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/drivers/mfd/tps65911-comparator.c

http://github.com/mirrors/linux
C | 177 lines | 136 code | 31 blank | 10 comment | 13 complexity | a1196838d1eb4b30cebbc97d370e0e7a MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * tps65910.c  --  TI TPS6591x
  4 *
  5 * Copyright 2010 Texas Instruments Inc.
  6 *
  7 * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
  8 */
  9
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/init.h>
 13#include <linux/slab.h>
 14#include <linux/err.h>
 15#include <linux/platform_device.h>
 16#include <linux/debugfs.h>
 17#include <linux/gpio.h>
 18#include <linux/mfd/tps65910.h>
 19
 20#define COMP1					0
 21#define COMP2					1
 22
 23/* Comparator 1 voltage selection table in millivolts */
 24static const u16 COMP_VSEL_TABLE[] = {
 25	0, 2500, 2500, 2500, 2500, 2550, 2600, 2650,
 26	2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050,
 27	3100, 3150, 3200, 3250, 3300, 3350, 3400, 3450,
 28	3500,
 29};
 30
 31struct comparator {
 32	const char *name;
 33	int reg;
 34	int uV_max;
 35	const u16 *vsel_table;
 36};
 37
 38static struct comparator tps_comparators[] = {
 39	{
 40		.name = "COMP1",
 41		.reg = TPS65911_VMBCH,
 42		.uV_max = 3500,
 43		.vsel_table = COMP_VSEL_TABLE,
 44	},
 45	{
 46		.name = "COMP2",
 47		.reg = TPS65911_VMBCH2,
 48		.uV_max = 3500,
 49		.vsel_table = COMP_VSEL_TABLE,
 50	},
 51};
 52
 53static int comp_threshold_set(struct tps65910 *tps65910, int id, int voltage)
 54{
 55	struct comparator tps_comp = tps_comparators[id];
 56	int curr_voltage = 0;
 57	int ret;
 58	u8 index = 0, val;
 59
 60	while (curr_voltage < tps_comp.uV_max) {
 61		curr_voltage = tps_comp.vsel_table[index];
 62		if (curr_voltage >= voltage)
 63			break;
 64		else if (curr_voltage < voltage)
 65			index ++;
 66	}
 67
 68	if (curr_voltage > tps_comp.uV_max)
 69		return -EINVAL;
 70
 71	val = index << 1;
 72	ret = tps65910_reg_write(tps65910, tps_comp.reg, val);
 73
 74	return ret;
 75}
 76
 77static int comp_threshold_get(struct tps65910 *tps65910, int id)
 78{
 79	struct comparator tps_comp = tps_comparators[id];
 80	unsigned int val;
 81	int ret;
 82
 83	ret = tps65910_reg_read(tps65910, tps_comp.reg, &val);
 84	if (ret < 0)
 85		return ret;
 86
 87	val >>= 1;
 88	return tps_comp.vsel_table[val];
 89}
 90
 91static ssize_t comp_threshold_show(struct device *dev,
 92				struct device_attribute *attr, char *buf)
 93{
 94	struct tps65910 *tps65910 = dev_get_drvdata(dev->parent);
 95	struct attribute comp_attr = attr->attr;
 96	int id, uVolt;
 97
 98	if (!strcmp(comp_attr.name, "comp1_threshold"))
 99		id = COMP1;
100	else if (!strcmp(comp_attr.name, "comp2_threshold"))
101		id = COMP2;
102	else
103		return -EINVAL;
104
105	uVolt = comp_threshold_get(tps65910, id);
106
107	return sprintf(buf, "%d\n", uVolt);
108}
109
110static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
111static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);
112
113static int tps65911_comparator_probe(struct platform_device *pdev)
114{
115	struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent);
116	struct tps65910_board *pdata = dev_get_platdata(tps65910->dev);
117	int ret;
118
119	ret = comp_threshold_set(tps65910, COMP1,  pdata->vmbch_threshold);
120	if (ret < 0) {
121		dev_err(&pdev->dev, "cannot set COMP1 threshold\n");
122		return ret;
123	}
124
125	ret = comp_threshold_set(tps65910, COMP2, pdata->vmbch2_threshold);
126	if (ret < 0) {
127		dev_err(&pdev->dev, "cannot set COMP2 threshold\n");
128		return ret;
129	}
130
131	/* Create sysfs entry */
132	ret = device_create_file(&pdev->dev, &dev_attr_comp1_threshold);
133	if (ret < 0)
134		dev_err(&pdev->dev, "failed to add COMP1 sysfs file\n");
135
136	ret = device_create_file(&pdev->dev, &dev_attr_comp2_threshold);
137	if (ret < 0)
138		dev_err(&pdev->dev, "failed to add COMP2 sysfs file\n");
139
140	return ret;
141}
142
143static int tps65911_comparator_remove(struct platform_device *pdev)
144{
145	struct tps65910 *tps65910;
146
147	tps65910 = dev_get_drvdata(pdev->dev.parent);
148	device_remove_file(&pdev->dev, &dev_attr_comp2_threshold);
149	device_remove_file(&pdev->dev, &dev_attr_comp1_threshold);
150
151	return 0;
152}
153
154static struct platform_driver tps65911_comparator_driver = {
155	.driver = {
156		.name = "tps65911-comparator",
157	},
158	.probe = tps65911_comparator_probe,
159	.remove = tps65911_comparator_remove,
160};
161
162static int __init tps65911_comparator_init(void)
163{
164	return platform_driver_register(&tps65911_comparator_driver);
165}
166subsys_initcall(tps65911_comparator_init);
167
168static void __exit tps65911_comparator_exit(void)
169{
170	platform_driver_unregister(&tps65911_comparator_driver);
171}
172module_exit(tps65911_comparator_exit);
173
174MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
175MODULE_DESCRIPTION("TPS65911 comparator driver");
176MODULE_LICENSE("GPL v2");
177MODULE_ALIAS("platform:tps65911-comparator");