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authorBen Dooks <ben@simtec.co.uk>2009-11-13 17:34:21 -0500
committerBen Dooks <ben-linux@fluff.org>2009-11-30 20:33:49 -0500
commit4fa084af28ca905e91895ae237e6cc4a31d2ff4d (patch)
treec300b5de76d942d835f0b2e7ccffa07541b1a63c /arch/arm/mach-s3c2440
parent4d3a3469dbabbcff4dab225bc3be0b247b36401c (diff)
ARM: OSIRIS: DVS (Dynamic Voltage Scaling) supoort.
Add a driver to provide DVS for the Simtec Osiris module to reduce the power consumption whilst idling. The DVS driver alters the voltage supplied to the ARM core depending on the frequency it is running at. The driver itself does not do any of the frequency alteration, which is left up to the cpufreq driver. Signed-off-by: Ben Dooks <ben@simtec.co.uk> Signed-off-by: Simtec Linux Team <linux@simtec.co.uk> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'arch/arm/mach-s3c2440')
-rw-r--r--arch/arm/mach-s3c2440/Kconfig13
-rw-r--r--arch/arm/mach-s3c2440/Makefile4
-rw-r--r--arch/arm/mach-s3c2440/mach-osiris-dvs.c194
-rw-r--r--arch/arm/mach-s3c2440/mach-osiris.c34
4 files changed, 245 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2440/Kconfig b/arch/arm/mach-s3c2440/Kconfig
index a8b69d77571b..cf10e14b7b49 100644
--- a/arch/arm/mach-s3c2440/Kconfig
+++ b/arch/arm/mach-s3c2440/Kconfig
@@ -53,6 +53,19 @@ config MACH_OSIRIS
53 Say Y here if you are using the Simtec IM2440D20 module, also 53 Say Y here if you are using the Simtec IM2440D20 module, also
54 known as the Osiris. 54 known as the Osiris.
55 55
56config MACH_OSIRIS_DVS
57 tristate "Simtec IM2440D20 (OSIRIS) Dynamic Voltage Scaling driver"
58 depends on MACH_OSIRIS
59 select TPS65010
60 help
61 Say Y/M here if you want to have dynamic voltage scaling support
62 on the Simtec IM2440D20 (OSIRIS) module via the TPS65011.
63
64 The DVS driver alters the voltage supplied to the ARM core
65 depending on the frequency it is running at. The driver itself
66 does not do any of the frequency alteration, which is left up
67 to the cpufreq driver.
68
56config MACH_RX3715 69config MACH_RX3715
57 bool "HP iPAQ rx3715" 70 bool "HP iPAQ rx3715"
58 select CPU_S3C2440 71 select CPU_S3C2440
diff --git a/arch/arm/mach-s3c2440/Makefile b/arch/arm/mach-s3c2440/Makefile
index bfadcf684a2a..5f3224531885 100644
--- a/arch/arm/mach-s3c2440/Makefile
+++ b/arch/arm/mach-s3c2440/Makefile
@@ -23,3 +23,7 @@ obj-$(CONFIG_ARCH_S3C2440) += mach-smdk2440.o
23obj-$(CONFIG_MACH_NEXCODER_2440) += mach-nexcoder.o 23obj-$(CONFIG_MACH_NEXCODER_2440) += mach-nexcoder.o
24obj-$(CONFIG_MACH_AT2440EVB) += mach-at2440evb.o 24obj-$(CONFIG_MACH_AT2440EVB) += mach-at2440evb.o
25obj-$(CONFIG_MACH_MINI2440) += mach-mini2440.o 25obj-$(CONFIG_MACH_MINI2440) += mach-mini2440.o
26
27# extra machine support
28
29obj-$(CONFIG_MACH_OSIRIS_DVS) += mach-osiris-dvs.o
diff --git a/arch/arm/mach-s3c2440/mach-osiris-dvs.c b/arch/arm/mach-s3c2440/mach-osiris-dvs.c
new file mode 100644
index 000000000000..ad2792dfbee1
--- /dev/null
+++ b/arch/arm/mach-s3c2440/mach-osiris-dvs.c
@@ -0,0 +1,194 @@
1/* linux/arch/arm/mach-s3c2440/mach-osiris-dvs.c
2 *
3 * Copyright (c) 2009 Simtec Electronics
