1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *  Driver for Analog Devices (Linear Technology) LT3651 charger IC.
4 *  Copyright (C) 2017, Topic Embedded Products
5 */
6
7#include <linux/device.h>
8#include <linux/gpio/consumer.h>
9#include <linux/init.h>
10#include <linux/interrupt.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/power_supply.h>
15#include <linux/slab.h>
16#include <linux/of.h>
17
18struct lt3651_charger {
19	struct power_supply *charger;
20	struct power_supply_desc charger_desc;
21	struct gpio_desc *acpr_gpio;
22	struct gpio_desc *fault_gpio;
23	struct gpio_desc *chrg_gpio;
24};
25
26static irqreturn_t lt3651_charger_irq(int irq, void *devid)
27{
28	struct power_supply *charger = devid;
29
30	power_supply_changed(charger);
31
32	return IRQ_HANDLED;
33}
34
35static inline struct lt3651_charger *psy_to_lt3651_charger(
36	struct power_supply *psy)
37{
38	return power_supply_get_drvdata(psy);
39}
40
41static int lt3651_charger_get_property(struct power_supply *psy,
42		enum power_supply_property psp, union power_supply_propval *val)
43{
44	struct lt3651_charger *lt3651_charger = psy_to_lt3651_charger(psy);
45
46	switch (psp) {
47	case POWER_SUPPLY_PROP_STATUS:
48		if (!lt3651_charger->chrg_gpio) {
49			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
50			break;
51		}
52		if (gpiod_get_value(lt3651_charger->chrg_gpio))
53			val->intval = POWER_SUPPLY_STATUS_CHARGING;
54		else
55			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
56		break;
57	case POWER_SUPPLY_PROP_ONLINE:
58		val->intval = gpiod_get_value(lt3651_charger->acpr_gpio);
59		break;
60	case POWER_SUPPLY_PROP_HEALTH:
61		if (!lt3651_charger->fault_gpio) {
62			val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
63			break;
64		}
65		if (!gpiod_get_value(lt3651_charger->fault_gpio)) {
66			val->intval = POWER_SUPPLY_HEALTH_GOOD;
67			break;
68		}
69		/*
70		 * If the fault pin is active, the chrg pin explains the type
71		 * of failure.
72		 */
73		if (!lt3651_charger->chrg_gpio) {
74			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
75			break;
76		}
77		val->intval = gpiod_get_value(lt3651_charger->chrg_gpio) ?
78				POWER_SUPPLY_HEALTH_OVERHEAT :
79				POWER_SUPPLY_HEALTH_DEAD;
80		break;
81	default:
82		return -EINVAL;
83	}
84
85	return 0;
86}
87
88static enum power_supply_property lt3651_charger_properties[] = {
89	POWER_SUPPLY_PROP_STATUS,
90	POWER_SUPPLY_PROP_ONLINE,
91	POWER_SUPPLY_PROP_HEALTH,
92};
93
94static int lt3651_charger_probe(struct platform_device *pdev)
95{
96	struct power_supply_config psy_cfg = {};
97	struct lt3651_charger *lt3651_charger;
98	struct power_supply_desc *charger_desc;
99	int ret;
100
101	lt3651_charger = devm_kzalloc(&pdev->dev, sizeof(*lt3651_charger),
102					GFP_KERNEL);
103	if (!lt3651_charger)
104		return -ENOMEM;
105
106	lt3651_charger->acpr_gpio = devm_gpiod_get(&pdev->dev,
107					"lltc,acpr", GPIOD_IN);
108	if (IS_ERR(lt3651_charger->acpr_gpio)) {
109		ret = PTR_ERR(lt3651_charger->acpr_gpio);
110		dev_err(&pdev->dev, "Failed to acquire acpr GPIO: %d\n", ret);
111		return ret;
112	}
113	lt3651_charger->fault_gpio = devm_gpiod_get_optional(&pdev->dev,
114					"lltc,fault", GPIOD_IN);
115	if (IS_ERR(lt3651_charger->fault_gpio)) {
