1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Power-source driver for Bay Trail Crystal Cove PMIC
4 *
5 * Copyright (c) 2023 Hans de Goede <hdegoede@redhat.com>
6 *
7 * Based on intel_crystalcove_pwrsrc.c from Android kernel sources, which is:
8 * Copyright (C) 2013 Intel Corporation
9 */
10
11 #include <linux/debugfs.h>
12 #include <linux/mfd/intel_soc_pmic.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16
17 #define CRYSTALCOVE_SPWRSRC_REG 0x1E
18 #define CRYSTALCOVE_RESETSRC0_REG 0x20
19 #define CRYSTALCOVE_RESETSRC1_REG 0x21
20 #define CRYSTALCOVE_WAKESRC_REG 0x22
21
22 struct crc_pwrsrc_data {
23 struct regmap *regmap;
24 struct dentry *debug_dentry;
25 unsigned int resetsrc0;
26 unsigned int resetsrc1;
27 unsigned int wakesrc;
28 };
29
30 static const char * const pwrsrc_pwrsrc_info[] = {
31 /* bit 0 */ "USB",
32 /* bit 1 */ "DC in",
33 /* bit 2 */ "Battery",
34 NULL,
35 };
36
37 static const char * const pwrsrc_resetsrc0_info[] = {
38 /* bit 0 */ "SOC reporting a thermal event",
39 /* bit 1 */ "critical PMIC temperature",
40 /* bit 2 */ "critical system temperature",
41 /* bit 3 */ "critical battery temperature",
42 /* bit 4 */ "VSYS under voltage",
43 /* bit 5 */ "VSYS over voltage",
44 /* bit 6 */ "battery removal",
45 NULL,
46 };
47
48 static const char * const pwrsrc_resetsrc1_info[] = {
49 /* bit 0 */ "VCRIT threshold",
50 /* bit 1 */ "BATID reporting battery removal",
51 /* bit 2 */ "user pressing the power button",
52 NULL,
53 };
54
55 static const char * const pwrsrc_wakesrc_info[] = {
56 /* bit 0 */ "user pressing the power button",
57 /* bit 1 */ "a battery insertion",
58 /* bit 2 */ "a USB charger insertion",
59 /* bit 3 */ "an adapter insertion",
60 NULL,
61 };
62
crc_pwrsrc_log(struct seq_file * seq,const char * prefix,const char * const * info,unsigned int reg_val)63 static void crc_pwrsrc_log(struct seq_file *seq, const char *prefix,
64 const char * const *info, unsigned int reg_val)
65 {
66 int i;
67
68 for (i = 0; info[i]; i++) {
69 if (reg_val & BIT(i))
70 seq_printf(seq, "%s by %s\n", prefix, info[i]);
71 }
72 }
73
pwrsrc_show(struct seq_file * seq,void * unused)74 static int pwrsrc_show(struct seq_file *seq, void *unused)
75 {
76 struct crc_pwrsrc_data *data = seq->private;
77 unsigned int reg_val;
78 int ret;
79
80 ret = regmap_read(data->regmap, CRYSTALCOVE_SPWRSRC_REG, ®_val);
81 if (ret)
82 return ret;
83
84 crc_pwrsrc_log(seq, "System powered", pwrsrc_pwrsrc_info, reg_val);
85 return 0;
86 }
87
resetsrc_show(struct seq_file * seq,void * unused)88 static int resetsrc_show(struct seq_file *seq, void *unused)
89 {
90 struct crc_pwrsrc_data *data = seq->private;
91
92 crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc0_info, data->resetsrc0);
93 crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc1_info, data->resetsrc1);
94 return 0;
95 }
96
wakesrc_show(struct seq_file * seq,void * unused)97 static int wakesrc_show(struct seq_file *seq, void *unused)
98 {
99 struct crc_pwrsrc_data *data = seq->private;
100
101 crc_pwrsrc_log(seq, "Last wake caused", pwrsrc_wakesrc_info, data->wakesrc);
102 return 0;
103 }
104
105 DEFINE_SHOW_ATTRIBUTE(pwrsrc);
106 DEFINE_SHOW_ATTRIBUTE(resetsrc);
107 DEFINE_SHOW_ATTRIBUTE(wakesrc);
108
crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data * data,unsigned int reg,unsigned int * val)109 static int crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data *data,
110 unsigned int reg, unsigned int *val)
111 {
112 int ret;
113
114 ret = regmap_read(data->regmap, reg, val);
115 if (ret)
116 return ret;
117
118 return regmap_write(data->regmap, reg, *val);
119 }
120
crc_pwrsrc_probe(struct platform_device * pdev)121 static int crc_pwrsrc_probe(struct platform_device *pdev)
122 {
123 struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
124 struct crc_pwrsrc_data *data;
125 int ret;
126
127 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
128 if (!data)
129 return -ENOMEM;
130
131 data->regmap = pmic->regmap;
132
133 /*
134 * Read + clear resetsrc0/1 and wakesrc now, so that they get
135 * cleared even if the debugfs interface is never used.
136 *
137 * Properly clearing the wakesrc is important, leaving bit 0 of it
138 * set turns reboot into poweroff on some tablets.
139 */
140 ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC0_REG, &data->resetsrc0);
141 if (ret)
142 return ret;
143
144 ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC1_REG, &data->resetsrc1);
145 if (ret)
146 return ret;
147
148 ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_WAKESRC_REG, &data->wakesrc);
149 if (ret)
150 return ret;
151
152 data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL);
153 debugfs_create_file("pwrsrc", 0444, data->debug_dentry, data, &pwrsrc_fops);
154 debugfs_create_file("resetsrc", 0444, data->debug_dentry, data, &resetsrc_fops);
155 debugfs_create_file("wakesrc", 0444, data->debug_dentry, data, &wakesrc_fops);
156
157 platform_set_drvdata(pdev, data);
158 return 0;
159 }
160
crc_pwrsrc_remove(struct platform_device * pdev)161 static int crc_pwrsrc_remove(struct platform_device *pdev)
162 {
163 struct crc_pwrsrc_data *data = platform_get_drvdata(pdev);
164
165 debugfs_remove_recursive(data->debug_dentry);
166 return 0;
167 }
168
169 static struct platform_driver crc_pwrsrc_driver = {
170 .probe = crc_pwrsrc_probe,
171 .remove = crc_pwrsrc_remove,
172 .driver = {
173 .name = "crystal_cove_pwrsrc",
174 },
175 };
176 module_platform_driver(crc_pwrsrc_driver);
177
178 MODULE_ALIAS("platform:crystal_cove_pwrsrc");
179 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
180 MODULE_DESCRIPTION("Power-source driver for Bay Trail Crystal Cove PMIC");
181 MODULE_LICENSE("GPL");
182