mfd: tps65090: fix compilation warning
[linux-2.6.git] / drivers / mfd / tps65911-comparator.c
1 /*
2  * tps65910.c  --  TI TPS6591x
3  *
4  * Copyright 2010 Texas Instruments Inc.
5  *
6  * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
7  *
8  *  This program is free software; you can redistribute it and/or modify it
9  *  under  the terms of the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the License, or (at your
11  *  option) any later version.
12  *
13  */
14
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/err.h>
20 #include <linux/platform_device.h>
21 #include <linux/debugfs.h>
22 #include <linux/gpio.h>
23 #include <linux/mfd/tps65910.h>
24
25 #define COMP                                    0
26 #define COMP1                                   1
27 #define COMP2                                   2
28
29 /* Comparator 1 voltage selection table in milivolts */
30 static const u16 COMP_VSEL_TABLE[] = {
31         0, 2500, 2500, 2500, 2500, 2550, 2600, 2650,
32         2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050,
33         3100, 3150, 3200, 3250, 3300, 3350, 3400, 3450,
34         3500,
35 };
36
37 struct comparator {
38         const char *name;
39         int reg;
40         int uV_max;
41         const u16 *vsel_table;
42 };
43
44 static struct comparator tps_comparators[] = {
45         {
46                 .name = "COMP1",
47                 .reg = TPS65911_VMBCH,
48                 .uV_max = 3500,
49                 .vsel_table = COMP_VSEL_TABLE,
50         },
51         {
52                 .name = "COMP2",
53                 .reg = TPS65911_VMBCH2,
54                 .uV_max = 3500,
55                 .vsel_table = COMP_VSEL_TABLE,
56         },
57 };
58
59 static int comp_threshold_set(struct tps65910 *tps65910, int id, int voltage)
60 {
61         struct comparator tps_comp = tps_comparators[id];
62         int curr_voltage = 0;
63         int ret;
64         u8 index = 0, val;
65
66         if (id == COMP)
67                 return 0;
68
69         while (curr_voltage < tps_comp.uV_max) {
70                 curr_voltage = tps_comp.vsel_table[index];
71                 if (curr_voltage >= voltage)
72                         break;
73                 else if (curr_voltage < voltage)
74                         index ++;
75         }
76
77         if (curr_voltage > tps_comp.uV_max)
78                 return -EINVAL;
79
80         val = index << 1;
81         ret = tps65910->write(tps65910, tps_comp.reg, 1, &val);
82
83         return ret;
84 }
85
86 static int comp_threshold_get(struct tps65910 *tps65910, int id)
87 {
88         struct comparator tps_comp = tps_comparators[id];
89         int ret;
90         u8 val;
91
92         if (id == COMP)
93                 return 0;
94
95         ret = tps65910->read(tps65910, tps_comp.reg, 1, &val);
96         if (ret < 0)
97                 return ret;
98
99         val >>= 1;
100         return tps_comp.vsel_table[val];
101 }
102
103 static ssize_t comp_threshold_show(struct device *dev,
104                                 struct device_attribute *attr, char *buf)
105 {
106         struct tps65910 *tps65910 = dev_get_drvdata(dev->parent);
107         struct attribute comp_attr = attr->attr;
108         int id, uVolt;
109
110         if (!strcmp(comp_attr.name, "comp1_threshold"))
111                 id = COMP1;
112         else if (!strcmp(comp_attr.name, "comp2_threshold"))
113                 id = COMP2;
114         else
115                 return -EINVAL;
116
117         uVolt = comp_threshold_get(tps65910, id);
118
119         return sprintf(buf, "%d\n", uVolt);
120 }
121
122 static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
123 static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);
124
125 static __devinit int tps65911_comparator_probe(struct platform_device *pdev)
126 {
127         struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent);
128         struct tps65910_board *pdata = dev_get_platdata(tps65910->dev);
129         int ret;
130
131         ret = comp_threshold_set(tps65910, COMP1,  pdata->vmbch_threshold);
132         if (ret < 0) {
133                 dev_err(&pdev->dev, "cannot set COMP1 threshold\n");
134                 return ret;
135         }
136
137         ret = comp_threshold_set(tps65910, COMP2, pdata->vmbch2_threshold);
138         if (ret < 0) {
139                 dev_err(&pdev->dev, "cannot set COMP2 theshold\n");
140                 return ret;
141         }
142
143         /* Create sysfs entry */
144         ret = device_create_file(&pdev->dev, &dev_attr_comp1_threshold);
145         if (ret < 0)
146                 dev_err(&pdev->dev, "failed to add COMP1 sysfs file\n");
147
148         ret = device_create_file(&pdev->dev, &dev_attr_comp2_threshold);
149         if (ret < 0)
150                 dev_err(&pdev->dev, "failed to add COMP2 sysfs file\n");
151
152         return ret;
153 }
154
155 static __devexit int tps65911_comparator_remove(struct platform_device *pdev)
156 {
157         struct tps65910 *tps65910;
158
159         tps65910 = dev_get_drvdata(pdev->dev.parent);
160         device_remove_file(&pdev->dev, &dev_attr_comp2_threshold);
161         device_remove_file(&pdev->dev, &dev_attr_comp1_threshold);
162
163         return 0;
164 }
165
166 static struct platform_driver tps65911_comparator_driver = {
167         .driver = {
168                 .name = "tps65911-comparator",
169                 .owner = THIS_MODULE,
170         },
171         .probe = tps65911_comparator_probe,
172         .remove = __devexit_p(tps65911_comparator_remove),
173 };
174
175 static int __init tps65911_comparator_init(void)
176 {
177         return platform_driver_register(&tps65911_comparator_driver);
178 }
179 subsys_initcall(tps65911_comparator_init);
180
181 static void __exit tps65911_comparator_exit(void)
182 {
183         platform_driver_unregister(&tps65911_comparator_driver);
184 }
185 module_exit(tps65911_comparator_exit);
186
187 MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
188 MODULE_DESCRIPTION("TPS65911 comparator driver");
189 MODULE_LICENSE("GPL v2");
190 MODULE_ALIAS("platform:tps65911-comparator");