116		ret = PTR_ERR(lt3651_charger->fault_gpio);
117		dev_err(&pdev->dev, "Failed to acquire fault GPIO: %d\n", ret);
118		return ret;
119	}
120	lt3651_charger->chrg_gpio = devm_gpiod_get_optional(&pdev->dev,
121					"lltc,chrg", GPIOD_IN);
122	if (IS_ERR(lt3651_charger->chrg_gpio)) {
123		ret = PTR_ERR(lt3651_charger->chrg_gpio);
124		dev_err(&pdev->dev, "Failed to acquire chrg GPIO: %d\n", ret);
125		return ret;
126	}
127
128	charger_desc = &lt3651_charger->charger_desc;
129	charger_desc->name = pdev->dev.of_node->name;
130	charger_desc->type = POWER_SUPPLY_TYPE_MAINS;
131	charger_desc->properties = lt3651_charger_properties;
132	charger_desc->num_properties = ARRAY_SIZE(lt3651_charger_properties);
133	charger_desc->get_property = lt3651_charger_get_property;
134	psy_cfg.of_node = pdev->dev.of_node;
135	psy_cfg.drv_data = lt3651_charger;
136
137	lt3651_charger->charger = devm_power_supply_register(&pdev->dev,
138						      charger_desc, &psy_cfg);
139	if (IS_ERR(lt3651_charger->charger)) {
140		ret = PTR_ERR(lt3651_charger->charger);
141		dev_err(&pdev->dev, "Failed to register power supply: %d\n",
142			ret);
143		return ret;
144	}
145
146	/*
147	 * Acquire IRQs for the GPIO pins if possible. If the system does not
148	 * support IRQs on these pins, userspace will have to poll the sysfs
149	 * files manually.
150	 */
151	if (lt3651_charger->acpr_gpio) {
152		ret = gpiod_to_irq(lt3651_charger->acpr_gpio);
153		if (ret >= 0)
154			ret = devm_request_any_context_irq(&pdev->dev, ret,
155				lt3651_charger_irq,
156				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
157				dev_name(&pdev->dev), lt3651_charger->charger);
158		if (ret < 0)
159			dev_warn(&pdev->dev, "Failed to request acpr irq\n");
160	}
161	if (lt3651_charger->fault_gpio) {
162		ret = gpiod_to_irq(lt3651_charger->fault_gpio);
163		if (ret >= 0)
164			ret = devm_request_any_context_irq(&pdev->dev, ret,
165				lt3651_charger_irq,
166				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
167				dev_name(&pdev->dev), lt3651_charger->charger);
168		if (ret < 0)
169			dev_warn(&pdev->dev, "Failed to request fault irq\n");
170	}
171	if (lt3651_charger->chrg_gpio) {
172		ret = gpiod_to_irq(lt3651_charger->chrg_gpio);
173		if (ret >= 0)
174			ret = devm_request_any_context_irq(&pdev->dev, ret,
175				lt3651_charger_irq,
176				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
177				dev_name(&pdev->dev), lt3651_charger->charger);
178		if (ret < 0)
179			dev_warn(&pdev->dev, "Failed to request chrg irq\n");
180	}
181
182	platform_set_drvdata(pdev, lt3651_charger);
183
184	return 0;
185}
186
187static const struct of_device_id lt3651_charger_match[] = {
188	{ .compatible = "lltc,ltc3651-charger" }, /* DEPRECATED */
189	{ .compatible = "lltc,lt3651-charger" },
190	{ }
191};
192MODULE_DEVICE_TABLE(of, lt3651_charger_match);
193
194static struct platform_driver lt3651_charger_driver = {
195	.probe = lt3651_charger_probe,
196	.driver = {
197		.name = "lt3651-charger",
198		.of_match_table = lt3651_charger_match,
199	},
200};
201
202module_platform_driver(lt3651_charger_driver);
203
204MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
205MODULE_DESCRIPTION("Driver for LT3651 charger");
206MODULE_LICENSE("GPL");
207MODULE_ALIAS("platform:lt3651-charger");
208