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 <[email protected]>
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/array_size.h>
12 #include <linux/bits.h>
13 #include <linux/debugfs.h>
14 #include <linux/interrupt.h>
15 #include <linux/mfd/intel_soc_pmic.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/power_supply.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21
22 #define CRYSTALCOVE_PWRSRC_IRQ 0x03
23 #define CRYSTALCOVE_SPWRSRC_REG 0x1E
24 #define CRYSTALCOVE_SPWRSRC_USB BIT(0)
25 #define CRYSTALCOVE_SPWRSRC_DC BIT(1)
26 #define CRYSTALCOVE_SPWRSRC_BATTERY BIT(2)
27 #define CRYSTALCOVE_RESETSRC0_REG 0x20
28 #define CRYSTALCOVE_RESETSRC1_REG 0x21
29 #define CRYSTALCOVE_WAKESRC_REG 0x22
30
31 struct crc_pwrsrc_data {
32 struct regmap *regmap;
33 struct dentry *debug_dentry;
34 struct power_supply *psy;
35 unsigned int resetsrc0;
36 unsigned int resetsrc1;
37 unsigned int wakesrc;
38 };
39
40 static const char * const pwrsrc_pwrsrc_info[] = {
41 /* bit 0 */ "USB",
42 /* bit 1 */ "DC in",
43 /* bit 2 */ "Battery",
44 NULL,
45 };
46
47 static const char * const pwrsrc_resetsrc0_info[] = {
48 /* bit 0 */ "SOC reporting a thermal event",
49 /* bit 1 */ "critical PMIC temperature",
50 /* bit 2 */ "critical system temperature",
51 /* bit 3 */ "critical battery temperature",
52 /* bit 4 */ "VSYS under voltage",
53 /* bit 5 */ "VSYS over voltage",
54 /* bit 6 */ "battery removal",
55 NULL,
56 };
57
58 static const char * const pwrsrc_resetsrc1_info[] = {
59 /* bit 0 */ "VCRIT threshold",
60 /* bit 1 */ "BATID reporting battery removal",
61 /* bit 2 */ "user pressing the power button",
62 NULL,
63 };
64
65 static const char * const pwrsrc_wakesrc_info[] = {
66 /* bit 0 */ "user pressing the power button",
67 /* bit 1 */ "a battery insertion",
68 /* bit 2 */ "a USB charger insertion",
69 /* bit 3 */ "an adapter insertion",
70 NULL,
71 };
72
crc_pwrsrc_log(struct seq_file * seq,const char * prefix,const char * const * info,unsigned int reg_val)73 static void crc_pwrsrc_log(struct seq_file *seq, const char *prefix,
74 const char * const *info, unsigned int reg_val)
75 {
76 int i;
77
78 for (i = 0; info[i]; i++) {
79 if (reg_val & BIT(i))
80 seq_printf(seq, "%s by %s\n", prefix, info[i]);
81 }
82 }
83
pwrsrc_show(struct seq_file * seq,void * unused)84 static int pwrsrc_show(struct seq_file *seq, void *unused)
85 {
86 struct crc_pwrsrc_data *data = seq->private;
87 unsigned int reg_val;
88 int ret;
89
90 ret = regmap_read(data->regmap, CRYSTALCOVE_SPWRSRC_REG, ®_val);
91 if (ret)
92 return ret;
93
94 crc_pwrsrc_log(seq, "System powered", pwrsrc_pwrsrc_info, reg_val);
95 return 0;
96 }
97
resetsrc_show(struct seq_file * seq,void * unused)98 static int resetsrc_show(struct seq_file *seq, void *unused)
99 {
100 struct crc_pwrsrc_data *data = seq->private;
101
102 crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc0_info, data->resetsrc0);
103 crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc1_info, data->resetsrc1);
104 return 0;
105 }
106
wakesrc_show(struct seq_file * seq,void * unused)107 static int wakesrc_show(struct seq_file *seq, void *unused)
108 {
109 struct crc_pwrsrc_data *data = seq->private;
110
111 crc_pwrsrc_log(seq, "Last wake caused", pwrsrc_wakesrc_info, data->wakesrc);
112 return 0;
113 }
114
115 DEFINE_SHOW_ATTRIBUTE(pwrsrc);
116 DEFINE_SHOW_ATTRIBUTE(resetsrc);
117 DEFINE_SHOW_ATTRIBUTE(wakesrc);
118
crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data * data,unsigned int reg,unsigned int * val)119 static int crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data *data,
120 unsigned int reg, unsigned int *val)
121 {
122 int ret;
123
124 ret = regmap_read(data->regmap, reg, val);
125 if (ret)
126 return ret;
127
128 return regmap_write(data->regmap, reg, *val);
129 }
130
crc_pwrsrc_irq_handler(int irq,void * _data)131 static irqreturn_t crc_pwrsrc_irq_handler(int irq, void *_data)
132 {
133 struct crc_pwrsrc_data *data = _data;
134 unsigned int irq_mask;
