summaryrefslogtreecommitdiffstats
path: root/drivers/mfd/tps65911-comparator.c
blob: 0b6e361432c4a6776813419d3384a23fa92b6645 (plain)
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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/*
 * tps65910.c  --  TI TPS6591x
 *
 * Copyright 2010 Texas Instruments Inc.
 *
 * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under  the terms of the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/debugfs.h>
#include <linux/gpio.h>
#include <linux/mfd/tps65910.h>

#define COMP					0
#define COMP1					1
#define COMP2					2

/* Comparator 1 voltage selection table in millivolts */
static const u16 COMP_VSEL_TABLE[] = {
	0, 2500, 2500, 2500, 2500, 2550, 2600, 2650,
	2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050,
	3100, 3150, 3200, 3250, 3300, 3350, 3400, 3450,
	3500,
};

struct comparator {
	const char *name;
	int reg;
	int uV_max;
	const u16 *vsel_table;
};

static struct comparator tps_comparators[] = {
	{
		.name = "COMP1",
		.reg = TPS65911_VMBCH,
		.uV_max = 3500,
		.vsel_table = COMP_VSEL_TABLE,
	},
	{
		.name = "COMP2",
		.reg = TPS65911_VMBCH2,
		.uV_max = 3500,
		.vsel_table = COMP_VSEL_TABLE,
	},
};

static int comp_threshold_set(struct tps65910 *tps65910, int id, int voltage)
{
	struct comparator tps_comp = tps_comparators[id];
	int curr_voltage = 0;
	int ret;
	u8 index = 0, val;

	if (id == COMP)
		return 0;

	while (curr_voltage < tps_comp.uV_max) {
		curr_voltage = tps_comp.vsel_table[index];
		if (curr_voltage >= voltage)
			break;
		else if (curr_voltage < voltage)
			index ++;
	}

	if (curr_voltage > tps_comp.uV_max)
		return -EINVAL;

	val = index << 1;
	ret = tps65910->write(tps65910, tps_comp.reg, 1, &val);

	return ret;
}

static int comp_threshold_get(struct tps65910 *tps65910, int id)
{
	struct comparator tps_comp = tps_comparators[id];
	int ret;
	u8 val;

	if (id == COMP)
		return 0;

	ret = tps65910->read(tps65910, tps_comp.reg, 1, &val);
	if (ret < 0)
		return ret;

	val >>= 1;
	return tps_comp.vsel_table[val];
}

static ssize_t comp_threshold_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct tps65910 *tps65910 = dev_get_drvdata(dev->parent);
	struct attribute comp_attr = attr->attr;
	int id, uVolt;

	if (!strcmp(comp_attr.name, "comp1_threshold"))
		id = COMP1;
	else if (!strcmp(comp_attr.name, "comp2_threshold"))
		id = COMP2;
	else
		return -EINVAL;

	uVolt = comp_threshold_get(tps65910, id);

	return sprintf(buf, "%d\n", uVolt);
}

static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);

static __devinit int tps65911_comparator_probe(struct platform_device *pdev)
{
	struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent);
	struct tps65910_board *pdata = dev_get_platdata(tps65910->dev);
	int ret;

	ret = comp_threshold_set(tps65910, COMP1,  pdata->vmbch_threshold);
	if (ret < 0) {
		dev_err(&pdev->dev, "cannot set COMP1 threshold\n");
		return ret;
	}

	ret = comp_threshold_set(tps65910, COMP2, pdata->vmbch2_threshold);
	if (ret < 0) {
		dev_err(&pdev->dev, "cannot set COMP2 threshold\n");
		return ret;
	}

	/* Create sysfs entry */
	ret = device_create_file(&pdev->dev, &dev_attr_comp1_threshold);
	if (ret < 0)
		dev_err(&pdev->dev, "failed to add COMP1 sysfs file\n");

	ret = device_create_file(&pdev->dev, &dev_attr_comp2_threshold);
	if (ret < 0)
		dev_err(&pdev->dev, "failed to add COMP2 sysfs file\n");

	return ret;
}

static __devexit int tps65911_comparator_remove(struct platform_device *pdev)
{
	struct tps65910 *tps65910;

	tps65910 = dev_get_drvdata(pdev->dev.parent);
	device_remove_file(&pdev->dev, &dev_attr_comp2_threshold);
	device_remove_file(&pdev->dev, &dev_attr_comp1_threshold);

	return 0;
}

static struct platform_driver tps65911_comparator_driver = {
	.driver = {
		.name = "tps65911-comparator",
		.owner = THIS_MODULE,
	},
	.probe = tps65911_comparator_probe,
	.remove = __devexit_p(tps65911_comparator_remove),
};

static int __init tps65911_comparator_init(void)
{
	return platform_driver_register(&tps65911_comparator_driver);
}
subsys_initcall(tps65911_comparator_init);

static void __exit tps65911_comparator_exit(void)
{
	platform_driver_unregister(&tps65911_comparator_driver);
}
module_exit(tps65911_comparator_exit);

MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
MODULE_DESCRIPTION("TPS65911 comparator driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:tps65911-comparator");