Commit | Line | Data |
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14b03204 MH |
1 | /* |
2 | * Copyright 2008 Analog Devices Inc. | |
3 | * | |
4 | * Licensed under the GPL-2 or later. | |
5 | */ | |
6 | ||
7 | #include <linux/cdev.h> | |
8 | #include <linux/device.h> | |
9 | #include <linux/errno.h> | |
10 | #include <linux/fs.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> | |
16 | ||
17 | #include <asm/delay.h> | |
18 | #include <asm/dpmc.h> | |
19 | ||
20 | #define DRIVER_NAME "bfin dpmc" | |
21 | ||
14b03204 MH |
22 | struct bfin_dpmc_platform_data *pdata; |
23 | ||
24 | /** | |
25 | * bfin_set_vlev - Update VLEV field in VR_CTL Reg. | |
26 | * Avoid BYPASS sequence | |
27 | */ | |
28 | static void bfin_set_vlev(unsigned int vlev) | |
29 | { | |
30 | unsigned pll_lcnt; | |
31 | ||
32 | pll_lcnt = bfin_read_PLL_LOCKCNT(); | |
33 | ||
34 | bfin_write_PLL_LOCKCNT(1); | |
35 | bfin_write_VR_CTL((bfin_read_VR_CTL() & ~VLEV) | vlev); | |
36 | bfin_write_PLL_LOCKCNT(pll_lcnt); | |
37 | } | |
38 | ||
39 | /** | |
40 | * bfin_get_vlev - Get CPU specific VLEV from platform device data | |
41 | */ | |
42 | static unsigned int bfin_get_vlev(unsigned int freq) | |
43 | { | |
44 | int i; | |
45 | ||
46 | if (!pdata) | |
47 | goto err_out; | |
48 | ||
49 | freq >>= 16; | |
50 | ||
51 | for (i = 0; i < pdata->tabsize; i++) | |
52 | if (freq <= (pdata->tuple_tab[i] & 0xFFFF)) | |
53 | return pdata->tuple_tab[i] >> 16; | |
54 | ||
55 | err_out: | |
56 | printk(KERN_WARNING "DPMC: No suitable CCLK VDDINT voltage pair found\n"); | |
57 | return VLEV_120; | |
58 | } | |
59 | ||
60 | #ifdef CONFIG_CPU_FREQ | |
6f546bc3 GY |
61 | # ifdef CONFIG_SMP |
62 | static void bfin_idle_this_cpu(void *info) | |
63 | { | |
64 | unsigned long flags = 0; | |
65 | unsigned long iwr0, iwr1, iwr2; | |
66 | unsigned int cpu = smp_processor_id(); | |
67 | ||
68 | local_irq_save_hw(flags); | |
69 | bfin_iwr_set_sup0(&iwr0, &iwr1, &iwr2); | |
70 | ||
71 | platform_clear_ipi(cpu, IRQ_SUPPLE_0); | |
72 | SSYNC(); | |
73 | asm("IDLE;"); | |
74 | bfin_iwr_restore(iwr0, iwr1, iwr2); | |
75 | ||
76 | local_irq_restore_hw(flags); | |
77 | } | |
78 | ||
79 | static void bfin_idle_cpu(void) | |
80 | { | |
81 | smp_call_function(bfin_idle_this_cpu, NULL, 0); | |
82 | } | |
83 | ||
84 | static void bfin_wakeup_cpu(void) | |
85 | { | |
86 | unsigned int cpu; | |
87 | unsigned int this_cpu = smp_processor_id(); | |
fecedc80 | 88 | cpumask_t mask; |
6f546bc3 | 89 | |
fecedc80 KM |
90 | cpumask_copy(&mask, cpu_online_mask); |
91 | cpumask_clear_cpu(this_cpu, &mask); | |
92 | for_each_cpu(cpu, &mask) | |
6f546bc3 GY |
93 | platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0); |
94 | } | |
95 | ||
96 | # else | |
97 | static void bfin_idle_cpu(void) {} | |
98 | static void bfin_wakeup_cpu(void) {} | |
99 | # endif | |
100 | ||
14b03204 MH |
101 | static int |
102 | vreg_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data) | |
103 | { | |
104 | struct cpufreq_freqs *freq = data; | |
105 | ||
6f546bc3 GY |
106 | if (freq->cpu != CPUFREQ_CPU) |
107 | return 0; | |
108 | ||
14b03204 | 109 | if (val == CPUFREQ_PRECHANGE && freq->old < freq->new) { |
6f546bc3 | 110 | bfin_idle_cpu(); |
14b03204 MH |
111 | bfin_set_vlev(bfin_get_vlev(freq->new)); |
112 | udelay(pdata->vr_settling_time); /* Wait until Volatge settled */ | |
6f546bc3 GY |
113 | bfin_wakeup_cpu(); |
114 | } else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) { | |
115 | bfin_idle_cpu(); | |
14b03204 | 116 | bfin_set_vlev(bfin_get_vlev(freq->new)); |
6f546bc3 GY |
117 | bfin_wakeup_cpu(); |
118 | } | |
14b03204 MH |
119 | |
120 | return 0; | |
121 | } | |
122 | ||
123 | static struct notifier_block vreg_cpufreq_notifier_block = { | |
124 | .notifier_call = vreg_cpufreq_notifier | |
125 | }; | |
126 | #endif /* CONFIG_CPU_FREQ */ | |
127 | ||
128 | /** | |
129 | * bfin_dpmc_probe - | |
130 | * | |
131 | */ | |
b881bc46 | 132 | static int bfin_dpmc_probe(struct platform_device *pdev) |
14b03204 MH |
133 | { |
134 | if (pdev->dev.platform_data) | |
135 | pdata = pdev->dev.platform_data; | |
136 | else | |
137 | return -EINVAL; | |
138 | ||
139 | return cpufreq_register_notifier(&vreg_cpufreq_notifier_block, | |
140 | CPUFREQ_TRANSITION_NOTIFIER); | |
141 | } | |
142 | ||
143 | /** | |
144 | * bfin_dpmc_remove - | |
145 | */ | |
b881bc46 | 146 | static int bfin_dpmc_remove(struct platform_device *pdev) |
14b03204 MH |
147 | { |
148 | pdata = NULL; | |
149 | return cpufreq_unregister_notifier(&vreg_cpufreq_notifier_block, | |
150 | CPUFREQ_TRANSITION_NOTIFIER); | |
151 | } | |
152 | ||
153 | struct platform_driver bfin_dpmc_device_driver = { | |
154 | .probe = bfin_dpmc_probe, | |
b881bc46 | 155 | .remove = bfin_dpmc_remove, |
14b03204 MH |
156 | .driver = { |
157 | .name = DRIVER_NAME, | |
158 | } | |
159 | }; | |
4452fec6 | 160 | module_platform_driver(bfin_dpmc_device_driver); |
14b03204 MH |
161 | |
162 | MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); | |
163 | MODULE_DESCRIPTION("cpu power management driver for Blackfin"); | |
164 | MODULE_LICENSE("GPL"); |