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 */
24 static 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 
31 struct comparator {
32 	const char *name;
33 	int reg;
34 	int uV_max;
35 	const u16 *vsel_table;
36 };
37 
38 static 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 
53 static 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 
77 static 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 
91 static 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 
110 static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
111 static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);
112 
113 static 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 
143 static 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 
154 static 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 
162 static int __init tps65911_comparator_init(void)
163 {
164 	return platform_driver_register(&tps65911_comparator_driver);
165 }
166 subsys_initcall(tps65911_comparator_init);
167 
168 static void __exit tps65911_comparator_exit(void)
169 {
170 	platform_driver_unregister(&tps65911_comparator_driver);
171 }
172 module_exit(tps65911_comparator_exit);
173 
174 MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
175 MODULE_DESCRIPTION("TPS65911 comparator driver");
176 MODULE_LICENSE("GPL v2");
177 MODULE_ALIAS("platform:tps65911-comparator");
178