max14656_charger_detector.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Maxim MAX14656 / AL32 USB Charger Detector driver
  4 *
  5 * Copyright (C) 2014 LG Electronics, Inc
  6 * Copyright (C) 2016 Alexander Kurz <akurz@blala.de>
  7 *
  8 * Components from Maxim AL32 Charger detection Driver for MX50 Yoshi Board
  9 * Copyright (C) Amazon Technologies Inc. All rights reserved.
 10 * Manish Lachwani (lachwani@lab126.com)
 11 */
 12#include <linux/module.h>
 13#include <linux/init.h>
 14#include <linux/delay.h>
 15#include <linux/i2c.h>
 16#include <linux/interrupt.h>
 17#include <linux/mod_devicetable.h>
 18#include <linux/slab.h>
 19#include <linux/workqueue.h>
 20#include <linux/power_supply.h>
 21#include <linux/devm-helpers.h>
 22
 23#define MAX14656_MANUFACTURER	"Maxim Integrated"
 24#define MAX14656_NAME		"max14656"
 25
 26#define MAX14656_DEVICE_ID	0x00
 27#define MAX14656_INTERRUPT_1	0x01
 28#define MAX14656_INTERRUPT_2	0x02
 29#define MAX14656_STATUS_1	0x03
 30#define MAX14656_STATUS_2	0x04
 31#define MAX14656_INTMASK_1	0x05
 32#define MAX14656_INTMASK_2	0x06
 33#define MAX14656_CONTROL_1	0x07
 34#define MAX14656_CONTROL_2	0x08
 35#define MAX14656_CONTROL_3	0x09
 36
 37#define DEVICE_VENDOR_MASK	0xf0
 38#define DEVICE_REV_MASK		0x0f
 39#define INT_EN_REG_MASK		BIT(4)
 40#define CHG_TYPE_INT_MASK	BIT(0)
 41#define STATUS1_VB_VALID_MASK	BIT(4)
 42#define STATUS1_CHG_TYPE_MASK	0xf
 43#define INT1_DCD_TIMEOUT_MASK	BIT(7)
 44#define CONTROL1_DEFAULT	0x0d
 45#define CONTROL1_INT_EN		BIT(4)
 46#define CONTROL1_INT_ACTIVE_HIGH	BIT(5)
 47#define CONTROL1_EDGE		BIT(7)
 48#define CONTROL2_DEFAULT	0x8e
 49#define CONTROL2_ADC_EN		BIT(0)
 50#define CONTROL3_DEFAULT	0x8d
 51
 52enum max14656_chg_type {
 53	MAX14656_NO_CHARGER	= 0,
 54	MAX14656_SDP_CHARGER,
 55	MAX14656_CDP_CHARGER,
 56	MAX14656_DCP_CHARGER,
 57	MAX14656_APPLE_500MA_CHARGER,
 58	MAX14656_APPLE_1A_CHARGER,
 59	MAX14656_APPLE_2A_CHARGER,
 60	MAX14656_SPECIAL_500MA_CHARGER,
 61	MAX14656_APPLE_12W,
 62	MAX14656_CHARGER_LAST
 63};
 64
 65static const struct max14656_chg_type_props {
 66	enum power_supply_type type;
 67} chg_type_props[] = {
 68	{ POWER_SUPPLY_TYPE_UNKNOWN },
 69	{ POWER_SUPPLY_TYPE_USB },
 70	{ POWER_SUPPLY_TYPE_USB_CDP },
 71	{ POWER_SUPPLY_TYPE_USB_DCP },
 72	{ POWER_SUPPLY_TYPE_USB_DCP },
 73	{ POWER_SUPPLY_TYPE_USB_DCP },
 74	{ POWER_SUPPLY_TYPE_USB_DCP },
 75	{ POWER_SUPPLY_TYPE_USB_DCP },
 76	{ POWER_SUPPLY_TYPE_USB },
 77};
 78
 79struct max14656_chip {
 80	struct i2c_client	*client;
 81	struct power_supply	*detect_psy;
 82	struct power_supply_desc psy_desc;
 83	struct delayed_work	irq_work;
 84
 85	int irq;
 86	int online;
 87};
 88
 89static int max14656_read_reg(struct i2c_client *client, int reg, u8 *val)
 90{
 91	s32 ret;
 92
 93	ret = i2c_smbus_read_byte_data(client, reg);
 94	if (ret < 0) {
 95		dev_err(&client->dev,
 96			"i2c read fail: can't read from %02x: %d\n",
 97			reg, ret);
 98		return ret;
 99	}
100	*val = ret;
101	return 0;
102}
103
