER);
145 static int __devexit bfin_dpmc_remove(struct platform_device *pdev)
148 return cpufreq_unregister_notifier(&vreg_cpufreq_notifier_block,
149 CPUFREQ_TRANSITION_NOTIFIER);
152 struct platform_driver bfin_dpmc_device_driver = {
153 .probe = bfin_dpmc_probe,
154 .remove = __devexit_p(bfin_dpmc_remove),
161 * bfin_dpmc_init - Init driver
163 static int __init bfin_dpmc_init(void)
165 return platform_driver_register(&bfin_dpmc_device_driver);
167 module_init(bfin_dpmc_init);
170 * bfin_dpmc_exit - break down driver
172 static void __exit bfin_dpmc_exit(void)
174 platform_driver_unregister(&bfin_dpmc_device_driver);
176 module_exit(bfin_dpmc_exit);
178 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
179 MODULE_DESCRIPTION("cpu power management driver for Blackfin");
180 MODULE_LICENSE("GPL");