Root/target/linux/s3c24xx/files-2.6.30/arch/arm/mach-s3c2442/gta02-pm-gps.c

1/*
2 * GPS Power Management code for the Openmoko Freerunner GSM Phone
3 *
4 * (C) 2007-2009 by Openmoko Inc.
5 * Author: Harald Welte <laforge@openmoko.org>
6 * All rights reserved.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/delay.h>
18#include <linux/platform_device.h>
19
20#include <mach/hardware.h>
21#include <mach/cpu.h>
22
23#include <asm/mach-types.h>
24
25#include <mach/gta02.h>
26#include <linux/mfd/pcf50633/core.h>
27#include <linux/mfd/pcf50633/pmic.h>
28
29#include <linux/regulator/consumer.h>
30#include <linux/err.h>
31
32struct gta02_pm_gps_data {
33#ifdef CONFIG_PM
34    int keep_on_in_suspend;
35#endif
36    int power_was_on;
37    struct regulator *regulator;
38};
39
40static struct gta02_pm_gps_data gta02_gps;
41
42int gta02_pm_gps_is_on(void)
43{
44    return gta02_gps.power_was_on;
45}
46EXPORT_SYMBOL_GPL(gta02_pm_gps_is_on);
47
48/* This is the POWERON pin */
49static void gps_pwron_set(int on)
50{
51    if (on) {
52        /* return UART pins to being UART pins */
53        s3c2410_gpio_cfgpin(S3C2410_GPH4, S3C2410_GPH4_TXD1);
54        /* remove pulldown now it won't be floating any more */
55        s3c2410_gpio_pullup(S3C2410_GPH5, 0);
56
57        if (!gta02_gps.power_was_on)
58            regulator_enable(gta02_gps.regulator);
59    } else {
60        /*
61         * take care not to power unpowered GPS from UART TX
62         * return them to GPIO and force low
63         */
64        s3c2410_gpio_cfgpin(S3C2410_GPH4, S3C2410_GPH4_OUTP);
65        s3c2410_gpio_setpin(S3C2410_GPH4, 0);
66        /* don't let RX from unpowered GPS float */
67        s3c2410_gpio_pullup(S3C2410_GPH5, 1);
68        if (gta02_gps.power_was_on)
69            regulator_disable(gta02_gps.regulator);
70    }
71}
72
73static int gps_pwron_get(void)
74{
75    return regulator_is_enabled(gta02_gps.regulator);
76}
77
78#ifdef CONFIG_PM
79/* This is the flag for keeping gps ON during suspend */
80static void gps_keep_on_in_suspend_set(int on)
81{
82    gta02_gps.keep_on_in_suspend = on;
83}
84
85static int gps_keep_on_in_suspend_get(void)
86{
87    return gta02_gps.keep_on_in_suspend;
88}
89#endif
90
91static ssize_t power_gps_read(struct device *dev,
92                  struct device_attribute *attr, char *buf)
93{
94    int ret = 0;
95
96    if (!strcmp(attr->attr.name, "power_on") ||
97        !strcmp(attr->attr.name, "pwron")) {
98        ret = gps_pwron_get();
99#ifdef CONFIG_PM
100    } else if (!strcmp(attr->attr.name, "keep_on_in_suspend")) {
101        ret = gps_keep_on_in_suspend_get();
102#endif
103    }
104    if (ret)
105        return strlcpy(buf, "1\n", 3);
106    else
107        return strlcpy(buf, "0\n", 3);
108}
109
110static ssize_t power_gps_write(struct device *dev,
111                   struct device_attribute *attr, const char *buf,
112                   size_t count)
113{
114    unsigned long on = simple_strtoul(buf, NULL, 10);
115
116    if (!strcmp(attr->attr.name, "power_on") ||
117        !strcmp(attr->attr.name, "pwron")) {
118        gps_pwron_set(on);
119        gta02_gps.power_was_on = !!on;
120#ifdef CONFIG_PM
121    } else if (!strcmp(attr->attr.name, "keep_on_in_suspend")) {
122        gps_keep_on_in_suspend_set(on);
123#endif
124    }
125    return count;
126}
127
128#ifdef CONFIG_PM
129static int gta02_pm_gps_suspend(struct platform_device *pdev,
130                pm_message_t state)
131{