104static int max14656_write_reg(struct i2c_client *client, int reg, u8 val)
105{
106	s32 ret;
107
108	ret = i2c_smbus_write_byte_data(client, reg, val);
109	if (ret < 0) {
110		dev_err(&client->dev,
111			"i2c write fail: can't write %02x to %02x: %d\n",
112			val, reg, ret);
113		return ret;
114	}
115	return 0;
116}
117
118static int max14656_read_block_reg(struct i2c_client *client, u8 reg,
119				  u8 length, u8 *val)
120{
121	int ret;
122
123	ret = i2c_smbus_read_i2c_block_data(client, reg, length, val);
124	if (ret < 0) {
125		dev_err(&client->dev, "failed to block read reg 0x%x: %d\n",
126				reg, ret);
127		return ret;
128	}
129
130	return 0;
131}
132
133#define        REG_TOTAL_NUM   5
134static void max14656_irq_worker(struct work_struct *work)
135{
136	struct max14656_chip *chip =
137		container_of(work, struct max14656_chip, irq_work.work);
138
139	u8 buf[REG_TOTAL_NUM];
140	u8 chg_type;
141
142	max14656_read_block_reg(chip->client, MAX14656_DEVICE_ID,
143				REG_TOTAL_NUM, buf);
144
145	if ((buf[MAX14656_STATUS_1] & STATUS1_VB_VALID_MASK) &&
146		(buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK)) {
147		chg_type = buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK;
148		if (chg_type < MAX14656_CHARGER_LAST)
149			chip->psy_desc.type = chg_type_props[chg_type].type;
150		else
151			chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
152		chip->online = 1;
153	} else {
154		chip->online = 0;
155		chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
156	}
157
158	power_supply_changed(chip->detect_psy);
159}
160
161static irqreturn_t max14656_irq(int irq, void *dev_id)
162{
163	struct max14656_chip *chip = dev_id;
164
165	schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(100));
166
167	return IRQ_HANDLED;
168}
169
170static int max14656_hw_init(struct max14656_chip *chip)
171{
172	uint8_t val = 0;
173	uint8_t rev;
174	struct i2c_client *client = chip->client;
175
176	if (max14656_read_reg(client, MAX14656_DEVICE_ID, &val))
177		return -ENODEV;
178
179	if ((val & DEVICE_VENDOR_MASK) != 0x20) {
180		dev_err(&client->dev, "wrong vendor ID %d\n",
181			((val & DEVICE_VENDOR_MASK) >> 4));
182		return -ENODEV;
183	}
184	rev = val & DEVICE_REV_MASK;
185
186	/* Turn on ADC_EN */
187	if (max14656_write_reg(client, MAX14656_CONTROL_2, CONTROL2_ADC_EN))
188		return -EINVAL;
189
190	/* turn on interrupts and low power mode */
191	if (max14656_write_reg(client, MAX14656_CONTROL_1,
192		CONTROL1_DEFAULT |
193		CONTROL1_INT_EN |
194		CONTROL1_INT_ACTIVE_HIGH |
195		CONTROL1_EDGE))
196		return -EINVAL;
197
198	if (max14656_write_reg(client, MAX14656_INTMASK_1, 0x3))
199		return -EINVAL;
200
201	if (max14656_write_reg(client, MAX14656_INTMASK_2, 0x1))
202		return -EINVAL;
203
204	dev_info(&client->dev, "detected revision %d\n", rev);
205	return 0;
206}
207
208static int max14656_get_property(struct power_supply *psy,
209			    enum power_supply_property psp,
210			    union power_supply_propval *val)
211{
212	struct max14656_chip *chip = power_supply_get_drvdata(psy);
213