4 * http://armlinux.simtec.co.uk/
5 * Ben Dooks <ben@simtec.co.uk>
6 *
7 * Simtec Osiris Dynamic Voltage Scaling support.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12*/
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/cpufreq.h>
18#include <linux/gpio.h>
19
20#include <linux/i2c/tps65010.h>
21
22#include <plat/cpu-freq.h>
23
24#define OSIRIS_GPIO_DVS S3C2410_GPB(5)
25
26static bool dvs_en;
27
28static void osiris_dvs_tps_setdvs(bool on)
29{
30 unsigned vregs1 = 0, vdcdc2 = 0;
31
32 if (!on) {
33 vdcdc2 = TPS_VCORE_DISCH | TPS_LP_COREOFF;
34 vregs1 = TPS_LDO1_OFF; /* turn off in low-power mode */
35 }
36
37 dvs_en = on;
38 vdcdc2 |= TPS_VCORE_1_3V | TPS_VCORE_LP_1_0V;
39 vregs1 |= TPS_LDO2_ENABLE | TPS_LDO1_ENABLE;
40
41 tps65010_config_vregs1(vregs1);
42 tps65010_config_vdcdc2(vdcdc2);
43}
44
45static bool is_dvs(struct s3c_freq *f)
46{
47 /* at the moment, we assume ARMCLK = HCLK => DVS */
48 return f->armclk == f->hclk;
49}
50
51/* keep track of current state */
52static bool cur_dvs = false;
53
54static int osiris_dvs_notify(struct notifier_block *nb,
55 unsigned long val, void *data)
56{
57 struct cpufreq_freqs *cf = data;
58 struct s3c_cpufreq_freqs *freqs = to_s3c_cpufreq(cf);
59 bool old_dvs = is_dvs(&freqs->old);
60 bool new_dvs = is_dvs(&freqs->new);
61 int ret = 0;
62
63 if (!dvs_en)
64 return 0;
65
66 printk(KERN_DEBUG "%s: old %ld,%ld new %ld,%ld\n", __func__,
67 freqs->old.armclk, freqs->old.hclk,
68 freqs->new.armclk, freqs->new.hclk);
69
70 switch (val) {
71 case CPUFREQ_PRECHANGE:
72 if (old_dvs & !new_dvs ||
73 cur_dvs & !new_dvs) {
74 pr_debug("%s: exiting dvs\n", __func__);
75 cur_dvs = false;
76 gpio_set_value(OSIRIS_GPIO_DVS, 1);
77 }
78 break;
79 case CPUFREQ_POSTCHANGE:
80 if (!old_dvs & new_dvs ||
81 !cur_dvs & new_dvs) {
82 pr_debug("entering dvs\n");
83 cur_dvs = true;
84 gpio_set_value(OSIRIS_GPIO_DVS, 0);
85 }
86 break;
87 }
88
89 return ret;
90}
91
92static struct notifier_block osiris_dvs_nb = {
93 .notifier_call = osiris_dvs_notify,
94};
95
96static int __devinit osiris_dvs_probe(struct platform_device *pdev)
97{
98 int ret;
99
100 dev_info(&pdev->dev, "initialising\n");
101
102 ret = gpio_request(OSIRIS_GPIO_DVS, "osiris-dvs");
103 if (ret) {
104 dev_err(&pdev->dev, "cannot claim gpio\n");
105 goto err_nogpio;
106 }
107
108 /* start with dvs disabled */
109 gpio_direction_output(OSIRIS_GPIO_DVS, 1);
110
111 ret = cpufreq_register_notifier(&osiris_dvs_nb,
112 CPUFREQ_TRANSITION_NOTIFIER);
113 if (ret) {
114 dev_err(&pdev->dev, "failed to register with cpufreq\n");
115 goto err_nofreq;
116 }
117
118 osiris_dvs_tps_setdvs(true);
119
120 return 0;
121
122err_nofreq:
123 gpio_free(OSIRIS_GPIO_DVS);
124
125err_nogpio:
126 return ret;
127}
128
129static int __devexit osiris_dvs_remove(struct platform_device *pdev)
130{
131 dev_info(&pdev->dev, "exiting\n");
132
133 /* disable any current dvs */
134 gpio_set_value(OSIRIS_GPIO_DVS, 1);
135 osiris_dvs_tps_setdvs(false);
136
137 cpufreq_unregister_notifier(&osiris_dvs_nb,
138 CPUFREQ_TRANSITION_NOTIFIER);
139
140 gpio_free(OSIRIS_GPIO_DVS);
141
142 return 0;
143}
144
145/* the CONFIG_PM block is so small, it isn't worth actaully compiling it
