linux/drivers/mfd/tps65911-comparator.c
<<
>>
Prefs
   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 = regmap_write(tps65910->regmap, 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 = regmap_read(tps65910->regmap, 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");
 178