135
136 if (regmap_read(data->regmap, CRYSTALCOVE_PWRSRC_IRQ, &irq_mask))
137 return IRQ_NONE;
138
139 regmap_write(data->regmap, CRYSTALCOVE_PWRSRC_IRQ, irq_mask);
140
141 power_supply_changed(data->psy);
142 return IRQ_HANDLED;
143 }
144
crc_pwrsrc_psy_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)145 static int crc_pwrsrc_psy_get_property(struct power_supply *psy,
146 enum power_supply_property psp,
147 union power_supply_propval *val)
148 {
149 struct crc_pwrsrc_data *data = power_supply_get_drvdata(psy);
150 unsigned int pwrsrc;
151 int ret;
152
153 if (psp != POWER_SUPPLY_PROP_ONLINE)
154 return -EINVAL;
155
156 ret = regmap_read(data->regmap, CRYSTALCOVE_SPWRSRC_REG, &pwrsrc);
157 if (ret)
158 return ret;
159
160 val->intval = !!(pwrsrc & (CRYSTALCOVE_SPWRSRC_USB |
161 CRYSTALCOVE_SPWRSRC_DC));
162 return 0;
163 }
164
165 static const enum power_supply_property crc_pwrsrc_psy_props[] = {
166 POWER_SUPPLY_PROP_ONLINE,
167 };
168
169 static const struct power_supply_desc crc_pwrsrc_psy_desc = {
170 .name = "crystal_cove_pwrsrc",
171 .type = POWER_SUPPLY_TYPE_MAINS,
172 .properties = crc_pwrsrc_psy_props,
173 .num_properties = ARRAY_SIZE(crc_pwrsrc_psy_props),
174 .get_property = crc_pwrsrc_psy_get_property,
175 };
176
crc_pwrsrc_probe(struct platform_device * pdev)177 static int crc_pwrsrc_probe(struct platform_device *pdev)
178 {
179 struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
180 struct device *dev = &pdev->dev;
181 struct crc_pwrsrc_data *data;
182 int irq, ret;
183
184 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
185 if (!data)
186 return -ENOMEM;
187
188 data->regmap = pmic->regmap;
189
190 /*
191 * Read + clear resetsrc0/1 and wakesrc now, so that they get
192 * cleared even if the debugfs interface is never used.
193 *
194 * Properly clearing the wakesrc is important, leaving bit 0 of it
195 * set turns reboot into poweroff on some tablets.
196 */
197 ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC0_REG, &data->resetsrc0);
198 if (ret)
199 return ret;
200
201 ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC1_REG, &data->resetsrc1);
202 if (ret)
203 return ret;
204
205 ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_WAKESRC_REG, &data->wakesrc);
206 if (ret)
207 return ret;
208
209 if (device_property_read_bool(dev->parent, "linux,register-pwrsrc-power_supply")) {
210 struct power_supply_config psy_cfg = { .drv_data = data };
211
212 irq = platform_get_irq(pdev, 0);
213 if (irq < 0)
214 return irq;
215
216 data->psy = devm_power_supply_register(dev, &crc_pwrsrc_psy_desc, &psy_cfg);
217 if (IS_ERR(data->psy))
218 return dev_err_probe(dev, PTR_ERR(data->psy), "registering power-supply\n");
219
220 ret = devm_request_threaded_irq(dev, irq, NULL,
221 crc_pwrsrc_irq_handler,
222 IRQF_ONESHOT, KBUILD_MODNAME, data);
223 if (ret)
224 return dev_err_probe(dev, ret, "requesting IRQ\n");
225 }
226
227 data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL);
228 debugfs_create_file("pwrsrc", 0444, data->debug_dentry, data, &pwrsrc_fops);
229 debugfs_create_file("resetsrc", 0444, data->debug_dentry, data, &resetsrc_fops);
230 debugfs_create_file("wakesrc", 0444, data->debug_dentry, data, &wakesrc_fops);
231
232 platform_set_drvdata(pdev, data);
233 return 0;
234 }
235
crc_pwrsrc_remove(struct platform_device * pdev)236 static void crc_pwrsrc_remove(struct platform_device *pdev)
237 {
238 struct crc_pwrsrc_data *data = platform_get_drvdata(pdev);
239
240 debugfs_remove_recursive(data->debug_dentry);
241 }
242
243 static struct platform_driver crc_pwrsrc_driver = {
244 .probe = crc_pwrsrc_probe,
245 .remove = crc_pwrsrc_remove,
246 .driver = {
247 .name = "crystal_cove_pwrsrc",
248 },
249 };
250 module_platform_driver(crc_pwrsrc_driver);
251
252 MODULE_ALIAS("platform:crystal_cove_pwrsrc");
253 MODULE_AUTHOR("Hans de Goede <[email protected]>");
254 MODULE_DESCRIPTION("Power-source driver for Bay Trail Crystal Cove PMIC");
255 MODULE_LICENSE("GPL");
256