214	switch (psp) {
215	case POWER_SUPPLY_PROP_ONLINE:
216		val->intval = chip->online;
217		break;
218	case POWER_SUPPLY_PROP_MODEL_NAME:
219		val->strval = MAX14656_NAME;
220		break;
221	case POWER_SUPPLY_PROP_MANUFACTURER:
222		val->strval = MAX14656_MANUFACTURER;
223		break;
224	default:
225		return -EINVAL;
226	}
227
228	return 0;
229}
230
231static enum power_supply_property max14656_battery_props[] = {
232	POWER_SUPPLY_PROP_ONLINE,
233	POWER_SUPPLY_PROP_MODEL_NAME,
234	POWER_SUPPLY_PROP_MANUFACTURER,
235};
236
237static int max14656_probe(struct i2c_client *client)
238{
239	struct i2c_adapter *adapter = client->adapter;
240	struct device *dev = &client->dev;
241	struct power_supply_config psy_cfg = {};
242	struct max14656_chip *chip;
243	int irq = client->irq;
244	int ret = 0;
245
246	if (irq <= 0) {
247		dev_err(dev, "invalid irq number: %d\n", irq);
248		return -ENODEV;
249	}
250
251	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
252		dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
253		return -ENODEV;
254	}
255
256	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
257	if (!chip)
258		return -ENOMEM;
259
260	psy_cfg.drv_data = chip;
261	chip->client = client;
262	chip->online = 0;
263	chip->psy_desc.name = MAX14656_NAME;
264	chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
265	chip->psy_desc.properties = max14656_battery_props;
266	chip->psy_desc.num_properties = ARRAY_SIZE(max14656_battery_props);
267	chip->psy_desc.get_property = max14656_get_property;
268	chip->irq = irq;
269
270	ret = max14656_hw_init(chip);
271	if (ret)
272		return -ENODEV;
273
274	chip->detect_psy = devm_power_supply_register(dev,
275		       &chip->psy_desc, &psy_cfg);
276	if (IS_ERR(chip->detect_psy)) {
277		dev_err(dev, "power_supply_register failed\n");
278		return -EINVAL;
279	}
280
281	ret = devm_delayed_work_autocancel(dev, &chip->irq_work,
282					   max14656_irq_worker);
283	if (ret) {
284		dev_err(dev, "devm_delayed_work_autocancel %d failed\n", ret);
285		return ret;
286	}
287
288	ret = devm_request_irq(dev, chip->irq, max14656_irq,
289			       IRQF_TRIGGER_FALLING,
290			       MAX14656_NAME, chip);
291	if (ret) {
292		dev_err(dev, "request_irq %d failed\n", chip->irq);
293		return -EINVAL;
294	}
295	enable_irq_wake(chip->irq);
296
297	schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(2000));
298
299	return 0;
300}
301
302static const struct i2c_device_id max14656_id[] = {
303	{ "max14656" },
304	{}
305};
306MODULE_DEVICE_TABLE(i2c, max14656_id);
307
308static const struct of_device_id max14656_match_table[] = {
309	{ .compatible = "maxim,max14656", },
310	{}
311};
312MODULE_DEVICE_TABLE(of, max14656_match_table);
313
314static struct i2c_driver max14656_i2c_driver = {
315	.driver = {
316		.name	= "max14656",
317		.of_match_table = max14656_match_table,
318	},
319	.probe		= max14656_probe,
320	.id_table	= max14656_id,
321};
322module_i2c_driver(max14656_i2c_driver);
323
324MODULE_DESCRIPTION("MAX14656 USB charger detector");
325MODULE_LICENSE("GPL v2");