146 * out if the configuration isn't set. */
147
148static int osiris_dvs_suspend(struct device *dev)
149{
150 gpio_set_value(OSIRIS_GPIO_DVS, 1);
151 osiris_dvs_tps_setdvs(false);
152 cur_dvs = false;
153
154 return 0;
155}
156
157static int osiris_dvs_resume(struct device *dev)
158{
159 osiris_dvs_tps_setdvs(true);
160 return 0;
161}
162
163static const struct dev_pm_ops osiris_dvs_pm = {
164 .suspend = osiris_dvs_suspend,
165 .resume = osiris_dvs_resume,
166};
167
168static struct platform_driver osiris_dvs_driver = {
169 .probe = osiris_dvs_probe,
170 .remove = __devexit_p(osiris_dvs_remove),
171 .driver = {
172 .name = "osiris-dvs",
173 .owner = THIS_MODULE,
174 .pm = &osiris_dvs_pm,
175 },
176};
177
178static int __init osiris_dvs_init(void)
179{
180 return platform_driver_register(&osiris_dvs_driver);
181}
182
183static void __exit osiris_dvs_exit(void)
184{
185 platform_driver_unregister(&osiris_dvs_driver);
186}
187
188module_init(osiris_dvs_init);
189module_exit(osiris_dvs_exit);
190
191MODULE_DESCRIPTION("Simtec OSIRIS DVS support");
192MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
193MODULE_LICENSE("GPL");
194MODULE_ALIAS("platform:osiris-dvs");
diff --git a/arch/arm/mach-s3c2440/mach-osiris.c b/arch/arm/mach-s3c2440/mach-osiris.c
index 2105a41281a4..8af9e9a104a5 100644
--- a/arch/arm/mach-s3c2440/mach-osiris.c
+++ b/arch/arm/mach-s3c2440/mach-osiris.c
@@ -23,6 +23,8 @@
23#include <linux/i2c.h> 23#include <linux/i2c.h>
24#include <linux/io.h> 24#include <linux/io.h>
25 25
26#include <linux/i2c/tps65010.h>
27
26#include <asm/mach/arch.h> 28#include <asm/mach/arch.h>
27#include <asm/mach/map.h> 29#include <asm/mach/map.h>
28#include <asm/mach/irq.h> 30#include <asm/mach/irq.h>
@@ -326,12 +328,44 @@ static struct sys_device osiris_pm_sysdev = {
326 .cls = &osiris_pm_sysclass, 328 .cls = &osiris_pm_sysclass,
327}; 329};
328 330
331/* Link for DVS driver to TPS65011 */
332
333static void osiris_tps_release(struct device *dev)
334{
335 /* static device, do not need to release anything */
336}
337
338static struct platform_device osiris_tps_device = {
339 .name = "osiris-dvs",
340 .id = -1,
341 .dev.release = osiris_tps_release,
342};
343
344static int osiris_tps_setup(struct i2c_client *client, void *context)
345{
346 osiris_tps_device.dev.parent = &client->dev;
347 return platform_device_register(&osiris_tps_device);
348}
349
350static int osiris_tps_remove(struct i2c_client *client, void *context)
351{
352 platform_device_unregister(&osiris_tps_device);
353 return 0;
354}
355
356static struct tps65010_board osiris_tps_board = {
357 .base = -1, /* GPIO can go anywhere at the moment */
358 .setup = osiris_tps_setup,
359 .teardown = osiris_tps_remove,
360};
361
329/* I2C devices fitted. */ 362/* I2C devices fitted. */
330 363
331static struct i2c_board_info osiris_i2c_devs[] __initdata = { 364static struct i2c_board_info osiris_i2c_devs[] __initdata = {
332 { 365 {
333 I2C_BOARD_INFO("tps65011", 0x48), 366 I2C_BOARD_INFO("tps65011", 0x48),
334 .irq = IRQ_EINT20, 367 .irq = IRQ_EINT20,
368 .platform_data = &osiris_tps_board,
335 }, 369 },
336}; 370};
337 371