bytcrc_pwrsrc.c

  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/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
 31struct 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
 40static const char * const pwrsrc_pwrsrc_info[] = {
 41	/* bit 0 */ "USB",
 42	/* bit 1 */ "DC in",
 43	/* bit 2 */ "Battery",
 44	NULL,
 45};
 46
 47static 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
 58static 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
 65static 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
 73static 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
 84static 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, &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
 98static 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
107static 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
115DEFINE_SHOW_ATTRIBUTE(pwrsrc);
116DEFINE_SHOW_ATTRIBUTE(resetsrc);
117DEFINE_SHOW_ATTRIBUTE(wakesrc);
118
119static 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
131static 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
145static 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
165static const enum power_supply_property crc_pwrsrc_psy_props[] = {
166	POWER_SUPPLY_PROP_ONLINE,
167};
168
169static 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
177static 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
236static 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
243static 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};
250module_platform_driver(crc_pwrsrc_driver);
251
252MODULE_ALIAS("platform:crystal_cove_pwrsrc");
253MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
254MODULE_DESCRIPTION("Power-source driver for Bay Trail Crystal Cove PMIC");
255MODULE_LICENSE("GPL");