132    if (!gta02_gps.keep_on_in_suspend ||
133        !gta02_gps.power_was_on)
134        gps_pwron_set(0);
135    else
136        dev_warn(&pdev->dev, "GTA02: keeping gps ON "
137             "during suspend\n");
138    return 0;
139}
140
141static int gta02_pm_gps_resume(struct platform_device *pdev)
142{
143    if (!gta02_gps.keep_on_in_suspend && gta02_gps.power_was_on)
144        gps_pwron_set(1);
145
146    return 0;
147}
148
149static DEVICE_ATTR(keep_on_in_suspend, 0644, power_gps_read, power_gps_write);
150#else
151#define gta02_pm_gps_suspend NULL
152#define gta02_pm_gps_resume NULL
153#endif
154
155static DEVICE_ATTR(power_on, 0644, power_gps_read, power_gps_write);
156
157static struct attribute *gta02_gps_sysfs_entries[] = {
158    &dev_attr_power_on.attr,
159#ifdef CONFIG_PM
160    &dev_attr_keep_on_in_suspend.attr,
161#endif
162    NULL
163};
164
165static struct attribute_group gta02_gps_attr_group = {
166    .name = NULL,
167    .attrs = gta02_gps_sysfs_entries,
168};
169
170static int __init gta02_pm_gps_probe(struct platform_device *pdev)
171{
172    gta02_gps.regulator = regulator_get(&pdev->dev, "RF_3V");
173    if (IS_ERR(gta02_gps.regulator)) {
174        dev_err(&pdev->dev, "probe failed %ld\n",
175            PTR_ERR(gta02_gps.regulator));
176
177        return PTR_ERR(gta02_gps.regulator);
178    }
179
180    dev_info(&pdev->dev, "starting\n");
181
182    /*
183     * Here we should call the code that handles the set GPS power
184     * off action. But, the regulator API does not allow us to
185     * reassert regulator state, and when we read the regulator API
186     * logical state, it can differ from the actual state, So
187     * a workaround for this is to just set the regulator off in the
188     * PMU directly. Because that's different from normal flow, we
189     * have to reproduce other things from the OFF action here too.
190     */
191
192    /*
193     * u-boot enables LDO5 (GPS), which doesn't make sense and
194     * causes confusion. We therefore disable the regulator here.
195     */
196    pcf50633_reg_write(gta02_pcf, PCF50633_REG_LDO5ENA, 0);
197
198    /*
199     * take care not to power unpowered GPS from UART TX
200     * return them to GPIO and force low
201     */
202    s3c2410_gpio_cfgpin(S3C2410_GPH4, S3C2410_GPH4_OUTP);
203    s3c2410_gpio_setpin(S3C2410_GPH4, 0);
204    /* don't let RX from unpowered GPS float */
205    s3c2410_gpio_pullup(S3C2410_GPH5, 1);
206
207    return sysfs_create_group(&pdev->dev.kobj,
208                  &gta02_gps_attr_group);
209}
210
211static int gta02_pm_gps_remove(struct platform_device *pdev)
212{
213    regulator_put(gta02_gps.regulator);
214    sysfs_remove_group(&pdev->dev.kobj, &gta02_gps_attr_group);
215    return 0;
216}
217
218static struct platform_driver gta02_pm_gps_driver = {
219    .probe = gta02_pm_gps_probe,
220    .remove = gta02_pm_gps_remove,
221    .suspend = gta02_pm_gps_suspend,
222    .resume = gta02_pm_gps_resume,
223    .driver = {
224        .name = "gta02-pm-gps",
225    },
226};
227
228static int __devinit gta02_pm_gps_init(void)
229{
230    return platform_driver_register(&gta02_pm_gps_driver);
231}
232
233static void gta02_pm_gps_exit(void)
234{
235    platform_driver_unregister(&gta02_pm_gps_driver);
236}
237
238module_init(gta02_pm_gps_init);
239module_exit(gta02_pm_gps_exit);
240
241MODULE_LICENSE("GPL");
242MODULE_AUTHOR("Harald Welte <laforge@openmoko.org>");
243

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