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 millivolts */
 30static 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
 37struct comparator {
 38	const char *name;
 39	int reg;
 40	int uV_max;
 41	const u16 *vsel_table;
 42};
 43
 44static 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
 59static 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
 86static 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
103static 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
122static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
123static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);
124
125static __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
155static __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
166static 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
175static int __init tps65911_comparator_init(void)
176{
177	return platform_driver_register(&tps65911_comparator_driver);
178}
179subsys_initcall(tps65911_comparator_init);
180
181static void __exit tps65911_comparator_exit(void)
182{
183	platform_driver_unregister(&tps65911_comparator_driver);
184}
185module_exit(tps65911_comparator_exit);
186
187MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
188MODULE_DESCRIPTION("TPS65911 comparator driver");
189MODULE_LICENSE("GPL v2");
190MODULE_ALIAS("platform:tps65911-comparator");