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(psy: 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(desc: 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(desc: 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(desc: 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(desc: 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(dev: &pdev->dev, size: sizeof(*lt3651_charger),
102 GFP_KERNEL);
103 if (!lt3651_charger)
104 return -ENOMEM;
105
106 lt3651_charger->acpr_gpio = devm_gpiod_get(dev: &pdev->dev,
107 con_id: "lltc,acpr", flags: GPIOD_IN);
108 if (IS_ERR(ptr: lt3651_charger->acpr_gpio)) {
109 ret = PTR_ERR(ptr: 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(dev: &pdev->dev,
114 con_id: "lltc,fault", flags: GPIOD_IN);
115 if (IS_ERR(ptr: lt3651_charger->fault_gpio)) {
116 ret = PTR_ERR(ptr: 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(dev: &pdev->dev,
121 con_id: "lltc,chrg", flags: GPIOD_IN);
122 if (IS_ERR(ptr: lt3651_charger->chrg_gpio)) {
123 ret = PTR_ERR(ptr: 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(parent: &pdev->dev,
138 desc: charger_desc, cfg: &psy_cfg);
139 if (IS_ERR(ptr: lt3651_charger->charger)) {
140 ret = PTR_ERR(ptr: 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(desc: lt3651_charger->acpr_gpio);
153 if (ret >= 0)
154 ret = devm_request_any_context_irq(dev: &pdev->dev, irq: ret,
155 handler: lt3651_charger_irq,
156 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
157 devname: dev_name(dev: &pdev->dev), dev_id: 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(desc: lt3651_charger->fault_gpio);
163 if (ret >= 0)
164 ret = devm_request_any_context_irq(dev: &pdev->dev, irq: ret,
165 handler: lt3651_charger_irq,
166 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
167 devname: dev_name(dev: &pdev->dev), dev_id: 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(desc: lt3651_charger->chrg_gpio);
173 if (ret >= 0)
174 ret = devm_request_any_context_irq(dev: &pdev->dev, irq: ret,
175 handler: lt3651_charger_irq,
176 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
177 devname: dev_name(dev: &pdev->dev), dev_id: 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, data: 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

source code of linux/drivers/power/supply/lt3651-charger.c