Blame view

kernel/linux-imx6_3.14.28/arch/blackfin/mach-common/dpmc.c 3.46 KB
6b13f685e   김민수   BSP 최초 추가
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
  /*
   * 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"
  
  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
  ");
  	return VLEV_120;
  }
  
  #ifdef CONFIG_CPU_FREQ
  # ifdef CONFIG_SMP
  static void bfin_idle_this_cpu(void *info)
  {
  	unsigned long flags = 0;
  	unsigned long iwr0, iwr1, iwr2;
  	unsigned int cpu = smp_processor_id();
  
  	local_irq_save_hw(flags);
  	bfin_iwr_set_sup0(&iwr0, &iwr1, &iwr2);
  
  	platform_clear_ipi(cpu, IRQ_SUPPLE_0);
  	SSYNC();
  	asm("IDLE;");
  	bfin_iwr_restore(iwr0, iwr1, iwr2);
  
  	local_irq_restore_hw(flags);
  }
  
  static void bfin_idle_cpu(void)
  {
  	smp_call_function(bfin_idle_this_cpu, NULL, 0);
  }
  
  static void bfin_wakeup_cpu(void)
  {
  	unsigned int cpu;
  	unsigned int this_cpu = smp_processor_id();
  	cpumask_t mask;
  
  	cpumask_copy(&mask, cpu_online_mask);
  	cpumask_clear_cpu(this_cpu, &mask);
  	for_each_cpu(cpu, &mask)
  		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
  }
  
  # else
  static void bfin_idle_cpu(void) {}
  static void bfin_wakeup_cpu(void) {}
  # endif
  
  static int
  vreg_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
  {
  	struct cpufreq_freqs *freq = data;
  
  	if (freq->cpu != CPUFREQ_CPU)
  		return 0;
  
  	if (val == CPUFREQ_PRECHANGE && freq->old < freq->new) {
  		bfin_idle_cpu();
  		bfin_set_vlev(bfin_get_vlev(freq->new));
  		udelay(pdata->vr_settling_time); /* Wait until Volatge settled */
  		bfin_wakeup_cpu();
  	} else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) {
  		bfin_idle_cpu();
  		bfin_set_vlev(bfin_get_vlev(freq->new));
  		bfin_wakeup_cpu();
  	}
  
  	return 0;
  }
  
  static struct notifier_block vreg_cpufreq_notifier_block = {
  	.notifier_call	= vreg_cpufreq_notifier
  };
  #endif /* CONFIG_CPU_FREQ */
  
  /**
   *	bfin_dpmc_probe -
   *
   */
  static int 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 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  = bfin_dpmc_remove,
  	.driver  = {
  		.name = DRIVER_NAME,
  	}
  };
  module_platform_driver(bfin_dpmc_device_driver);
  
  MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
  MODULE_DESCRIPTION("cpu power management driver for Blackfin");
  MODULE_LICENSE("GPL");